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Sample records for activated receptor alpha

  1. Tetrahydro-iso-alpha Acids Antagonize Estrogen Receptor Alpha Activity in MCF-7 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Maëlle Lempereur

    2016-01-01

    Full Text Available Tetrahydro-iso-alpha acids commonly called THIAA or Tetra are modified hop acids extracted from hop (Humulus lupulus L. which are frequently used in brewing industry mainly in order to provide beer bitterness and foam stability. Interestingly, molecular structure of tetrahydro-iso-alpha acids is close to a new type of estrogen receptor alpha (ERα antagonists aimed at disrupting the binding of coactivators containing an LxxLL motif (NR-box. In this work we show that THIAA decreases estradiol-stimulated proliferation of MCF-7 (ERα-positive breast cancer cells. Besides, we show that it inhibits ERα transcriptional activity. Interestingly, this extract fails to compete with estradiol for ERα binding and does not significantly impact the receptor turnover rate in MCF-7 cells, suggesting that it does not act like classical antiestrogens. Hence, we demonstrate that THIAA is able to antagonize ERα estradiol-induced recruitment of the LxxLL binding motif.

  2. Tetrahydro-iso-alpha Acids Antagonize Estrogen Receptor Alpha Activity in MCF-7 Breast Cancer Cells.

    Science.gov (United States)

    Lempereur, Maëlle; Majewska, Claire; Brunquers, Amandine; Wongpramud, Sumalee; Valet, Bénédicte; Janssens, Philippe; Dillemans, Monique; Van Nedervelde, Laurence; Gallo, Dominique

    2016-01-01

    Tetrahydro-iso-alpha acids commonly called THIAA or Tetra are modified hop acids extracted from hop (Humulus lupulus L.) which are frequently used in brewing industry mainly in order to provide beer bitterness and foam stability. Interestingly, molecular structure of tetrahydro-iso-alpha acids is close to a new type of estrogen receptor alpha (ERα) antagonists aimed at disrupting the binding of coactivators containing an LxxLL motif (NR-box). In this work we show that THIAA decreases estradiol-stimulated proliferation of MCF-7 (ERα-positive breast cancer cells). Besides, we show that it inhibits ERα transcriptional activity. Interestingly, this extract fails to compete with estradiol for ERα binding and does not significantly impact the receptor turnover rate in MCF-7 cells, suggesting that it does not act like classical antiestrogens. Hence, we demonstrate that THIAA is able to antagonize ERα estradiol-induced recruitment of the LxxLL binding motif. PMID:27190515

  3. Diabetes or peroxisome proliferator-activated receptor alpha agonist increases mitochondrial thioesterase I activity in heart

    Science.gov (United States)

    Peroxisome proliferator-activated receptor alpha (PPAR alpha) is a transcriptional regulator of the expression of mitochondrial thioesterase I (MTE-I) and uncoupling protein 3 (UCP3), which are induced in the heart at the mRNA level in response to diabetes. Little is known about the regulation of pr...

  4. Binding of receptor-recognized forms of alpha2-macroglobulin to the alpha2-macroglobulin signaling receptor activates phosphatidylinositol 3-kinase.

    Science.gov (United States)

    Misra, U K; Pizzo, S V

    1998-05-29

    Ligation of the alpha2-macroglobulin (alpha2M) signaling receptor by receptor-recognized forms of alpha2M (alpha2M*) initiates mitogenesis secondary to increased intracellular Ca2+. We report here that ligation of the alpha2M signaling receptor also causes a 1. 5-2.5-fold increase in wortmannin-sensitive phosphatidylinositol 3-kinase (PI3K) activity as measured by the quantitation of phosphatidylinositol 3,4,5-trisphosphate (PIP3). PIP3 formation was alpha2M* concentration-dependent with a maximal response at approximately 50 pM ligand concentration. The peak formation of PIP3 occurred at 10 min of incubation. The alpha2M receptor binding fragment mutant K1370R which binds to the alpha2M signaling receptor activating the signaling cascade, increased PIP3 formation by 2-fold. The mutant K1374A, which binds very poorly to the alpha2M signaling receptor, did not cause any increase in PIP3 formation. alpha2M*-induced DNA synthesis was inhibited by wortmannin. 1, 2Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acetoxymethylester a chelator of intracellular Ca2+, drastically reduced alpha2M*-induced increases in PIP3 formation. We conclude that PI3K is involved in alpha2M*-induced mitogenesis in macrophages and intracellular Ca2+ plays a role in PI3K activation. PMID:9593670

  5. Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

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    Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi; Sakamoto, Tomoya; Takahashi, Nobuyuki [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kawada, Teruo, E-mail: fat@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2011-04-22

    Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a human adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected

  6. Two farnesoid X receptor alpha isoforms in Japanese medaka (Oryzias latipes) are differentially activated in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Howarth, Deanna L. [Integrated Toxicology and Environmental Health Program and Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC 27708 (United States); Hagey, Lee R. [Department of Medicine, University of California at San Diego, La Jolla, CA 92093 (United States); Law, Sheran H.W. [Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695 (United States); Ai, Ni [Department of Pharmacology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854 (United States); Krasowski, Matthew D. [Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, IA (United States); Ekins, Sean [Department of Pharmacology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854 (United States); Collaboration in Chemistry, Jenkintown, PA 19046 (United States); Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD 21201 (United States); Moore, John T. [GlaxoSmithKline Discovery Research, Research Triangle Park, NC 27709 (United States); Kollitz, Erin M. [Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695 (United States); Hinton, David E. [Integrated Toxicology and Environmental Health Program and Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC 27708 (United States); Kullman, Seth W., E-mail: swkullma@ncsu.edu [Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695 (United States)

    2010-07-01

    The nuclear receptor farnesoid X receptor alpha (FXR{alpha}, NR1H4) is activated by bile acids in multiple species including mouse, rat, and human and in this study we have identified two isoforms of Fxr{alpha} in Japanese medaka (Oryzias latipes), a small freshwater teleost. Both isoforms share a high amino acid sequence identity to mammalian FXR{alpha} ({approx}70% in the ligand-binding domain). Fxr{alpha}1 and Fxr{alpha}2 differ within the AF1 domain due to alternative splicing at the fourth intron-exon boundary. This process results in Fxr{alpha}1 having an extended N-terminus compared to Fxr{alpha}2. A Gal4DBD-Fxr{alpha}LBD fusion construct was activated by chenodeoxycholic, cholic, deoxycholic and lithocholic acids, and the synthetic agonist GW4064 in transient transactivation assays. Activation of the Gal4DBD-Fxr{alpha}LBD fusion construct was enhanced by addition of PGC-1{alpha}, as demonstrated through titration assays. Surprisingly, when the full-length versions of the two Fxr{alpha} isoforms were compared in transient transfection assays, Fxr{alpha}2 was activated by C{sub 24} bile acids and GW4064, while Fxr{alpha}1 was not significantly activated by any of the compounds tested. Since the only significant difference between the full-length constructs was sequence in the AF1 domain, these experiments highlight a key functional region in the Fxr{alpha} AF1 domain. Furthermore, mammalian two-hybrid studies demonstrated the ability of Fxr{alpha}2, but not Fxr{alpha}1, to interact with PGC-1{alpha} and SRC-1, and supported our results from the transient transfection reporter gene activation assays. These data demonstrate that both mammalian and teleost FXR (Fxr{alpha}2 isoform) are activated by primary and secondary bile acids.

  7. Activity of L-alpha-amino acids at the promiscuous goldfish odorant receptor 5.24

    DEFF Research Database (Denmark)

    Christiansen, Bolette; Wellendorph, Petrine; Bräuner-Osborne, Hans

    2006-01-01

    report the agonist activities of the 20 proteinogenic L-alpha-amino acids, and L-ornithine and L-citrulline, measured in an intracellular calcium release assay in mammalian tsA cells. The results show that receptor 5.24 is broadly activated by 19 of the tested L-alpha-amino acids and displays...

  8. Distinct neural pathways mediate alpha7 nicotinic acetylcholine receptor-dependent activation of the forebrain

    DEFF Research Database (Denmark)

    Thomsen, Morten S; Hay-Schmidt, Anders; Hansen, Henrik H;

    2010-01-01

    alpha(7) nicotinic acetylcholine receptor (nAChR) agonists are candidates for the treatment of cognitive deficits in schizophrenia. Selective alpha(7) nAChR agonists, such as SSR180711, activate neurons in the medial prefrontal cortex (mPFC) and nucleus accumbens shell (ACCshell) in rats, regions...

  9. Cytosolic PLA2(alpha) activation in Purkinje neurons and its role in AMPA-receptor trafficking.

    Science.gov (United States)

    Mashimo, Masato; Hirabayashi, Tetsuya; Murayama, Toshihiko; Shimizu, Takao

    2008-09-15

    Cytosolic phospholipase A(2)alpha (cPLA(2)alpha) selectively releases arachidonic acid from membrane phospholipids and has been proposed to be involved in the induction of long-term depression (LTD), a form of synaptic plasticity in the cerebellum. This enzyme requires two events for its full activation: Ca(2+)-dependent translocation from the cytosol to organelle membranes in order to access phospholipids as substrates, and phosphorylation by several kinases. However, the subcellular distribution and activation of cPLA(2)alpha in Purkinje cells and the role of arachidonic acid in cerebellar LTD have not been fully elucidated. In cultured Purkinje cells, stimulation of AMPA receptors, but not metabotropic glutamate receptors, triggered translocation of cPLA(2)alpha to the somatic and dendritic Golgi compartments. This translocation required Ca(2+) influx through P-type Ca(2+) channels. AMPA plus PMA, a chemical method for inducing LTD, released arachidonic acid via phosphorylation of cPLA(2)alpha. AMPA plus PMA induced a decrease in surface GluR2 for more than 2 hours. Interestingly, this reduction was occluded by a cPLA(2)alpha-specific inhibitor. Furthermore, PMA plus arachidonic acid caused the prolonged internalization of GluR2 without activating AMPA receptors. These results suggest that cPLA(2)alpha regulates the persistent decrease in the expression of AMPA receptors, underscoring the role of cPLA(2)alpha in cerebellar LTD. PMID:18713832

  10. Conditional expression of constitutively active estrogen receptor {alpha} in chondrocytes impairs longitudinal bone growth in mice

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Kazuhiro [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Tsukui, Tohru [Experimental Animal Laboratory, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Imazawa, Yukiko; Horie-Inoue, Kuniko [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Inoue, Satoshi, E-mail: INOUE-GER@h.u-tokyo.ac.jp [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan); Department of Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Conditional transgenic mice expressing constitutively active estrogen receptor {alpha} (caER{alpha}) in chondrocytes were developed. Black-Right-Pointing-Pointer Expression of caER{alpha} in chondrocytes impaired longitudinal bone growth in mice. Black-Right-Pointing-Pointer caER{alpha} affects chondrocyte proliferation and differentiation. Black-Right-Pointing-Pointer This mouse model is useful for understanding the physiological role of ER{alpha}in vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caER{alpha}{sup ColII}, expressing constitutively active mutant estrogen receptor (ER) {alpha} in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caER{alpha}{sup ColII} mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caER{alpha}{sup ColII} mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caER{alpha}{sup ColII} mice. These results suggest that ER{alpha} is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.

  11. Receptor density is key to the alpha2/beta interferon differential activities.

    Science.gov (United States)

    Moraga, Ignacio; Harari, Daniel; Schreiber, Gideon; Uzé, Gilles; Pellegrini, Sandra

    2009-09-01

    Multiple type I interferons (IFN-alpha/beta) elicit Jak/Stat activation, rapid gene induction, and pleiotropic effects, such as differentiation, antiviral protection, and blocks in proliferation, which are dependent on the IFN subtype and the cellular context. To date, ligand- and receptor-specific molecular determinants underlying IFN-alpha/beta differential activities or potencies have been well characterized. To analyze cellular determinants that impact subtype-specific potency, human fibrosarcoma U5A-derived clones, exhibiting a gradient of IFN sensitivity by virtue of increasing receptor levels, were monitored for Jak/Stat signaling, gene induction, cell cycle lengthening, and apoptosis. In cells with scarce receptors, IFN-beta was more potent than IFN-alpha2 in antiproliferative activity, while the two subtypes were equipotent in all other readouts. Conversely, in cells with abundant receptors, IFN-alpha2 matched or even surpassed IFN-beta in all readouts tested. Our results suggest that the differential activities of the IFN subtypes are dictated not only by the intrinsic ligand/receptor binding kinetics but also by the density of cell surface receptor components.

  12. Activation of Penile Proadipogenic Peroxisome Proliferator-Activated Receptor with an Estrogen: Interaction with Estrogen Receptor Alpha during Postnatal Development

    Directory of Open Access Journals (Sweden)

    Mahmoud M. Mansour

    2008-01-01

    Full Text Available Exposure to the estrogen receptor alpha (ER ligand diethylstilbesterol (DES between neonatal days 2 to 12 induces penile adipogenesis and adult infertility in rats. The objective of this study was to investigate the in vivo interaction between DES-activated ER and the proadipogenic transcription factor peroxisome proliferator-activated receptor gamma (PPAR. Transcripts for PPARs , , and and 1a splice variant were detected in Sprague-Dawley normal rat penis with PPAR predominating. In addition, PPAR1b and PPAR2 were newly induced by DES. The PPAR transcripts were significantly upregulated with DES and reduced by antiestrogen ICI 182, 780. At the cellular level, PPAR protein was detected in urethral transitional epithelium and stromal, endothelial, neuronal, and smooth muscular cells. Treatment with DES activated ER and induced adipocyte differentiation in corpus cavernosum penis. Those adipocytes exhibited strong nuclear PPAR expression. These results suggest a biological overlap between PPAR and ER and highlight a mechanism for endocrine disruption.

  13. Analysis of the Heat Shock Response in Mouse Liver Reveals Transcriptional Dependence on the Nuclear Receptor Peroxisome Proliferator-Activated Receptor alpha (PPARα)

    Science.gov (United States)

    BACKGROUND: The nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha) regulates responses to chemical or physical stress in part by altering expression of genes involved in proteome maintenance. Many of these genes are also transcriptionally regulated by h...

  14. The low density lipoprotein receptor-related protein/alpha2-macroglobulin receptor regulates cell surface plasminogen activator activity on human trophoblast cells.

    Science.gov (United States)

    Zhang, J C; Sakthivel, R; Kniss, D; Graham, C H; Strickland, D K; McCrae, K R

    1998-11-27

    The low density lipoprotein receptor-related protein/alpha2-macroglobulin receptor (LRP/alpha2MR) mediates the internalization of numerous ligands, including prourokinase (pro-UK) and complexes between two-chain urokinase (tc-u-PA) and plasminogen activator inhibitor type-1 (PAI-1). It has been suggested that through its ability to internalize these ligands, LRP/alpha2MR may regulate the expression of plasminogen activator activity on cell surfaces; this hypothesis, however, has not been experimentally confirmed. To address this issue, we assessed the ability of LRP/alpha2MR to regulate plasminogen activator activity on human trophoblast cells, which express both LRP/alpha2MR and the urokinase receptor (uPAR). Trophoblasts internalized and degraded exogenous 125I-pro-UK (primarily following its conversion to tc-u-PA and incorporation into tc-u-PA.PAI complexes) in an LRP/alpha2MR-dependent manner, which was inhibited by the LRP/alpha2MR receptor-associated protein. Receptor-associated protein also caused a approximately 50% reduction in cell surface plasminogen activator activity and delayed the regeneration of unoccupied uPAR by cells on which uPAR were initially saturated with pro-UK. Identical effects were caused by anti-LRP/alpha2MR antibodies. These results demonstrate that LRP/alpha2MR promotes the expression of cell surface plasminogen activator activity on trophoblasts by facilitating the clearance of tc-u-PA.PAI complexes and regeneration of unoccupied cell surface uPAR. PMID:9822706

  15. Catalposide is a natural agonistic ligand of peroxisome proliferator-activated receptor-{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Hae; Jun, Hee-jin; Hoang, Minh-Hien; Jia, Yaoyao [Division of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of); Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of); Han, Xiang Hua [College of Pharmacy, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of); Lee, Dong-Ho [Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of); Lee, Hak-Ju [Division of Green Business Management, Department of Forest Resources Utilization, Korean Forest Research Institute, Seoul 130-712 (Korea, Republic of); Hwang, Bang Yeon, E-mail: byhwang@chungbuk.ac.kr [College of Pharmacy, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of); Lee, Sung-Joon, E-mail: junelee@korea.ac.kr [Division of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of); Department of Biotechnology, Graduate School of Life Sciences and Biotechnology, Korea University, Seoul 136-713 (Korea, Republic of)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Catalposide is a novel ligand for PPAR{alpha}. Black-Right-Pointing-Pointer Cell stimulated with catalposide improved fatty acid uptake, regulated target genes in fatty acid {beta}-oxidation and synthesis. Black-Right-Pointing-Pointer Catalposdie reduces hepatic triacylglycerides. Black-Right-Pointing-Pointer Theses demonstrate catalposide could ameliorate hyperlipidemia and hepatic steatosis. -- Abstract: Peroxisome proliferator-activated receptor-alpha (PPAR{alpha}) is a nuclear receptor that regulates the expression of genes related to cellular lipid uptake and oxidation. Thus, PPAR{alpha} agonists may be important in the treatment of hypertriglyceridemia and hepatic steatosis. In this study, we demonstrated that catalposide is a novel natural PPAR{alpha} agonist, identified from reporter gene assay-based activity screening with approximately 900 natural plant and seaweed extracts. Results of time-resolved fluorescence resonance energy transfer analyses suggested that the compound interacted directly with the ligand-binding domain of PPAR{alpha}. Cultured hepatocytes stimulated with catalposide exhibited significantly reduced cellular triglyceride concentrations, by 21%, while cellular uptake of fatty acids was increased, by 70% (P < 0.05). Quantitative PCR analysis revealed that the increase in cellular fatty acid uptake was due to upregulation of fatty acid transporter protein-4 (+19% vs. the control) in cells stimulated with catalposide. Additionally, expression of genes related to fatty acid oxidation and high-density lipoprotein metabolism were upregulated, while that of genes related to fatty acid synthesis were suppressed. In conclusion, catalposide is hypolipidemic by activation of PPAR{alpha} via a ligand-mediated mechanism that modulates the expression of in lipid metabolism genes in hepatocytes.

  16. Discovery of an Oxybenzylglycine Based Peroxisome Proliferator Activated Receptor Alpha Selective

    Energy Technology Data Exchange (ETDEWEB)

    Li, J.; Kennedy, L; Shi, Y; Tao, S; Ye, X; Chen, S; Wang, Y; Hernandez, A; Wang, W; et al.

    2010-01-01

    An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) {alpha} agonist, with an EC{sub 50} of 10 nM for human PPAR{alpha} and {approx}410-fold selectivity vs human PPAR{gamma} in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPAR{delta}. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystal structures of the early lead compound 12 and compound 2 in complex with PPAR{alpha} ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPAR{alpha} in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.

  17. Adaptation of peroxisome proliferator-activated receptor alpha to hibernation in bats

    OpenAIRE

    Han, Yijie; Zheng, Guantao; Yang, Tianxiao; Zhang, Shuyi; Dong, Dong; Pan, Yi-Hsuan

    2015-01-01

    Background Hibernation is a survival mechanism in the winter for some animals. Fat preserved instead of glucose produced is the primary fuel during winter hibernation of mammals. Many genes involved in lipid metabolism are regulated by the peroxisome proliferator-activated receptor alpha (PPARα). The role of PPARα in hibernation of mammals remains largely unknown. Using a multidisciplinary approach, we investigated whether PPARα is adapted to hibernation in bats. Results Evolutionary analyses...

  18. Two farnesoid X receptor alpha isoforms in Japanese medaka (Oryzias latipes) are differentially activated in vitro

    OpenAIRE

    Howarth, Deanna L.; Hagey, Lee R.; Law, Sheran H.W.; Ai, Ni; Krasowski, Matthew D.; Ekins, Sean; Moore, John T.; Erin M Kollitz; Hinton, David E.; Kullman, Seth W.

    2010-01-01

    The nuclear receptor farnesoid X receptor alpha (FXRα, NR1H4) is activated by bile acids in multiple species including mouse, rat, and human and in this study we have identified two isoforms of Fxrα in Japanese medaka (Oryzias latipes), a small freshwater teleost. Both isoforms share a high amino acid sequence identity to mammalian FXRα (~70% in the ligand-binding domain). Fxrα1 and Fxrα2 differ within the AF1 domain due to alternative splicing at the fourth intron-exon boundary. This process...

  19. Stimulation of receptor protein-tyrosine phosphatase alpha activity and phosphorylation by phorbol ester

    DEFF Research Database (Denmark)

    den Hertog, J; Sap, J; Pals, C E;

    1995-01-01

    Receptor Protein-Tyrosine Phosphatase alpha (RPTP alpha) is a transmembrane protein with two cytoplasmic catalytic protein-tyrosine phosphatase (PTP) domains and a relatively short (123 amino acids) extracellular domain. Here we report that treatment of transfected cells that express RPTP alpha...

  20. Triclocarban mediates induction of xenobiotic metabolism through activation of the constitutive androstane receptor and the estrogen receptor alpha.

    Directory of Open Access Journals (Sweden)

    Mei-Fei Yueh

    Full Text Available Triclocarban (3,4,4'-trichlorocarbanilide, TCC is used as a broad-based antimicrobial agent that is commonly added to personal hygiene products. Because of its extensive use in the health care industry and resistance to degradation in sewage treatment processes, TCC has become a significant waste product that is found in numerous environmental compartments where humans and wildlife can be exposed. While TCC has been linked to a range of health and environmental effects, few studies have been conducted linking exposure to TCC and induction of xenobiotic metabolism through regulation by environmental sensors such as the nuclear xenobiotic receptors (XenoRs. To identify the ability of TCC to activate xenobiotic sensors, we monitored XenoR activities in response to TCC treatment using luciferase-based reporter assays. Among the XenoRs in the reporter screening assay, TCC promotes both constitutive androstane receptor (CAR and estrogen receptor alpha (ERα activities. TCC treatment to hUGT1 mice resulted in induction of the UGT1A genes in liver. This induction was dependent upon the constitutive active/androstane receptor (CAR because no induction occurred in hUGT1Car(-/- mice. Induction of the UGT1A genes by TCC corresponded with induction of Cyp2b10, another CAR target gene. TCC was demonstrated to be a phenobarbital-like activator of CAR in receptor-based assays. While it has been suggested that TCC be classified as an endocrine disruptor, it activates ERα leading to induction of Cyp1b1 in female ovaries as well as in promoter activity. Activation of ERα by TCC in receptor-based assays also promotes induction of human CYP2B6. These observations demonstrate that TCC activates nuclear xenobiotic receptors CAR and ERα both in vivo and in vitro and might have the potential to alter normal physiological homeostasis. Activation of these xenobiotic-sensing receptors amplifies gene expression profiles that might represent a mechanistic base for

  1. Activation of peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) suppresses postprandial lipidemia through fatty acid oxidation in enterocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Rino [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan); Takahashi, Nobuyuki, E-mail: nobu@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan); Murota, Kaeko [Department of Life Science, School of Science and Engineering, Kinki University, Osaka 770-8503 (Japan); Yamada, Yuko [Laboratory of Physiological Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan); Niiya, Saori; Kanzaki, Noriyuki; Murakami, Yoko [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan); Moriyama, Tatsuya [Department of Applied Cell Biology, Graduate School of Agriculture, Kinki University, Nara 631-8505 (Japan); Goto, Tsuyoshi; Kawada, Teruo [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2011-06-24

    Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of fatty acid oxidation-related genes in human intestinal epithelial Caco-2 cells. {yields} PPAR{alpha} activation also increased oxygen consumption rate and CO{sub 2} production and decreased secretion of triglyceride and ApoB from Caco-2 cells. {yields} Orally administration of bezafibrate increased mRNA expression levels of fatty acid oxidation-related genes and CO{sub 2} production in small intestinal epithelial cells. {yields} Treatment with bezafibrate decreased postprandial serum concentration of triglyceride after oral injection of olive oil in mice. {yields} It suggested that intestinal lipid metabolism regulated by PPAR{alpha} activation suppresses postprandial lipidemia. -- Abstract: Activation of peroxisome proliferator-activated receptor (PPAR)-{alpha} which regulates lipid metabolism in peripheral tissues such as the liver and skeletal muscle, decreases circulating lipid levels, thus improving hyperlipidemia under fasting conditions. Recently, postprandial serum lipid levels have been found to correlate more closely to cardiovascular diseases than fasting levels, although fasting hyperlipidemia is considered an important risk of cardiovascular diseases. However, the effect of PPAR{alpha} activation on postprandial lipidemia has not been clarified. In this study, we examined the effects of PPAR{alpha} activation in enterocytes on lipid secretion and postprandial lipidemia. In Caco-2 enterocytes, bezafibrate, a potent PPAR{alpha} agonist, increased mRNA expression levels of fatty acid oxidation-related genes, such as acyl-CoA oxidase, carnitine palmitoyl transferase, and acyl-CoA synthase, and oxygen consumption rate (OCR) and suppressed secretion levels of both triglycerides and apolipoprotein B into the basolateral side. In vivo experiments revealed that feeding high-fat-diet containing bezafibrate increased mRNA expression levels of fatty acid oxidation-related genes and

  2. alpha(7) Nicotinic acetylcholine receptor activation prevents behavioral and molecular changes induced by repeated phencyclidine treatment

    DEFF Research Database (Denmark)

    Thomsen, Morten Skøtt; Christensen, Ditte Z; Hansen, Henrik H;

    2009-01-01

    in a modified Y-maze test. Polymorphisms in the alpha(7) nicotinic acetylcholine receptor (nAChR) gene have been linked to schizophrenia. Here we demonstrate that acute administration of the selective alpha(7) nAChR partial agonist SSR180711 dose-dependently reversed the behavioral impairment induced by PCP...

  3. Cognitive improvement by activation of alpha7 nicotinic acetylcholine receptors: from animal models to human pathophysiology

    DEFF Research Database (Denmark)

    Thomsen, Morten S; Hansen, Henrik H; Timmerman, Daniel B;

    2010-01-01

    Agonists and positive allosteric modulators of the alpha(7) nicotinic acetylcholine receptor (nAChR) are currently being developed for the treatment of cognitive disturbances in patients with schizophrenia or Alzheimer's disease. This review describes the neurobiological properties of the alpha n...

  4. Analysis of the heat shock response in mouse liver reveals dependence on the Nuclear Receptor Peroxisome Proliferator-Activated Receptor alpha (PPARalpha)

    NARCIS (Netherlands)

    Vallanat, B.; Anderson, S.P.; Brown-Borg, H.M.; Ren, H.; Kersten, A.H.; Jonnalagadda, S.; Srinivasan, S.; Corton, J.C.

    2010-01-01

    Background - The nuclear receptor peroxisome proliferator-activated receptor alpha (PPARa) regulates responses to chemical or physical stress in part by altering expression of genes involved in proteome maintenance. Many of these genes are also transcriptionally regulated by heat shock (HS) through

  5. Cognitive improvement by activation of alpha7 nicotinic acetylcholine receptors: from animal models to human pathophysiology

    DEFF Research Database (Denmark)

    Thomsen, Morten S; Hansen, Henrik H; Timmerman, Daniel B;

    2010-01-01

    AChR agonists improves learning, memory, and attentional function in variety of animal models, and pro-cognitive effects of alpha(7) nAChR agonists have recently been demonstrated in patients with schizophrenia or Alzheimer's disease. The alpha(7) nAChR desensitizes rapidly in vitro, and this has been a major......Agonists and positive allosteric modulators of the alpha(7) nicotinic acetylcholine receptor (nAChR) are currently being developed for the treatment of cognitive disturbances in patients with schizophrenia or Alzheimer's disease. This review describes the neurobiological properties of the alpha n...... concern in the development of alpha(7) nAChR agonists as putative drugs. Our review of the existing literature shows that development of tolerance to the behavioral effects of alpha(7) nAChR agonists does not occur in animal models or humans. However, the long-term memory-enhancing effects seen in animal...

  6. The nicotinic alpha7 acetylcholine receptor agonist ssr180711 is unable to activate limbic neurons in mice overexpressing human amyloid-beta1-42

    DEFF Research Database (Denmark)

    Soderman, A.; Spang-Thomsen, Mogens; Hansen, H.;

    2008-01-01

    Recent studies have demonstrated that amyloid-beta1-42 (Abeta1-42) binds to the nicotinergic alpha7 acetylcholine receptor (alpha7 nAChR) and that the application of Abeta1-42 to cells inhibits the function of the alpha7 nAChR. The in vivo consequences of the pharmacological activation of the alpha...

  7. Regulation of the human SLC25A20 expression by peroxisome proliferator-activated receptor alpha in human hepatoblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Tachibana, Keisuke, E-mail: nya@phs.osaka-u.ac.jp [Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Takeuchi, Kentaro; Inada, Hirohiko [Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Yamasaki, Daisuke [Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); The Center for Advanced Medical Engineering and Informatics, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ishimoto, Kenji [Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Tanaka, Toshiya; Hamakubo, Takao; Sakai, Juro; Kodama, Tatsuhiko [Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904 (Japan); Doi, Takefumi [Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); The Center for Advanced Medical Engineering and Informatics, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2009-11-20

    Solute carrier family 25, member 20 (SLC25A20) is a key molecule that transfers acylcarnitine esters in exchange for free carnitine across the mitochondrial membrane in the mitochondrial {beta}-oxidation. The peroxisome proliferator-activated receptor alpha (PPAR{alpha}) is a ligand-activated transcription factor that plays an important role in the regulation of {beta}-oxidation. We previously established tetracycline-regulated human cell line that can be induced to express PPAR{alpha} and found that PPAR{alpha} induces the SLC25A20 expression. In this study, we analyzed the promoter region of the human slc25a20 gene and showed that PPAR{alpha} regulates the expression of human SLC25A20 via the peroxisome proliferator responsive element.

  8. Two farnesoid X receptor alpha isoforms in Japanese medaka (Oryzias latipes) are differentially activated in vitro

    International Nuclear Information System (INIS)

    The nuclear receptor farnesoid X receptor alpha (FXRα, NR1H4) is activated by bile acids in multiple species including mouse, rat, and human and in this study we have identified two isoforms of Fxrα in Japanese medaka (Oryzias latipes), a small freshwater teleost. Both isoforms share a high amino acid sequence identity to mammalian FXRα (∼70% in the ligand-binding domain). Fxrα1 and Fxrα2 differ within the AF1 domain due to alternative splicing at the fourth intron-exon boundary. This process results in Fxrα1 having an extended N-terminus compared to Fxrα2. A Gal4DBD-FxrαLBD fusion construct was activated by chenodeoxycholic, cholic, deoxycholic and lithocholic acids, and the synthetic agonist GW4064 in transient transactivation assays. Activation of the Gal4DBD-FxrαLBD fusion construct was enhanced by addition of PGC-1α, as demonstrated through titration assays. Surprisingly, when the full-length versions of the two Fxrα isoforms were compared in transient transfection assays, Fxrα2 was activated by C24 bile acids and GW4064, while Fxrα1 was not significantly activated by any of the compounds tested. Since the only significant difference between the full-length constructs was sequence in the AF1 domain, these experiments highlight a key functional region in the Fxrα AF1 domain. Furthermore, mammalian two-hybrid studies demonstrated the ability of Fxrα2, but not Fxrα1, to interact with PGC-1α and SRC-1, and supported our results from the transient transfection reporter gene activation assays. These data demonstrate that both mammalian and teleost FXR (Fxrα2 isoform) are activated by primary and secondary bile acids.

  9. Studies of the Gly482Ser polymorphism of the peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha) gene in Danish subjects with the metabolic syndrome

    DEFF Research Database (Denmark)

    Ambye, Louise; Rasmussen, Susanne; Fenger, Mogens;

    2005-01-01

    The peroxisome proliferator-activated receptor gamma co-activator 1alpha (PGC-1alpha) is a novel transcriptional co-activator that holds an important role in lipid and glucose metabolism. PGC-1alpha is a candidate gene for the metabolic syndrome (MS) as well as type 2 diabetes. Recent studies...

  10. Plasmin-induced migration requires signaling through protease-activated receptor 1 and integrin alpha(9)beta(1).

    Science.gov (United States)

    Majumdar, Mousumi; Tarui, Takehiko; Shi, Biao; Akakura, Nobuaki; Ruf, Wolfram; Takada, Yoshikazu

    2004-09-01

    Plasmin is a major extracellular protease that elicits intracellular signals to mediate platelet aggregation, chemotaxis of peripheral blood monocytes, and release of arachidonate and leukotriene from several cell types in a G protein-dependent manner. Angiostatin, a fragment of plasmin(ogen), is a ligand and an antagonist for integrin alpha(9)beta(1). Here we report that plasmin specifically interacts with alpha(9)beta(1) and that plasmin induces of cells expressing migration recombinant alpha(9)beta(1) (alpha(9)-Chinese hamster ovary (CHO) cells). Migration was dependent on an interaction of the kringle domains of plasmin with alpha(9)beta(1) as well as the catalytic activity of plasmin. Angiostatin, representing the kringle domains of plasmin, alone did not induce the migration of alpha(9)-CHO cells, but simultaneous activation of the G protein-coupled protease-activated receptor (PAR)-1 with an agonist peptide induced the migration on angiostatin, whereas PAR-2 or PAR-4 agonist peptides were without effect. Furthermore, a small chemical inhibitor of PAR-1 (RWJ 58259) and a palmitoylated PAR-1-blocking peptide inhibited plasmin-induced migration of alpha(9)-CHO cells. These results suggest that plasmin induces migration by kringle-mediated binding to alpha(9)beta(1) and simultaneous proteolytic activation of PAR-1. PMID:15247268

  11. Mechanisms of transcriptional activation of the mouse claudin-5 promoter by estrogen receptor alpha and beta.

    Science.gov (United States)

    Burek, Malgorzata; Steinberg, Katrin; Förster, Carola Y

    2014-07-01

    Claudin-5 is an integral membrane protein and a critical component of endothelial tight junctions that control paracellular permeability. Claudin-5 is expressed at high levels in the brain vascular endothelium. Estrogens have multiple effects on vascular physiology and function. The biological actions of estrogens are mediated by two different estrogen receptor (ER) subtypes, ER alpha and ER beta. Estrogens have beneficial effects in several vascular disorders. Recently we have cloned and characterized a murine claudin-5 promoter and demonstrated 17beta-estradiol (E2)-mediated regulation of claudin-5 in brain and heart microvascular endothelium on promoter, mRNA and protein level. Sequence analysis revealed a putative estrogen response element (ERE) and a putative Sp1 transcription factor binding site in the claudin-5 promoter. The aim of the present study was to further characterize the estrogen-responsive elements of claudin-5 promoter. First, we introduced point mutations in ERE or Sp1 site in -500/+111 or in Sp1 site of -268/+111 claudin-5 promoter construct, respectively. Basal and E2-mediated transcriptional activation of mutated constructs was abrogated in the luciferase reporter gene assay. Next, we examined whether estrogen receptor subtypes bind to the claudin-5 promoter region. For this purpose we performed chromatin immunoprecipitation assays using anti-estrogen receptor antibodies and cellular lysates of E2-treated endothelial cells followed by quantitative PCR analysis. We show enrichment of claudin-5 promoter fragments containing the ERE- and Sp1-binding site in immunoprecipitates after E2 treatment. Finally, in a gel mobility shift assay, we demonstrated DNA-protein interaction of both ER subtypes at ERE. In summary, this study provides evidence that both a non-consensus ERE and a Sp1 site in the claudin-5 promoter are functional and necessary for the basal and E2-mediated activation of the promoter.

  12. Alpha-latrotoxin modulates the secretory machinery via receptor-mediated activation of protein kinase C.

    Science.gov (United States)

    Liu, Jie; Wan, Qunfang; Lin, Xianguang; Zhu, Hongliang; Volynski, Kirill; Ushkaryov, Yuri; Xu, Tao

    2005-09-01

    The hypothesis whether alpha-latrotoxin (LTX) could directly regulate the secretory machinery was tested in pancreatic beta cells using combined techniques of membrane capacitance (Cm) measurement and Ca2+ uncaging. Employing ramp increase in [Ca2+]i to stimulate exocytosis, we found that LTX lowers the Ca2+ threshold required for exocytosis without affecting the size of the readily releasable pool (RRP). The burst component of exocytosis in response to step-like [Ca2+]i increase generated by flash photolysis of caged Ca2+ was also speeded up by LTX treatment. LTX increased the maximum rate of exocytosis compared with control responses with similar postflash [Ca2+]i and shifted the Ca2+ dependence of the exocytotic machinery toward lower Ca2+ concentrations. LTXN4C, a LTX mutant which cannot form membrane pores or penetrate through the plasma membrane but has similar affinity for the receptors as the wild-type LTX, mimicked the effect of LTX. Moreover, the effects of both LTX and LTXN4C) were independent of intracellular or extracellular Ca2+ but required extracellular Mg2+. Our data propose that LTX, by binding to the membrane receptors, sensitizes the fusion machinery to Ca2+ and, hence, may permit release at low [Ca2+]i level. This sensitization is mediated by activation of protein kinase C. PMID:16101679

  13. Biologically active monoiodinated alpha-MSH derivatives for receptor binding studies using human melanoma cells

    International Nuclear Information System (INIS)

    Three different monoiodinated radioligands of alpha-MSH (alpha-melanocyte-stimulating hormone) were compared in a binding assay with human D10 melanoma cells: [Tyr(125I)2]-alpha-MSH, [Tyr(125I)2,NIe4]-alpha-MSH, and [Tyr(125I)2,NIe4,D-Phe7]-alpha-MSH. They were prepared either by the classical chloramine T method or by the Enzymobead method. A simple and rapid purification scheme was developed consisting of a primary separation on reversed-phase C18 silica cartridges immediately after the iodination, followed by HPLC purification before each binding experiment. Biological testing of the three radioligands showed that they all retained high melanotropic activity in the B16 melanin assay and the Anolis melanophore assay. However, in human D10 melanoma cells, [Tyr(125I)2,NIe4]-alpha-MSH led to a high degree of non-specific binding to the cells which could not be displaced by excess alpha-MSH and only partially by [NIe4]-alpha-MSH. The [Tyr(125I)2,NIe4,D-Phe7]-alpha-MSH tracer gave similar results but with a much lower proportion of non-specific binding. On the other hand, [Tyr(125I)2]-alpha-MSH proved to be an excellent radioligand whose non-specific binding to the D10 cells was not higher than 20% of the total binding

  14. A polymorphic autoregulatory hormone response element in the human estrogen-related receptor alpha (ERRalpha) promoter dictates peroxisome proliferator-activated receptor gamma coactivator-1alpha control of ERRalpha expression.

    Science.gov (United States)

    Laganière, Josée; Tremblay, Gilles B; Dufour, Catherine R; Giroux, Sylvie; Rousseau, François; Giguère, Vincent

    2004-04-30

    The orphan nuclear estrogen-related receptor alpha (ERRalpha) and transcriptional cofactor peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha) are involved in the regulation of energy metabolism. Recently, extensive cross-talk between PGC-1alpha and ERRalpha has been demonstrated. The presence of PGC-1alpha is associated with an elevated expression of ERRalpha, and the two proteins can influence the transcriptional activities of one another. Using a candidate gene approach to detect regulatory variants within genes encoding nuclear receptors, we have identified a 23-bp sequence (ESRRA23) containing two nuclear receptor recognition half-site motifs that is present in 1-4 copies within the promoter of the human ESRRA gene encoding ERRalpha. The ESRRA23 sequence contains a functional ERR response element that is specifically bound by ERRalpha, and chromatin immunoprecipitation shows that endogenous ERRalpha occupies its own promoter in vivo. Strikingly, introduction of PGC-1alpha in HeLa cells by transient transfection induces the activity of the ESRRA promoter in a manner that is dependent on the presence of the ESRRA23 element and on its dosage. Coexpression of ERRalpha and PGC-1alpha results in a synergistic activation of the ESRRA promoter. In experiments using ERRalpha null fibroblasts, the ability of PGC-1alpha to stimulate the ESRRA promoter is considerably reduced but can be restored by addition of ERRalpha. Taken together, these results demonstrate that an interdependent ERRalpha/PGC-1alpha-based transcriptional pathway targets the ESRRA23 element to dictate the level of ERRalpha expression. This study further suggests that this regulatory polymorphism may provide differential responses to ERRalpha/PGC-1alpha-mediated metabolic cues in the human population.

  15. Regulation of skeletal muscle cell plasticity by the peroxisome proliferator-activated receptor gamma coactivator 1alpha

    OpenAIRE

    Handschin, C.

    2010-01-01

    Exercise triggers a pleiotropic response in skeletal muscle, which results in a profound remodeling of this tissue. Physical activity-dependent muscle fiber plasticity is regulated by a number of distinct signaling pathways. Even though most of these pathways are activated by different stimuli and in a temporally and spatially separated manner during exercise, many of the major signal transduction events converge on the peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-...

  16. Berberine is a potent agonist of peroxisome proliferator activated receptor alpha.

    Science.gov (United States)

    Yu, Huarong; Li, Changqing; Yang, Junqing; Zhang, Tao; Zhou, Qixin

    2016-01-01

    Although berberine has hypolipidemic effects with a high affinity to nuclear proteins, the underlying molecular mechanism for this effect remains unclear. Here, we determine whether berberine is an agonist of peroxisome proliferator-activated receptor alpha (PPARalpha), with a lipid-lowering effect. The cell-based reporter gene analysis showed that berberine selectively activates PPARalpha (EC50 =0.58 mM, Emax =102.4). The radioligand binding assay shows that berberine binds directly to the ligand-binding domain of PPARalpha (Ki=0.73 mM) with similar affinity to fenofibrate. The mRNA and protein levels of CPT-Ialpha gene from HepG2 cells and hyperlipidemic rat liver are remarkably up-regulated by berberine, and this effect can be blocked by MK886, a non-competitive antagonist of PPARalpha. A comparison assay in which berberine and fenofibrate were used to treat hyperlipidaemic rats for three months shows that these drugs produce similar lipid-lowering effects, except that berberine increases high-density lipoprotein cholesterol more effectively than fenofibrate. These findings provide the first evidence that berberine is a potent agonist of PPARalpha and seems to be superior to fenofibrate for treating hyperlipidemia. PMID:27100490

  17. Activation of Peroxisome Proliferator-Activated Receptor Alpha Improves Aged and UV-Irradiated Skin by Catalase Induction

    Science.gov (United States)

    Shin, Mi Hee; Lee, Se-Rah; Kim, Min-Kyoung; Shin, Chang-Yup

    2016-01-01

    Peroxisome proliferator-activated receptor alpha (PPARα) is a nuclear hormone receptor involved in the transcriptional regulation of lipid metabolism, fatty acid oxidation, and glucose homeostasis. Its activation stimulates antioxidant enzymes such as catalase, whose expression is decreased in aged human skin. Here we investigated the expression of PPARα in aged and ultraviolet (UV)-irradiated skin, and whether PPARα activation can modulate expressions of matrix metalloproteinase (MMP)-1 and procollagen through catalase regulation. We found that PPARα mRNA level was significantly decreased in intrinsically aged and photoaged human skin as well as in UV-irradiated skin. A PPARα activator, Wy14643, inhibited UV-induced increase of MMP-1 and decrease of procollagen expression and caused marked increase in catalase expression. Furthermore, production of reactive oxygen species (ROS) was suppressed by Wy14643 in UV-irradiated and aged dermal fibroblasts, suggesting that the PPARα activation-induced upregulation of catalase leads to scavenging of ROS produced due to UV irradiation or aging. PPARα knockdown decreased catalase expression and abolished the beneficial effects of Wy14643. Topical application of Wy14643 on hairless mice restored catalase activity and prevented MMP-13 and inflammatory responses in skin. Our findings indicate that PPARα activation triggers catalase expression and ROS scavenging, thereby protecting skin from UV-induced damage and intrinsic aging. PMID:27611371

  18. Peroxisome Proliferator-Activated Receptor-alpha Is a Functional Target of p63 in Adult Human Keratinocytes

    DEFF Research Database (Denmark)

    Pozzi, Silvia; Boergesen, Michael; Sinha, Satrajit;

    2009-01-01

    healing process, is a target of p63 in human keratinocytes. Silencing of p63 by RNA interference and transient transfections showed that p63 represses PPARalpha through a functional region of promoter B. Chromatin immunoprecipitation analyses indicate that p63 is bound to this region, in the absence......p63 is a master switch in the complex network of signaling pathways controlling the establishment and maintenance of stratified epithelia. We provide evidence that peroxisome proliferator-activated receptor-alpha (PPARalpha), a ligand-activated nuclear receptor that participates in the skin wound...

  19. Peroxisome proliferator-activated receptor-alpha control of lipid and glucose metabolism in human white adipocytes.

    Science.gov (United States)

    Ribet, Carole; Montastier, Emilie; Valle, Carine; Bezaire, Véronic; Mazzucotelli, Anne; Mairal, Aline; Viguerie, Nathalie; Langin, Dominique

    2010-01-01

    This work aimed at characterizing the role of peroxisome proliferator-activated receptors (PPAR)alpha in human white adipocyte metabolism and at comparing PPAR alpha and PPAR gamma actions in these cells. Primary cultures of human fat cells were treated with the PPAR alpha agonist GW7647 or the PPAR gamma agonist rosiglitazone. Changes in gene expression were determined using DNA microarrays and quantitative RT-PCR. Western blot and metabolic studies were performed to identify the biological effects elicited by PPAR agonist treatments. GW7647 induced an up-regulation of beta-oxidation gene expression and increased palmitate oxidation. Unexpectedly, glycolysis was strongly reduced at transcriptional and functional levels by GW7647 leading to a decrease in pyruvate and lactate production. Glucose oxidation was decreased. Triglyceride esterification and de novo lipogenesis were inhibited by the PPAR alpha agonist. GW7647-induced alterations were abolished by a treatment with a PPAR alpha antagonist. Small interfering RNA-mediated extinction of PPAR alpha gene expression in hMADS adipocytes attenuated GW7647 induction of palmitate oxidation. Rosiglitazone had no major impact on glycolysis and beta-oxidation. Altogether these results show that PPAR alpha can selectively up-regulate beta-oxidation and decrease glucose utilization in human white adipocytes. PMID:19887568

  20. Neu1 desialylation of sialyl alpha-2,3-linked beta-galactosyl residues of TOLL-like receptor 4 is essential for receptor activation and cellular signaling.

    Science.gov (United States)

    Amith, Schammim Ray; Jayanth, Preethi; Franchuk, Susan; Finlay, Trisha; Seyrantepe, Volkan; Beyaert, Rudi; Pshezhetsky, Alexey V; Szewczuk, Myron R

    2010-02-01

    The ectodomain of TOLL-like receptors (TLR) is highly glycosylated with several N-linked gylcosylation sites located in the inner concave surface. The precise role of these sugar N-glycans in TLR receptor activation is unknown. Recently, we have shown that Neu1 sialidase and not Neu2, -3 and -4 forms a complex with TLR-2, -3 and -4 receptors on the cell-surface membrane of naïve and activated macrophage cells (Glycoconj J DOI 10.1007/s10719-009-9239-8). Activation of Neu1 is induced by TLR ligands binding to their respective receptors. Here, we show that endotoxin lipopolysaccharide (LPS)-induced MyD88/TLR4 complex formation and subsequent NFkappaB activation is dependent on the removal of alpha-2,3-sialyl residue linked to beta-galactoside of TLR4 by the Neu1 activity associated with LPS-stimulated live primary macrophage cells, macrophage and dendritic cell lines but not with primary Neu1-deficient macrophage cells. Exogenous alpha-2,3 sialyl specific neuraminidase (Streptoccocus pneumoniae) and wild-type T. cruzi trans-sialidase (TS) but not the catalytically inactive mutant TSAsp98-Glu mediate TLR4 dimerization to facilitate MyD88/TLR4 complex formation and NFkappaB activation similar to those responses seen with LPS. These same TLR ligand-induced NFkappaB responses are not observed in TLR deficient HEK293 cells, but are re-established in HEK293 cells stably transfected with TLR4/MD2, and are significantly inhibited by alpha-2,3-sialyl specific Maackia amurensis (MAL-2) lectin, alpha-2,3-sialyl specific galectin-1 and neuraminidase inhibitor Tamiflu but not by alpha-2,6-sialyl specific Sambucus nigra lectin (SNA). Taken together, the findings suggest that Neu1 desialylation of alpha-2,3-sialyl residues of TLR receptors enables in removing a steric hinderance to receptor association for TLR activation and cellular signaling. PMID:19796680

  1. NAD(P)H oxidase/nitric oxide interactions in peroxisome proliferator activated receptor (PPAR){alpha}-mediated cardiovascular effects

    Energy Technology Data Exchange (ETDEWEB)

    Newaz, Mohammad [Center for Cardiovascular Diseases, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004 (United States); Blanton, Ahmad [Center for Cardiovascular Diseases, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004 (United States); Fidelis, Paul [Center for Cardiovascular Diseases, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004 (United States); Oyekan, Adebayo [Center for Cardiovascular Diseases, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004 (United States)]. E-mail: Oyekan_AO@TSU.EDU

    2005-11-11

    Activation of peroxisome proliferator activated receptor (PPAR){alpha} and its protective role in cardiovascular function has been reported but the exact mechanism(s) involved is not clear. As we have shown that PPAR{alpha} ligands increased nitric oxide (NO) production and cardiovascular function is controlled by a balance between NO and free radicals, we hypothesize that PPAR{alpha} activation tilts the balance between NO and free radicals and that this mechanism defines the protective effects of PPAR{alpha} ligands on cardiovascular system. Systolic blood pressure (SBP) was greater in PPAR{alpha} knockout (KO) mice compared with its wild type (WT) litter mates (130 {+-} 10 mmHg versus 107 {+-} 4 mmHg). L-NAME (100 mg/L p.o.), the inhibitor of NO production abolished the difference between PPAR{alpha} KO and WT mice. In kidney homogenates, tissue lipid hydroperoxide generation was greater in KO mice (11.8 {+-} 1.4 pM/mg versus 8.3 {+-} 0.6 pM/mg protein). This was accompanied by a higher total NOS activity (46 {+-} 6%, p < 0.05) and a {approx}3 fold greater Ca{sup 2+}-dependent NOS activity in kidney homogenates of untreated PPAR{alpha} WT compared with the KO mice. Clofibrate, a PPAR{alpha} ligand, increased NOS activity in WT but not KO mice. Bezafibrate (30 mg/kg) reduced SBP in conscious rats (19 {+-} 4%, p < 0.05), increased urinary NO excretion (4.06 {+-} 0.53-7.07 {+-} 1.59 {mu}M/24 h; p < 0.05) and reduced plasma 8-isoprostane level (45.8 {+-} 15 {mu}M versus 31.4 {+-} 8 {mu}M), and NADP(H) oxidase activity (16 {+-} 5%). Implantation of DOCA pellet (20 mg s.c.) in uninephrectomized mice placed on 1% NaCl drinking water increased SBP by a margin that was markedly greater in KO mice (193 {+-} 13 mmHg versus 130 {+-} 12 mmHg). In the rat, DOCA increased SBP and NAD(P)H oxidase activity and both effects were diminished by clofibrate. In addition, clofibrate reduced ET-1 production in DOCA/salt hypertensive rats. Thus, apart from inhibition of ET-1 production

  2. alpha-MSH tripeptide analogs activate the melanocortin 1 receptor and reduce UV-induced DNA damage in human melanocytes.

    Science.gov (United States)

    Abdel-Malek, Zalfa A; Ruwe, Andrew; Kavanagh-Starner, Renny; Kadekaro, Ana Luisa; Swope, Viki; Haskell-Luevano, Carrie; Koikov, Leonid; Knittel, James J

    2009-10-01

    One skin cancer prevention strategy that we are developing is based on synthesizing and testing melanocortin analogs that reduce and repair DNA damage resulting from exposure to solar ultraviolet (UV) radiation, in addition to stimulating pigmentation. Previously, we reported the effects of tetrapeptide analogs of alpha-melanocortin (alpha-MSH) that were more potent and stable than the physiological alpha-MSH, and mimicked its photoprotective effects against UV-induced DNA damage in human melanocytes. Here, we report on a panel of tripeptide analogs consisting of a modified alpha-MSH core His(6)-d-Phe(7)-Arg(8), which contained different N-capping groups, C-terminal modifications, or arginine mimics. The most potent tripeptides in activating cAMP formation and tyrosinase of human melanocytes were three analogs with C-terminal modifications. The most effective C-terminal tripeptide mimicked alpha-MSH in reducing hydrogen peroxide generation and enhancing nucleotide excision repair following UV irradiation. The effects of these three analogs required functional MC1R, as they were absent in human melanocytes that expressed non-functional receptor. These results demonstrate activation of the MC1R by tripeptide melanocortin analogs. Designing small analogs for topical delivery should prove practical and efficacious for skin cancer prevention.

  3. Modulation of the transient receptor potential vanilloid channel TRPV4 by 4alpha-phorbol esters: a structure-activity study

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjaer; Pagani, Alberto; Minassi, Alberto;

    2009-01-01

    The mechanism of activation of the transient receptor potential vanilloid 4 (TRPV4) channel by 4alpha-phorbol esters was investigated by combining information from chemical modification of 4alpha-phorbol-didecanoate (4alpha-PDD, 2a), site-directed mutagenesis, Ca(2+) imaging, and electrophysiolog...... of TRPV4 activation by small molecules and obtain information for the rational design of structurally simpler ligands for this ion channel....

  4. Estrogen receptor alpha activation enhances mitochondrial function and systemic metabolism in high-fat-fed ovariectomized mice.

    Science.gov (United States)

    Hamilton, Dale J; Minze, Laurie J; Kumar, Tanvi; Cao, Tram N; Lyon, Christopher J; Geiger, Paige C; Hsueh, Willa A; Gupte, Anisha A

    2016-09-01

    Estrogen impacts insulin action and cardiac metabolism, and menopause dramatically increases cardiometabolic risk in women. However, the mechanism(s) of cardiometabolic protection by estrogen remain incompletely understood. Here, we tested the effects of selective activation of E2 receptor alpha (ERα) on systemic metabolism, insulin action, and cardiac mitochondrial function in a mouse model of metabolic dysfunction (ovariectomy [OVX], insulin resistance, hyperlipidemia, and advanced age). Middle-aged (12-month-old) female low-density lipoprotein receptor (Ldlr)(-/-) mice were subjected to OVX or sham surgery and fed "western" high-fat diet (WHFD) for 3 months. Selective ERα activation with 4,4',4″-(4-Propyl-[1H]-pyrazole-1,3,5-triyl) (PPT), prevented weight gain, improved insulin action, and reduced visceral fat accumulation in WHFD-fed OVX mice. PPT treatment also elevated systemic metabolism, increasing oxygen consumption and core body temperature, induced expression of several metabolic genes such as peroxisome proliferator-activated receptor gamma, coactivator 1 alpha, and nuclear respiratory factor 1 in heart, liver, skeletal muscle, and adipose tissue, and increased cardiac mitochondrial function. Taken together, selective activation of ERα with PPT enhances metabolic effects including insulin resistance, whole body energy metabolism, and mitochondrial function in OVX mice with metabolic syndrome. PMID:27582063

  5. Up-Regulation of Hepatic Alpha-2-HS-Glycoprotein Transcription by Testosterone via Androgen Receptor Activation

    Directory of Open Access Journals (Sweden)

    Jakob Voelkl

    2014-06-01

    Full Text Available Background/Aims: Fetuin-A (alpha-2-HS-glycoprotein, AHSG, a liver borne plasma protein, contributes to the prevention of soft tissue calcification, modulates inflammation, reduces insulin sensitivity and fosters weight gain following high fat diet or ageing. In polycystic ovary syndrome, fetuin-A levels correlate with free androgen levels, an observation pointing to androgen sensitivity of fetuin-A expression. The present study thus explored whether the expression of hepatic fetuin-A is modified by testosterone. Methods: HepG2 cells were treated with testosterone and androgen receptor antagonist flutamide, and were silenced with androgen receptor siRNA. To test the in vivo relevance, male mice were subjected to androgen deprivation therapy (ADT for 7 weeks. AHSG mRNA levels were determined by quantitative RT-PCR and fetuin-A protein abundance by Western blotting. Results: In HepG2 cells, AHSG mRNA expression and fetuin-A protein abundance were both up-regulated following testosterone treatment. The human alpha-2-HS-glycoprotein gene harbors putative androgen receptor response elements in the proximal 5 kb promoter sequence relative to TSS. The effect of testosterone on AHSG mRNA levels was abrogated by silencing of the androgen receptor in HepG2 cells. Moreover, treatment of HepG2 cells with the androgen receptor antagonist flutamide in presence of endogenous ligands in the medium significantly down-regulated AHSG mRNA expression and fetuin-A protein abundance. In addition, ADT of male mice was followed by a significant decrease of hepatic Ahsg mRNA expression and fetuin-A protein levels. Conclusions: Testosterone participates in the regulation of hepatic fetuin-A expression, an effect mediated, at least partially, by androgen receptor activation.

  6. Receptor Density Is Key to the Alpha2/Beta Interferon Differential Activities

    OpenAIRE

    Moraga, I.; Harari, D.; Schreiber, G.; Uze, G.; Pellegrini, S.

    2009-01-01

    Multiple type I interferons (IFN-α/β) elicit Jak/Stat activation, rapid gene induction, and pleiotropic effects, such as differentiation, antiviral protection, and blocks in proliferation, which are dependent on the IFN subtype and the cellular context. To date, ligand- and receptor-specific molecular determinants underlying IFN-α/β differential activities or potencies have been well characterized. To analyze cellular determinants that impact subtype-specific potency, human fibrosarcoma U5A-d...

  7. Deletion of Asn{sup 281} in the {alpha}-subunit of the human insulin receptor causes constitutive activation of the receptor and insulin desensitization

    Energy Technology Data Exchange (ETDEWEB)

    Desbois-Mouthon, C.; Sert-Langeron, C.; Magre, J.; Blivet, M.J. [INSERM, Paris (France)] [and others

    1996-02-01

    We studied the structure and function of the insulin receptor (IR) in two sisters with leprechaunism. The patients had inherited alterations in the IR gene and were compound heterozygotes. Their paternal IR allele carried a major deletion, including exons 10-13, which shifted the reading frame and introduced a premature chain termination codon in the IR sequence. This allele was expressed at a very low level in cultured fibroblasts (<10% of total IR messenger ribonucleic acid content) and encoded a truncated protein lacking transmembrane and tyrosine kinase domains. The maternal IR allele was deleted of 3 bp in exon 3, causing the loss of Asn{sup 281} in the {alpha}-subunit. This allele generated levels of IR messenger ribonucleic acid and cell surface receptors similar to those seen in control fibroblasts. However, IRs from patients` cells had impaired insulin binding and exhibited in vivo and in vitro constitutive activation of autophosphorylation and tyrosine kinase activity. As a result of this IR-preactivated state, the cells were desensitized to insulin stimulation of glycogen and DNA syntheses. These findings strongly suggest that Asn{sup 281} of the IR {alpha}-subunit plays a critical role in the inhibitory constraint exerted by the extracellular {alpha}-subunit over the intracellular kinase activity. 59 refs., 6 figs.

  8. The role of 14-3-3{beta} in transcriptional activation of estrogen receptor {alpha} and its involvement in proliferation of breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoonseo; Kim, Hyungjin; Jang, Sung-Wuk [School of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Ko, Jesang, E-mail: jesangko@korea.ac.kr [School of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of)

    2011-10-14

    Highlights: {yields} 14-3-3{beta} interacts with ER{alpha} and the interaction is Akt-dependent. {yields} 14-3-3{beta} regulates the transcriptional activity of ER{alpha} in a ligand-dependent manner. {yields} 14-3-3{beta} increases expressions of ER{alpha} target genes. {yields} 14-3-3{beta} increases breast cancer cell proliferation. -- Abstract: The estrogen receptor (ER) functions as a transcription factor that mediates the effects of estrogen. ER{alpha}, which plays a crucial role in the development and progression of breast cancer, is activated by estrogen binding, leading to receptor phosphorylation, dimerization, and recruitment of co-activators and chaperons to the estrogen-bound receptor complex. The 14-3-3 proteins bind to target proteins via phosphorylation and influence many cellular events by altering their subcellular localization or acting as a chaperone. However, regulation of ER{alpha} expression and transactivation by the 14-3-3 proteins has not been reported. We demonstrate that 14-3-3{beta} functions as a positive regulator of ER{alpha} through a direct protein-protein interaction in an estrogen-dependent manner. Ectopic expression of 14-3-3{beta} stimulated ER{alpha}-mediated transcriptional activity in MCF-7 breast cancer cells. Enhanced ER{alpha} transcriptional activity due to 14-3-3{beta} increased the expressions of the endogenous ER{alpha} target genes, leading to proliferation of breast cancer cells. We suggest that 14-3-3{beta} has oncogenic potential in breast cancer via binding to ER{alpha} and activation of the transcriptional activity of ER{alpha}.

  9. Folic acid mediates activation of the pro-oncogene STAT3 via the Folate Receptor alpha.

    Science.gov (United States)

    Hansen, Mariann F; Greibe, Eva; Skovbjerg, Signe; Rohde, Sarah; Kristensen, Anders C M; Jensen, Trine R; Stentoft, Charlotte; Kjær, Karina H; Kronborg, Camilla S; Martensen, Pia M

    2015-07-01

    The signal transducer and activator of transcription 3 (STAT3) is a well-described pro-oncogene found constitutively activated in several cancer types. Folates are B vitamins that, when taken up by cells through the Reduced Folate Carrier (RFC), are essential for normal cell growth and replication. Many cancer cells overexpress a glycophosphatidylinositol (GPI)-anchored Folate Receptor α (FRα). The function of FRα in cancer cells is still poorly described, and it has been suggested that transport of folate is not its primary function in these cells. We show here that folic acid and folinic acid can activate STAT3 through FRα in a Janus Kinase (JAK)-dependent manner, and we demonstrate that gp130 functions as a transducing receptor for this signalling. Moreover, folic acid can promote dose dependent cell proliferation in FRα-positive HeLa cells, but not in FRα-negative HEK293 cells. After folic acid treatment of HeLa cells, up-regulation of the STAT3 responsive genes Cyclin A2 and Vascular Endothelial Growth Factor (VEGF) were verified by qRT-PCR. The identification of this FRα-STAT3 signal transduction pathway activated by folic and folinic acid contributes to the understanding of the involvement of folic acid in preventing neural tube defects as well as in tumour growth. Previously, the role of folates in these diseases has been attributed to their roles as one-carbon unit donors following endocytosis into the cell. Our finding that folic acid can activate STAT3 via FRα adds complexity to the established roles of B9 vitamins in cancer and neural tube defects.

  10. Inhibition of alpha oscillations through serotonin-2A receptor activation underlies the visual effects of ayahuasca in humans.

    Science.gov (United States)

    Valle, Marta; Maqueda, Ana Elda; Rabella, Mireia; Rodríguez-Pujadas, Aina; Antonijoan, Rosa Maria; Romero, Sergio; Alonso, Joan Francesc; Mañanas, Miquel Àngel; Barker, Steven; Friedlander, Pablo; Feilding, Amanda; Riba, Jordi

    2016-07-01

    Ayahuasca is an Amazonian psychotropic plant tea typically obtained from two plants, Banisteriopsis caapi and Psychotria viridis. It contains the psychedelic 5-HT2A and sigma-1 agonist N,N-dimethyltryptamine (DMT) plus β-carboline alkaloids with monoamine-oxidase (MAO)-inhibiting properties. Although the psychoactive effects of ayahuasca have commonly been attributed solely to agonism at the 5-HT2A receptor, the molecular target of classical psychedelics, this has not been tested experimentally. Here we wished to study the contribution of the 5-HT2A receptor to the neurophysiological and psychological effects of ayahuasca in humans. We measured drug-induced changes in spontaneous brain oscillations and subjective effects in a double-blind randomized placebo-controlled study involving the oral administration of ayahuasca (0.75mg DMT/kg body weight) and the 5-HT2A antagonist ketanserin (40mg). Twelve healthy, experienced psychedelic users (5 females) participated in four experimental sessions in which they received the following drug combinations: placebo+placebo, placebo+ayahuasca, ketanserin+placebo and ketanserin+ayahuasca. Ayahuasca induced EEG power decreases in the delta, theta and alpha frequency bands. Current density in alpha-band oscillations in parietal and occipital cortex was inversely correlated with the intensity of visual imagery induced by ayahuasca. Pretreatment with ketanserin inhibited neurophysiological modifications, reduced the correlation between alpha and visual effects, and attenuated the intensity of the subjective experience. These findings suggest that despite the chemical complexity of ayahuasca, 5-HT2A activation plays a key role in the neurophysiological and visual effects of ayahuasca in humans. PMID:27039035

  11. Effects of L-carnitine against oxidative stress in human hepatocytes: involvement of peroxisome proliferator-activated receptor alpha

    Directory of Open Access Journals (Sweden)

    Li Jin-Lian

    2012-03-01

    Full Text Available Abstract Background Excessive oxidative stress and lipid peroxidation have been demonstrated to play important roles in the production of liver damage. L-carnitine is a natural substance and acts as a carrier for fatty acids across the inner mitochondrial membrane for subsequent beta-oxidation. It is also an antioxidant that reduces metabolic stress in the cells. Recent years L-carnitine has been proposed for treatment of various kinds of disease, including liver injury. This study was conducted to evaluate the protective effect of L-carnitine against hydrogen peroxide (H2O2-induced cytotoxicity in a normal human hepatocyte cell line, HL7702. Methods We analyzed cytotoxicity using MTT assay and lactate dehydrogenase (LDH release. Antioxidant activity and lipid peroxidation were estimated by reactive oxygen species (ROS levels, activities and protein expressions of superoxide dismutase (SOD and catalase (CAT, and malondialdehyde (MDA formation. Expressions of peroxisome proliferator-activated receptor (PPAR-alpha and its target genes were evaluated by RT-PCR or western blotting. The role of PPAR-alpha in L-carnitine-enhanced expression of SOD and CAT was also explored. Statistical analysis was performed by a one-way analysis of variance, and its significance was assessed by Dennett's post-hoc test. Results The results showed that L-carnitine protected HL7702 cells against cytotoxity induced by H2O2. This protection was related to the scavenging of ROS, the promotion of SOD and CAT activity and expression, and the prevention of lipid peroxidation in cultured HL7702 cells. The decreased expressions of PPAR-alpha, carnitine palmitoyl transferase 1 (CPT1 and acyl-CoA oxidase (ACOX induced by H2O2 can be attenuated by L-carnitine. Besides, we also found that the promotion of SOD and CAT protein expression induced by L-carnitine was blocked by PPAR-alpha inhibitor MK886. Conclusions Taken together, our findings suggest that L-carnitine could protect HL

  12. pRb controls estrogen receptor alpha protein stability and activity.

    Science.gov (United States)

    Caligiuri, Isabella; Toffoli, Giuseppe; Giordano, Antonio; Rizzolio, Flavio

    2013-06-01

    A cross talk between the Estrogen Receptor (ESR1) and the Retinoblastoma (pRb) pathway has been demonstrated to influence the therapeutic response of breast cancer patients but the full mechanism remains poorly understood. Here we show that the N-terminal domain of pRb interacts with the CD domain of ESR1 to allow for the assembly of intermediate complex chaperone proteins HSP90 and p23. We demonstrated that a loss of pRb in human/mouse breast cells decreases the expression of the ESR1 protein through the proteasome pathway. Our work reveals a novel regulatory mechanism of ESR1 basal turnover and activity and an unanticipated relationship with the pRb tumor suppressor.

  13. Transcriptomic signatures of peroxisome proliferator-activated receptor alpha (PPARalpha) in different mouse liver models identify novel aspects of its biology

    NARCIS (Netherlands)

    Szalowska, E.; Tesfay, H.A.; Hijum, S.A.F.T. van; Kersten, S.

    2014-01-01

    BACKGROUND: The peroxisome proliferator-activated receptor alpha (PPARalpha) is a ligand-activated transcription factor that regulates lipid catabolism and inflammation and is hepatocarcinogenic in rodents. It is presumed that the functions of PPARalpha in liver depend on cross-talk between parenchy

  14. The selective alpha7 nicotinic acetylcholine receptor agonist A-582941 activates immediate early genes in limbic regions of the forebrain

    DEFF Research Database (Denmark)

    Thomsen, M S; Mikkelsen, J D; Timmermann, D B;

    2008-01-01

    Due to the cognitive-enhancing properties of alpha7 nicotinic acetylcholine receptor (alpha7 nAChR) agonists, they have attracted interest for the treatment of cognitive disturbances in schizophrenia. Schizophrenia typically presents in late adolescence or early adulthood. It is therefore important...... regions critically involved in working memory and attention. Furthermore, this effect is more pronounced in juvenile than adult rats, indicating that the juvenile forebrain is more responsive to alpha7 nAChR stimulation. This observation may be relevant in the treatment of juvenile-onset schizophrenia....

  15. Acetylcholine release in mouse hippocampal CA1 preferentially activates inhibitory-selective interneurons via alpha4 beta2* nicotinic receptor activation

    Directory of Open Access Journals (Sweden)

    L. Andrew Bell

    2015-04-01

    Full Text Available Acetylcholine (ACh release onto nicotinic receptors directly activates subsets of inhibitory interneurons in hippocampal CA1. However, the specific interneurons activated and their effect on the hippocampal network is not completely understood. Therefore, we investigated subsets of hippocampal CA1 interneurons that respond to ACh release through the activation of nicotinic receptors and the potential downstream effects this may have on hippocampal CA1 network function. ACh was optogenetically released in mouse hippocampal slices by expressing the excitatory optogenetic protein oChIEF-tdTomato in medial septum/diagonal band of Broca cholinergic neurons using Cre recombinase-dependent adeno-associated viral mediated transfection. The actions of optogenetically released ACh were assessed on both pyramidal neurons and different interneuron subtypes via whole cell patch clamp methods. Vasoactive intestinal peptide (VIP-expressing interneurons that selectively innervate other interneurons (VIP/IS were excited by ACh through the activation of nicotinic receptors containing alpah4 and beta2 subunits (alpha4 beta2*. ACh release onto VIP/IS was presynaptically inhibited by M2 muscarinic autoreceptors. ACh release produced spontaneous inhibitory postsynaptic current (sIPSC barrages blocked by dihydro-beta-erythroidine in interneurons but not pyramidal neurons. Optogenetic suppression of VIP interneurons did not inhibit these sIPSC barrages suggesting other interneuron-selective interneurons were also excited by 42* nicotinic receptor activation. In contrast, interneurons that innervate pyramidal neuron perisomatic regions were not activated by ACh release onto nicotinic receptors. Therefore, we propose ACh release in CA1 facilitates disinhibition through activation of 42* nicotinic receptors on interneuron-selective interneurons whereas interneurons that innervate pyramidal neurons are less affected by nicotinic receptor activation.

  16. Acyl-CoA esters antagonize the effects of ligands on peroxisome proliferator-activated receptor alpha conformation, DNA binding, and interaction with Co-factors

    DEFF Research Database (Denmark)

    Elholm, M; Dam, I; Jorgensen, C;

    2001-01-01

    The peroxisome proliferator-activated receptor alpha (PPARalpha) is a ligand-activated transcription factor and a key regulator of lipid homeostasis. Numerous fatty acids and eicosanoids serve as ligands and activators for PPARalpha. Here we demonstrate that S-hexadecyl-CoA, a nonhydrolyzable...... palmitoyl-CoA analog, antagonizes the effects of agonists on PPARalpha conformation and function in vitro. In electrophoretic mobility shift assays, S-hexadecyl-CoA prevented agonist-induced binding of the PPARalpha-retinoid X receptor alpha heterodimer to the acyl-CoA oxidase peroxisome proliferator...... a functional PPARalpha ligand-binding pocket. S-Hexadecyl-CoA prevented ligand-induced interaction between the co-activator SRC-1 and PPARalpha but increased recruitment of the nuclear receptor co-repressor NCoR. In cells, the concentration of free acyl-CoA esters is kept in the low nanomolar range due...

  17. Peroxisome proliferator-activated receptor alpha induction of uncoupling protein 2 protects against acetaminophen-induced liver toxicity.

    Science.gov (United States)

    Patterson, Andrew D; Shah, Yatrik M; Matsubara, Tsutomu; Krausz, Kristopher W; Gonzalez, Frank J

    2012-07-01

    Acetaminophen (APAP) overdose causes acute liver failure in humans and rodents due in part to the destruction of mitochondria as a result of increased oxidative stress followed by hepatocellular necrosis. Activation of the peroxisome proliferator-activated receptor alpha (PPARα), a member of the nuclear receptor superfamily that controls the expression of genes encoding peroxisomal and mitochondrial fatty acid β-oxidation enzymes, with the experimental ligand Wy-14,643 or the clinically used fibrate drug fenofibrate, fully protects mice from APAP-induced hepatotoxicity. PPARα-humanized mice were also protected, whereas Ppara-null mice were not, thus indicating that the protection extends to human PPARα and is PPARα-dependent. This protection is due in part to induction of the PPARα target gene encoding mitochondrial uncoupling protein 2 (UCP2). Forced overexpression of UCP2 protected wildtype mice against APAP-induced hepatotoxicity in the absence of PPARα activation. Ucp2-null mice, however, were sensitive to APAP-induced hepatotoxicity despite activation of PPARα with Wy-14,643. Protection against hepatotoxicity by UCP2-induction through activation of PPARα is associated with decreased APAP-induced c-jun and c-fos expression, decreased phosphorylation of JNK and c-jun, lower mitochondrial H(2)O(2) levels, increased mitochondrial glutathione in liver, and decreased levels of circulating fatty acyl-carnitines. These studies indicate that the PPARα target gene UCP2 protects against elevated reactive oxygen species generated during drug-induced hepatotoxicity and suggest that induction of UCP2 may also be a general mechanism for protection of mitochondria during fatty acid β-oxidation.

  18. Regulation of hepatic peroxisome proliferator-activated receptor-alpha (PPAR-a) expression but not adiponectin by dietary protein in finishing pigs

    Science.gov (United States)

    Dietary soy protein reduction and supplemental leucine (Leu) have been found to decrease leanness and increase muscle lipid content of pig carcasses respectively. Soy protein regulates adiponectin and peroxisome proliferator activated receptor-alpha (PPAR-a) in some species, but the effect of dieta...

  19. Peroxisome proliferator-activated receptor {alpha} agonists modulate Th1 and Th2 chemokine secretion in normal thyrocytes and Graves' disease

    Energy Technology Data Exchange (ETDEWEB)

    Antonelli, Alessandro, E-mail: a.antonelli@med.unipi.it [Department of Internal Medicine, University of Pisa-School of Medicine, Via Roma 67, I-56100, Pisa (Italy); Ferrari, Silvia Martina, E-mail: sm.ferrari@int.med.unipi.it [Department of Internal Medicine, University of Pisa-School of Medicine, Via Roma 67, I-56100, Pisa (Italy); Frascerra, Silvia, E-mail: lafrasce@gmail.com [Department of Internal Medicine, University of Pisa-School of Medicine, Via Roma 67, I-56100, Pisa (Italy); Corrado, Alda, E-mail: dala_res@hotmail.it [Department of Internal Medicine, University of Pisa-School of Medicine, Via Roma 67, I-56100, Pisa (Italy); Pupilli, Cinzia, E-mail: c.pupilli@dfc.unifi.it [Endocrinology Unit, Azienda Ospedaliera Careggi and University of Florence, Viale Morgagni 85, I-50134, Florence (Italy); Bernini, Giampaolo, E-mail: g.bernini@int.med.unipi.it [Department of Internal Medicine, University of Pisa-School of Medicine, Via Roma 67, I-56100, Pisa (Italy); Benvenga, Salvatore, E-mail: s.benvenga@me.nettuno.it [Department of Clinical and Experimental Medicine, Section of Endocrinology, University of Messina, Piazza Pugliatti 1, I-98122, Messina (Italy); Ferrannini, Ele, E-mail: eferrannini@med.unipi.it [Department of Internal Medicine, University of Pisa-School of Medicine, Via Roma 67, I-56100, Pisa (Italy); Fallahi, Poupak, E-mail: poupak@int.med.unipi.it [Department of Internal Medicine, University of Pisa-School of Medicine, Via Roma 67, I-56100, Pisa (Italy)

    2011-07-01

    Until now, no data are present about the effect of peroxisome proliferator-activated receptor (PPAR){alpha} activation on the prototype Th1 [chemokine (C-X-C motif) ligand (CXCL)10] (CXCL10) and Th2 [chemokine (C-C motif) ligand 2] (CCL2) chemokines secretion in thyroid cells. The role of PPAR{alpha} and PPAR{gamma} activation on CXCL10 and CCL2 secretion was tested in Graves' disease (GD) and control primary thyrocytes stimulated with interferon (IFN){gamma} and tumor necrosis factor (TNF){alpha}. IFN{gamma} stimulated both CXCL10 and CCL2 secretion in primary GD and control thyrocytes. TNF{alpha} alone stimulated CCL2 secretion, while had no effect on CXCL10. The combination of IFN{gamma} and TNF{alpha} had a synergistic effect both on CXCL10 and CCL2 chemokines in GD thyrocytes at levels comparable to those of controls. PPAR{alpha} activators inhibited the secretion of both chemokines (stimulated with IFN{gamma} and TNF{alpha}) at a level higher (for CXCL10, about 60-72%) than PPAR{gamma} agonists (about 25-35%), which were confirmed to inhibit CXCL10, but not CCL2. Our data show that CCL2 is modulated by IFN{gamma} and TNF{alpha} in GD and normal thyrocytes. Furthermore we first show that PPAR{alpha} activators inhibit the secretion of CXCL10 and CCL2 in thyrocytes, suggesting that PPAR{alpha} may be involved in the modulation of the immune response in the thyroid.

  20. Expression of the GABA(A) receptor alpha6 subunit in cultured cerebellar granule cells is developmentally regulated by activation of GABA(A) receptors

    DEFF Research Database (Denmark)

    Carlson, B X; Belhage, B; Hansen, G H;

    1997-01-01

    Primary cultures of cerebellar granule cells, prepared from cerebella of 7-day-old rats and cultured for 4 or 8 days, were used to study the neurodifferentiative effect of a GABA(A) receptor agonist, 4,5,6,7-tetrahydroisoxazol[5,4-c]pyridin-3-ol (THIP), on the expression of the alpha6 GABA...... suggest that THIP has a trophic effect on alpha6 subunit expression, and this effect occurs only at an early developmental stage. Moreover, this study presents further evidence for the role of GABA(A) agonists, and thus the neurotransmitter, GABA, in regulating the expression of GABA(A) receptor subunits...

  1. The alpha7 nicotinic receptor agonist SSR180711 increases activity regulated cytoskeleton protein (Arc) gene expression in the prefrontal cortex of the rat

    DEFF Research Database (Denmark)

    Kristensen, Søren; Thomsen, Morten Skøtt; Hansen, Henrik H;

    2007-01-01

    Nicotinic alpha7 acetylcholine receptors (alpha7 nAChR) have been shown to enhance attentional function and aspects of memory function in experimental models and in man. The protein Arc encoded by the effector immediate early gene arc or arg3.1 has been shown to be strongly implicated in long......-term memory function. We have sought to determine if alpha7 nAChR mediate the stimulation of arc gene expression, and if so, where in the brain such activation may occur using semi-quantitative in situ hybridisation. Administration of the novel and selective alpha7 nAChR agonist, SSR180711 (1, 3 and 10 mg...

  2. IL-6 cooperates with peroxisome proliferator-activated receptor-alpha-ligands to induce liver fatty acid binding protein (LFABP) up-regulation

    OpenAIRE

    Vida, Margarita; Serrano, Antonia; Romero-Cuevas, Miguel; Pavón, Francisco J.; González-Rodriguez, Águeda; Gavito, Ana L.; Cuesta, Antonio L.; Valverde, Ángela M.; Rodríguez de Fonseca, Fernando; Baixeras, Elena

    2013-01-01

    [Background]: LFABP plays a critical role in the uptake and intracellular transport of fatty acids (FA) and other peroxisome proliferator-activated receptor alpha (PPARα) ligands. PPARα activation by PPARα ligands bound to LFABP results in gene expression of FA oxidation enzymes and de novo LFABP. The cytokine IL-6 is involved in regulating liver lipid oxidation. [Aims]: To study the ability of IL-6 to modulate the expression of the LFABP in hepatocytes. Methods: HepG2 and mouse primary hepat...

  3. A selective estrogen receptor modulator inhibits TNF-alpha-induced apoptosis by activating ERK1/2 signaling pathway in vascular endothelial cells.

    Science.gov (United States)

    Yu, Jing; Eto, Masato; Akishita, Masahiro; Okabe, Tetsuro; Ouchi, Yasuyoshi

    2009-07-01

    Tumor necrosis factor (TNF-alpha) is a pleiotropic cytokine exerting both inflammatory and cell death activity and is thought to play a role in the pathogenesis of atherosclerosis. The present study was designed to examine whether the raloxifene analogue, LY117018 could inhibit TNF-alpha-induced apoptosis in vascular endothelial cells and to clarify the involved mechanisms. Apoptosis of endothelial cells was determined by DNA fragmentation assay and the activation of caspase-3. LY117018 significantly inhibited TNF-alpha-induced caspase-3 activation and cell DNA fragmentation levels in bovine carotid artery endothelial cells. The inhibitory effect of LY117018 was abolished by an estrogen receptor antagonist ICI 182,780. p38 MAPK, JNK, ERK1/2 and Akt have been shown to act as apoptotic or anti-apoptotic signals. TNF-alpha stimulated the phosphorylation levels of p38 MAPK, JNK, ERK1/2 and Akt in vascular endothelial cells. TNF-alpha-induced apoptosis was significantly decreased by SB203580, a p38 MAPK inhibitor or SP600125, a JNK inhibitor, but was enhanced by an ERK1/2 pathway inhibitor, PD98059 or a PI3-kinase/Akt pathway inhibitor, wortmannin. The anti-apoptotic effect of LY117018 was abrogated only by PD98059 but was not affected by the inhibitors for p38 MAPK, JNK, or Akt. LY117018 stimulated the further increase in phosphorylation of ERK1/2 in TNF-alpha treated endothelial cells but it did not affect phosphorylation levels of p38 MAPK, JNK or Akt. These results suggest that LY 110718 prevents caspase-3 dependent apoptosis induced by TNF-alpha in vascular endothelial cells through activation of the estrogen receptors and the ERK1/2 signaling pathway. PMID:19275968

  4. Alpha-lipoic acid-mediated activation of muscarinic receptors improves hippocampus- and amygdala-dependent memory.

    Science.gov (United States)

    Mahboob, Aamra; Farhat, Syeda Mehpara; Iqbal, Ghazala; Babar, Mustafeez Mujtaba; Zaidi, Najam-us-Sahar Sadaf; Nabavi, Seyed Mohammad; Ahmed, Touqeer

    2016-04-01

    Aluminum (Al) is a neurotoxic agent which readily crosses the blood-brain-barrier (BBB) and accumulates in the brain leading to neurodegenerative disorders, characterised by cognitive impairment. Alpha-lipoic acid (ALA) is an antioxidant and has a potential to improve cognitive functions. This study aimed to evaluate the neuroprotective effect of ALA in AlCl3-induced neurotoxicity mouse model. Effect of ALA (25mg/kg/day) was evaluated in the AlCl3-induced neurotoxicity (AlCl3 150 mg/kg/day) mouse model on learning and memory using behaviour tests and on the expression of muscarinic receptor genes (using RT-PCR), in hippocampus and amygdala. Following ALA treatment, the expression of muscarinic receptor genes M1, M2 and choline acetyltransferase (ChaT) were significantly improved (penhanced fear memory (pmemory was remarkably restored (penhancement thus presenting it an enviable therapeutic candidate for the treatment of neurodegenerative disorders. PMID:26912408

  5. Expression of the GABA(A) receptor alpha6 subunit in cultured cerebellar granule cells is developmentally regulated by activation of GABA(A) receptors

    DEFF Research Database (Denmark)

    Carlson, B X; Belhage, B; Hansen, Gert Helge;

    1997-01-01

    Primary cultures of cerebellar granule cells, prepared from cerebella of 7-day-old rats and cultured for 4 or 8 days, were used to study the neurodifferentiative effect of a GABA(A) receptor agonist, 4,5,6,7-tetrahydroisoxazol[5,4-c]pyridin-3-ol (THIP), on the expression of the alpha6 GABA......Da (alpha6 subunit) radioactive peaks in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In contrast, THIP-treated granule cells at 8 DIV demonstrated a small but significant decrease from control cultures in the photoincorporation of [3H]Ro15-4513 in the 51-kDa peak; however......, no significant change in [3H]Ro15-4513 binding was observed for the 56-kDa polypeptide. Immunolabeling of the alpha6 subunit using silver-enhanced, immuno-gold staining of granule cells showed a significant effect with THIP treatment only at 4 DIV and not at 8 DIV. Examination by light microscopy demonstrated...

  6. The fibrate decreases radiation sensitivity via peroxisome proliferator-activated receptor {alpha}-mediated superoxide dismutase induction in HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianguang; An, Zhengzhe; Song, Hye Jin; Kim, Won Dong; Park, Woo Yoon [Chungbuk National University College of Medicine, Cheongju (Korea, Republic of); Jang, Seong Soon [The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of); Yu, Jae Ran [Konkuk University College of Medicine, Chungju (Korea, Republic of)

    2012-06-15

    The fibrates are ligands for peroxisome proliferator-activated receptor (PPAR) {alpha} and used clinically as hypolipidemic drugs. The fibrates are known to cause peroxisome proliferation, enhance superoxide dismutase (SOD) expression and catalase activity. The antioxidant actions of the fibrates may modify radiation sensitivity. Here, we investigated the change of the radiation sensitivity in two cervix cancer cell lines in combination with fenofi brate (FF). Activity and protein expression of SOD were measured according to the concentration of FF. The mRNA expressions were measured by using real time reverse-transcription polymerase chain reaction. Combined cytotoxic effect of FF and radiation was measured by using clonogenic assay. In HeLa cells total SOD activity was increased with increasing FF doses up to 30 {mu}M. In the other hand, the catalase activity was increased a little. As with activity the protein expression of SOD1 and SOD2 was increased with increasing doses of FF. The mRNAs of SOD1, SOD2, PPAR{alpha} and PPAR{gamma} were increased with increasing doses of FF. The reactive oxygen species (ROS) produced by radiation was decreased by preincubation with FF. The surviving fractions (SF) by combining FF and radiation was higher than those of radiation alone. In Me180 cells SOD and catalase activity were not increased with FF. Also, the mRNAs of SOD1, SOD2, and PPAR{alpha} were not increased with FF. However, the mRNA of PPAR{gamma} was increased with FF. FF can reduce radiation sensitivity by ROS scavenging via SOD induction in HeLa. SOD induction by FF is related with PPAR{alpha}.

  7. Role of peroxisome proliferator-activated receptors alpha and gamma in gastric ulcer: An overview of experimental evidences.

    Science.gov (United States)

    Saha, Lekha

    2015-11-01

    Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Three subtypes, PPARα, PPARβ/δ, and PPARγ, have been identified so far. PPARα is expressed in the liver, kidney, small intestine, heart, and muscle, where it activates the fatty acid catabolism and control lipoprotein assembly in response to long-chain unsaturated fatty acids, eicosanoids, and hypolipidemic drugs (e.g., fenofibrate). PPARβ/δ is more broadly expressed and is implicated in fatty acid oxidation, keratinocyte differentiation, wound healing, and macrophage response to very low density lipoprotein metabolism. This isoform has been implicated in transcriptional-repression functions and has been shown to repress the activity of PPARα or PPARγ target genes. PPARγ1 and γ2 are generated from a single-gene peroxisome proliferator-activated receptors gamma by differential promoter usage and alternative splicing. PPARγ1 is expressed in colon, immune system (e.g., monocytes and macrophages), and other tissues where it participates in the modulation of inflammation, cell proliferation, and differentiation. PPARs regulate gene expression through distinct mechanisms: Ligand-dependent transactivation, ligand-independent repression, and ligand-dependent transrepression. Studies in animals have demonstrated the gastric antisecretory activity of PPARα agonists like ciprofibrate, bezafibrate and clofibrate. Study by Pathak et al also demonstrated the effect of PPARα agonist, bezafibrate, on gastric secretion and gastric cytoprotection in various gastric ulcer models in rats. The majority of the experimental studies is on pioglitazone and rosiglitazone, which are PPARγ activators. In all the studies, both the PPARγ activators showed protection against the gastric ulcer and also accelerate the ulcer healing in gastric ulcer model in rats. Therefore, PPARα and PPARγ may be a target for gastric ulcer therapy

  8. Role of peroxisome proliferator-activated receptors alpha and gamma in gastric ulcer: An overview of experimental evidences

    Institute of Scientific and Technical Information of China (English)

    Lekha; Saha

    2015-01-01

    Peroxisome proliferator-activated receptors(PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Three subtypes, PPARα, PPARβ/δ, and PPARγ, have been identifiedso far. PPARα is expressed in the liver, kidney, small intestine, heart, and muscle, where it activates the fatty acid catabolism and control lipoprotein assembly in response to long-chain unsaturated fatty acids, eicosanoids, and hypolipidemic drugs(e.g., fenofibrate). PPARβ/δ is more broadly expressed and is implicated in fatty acid oxidation, keratinocyte differentiation, wound healing, and macrophage response to very low density lipoprotein metabolism. This isoform has been implicated in transcriptional-repression functions and has been shown to repress the activity of PPARα or PPARγ target genes. PPARγ1 and γ2 are generated from a single-gene peroxisome proliferator-activated receptors gamma by differential promoter usage and alternative splicing. PPARγ1 is expressed in colon, immune system(e.g., monocytes and macrophages), and other tissues where it participates in the modulation of inflammation, cell proliferation, and differentiation. PPARs regulate gene expression through distinct mechanisms: Liganddependent transactivation, ligand-independent repression, and ligand-dependent transrepression. Studies in animals have demonstrated the gastric antisecretory activity of PPARα agonists like ciprofibrate, bezafibrate and clofibrate. Study by Pathak et al also demonstrated the effect of PPARα agonist, bezafibrate, on gastric secretion and gastric cytoprotection in various gastric ulcer models in rats. The majority of the experimental studies is on pioglitazone and rosiglitazone, which are PPARγ activators. In all the studies, both the PPARγ activators showed protection against the gastric ulcer and also accelerate the ulcer healing in gastric ulcer model in rats. Therefore, PPARα and PPARγ may be a target for gastric ulcer therapy

  9. Influence of peroxisome proliferator-activated receptor alpha agonists on the intracellular turnover and secretion of apolipoprotein (Apo) B-100 and ApoB-48.

    Science.gov (United States)

    Lindén, Daniel; Lindberg, Karin; Oscarsson, Jan; Claesson, Catharina; Asp, Lennart; Li, Lu; Gustafsson, Maria; Borén, Jan; Olofsson, Sven-Olof

    2002-06-21

    The peroxisome proliferator-activated receptor (PPAR) alpha agonist WY 14,643 increased the secretion of apolipoprotein (apo) B-100, but not that of apoB-48, and decreased triglyceride biosynthesis and secretion from primary rat hepatocytes. These effects resulted in decreased secretion of apoB-100-very low density lipoprotein (VLDL) and an increased secretion of apoB-100 on low density lipoproteins/intermediate density lipoproteins. ApoB-48-VLDL was also replaced by more dense particles. The proteasomal inhibitor lactacystin did not influence the recovery of apoB-100 or apoB-48 in primary rat hepatocytes, indicating that co-translational (proteasomal) degradation is of less importance in these cells. Treatment with WY 14,643 made the recovery of apoB-100 sensitive to lactacystin, most likely reflecting the decreased biosynthesis of triglycerides. The PPAR alpha agonist induced a significant increase in the accumulation of pulse-labeled apoB-100 even after a short pulse (2-5 min). There was also an increase in apoB-100 nascent polypeptides, indicating that the co-translational degradation of apoB-100 was inhibited. However, a minor influence on an early posttranslation degradation cannot be excluded. This decreased co-translational degradation of apoB-100 explained the increased secretion of the protein. The levels of apoB-48 remained unchanged during these pulse-chase experiments, and albumin production was not affected, indicating a specific effect of PPAR alpha agonists on the co-translational degradation of apoB-100. These findings explain the difference in the rate of secretion of the two apoB proteins seen after PPAR alpha activation. PPAR alpha agonists increased the expression and biosynthesis of liver fatty acid-binding protein (LFABP). Increased expression of LFABP by transfection of McA-RH7777 cells increased the secretion of apoB-100, decreased triglyceride biosynthesis and secretion, and increased PPAR alpha mRNA levels. These findings suggest that

  10. ChREBP Mediates Glucose Repression of Peroxisome Proliferator-activated Receptor {alpha} Expression in Pancreatic {beta}-Cells

    DEFF Research Database (Denmark)

    Boergesen, Michael; Poulsen, Lars la Cour; Schmidt, Søren Fisker;

    2011-01-01

    Chronic exposure to elevated levels of glucose and fatty acids leads to dysfunction of pancreatic β-cells by mechanisms that are only partly understood. The transcription factor peroxisome proliferator-activated receptor α (PPARα) is an important regulator of genes involved in fatty acid metaboli...... of glucose repression of PPARα gene expression in pancreatic β-cells, suggesting that ChREBP may be important for glucose suppression of the fatty acid oxidation capacity of β-cells....

  11. Anticonvulsant activity of a mGlu(4alpha) receptor selective agonist, (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid.

    Science.gov (United States)

    Chapman, A G; Talebi, A; Yip, P K; Meldrum, B S

    2001-07-20

    The metabotropic Group III agonist, (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid (ACPT-1), selective for the mGlu(4alpha) receptor, suppresses sound-induced seizures in DBA/2 mice following its intracerebroventricular (i.c.v.) administration (ED(50) 5.6 [2.9-10.7], nmol i.c.v., 15 min, clonic phase) and in genetically epilepsy-prone (GEP) rats following focal administration into the inferior colliculus (ED(50) 0.08 [0.01-0.50], nmol, 60 min, clonic phase). ACPT-1 also protects against clonic seizures induced in DBA/2 mice by the Group I agonist, (RS)-3,5-dihydroxyphenylglycine (3,5-DHPG) (ED(50) 0.60 [0.29-1.2], nmol i.c.v.) and by the Group III antagonist, (RS)-alpha-methylserine-O-phosphate (MSOP) (ED(50) 49.3 [37.9-64.1], nmol i.c.v.). Another Group III agonist, (RS)-4-phosphonophenyl-glycine (PPG), preferentially activating the mGlu(8) receptor, previously shown to protect against sound-induced seizures in DBA/2 mice and GEP rats, also protects against seizures induced in DBA/2 by 3,5-DHPG (ED(50) 3.7 [2.4-5.7], nmol i.c.v.) and by the Group III antagonist, MSOP (ED(50) 40.2 [21.0-77.0], nmol i.c.v.). At very high doses (500 nmol i.c.v. and above), Group III antagonists have pro-convulsant and convulsant activity. The anticonvulsant protection against sound-induced seizures in DBA/2 mice provided by a fully protective dose (20 nmol, i.c.v.) of the mGlu(4) receptor agonist ACPT-1, is partially reversed by the co-administration of the Group III antagonists, MSOP, (RS)-alpha-methyl-4-phosphonophenylglycine (MPPG) or (S)-2-amino-2-methyl-4-phosphonobutanoic acid (MAP4), in the 20-50 nmol dose range. At doses of 50-200 nmol, MPPG and MAP4 cause further reversal of the ACPT-1 anticonvulsant protection, while the MSOP effect on ACPT-1 protection is abolished at higher doses. In contrast, the anticonvulsant protection against sound-induced seizures in DBA/2 mice provided by a fully protective dose (20 nmol, i.c.v.) of the mGlu(8) receptor agonist PPG, is not

  12. Evaluation of potential implication of membrane estrogen binding sites on ERE-dependent transcriptional activity and intracellular estrogen receptor-alpha regulation in MCF-7 breast cancer cells.

    Science.gov (United States)

    Seo, Hye Sook; Leclercq, Guy

    2002-01-01

    The potential involvement of membrane estrogen binding sites in the induction of ERE-dependent transcriptional activity as well as in the regulation of intracellular estrogen receptor alpha (ER-alpha) level under estradiol (E2) stimulation was investigated. Our approach relied upon the use of two DCC-treated E2-BSA (bovine serum albumin) solutions (E2-6-BSA and E2-17-BSA). The absence of detectable free E2 in these solutions was established. Both E2-BSA conjugates led to a transient dose-dependent stimulation of the expression of ERE-luciferase (LUC) reporter gene in MVLN cells (MCF-7 cells stably transfected with a pVit-tk-LUC reporter plasmid), a property not recorded with free E2, which maintained enhanced transcriptional activity during the whole experiment. A very low concentration of E2 (10 pM) synergistically acted with E2-BSA conjugates. Hence, ERE-dependent transcriptional activity induced by these conjugates appeared to result from their known interactions with membrane estrogen binding sites. Anti-estrogens (AEs: 4-OH-TAM and RU 58,668), which antagonize genomic ER responses, abrogated the luciferase activity induced by E2-BSA conjugates, confirming a potential relationship between membrane-related signals and intracellular ER. Moreover, induction of luciferase was recorded when the cells were exposed to IBMX (3-isobutyl-1-methylxanthine) and cyclic nucleotides (cAMP/cGMP), suggesting the implication of the latter in the signal transduction pathway leading to the expression of the reporter gene. Growth factors (IGF-I, EGF and TGF-alpha) also slightly stimulated luciferase and synergistically acted with 10 pM E2, or 1 microM E2-BSA conjugates, in agreement with the concept of a cross-talk between steroids and peptides acting on the cell membrane. Remarkably, E2-BSA conjugates, IBMX and all investigated growth factors failed to down-regulate intracellular ER in MCF-7 cells, indicating the need for a direct intracellular interaction of the ligand with the

  13. The Synonymous Ala87 Mutation of Estrogen Receptor Alpha Modifies Transcriptional Activation Through Both ERE and AP1 Sites.

    Science.gov (United States)

    Fernández-Calero, Tamara; Flouriot, Gilles; Marín, Mónica

    2016-01-01

    Estrogen receptor α (ERα) exerts regulatory actions through genomic mechanisms. In the classical pathway, ligand-activated ERα binds directly to DNA through estrogen response elements (ERE) located in the promoter of target genes. ERα can also exert indirect regulation of transcription via protein-protein interaction with other transcription factors such as AP-1.S everal ERα synonymous polymorphisms have been identified and efforts to understand their implications have been made. Nevertheless effects of synonymous polymorphisms are still neglected. This chapter focuses on the experimental procedure employed in order to characterize the transcriptional activity of a synonymous polymorphism of the ERα (rs746432) called Alanine 87 (Ala87). Activity of both WT and Ala87 ERα isoforms on transcriptional pathways can be analyzed in transiently transfected cells using different reporter constructs. ERα efficiency on the classical genomic pathway can be analyzed by determining its transactivation activity on an ERE-driven thymidine kinase (TK) promoter controlling the expression of the luciferase reporter gene. Transcriptional activity through the indirect genomic pathway can be analyzed by employing an AP-1 DNA response element-driven promoter also controlling the expression of luciferase reporter gene.

  14. Resting alpha activity predicts learning ability in alpha neurofeedback

    OpenAIRE

    Wenya eNan; Feng eWan; Mang I eVai; Agostinho eRosa

    2014-01-01

    Individuals differ in their ability to learn how to regulate the alpha activity by neurofeedback. This study aimed to investigate whether the resting alpha activity is related to the learning ability of alpha enhancement in neurofeedback and could be used as a predictor. A total of 25 subjects performed 20 sessions of individualized alpha neurofeedback in order to learn how to enhance activity in the alpha frequency band. The learning ability was assessed by three indices respectively: the tr...

  15. Kaempferol is an estrogen-related receptor alpha and gamma inverse agonist.

    Science.gov (United States)

    Wang, Junjian; Fang, Fang; Huang, Zhiyan; Wang, Yanfei; Wong, Chiwai

    2009-02-18

    Kaempferol is a dietary flavonoid that is thought to function as a selective estrogen receptor modulator. In this study, we established that kaempferol also functions as an inverse agonist for estrogen-related receptors alpha and gamma (ERRalpha and ERRgamma). We demonstrated that kaempferol binds to ERRalpha and ERRgamma and blocks their interaction with coactivator peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha). Kaempferol also suppressed the expressions of ERR-target genes pyruvate dehydrogenase kinase 2 and 4 (PDK2 and PDK4). This evidence suggests that kaempferol may exert some of its biological effect through both estrogen receptors and estrogen-related receptors. PMID:19171140

  16. The gene encoding acyl-CoA-binding protein is subject to metabolic regulation by both sterol regulatory element-binding protein and peroxisome proliferator-activated receptor alpha in hepatocytes

    DEFF Research Database (Denmark)

    Sandberg, Maria B; Bloksgaard, Maria; Duran-Sandoval, Daniel;

    2005-01-01

    gene in hepatocytes. Members of the SREBP family activate the rat ACBP gene through binding sites for SREBP and the auxiliary factors Sp1 and nuclear factor Y in the proximal promoter. In addition, we show that ACBP is a peroxisome proliferator-activated receptor (PPAR) alpha target gene in cultured...

  17. Adiponectin promotes hyaluronan synthesis along with increases in hyaluronan synthase 2 transcripts through an AMP-activated protein kinase/peroxisome proliferator-activated receptor-{alpha}-dependent pathway in human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Takumi; Kobayashi-Hattori, Kazuo [Department of Nutritional Sciences, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502 (Japan); Oishi, Yuichi, E-mail: y3oishi@nodai.ac.jp [Department of Nutritional Sciences, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502 (Japan)

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer Adiponectin promotes hyaluronan synthesis along with an increase in HAS2 transcripts. Black-Right-Pointing-Pointer Adiponectin also increases the phosphorylation of AMPK. Black-Right-Pointing-Pointer A pharmacological activator of AMPK increases mRNA levels of PPAR{alpha} and HAS2. Black-Right-Pointing-Pointer Adiponectin-induced HAS2 mRNA expression is blocked by a PPAR{alpha} antagonist. Black-Right-Pointing-Pointer Adiponectin promotes hyaluronan synthesis via an AMPK/PPAR{alpha}-dependent pathway. -- Abstract: Although adipocytokines affect the functions of skin, little information is available on the effect of adiponectin on the skin. In this study, we investigated the effect of adiponectin on hyaluronan synthesis and its regulatory mechanisms in human dermal fibroblasts. Adiponectin promoted hyaluronan synthesis along with an increase in the mRNA levels of hyaluronan synthase 2 (HAS2), which plays a primary role in hyaluronan synthesis. Adiponectin also increased the phosphorylation of AMP-activated protein kinase (AMPK). A pharmacological activator of AMPK, 5-aminoimidazole-4-carboxamide-1{beta}-ribofuranoside (AICAR), increased mRNA levels of peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}), which enhances the expression of HAS2 mRNA. In addition, AICAR increased the mRNA levels of HAS2. Adiponectin-induced HAS2 mRNA expression was blocked by GW6471, a PPAR{alpha} antagonist, in a concentration-dependent manner. These results show that adiponectin promotes hyaluronan synthesis along with increases in HAS2 transcripts through an AMPK/PPAR{alpha}-dependent pathway in human dermal fibroblasts. Thus, our study suggests that adiponectin may be beneficial for retaining moisture in the skin, anti-inflammatory activity, and the treatment of a variety of cutaneous diseases.

  18. Correlation of serum tumor necrosis factor-alpha, interleukin-4 and soluble interleukin-2 receptor levels with radiologic and clinical manifestations in active pulmonary tuberculosis.

    OpenAIRE

    Levent Kart; Hakan Buyukoglan; Ishak O. Tekin; Remzi Altin; Zuhal Senturk; Inci Gulmez; Ramazan Demir; Mustafa Ozesmi

    2003-01-01

    The precise clinical manifestations of tuberculosis are likely to result from a complex interaction between the host and the pathogen. We took serum samples from a group of patients with a variety of clinical and radiological stages of pulmonary tuberculosis in order to characterize tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4) and soluble interleukin-2 receptor (sIL-2R) response. We further evaluated whether the levels of TNF-alpha, IL-4 and soluble IL-2R are related with eac...

  19. Mulberry leaf aqueous fractions inhibit TNF-alpha-induced nuclear factor kappaB (NF-kappaB) activation and lectin-like oxidized LDL receptor-1 (LOX-1) expression in vascular endothelial cells.

    Science.gov (United States)

    Shibata, Yusuke; Kume, Noriaki; Arai, Hidenori; Hayashida, Kazutaka; Inui-Hayashida, Atsuko; Minami, Manabu; Mukai, Eri; Toyohara, Masako; Harauma, Akiko; Murayama, Toshinori; Kita, Toru; Hara, Saburo; Kamei, Kaeko; Yokode, Masayuki

    2007-07-01

    Mulberry (Morus Alba L., family Moraceae) leaf extracts have various biological effects including inhibition of oxidative modification of low-density lipoprotein (LDL), which is the major cause of atherosclerosis. Endothelial dysfunction elicited by oxidized LDL (Ox-LDL) has been implicated in atherogenesis. Lectin-like Ox-LDL receptor-1 (LOX-1), a cell-surface receptor for atherogenic Ox-LDL, appears to mediate Ox-LDL-induced inflammation, which may be crucial in atherogenesis. Previous studies revealed that expression of LOX-1 is highly inducible by proinflammatory stimuli, including tumor necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), and transforming growth factor-beta (TGF-beta). Therefore, we examined whether mulberry leaf aqueous fractions inhibit LOX-1 expression induced by proinflammatory stimuli. Pretreatment of cultured bovine aortic endothelial cells (BAECs) with mulberry leaf aqueous fractions inhibited TNF-alpha- and LPS-induced expression of LOX-1 at both protein and mRNA levels in a time- and concentration-dependent manner. In contrast, mulberry leaf aqueous fractions did not affect TGF-beta-induced LOX-1 expression. Furthermore, mulberry leaf aqueous fractions inhibited TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) and phosphorylation of inhibitory factor of NF-kappaB-alpha (IkappaB-alpha) in a time- and concentration-dependent fashion. Thus, mulberry leaf aqueous fractions suppress TNF-alpha- and LPS-induced LOX-1 gene expression, by inhibiting NF-kappaB activation.

  20. Alpha7 nicotinic acetylcholine receptor activation ameliorates scopolamine-induced behavioural changes in a modified continuous Y-maze task in mice.

    Science.gov (United States)

    Redrobe, John P; Nielsen, Elsebet Ø; Christensen, Jeppe K; Peters, Dan; Timmermann, Daniel B; Olsen, Gunnar M

    2009-01-01

    The alpha7 (alpha7) nicotinic acetylcholine receptor may represent a drug target for the treatment of disorders associated with working memory/attentional dysfunction. We investigated the effects of three distinct alpha7 nicotinic acetylcholine receptor agonists: 2-methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole (A-582941; 0.01-0.1 mg/kg), 4-bromophenyl 1,4-diazabicyclo(3.2.2) nonane-4-carboxylate (SSR180711; 0.3-3 mg/kg) and N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-4-chlorobenzamide (PNU-282987; 1-10 mg/kg), on scopolamine-induced deficits in a modified Y-maze procedure. Mice were forced to choose one of two visually distinct arms, and were confined there for a 5 min exploration period before being allowed to explore both arms for a 2 min test session, immediately thereafter. The time spent in each arm, entries and total distance travelled were recorded using an automated system. Characterisation experiments showed that scopolamine-treated (1 mg/kg) mice spent less time exploring the unfamiliar arm, when compared with vehicle-treated animals. Combination experiments showed that all three alpha7 agonists ameliorated scopolamine-induced changes in unfamiliar arm exploration. In conclusion, the present data support the idea that alpha7 nicotinic acetylcholine receptors may represent an interesting target for the treatment of conditions associated with attentional/working memory dysfunction.

  1. Myxoma virus expressing a fusion protein of interleukin-15 (IL15 and IL15 receptor alpha has enhanced antitumor activity.

    Directory of Open Access Journals (Sweden)

    Vesna Tosic

    Full Text Available Myxoma virus, a rabbit poxvirus, can efficiently infect various types of mouse and human cancer cells. It is a strict rabbit-specific pathogen, and is thought to be safe as a therapeutic agent in all non-rabbit hosts tested including mice and humans. Interleukin-15 (IL15 is an immuno-modulatory cytokine with significant potential for stimulating anti-tumor T lymphocytes and NK cells. Co-expression of IL15 with the α subunit of IL15 receptor (IL15Rα greatly enhances IL15 stability and bioavailability. Therefore, we engineered a new recombinant myxoma virus (vMyx-IL15Rα-tdTr, which expresses an IL15Rα-IL15 fusion protein plus tdTomato red fluorescent reporter protein. Permissive rabbit kidney epithelial (RK-13 cells infected with vMyx-IL15Rα-tdTr expressed and secreted the IL15Rα-IL15 fusion protein. Functional activity was confirmed by demonstrating that the secreted fusion protein stimulated proliferation of cytokine-dependent CTLL-2 cells. Multi-step growth curves showed that murine melanoma (B16-F10 and B16.SIY cell lines were permissive to vMyx-IL15Rα-tdTr infection. In vivo experiments in RAG1-/- mice showed that subcutaneous B16-F10 tumors treated with vMyx-IL15Rα-tdTr exhibited attenuated tumor growth and a significant survival benefit for the treated group compared to the PBS control and the control viruses (vMyx-IL15-tdTr and vMyx-tdTr. Immunohistological analysis of the subcutaneous tumors showed dramatically increased infiltration of NK cells in vMyx-IL15Rα-tdTr treated tumors compared to the controls. In vivo experiments with immunocompetent C57BL/6 mice revealed a strong infiltrate of both NK cells and CD8+ T cells in response to vMyx-IL15Rα-tdTr, and prolonged survival. We conclude that delivery of IL15Rα-IL15 in a myxoma virus vector stimulates both innate and adaptive components of the immune system.

  2. Evidence for Alpha Receptors in the Human Ureter

    Science.gov (United States)

    Madeb, Ralph; Knopf, Joy; Golijanin, Dragan; Bourne, Patricia; Erturk, Erdal

    2007-04-01

    An immunohistochemical and western blot expression analysis of human ureters was performed in order to characterize the alpha-1-adrenergic receptor distribution along the length of the human ureteral wall. Mapping the distribution will assist in understanding the potential role alpha -1-adrenergic receptors and their subtype density might have in the pathophysiology of ureteral colic and stone passage. Patients diagnosed with renal cancer or bladder cancer undergoing nephrectomy, nephroureterectomy, or cystectomy had ureteral specimens taken from the proximal, mid, distal and tunneled ureter. Tissues were processed for fresh frozen examination and fixed in formalin. None of the ureteral specimens were involved with cancer. Serial histologic sections and immunohistochemical studies were performed using antibodies specific for alpha-1-adrenergic receptor subtypes (alpha 1a, alpha 1b, alpha 1d). The sections were examined under a light microscope and scored as positive or negative. In order to validate and quantify the alpha receptor subtypes along the human ureter. Western blotting techniques were applied. Human ureter stained positively for alpha -1-adrenergic receptors. Immunostaining appeared red, with intense reaction in the smooth muscle of the ureter and endothelium of the neighboring blood vessels. There was differential expression between all the receptors with the highest staining for alpha-1D subtype. The highest protein expression for all three subtypes was in the renal pelvis and decreased with advancement along the ureter to the distal ureter. At the distal ureter, there was marked increase in expression as one progressed towards the ureteral orifice. The same pattern of protein expression was exhibited for all three alpha -1-adrenergic receptor subtypes. We provide preliminary evidence for the ability to detect and quantify the alpha-1-receptor subtypes along the human ureter which to the best of our knowledge has never been done with

  3. Potential relevance of alpha(1-adrenergic receptor autoantibodies in refractory hypertension.

    Directory of Open Access Journals (Sweden)

    Katrin Wenzel

    Full Text Available BACKGROUND: Agonistic autoantibodies directed at the alpha(1-adrenergic receptor (alpha(1-AAB have been described in patients with hypertension. We implied earlier that alpha(1-AAB might have a mechanistic role and could represent a therapeutic target. METHODOLOGY/PRINCIPAL FINDINGS: To pursue the issue, we performed clinical and basic studies. We observed that 41 of 81 patients with refractory hypertension had alpha(1-AAB; after immunoadsorption blood pressure was significantly reduced in these patients. Rabbits were immunized to generate alpha(1-adrenergic receptor antibodies (alpha(1-AB. Patient alpha(1-AAB and rabbit alpha(1-AB were purified using affinity chromatography and characterized both by epitope mapping and surface plasmon resonance measurements. Neonatal rat cardiomyocytes, rat vascular smooth muscle cells (VSMC, and Chinese hamster ovary cells transfected with the human alpha(1A-adrenergic receptor were incubated with patient alpha(1-AAB and rabbit alpha(1-AB and the activation of signal transduction pathways was investigated by Western blot, confocal laser scanning microscopy, and gene expression. We found that phospholipase A2 group IIA (PLA2-IIA and L-type calcium channel (Cacna1c genes were upregulated in cardiomyocytes and VSMC after stimulation with both purified antibodies. We showed that patient alpha(1-AAB and rabbit alpha(1-AB result in protein kinase C alpha activation and transient extracellular-related kinase (EKR1/2 phosphorylation. Finally, we showed that the antibodies exert acute effects on intracellular Ca(2+ in cardiomyocytes and induce mesentery artery segment contraction. CONCLUSIONS/SIGNIFICANCE: Patient alpha(1-AAB and rabbit alpha(1-AB can induce signaling pathways important for hypertension and cardiac remodeling. Our data provide evidence for a potential clinical relevance for alpha(1-AAB in hypertensive patients, and the notion of immunity as a possible cause of hypertension.

  4. Resting alpha activity predicts learning ability in alpha neurofeedback

    Directory of Open Access Journals (Sweden)

    Wenya eNan

    2014-07-01

    Full Text Available Individuals differ in their ability to learn how to regulate the alpha activity by neurofeedback. This study aimed to investigate whether the resting alpha activity is related to the learning ability of alpha enhancement in neurofeedback and could be used as a predictor. A total of 25 subjects performed 20 sessions of individualized alpha neurofeedback in order to learn how to enhance activity in the alpha frequency band. The learning ability was assessed by three indices respectively: the training parameter changes between two periods, within a short period and across the whole training time. It was found that the resting alpha amplitude measured before training had significant positive correlations with all learning indices and could be used as a predictor for the learning ability prediction. This finding would help the researchers in not only predicting the training efficacy in individuals but also gaining further insight into the mechanisms of alpha neurofeedback.

  5. p21-activated kinase group II small compound inhibitor GNE-2861 perturbs estrogen receptor alpha signaling and restores tamoxifen-sensitivity in breast cancer cells

    OpenAIRE

    Zhuang, Ting; Zhu, Jian; Li, Zhilun; Lorent, Julie; Zhao, Chunyan; Dahlman-Wright, Karin; Strömblad, Staffan

    2015-01-01

    Estrogen receptor alpha (ERα) is highly expressed in most breast cancers. Consequently, ERα modulators, such as tamoxifen, are successful in breast cancer treatment, although tamoxifen resistance is commonly observed. While tamoxifen resistance may be caused by altered ERα signaling, the molecular mechanisms regulating ERα signaling and tamoxifen resistance are not entirely clear. Here, we found that PAK4 expression was consistently correlated to poor patient outcome in endocrine treated and ...

  6. TISSUE INHIBITOR OF METALLOPROTEINASE 1, MATRIX METALLOPROTEINASE 9, ALPHA-1 ANTITRYPSIN, METALLOTHIONEIN AND UROKINASE TYPE PLASMINOGEN ACTIVATOR RECEPTOR IN SKIN BIOPSIES FROM PATIENTS AFFECTED BY AUTOIMMUNE BLISTERING DISEASES

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu Velez

    2013-07-01

    Full Text Available Introduction: Proteinases and proteinase inhibitors have been described to play a role in autoimmune skin blistering diseases. We studied skin lesional biopsies from patients affected by several autoimmune skin blistering diseases for proteinases and proteinase inhibitors. Methods: We utilized immunohistochemistry to evaluate biopsies for alpha-1-antitrypsin, human matrix metalloproteinase 9 (MMP9, human tissue inhibitor of metalloproteinases 1 (TIMP-1, metallothionein and urokinase type plasminogen activator receptor (uPAR. We tested 30 patients affected by endemic pemphigus, 30 controls from the endemic area, and 15 normal controls. We also tested 30 biopsies from patients with bullous pemphigoid (BP, 20 with pemphigus vulgaris (PV, 8 with pemphigus foliaceus, and 14 with dermatitis herpetiformis (DH. Results: Contrary to findings in the current literature, most autoimmune skin blistering disease biopsies were negative for uPAR and MMP9. Only some chronic patients with El Bagre-EPF were positive to MMP9 in the dermis, in proximity to telocytes. TIMP-1 and metallothionein were positive in half of the biopsies from BP patients at the basement membrane of the skin, within several skin appendices, in areas of dermal blood vessel inflammation and within dermal mesenchymal-epithelial cell junctions.

  7. Knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha increased apoptosis of human endometrial cancer HEC-1A cells

    Directory of Open Access Journals (Sweden)

    Yang H

    2016-08-01

    Full Text Available Hui Yang, Rui Yang, Hao Liu, Zhongqian Ren, Cuicui Wang, Da Li, Xiaoxin Ma Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, People’s Republic of China Background: Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α coactivates multiple transcription factors and regulates several metabolic processes. In this study, we focused on the roles of PGC-1α in the apoptosis of endometrial cancer HEC-1A cells. Materials and methods: PGC-1α expression in the HEC-1A cells was detected with real-time polymerase chain reaction and Western blot. Small interfering RNA directed against PGC-1α was designed and synthesized, and RNA interference technology was used to knock down PGC-1α mRNA and protein expression. Cell apoptosis, cell cycle, and mitochondrial membrane potential were then analyzed using flow cytometry. The expression of apoptotic proteins, Bcl-2 and Bax, was detected with Western blot. Results: The specific downregulation of PGC-1α expression in the HEC-1A cells increased their apoptosis through the mitochondrial apoptotic pathway by reducing the expression of Bcl-2 and increasing the expression of Bax. Conclusion: These results suggest that PGC-1α influences the apoptosis of HEC-1A cells and also provides a molecular basis for further investigation of the apoptotic mechanism in human endometrial cancer. Keywords: endometrial cancer, PGC-1α, apoptosis, Bcl-2, Bax

  8. Activation of JAK3, but not JAK1, is critical to interleukin-4 (IL4) stimulated proliferation and requires a membrane-proximal region of IL4 receptor alpha.

    Science.gov (United States)

    Malabarba, M G; Kirken, R A; Rui, H; Koettnitz, K; Kawamura, M; O'Shea, J J; Kalthoff, F S; Farrar, W L

    1995-04-21

    The tyrosine kinases JAK1 and JAK3 have been shown to undergo tyrosine phosphorylation in response to interleukin-2 (IL), IL4, IL7, and IL9, cytokines which share the common IL2 receptor gamma-chain (IL2R gamma), and evidence has been found for a preferential coupling of JAK3 to IL2R gamma and JAK1 to IL2R beta. Here we show, using human premyeloid TF-1 cells, that IL4 stimulates JAK3 to a larger extent than JAK1, based upon three different evaluation criteria. These include a more vigorous tyrosine phosphorylation of JAK3 as measured by anti-phosphotyrosine immunoblotting, a more marked activation of JAK3 as determined by in vitro tyrosine kinase assays and a more manifest presence of JAK3 in activated IL4-receptor complexes. These observations suggest that IL4 receptor signal transduction does not depend on equimolar heterodimerization of JAK1 and JAK3 following IL4-induced heterodimerization of IL4R alpha and IL2R gamma. Indeed, when human IL4R alpha was stably expressed in mouse BA/F3 cells, robust IL4-induced proliferation and JAK3 activation occurred without detectable involvement of JAK1, JAK2, or TYK2. The present study suggests that JAK1 plays a subordinate role in IL4 receptor signaling, and that in certain cells exclusive JAK3 activation may mediate IL4-induced cell growth. Moreover, mutational analysis of human IL4R alpha showed that a membrane-proximal cytoplasmic region was critical for JAK3 activation, while the I4R motif was not, which is compatible with a role of JAK3 upstream of the recruitment of the insulin receptor substrate-1/4PS signaling proteins by IL4 receptors.

  9. Effects of alpha-calcitonin gene-related peptide on osteoprotegerin and receptor activator of nuclear factor-κB ligand expression in MG-63 osteoblast-like cells exposed to polyethylene particles

    Directory of Open Access Journals (Sweden)

    Kauther Max D

    2010-11-01

    Full Text Available Abstract Background Recent studies demonstrated an impact of the nervous system on particle-induced osteolysis, the major cause of aseptic loosening of joint replacements. Methods In this study of MG-63 osteoblast-like cells we analyzed the influence of ultra-high molecular weight polyethylene (UHMWPE particles and the neurotransmitter alpha-calcitonin gene-related peptide (CGRP on the osteoprotegerin/receptor activator of nuclear factor-κB ligand/receptor activator of nuclear factorκB (OPG/RANKL/RANK system. MG-63 cells were stimulated by different UHMWPE particle concentrations (1:100, 1:500 and different doses of alpha-CGRP (10-7 M, 10-9 M, 10-11 M. RANKL and OPG mRNA expression and protein levels were measured by RT-PCR and Western blot. Results Increasing particle concentrations caused an up-regulation of RANKL after 72 hours. Alpha-CGRP showed a dose-independent depressive effect on particle-induced expression of RANKL mRNA in both cell-particle ratios. RANKL gene transcripts were significantly (P -7 M lead to an up-regulation of OPG protein. Conclusion In conclusion, a possible osteoprotective influence of the neurotransmitter alpha-CGRP on particle stimulated osteoblast-like cells could be shown. Alpha-CGRP might be important for bone metabolism under conditions of particle-induced osteolysis.

  10. Discovery of an Oxybenzylglycine Based Peroxisome Proliferator Activated Receptor [alpha] Selective Agonist 2-((3-((2-(4-Chlorophenyl)-5-methyloxazol-4-yl)methoxy)benzyl)(methoxycarbonyl)amino)acetic Acid (BMS-687453)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jun; Kennedy, Lawrence J.; Shi, Yan; Tao, Shiwei; Ye, Xiang-Yang; Chen, Stephanie Y.; Wang, Ying; Hernndez, Andrs S.; Wang, Wei; Devasthale, Pratik V.; Chen, Sean; Lai, Zhi; Zhang, Hao; Wu, Shung; Smirk, Rebecca A.; Bolton, Scott A.; Ryono, Denis E.; Zhang, Huiping; Lim, Ngiap-Kie; Chen, Bang-Chi; Locke, Kenneth T.; O’Malley, Kevin M.; Zhang, Litao; Srivastava, Rai Ajit; Miao, Bowman; Meyers, Daniel S.; Monshizadegan, Hossain; Search, Debra; Grimm, Denise; Zhang, Rongan; Harrity, Thomas; Kunselman, Lori K.; Cap, Michael; Kadiyala, Pathanjali; Hosagrahara, Vinayak; Zhang, Lisa; Xu, Carrie; Li, Yi-Xin; Muckelbauer, Jodi K.; Chang, Chiehying; An, Yongmi; Krystek, Stanley R.; Blanar, Michael A.; Zahler, Robert; Mukherjee, Ranjan; Cheng, Peter T.W.; Tino, Joseph A. (BMS)

    2010-04-12

    An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) {alpha} agonist, with an EC{sub 50} of 10 nM for human PPAR{alpha} and 410-fold selectivity vs human PPAR{gamma} in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPAR{delta}. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystal structures of the early lead compound 12 and compound 2 in complex with PPAR{alpha} ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPAR{alpha} in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.

  11. The Alpha-1A Adrenergic Receptor in the Rabbit Heart

    OpenAIRE

    R Croft Thomas; Cowley, Patrick M.; Abhishek Singh; Bat-Erdene Myagmar; Swigart, Philip M.; Baker, Anthony J.; Simpson, Paul C.

    2016-01-01

    The alpha-1A-adrenergic receptor (AR) subtype is associated with cardioprotective signaling in the mouse and human heart. The rabbit is useful for cardiac disease modeling, but data on the alpha-1A in the rabbit heart are limited. Our objective was to test for expression and function of the alpha-1A in rabbit heart. By quantitative real-time reverse transcription PCR (qPCR) on mRNA from ventricular myocardium of adult male New Zealand White rabbits, the alpha-1B was 99% of total alpha-1-AR mR...

  12. Role of TNF-alpha and its receptors in pericoronitis.

    Science.gov (United States)

    Beklen, A; Laine, M; Ventä, I; Hyrkäs, T; Konttinen, Y T

    2005-12-01

    The classic stimulus for cellular cytokine production is bacterial lipopolysaccharide (endotoxin). It was therefore hypothesized that tumor necrosis factor-alpha (TNF-alpha) may be responsible for pericoronitis. TNF-alpha and its receptors were detected by immunohistochemical staining in third molar pericoronitis in ten patients and ten healthy control samples. The percentage of TNF-alpha positive cells was high in pericoronitis (p = 0.0317). TNF receptors TNF-R1 and TNF-R2 were found in macrophage- and fibroblast-like cells, vascular endothelial cells in post-capillary venules, and basal epithelial cells in pericoronitis, but were only weakly expressed in controls. Increased expression of interleukin-1beta and vascular cell adhesion molecule-1 was found as a biological indicator of TNF-alpha ligand-receptor interaction. Explanted tissues acquired destructive potential upon TNF-alpha stimulation, whereas TNF-alpha blockers controlled it in inflamed tissues. These findings suggest that, in pericoronitis, inflammatory and resident cells produce and respond to potent pro-inflammatory cytokine TNF-alpha, with pathogenic and potential therapeutic relevance.

  13. The human poliovirus receptor alpha is a serine phosphoprotein.

    OpenAIRE

    Bibb, J. A.; Bernhardt, G; Wimmer, E

    1994-01-01

    The human receptors for poliovirus (hPVR) are members of the immunoglobulin superfamily. Whereas the two membrane-bound isoforms, hPVR alpha and hPVR delta, share identical three-domain extracellular portions, their C-terminal cytoplasmic parts differ considerably. This feature is well conserved in the corresponding monkey proteins AGM alpha 1, AGM delta 1, and AGM alpha 2. The cellular function of these proteins is presently unknown. In this short communication we report that hPVR alpha and ...

  14. Intracellular Transactivation of Epidermal Growth Factor Receptor by alpha(1A)-Adrenoceptor Is Mediated by Phosphatidylinositol 3-Kinase Independently of Activation of Extracellular Signal Regulated Kinases 1/2 and Serine-Threonine Kinases in Chinese Hamster Ovary Cells

    NARCIS (Netherlands)

    Ulu, Nadir; Henning, Robert H.; Guner, Sahika; Zoto, Teuta; Duman-Dalkilic, Basak; Duin, Marry; Gurdal, Hakan

    2013-01-01

    Transactivation of epidermal growth factor receptor (EGFR) by alpha(1)-adrenoceptor (alpha(1)-AR) is implicated in contraction and hypertrophy of vascular smooth muscle (VSM). We examine whether all alpha(1)-AR subtypes transactivate EGFR and explore the mechanism of transactivation. Chinese hamster

  15. Novel drugs that target the estrogen-related receptor alpha: their therapeutic potential in breast cancer

    International Nuclear Information System (INIS)

    The incidence of breast cancer continues to rise: 1.7 million women were diagnosed with and 521,000 women died from breast cancer in 2012. This review considers first current treatment options: surgery; radiotherapy; and systemic endocrine, anti-biological, and cytotoxic therapies. Clinical management includes prevention, early detection by screening, treatment with curative intent, management of chronic disease, and palliative control of advanced breast cancer. Next, the potential of novel drugs that target DNA repair, growth factor dependence, intracellular and intercellular signal transduction, and cell cycle are considered. Estrogen-related receptor alpha has attracted attention as a therapeutic target in triple-negative breast cancers with de novo resistance to, and in breast cancers with acquired resistance to, endocrine therapies such as antiestrogens and aromatase inhibitors. Estrogen-related receptor alpha is an orphan receptor and transcription factor. Its activity is regulated by coregulator proteins and posttranslational modification. It is an energy sensor that controls adaptation to energy demand and may facilitate glycolytic metabolism and mitochondrial oxidative respiration in breast cancer cells. Estrogen-related receptor alpha increases breast cancer cell migration, proliferation, and tumor development. It is expressed at high levels in estrogen receptor-negative tumors, and is proposed to activate estrogen-responsive genes in endocrine-resistant tumors. The structures and functions of the ligand-binding domains of estrogen receptor alpha and estrogen-related receptor alpha, their ability to bind estrogens, phytoestrogens, and synthetic ligands, and the effects of ligand agonists, antagonists, and inverse agonists on biological activity, are evaluated. Synthetic ligands of estrogen-related receptor alpha have activity in preclinical models of metabolic disorders, diabetes, osteoporosis, and oncology. The clinical settings in which these novel

  16. Epstein Barr virus/complement C3d receptor is an interferon alpha receptor.

    OpenAIRE

    Delcayre, A X; Salas, F.; Mathur, S; Kovats, K; Lotz, M.; Lernhardt, W

    1991-01-01

    Interferon alpha contains a sequence motif similar to the complement receptor type two (CR2/CD21) binding site on complement fragment C3d. Antibodies against a peptide with the CR2 binding sequence on C3d react with a peptide carrying the IFN alpha CR2 binding motif (residues 92-99) and with recombinant IFN alpha. The IFN alpha-derived peptide, as well as recombinant IFN alpha, inhibits C3bi/C3d interaction with CR2 on the Burkitt lymphoma Raji. The direct interaction of IFN alpha and CR2 is ...

  17. Crosstalk between the peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) and the vitamin D receptor (VDR) in human breast cancer cells: PPAR{gamma} binds to VDR and inhibits 1{alpha},25-dihydroxyvitamin D{sub 3} mediated transactivation

    Energy Technology Data Exchange (ETDEWEB)

    Alimirah, Fatouma; Peng, Xinjian; Yuan, Liang; Mehta, Rajeshwari R. [Cancer Biology Division, IIT Research Institute, 10 West 35th Street, Chicago, IL 60616 (United States); Knethen, Andreas von [Institute of Biochemistry, Johann Wolfgang Goethe University, Frankfurt (Germany); Choubey, Divaker [Department of Environmental Health, University of Cincinnati, 3223 Eden Avenue, P.O. Box 670056, Cincinnati, OH 45267 (United States); Mehta, Rajendra G., E-mail: rmehta@iitri.org [Cancer Biology Division, IIT Research Institute, 10 West 35th Street, Chicago, IL 60616 (United States)

    2012-11-15

    Heterodimerization and cross-talk between nuclear hormone receptors often occurs. For example, estrogen receptor alpha (ER{alpha}) physically binds to peroxisome proliferator-activated receptor gamma (PPAR{gamma}) and inhibits its transcriptional activity. The interaction between PPAR{gamma} and the vitamin D receptor (VDR) however, is unknown. Here, we elucidate the molecular mechanisms linking PPAR{gamma} and VDR signaling, and for the first time we show that PPAR{gamma} physically associates with VDR in human breast cancer cells. We found that overexpression of PPAR{gamma} decreased 1{alpha},25-dihydroxyvitamin D{sub 3} (1,25D{sub 3}) mediated transcriptional activity of the vitamin D target gene, CYP24A1, by 49% and the activity of VDRE-luc, a vitamin D responsive reporter, by 75% in T47D human breast cancer cells. Deletion mutation experiments illustrated that helices 1 and 4 of PPAR{gamma}'s hinge and ligand binding domains, respectively, governed this suppressive function. Additionally, abrogation of PPAR{gamma}'s AF2 domain attenuated its repressive action on 1,25D{sub 3} transactivation, indicating that this domain is integral in inhibiting VDR signaling. PPAR{gamma} was also found to compete with VDR for their binding partner retinoid X receptor alpha (RXR{alpha}). Overexpression of RXR{alpha} blocked PPAR{gamma}'s suppressive effect on 1,25D{sub 3} action, enhancing VDR signaling. In conclusion, these observations uncover molecular mechanisms connecting the PPAR{gamma} and VDR pathways. -- Highlights: PPAR{gamma}'s role on 1{alpha},25-dihydroxyvitamin D{sub 3} transcriptional activity is examined. Black-Right-Pointing-Pointer PPAR{gamma} physically binds to VDR and inhibits 1{alpha},25-dihydroxyvitamin D{sub 3} action. Black-Right-Pointing-Pointer PPAR{gamma}'s hinge and ligand binding domains are important for this inhibitory effect. Black-Right-Pointing-Pointer PPAR{gamma} competes with VDR for the availability of their binding

  18. Folate receptor {alpha} regulates cell proliferation in mouse gonadotroph {alpha}T3-1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Congjun; Evans, Chheng-Orn [Department of Neurosurgery and Laboratory of Molecular Neurosurgery and Biotechnology, Emory University, School of Medicine, Atlanta, Georgia (United States); Stevens, Victoria L. [Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Georgia (United States); Owens, Timothy R. [Emory University, School of Medicine, Atlanta, Georgia (United States); Oyesiku, Nelson M., E-mail: noyesik@emory.edu [Department of Neurosurgery and Laboratory of Molecular Neurosurgery and Biotechnology, Emory University, School of Medicine, Atlanta, Georgia (United States)

    2009-11-01

    We have previously found that the mRNA and protein levels of the folate receptor alpha (FR{alpha}) are uniquely over-expressed in clinically human nonfunctional (NF) pituitary adenomas, but the mechanistic role of FR{alpha} has not fully been determined. We investigated the effect of FR{alpha} over-expression in the mouse gonadotroph {alpha}T3-1 cell line as a model for NF pituitary adenomas. We found that the expression and function of FR{alpha} were strongly up-regulated, by Western blotting and folic acid binding assay. Furthermore, we found a higher cell growth rate, an enhanced percentage of cells in S-phase by BrdU assay, and a higher PCNA staining. These observations indicate that over-expression of FR{alpha} promotes cell proliferation. These effects were abrogated in the same {alpha}T3-1 cells when transfected with a mutant FR{alpha} cDNA that confers a dominant-negative phenotype by inhibiting folic acid binding. Finally, by real-time quantitative PCR, we found that mRNA expression of NOTCH3 was up-regulated in FR{alpha} over-expressing cells. In summary, our data suggests that FR{alpha} regulates pituitary tumor cell proliferation and mechanistically may involve the NOTCH pathway. Potentially, this finding could be exploited to develop new, innovative molecular targeted treatment for human NF pituitary adenomas.

  19. The Alpha-1A Adrenergic Receptor in the Rabbit Heart.

    Directory of Open Access Journals (Sweden)

    R Croft Thomas

    Full Text Available The alpha-1A-adrenergic receptor (AR subtype is associated with cardioprotective signaling in the mouse and human heart. The rabbit is useful for cardiac disease modeling, but data on the alpha-1A in the rabbit heart are limited. Our objective was to test for expression and function of the alpha-1A in rabbit heart. By quantitative real-time reverse transcription PCR (qPCR on mRNA from ventricular myocardium of adult male New Zealand White rabbits, the alpha-1B was 99% of total alpha-1-AR mRNA, with <1% alpha-1A and alpha-1D, whereas alpha-1A mRNA was over 50% of total in brain and liver. Saturation radioligand binding identified ~4 fmol total alpha-1-ARs per mg myocardial protein, with 17% alpha-1A by competition with the selective antagonist 5-methylurapidil. The alpha-1D was not detected by competition with BMY-7378, indicating that 83% of alpha-1-ARs were alpha-1B. In isolated left ventricle and right ventricle, the selective alpha-1A agonist A61603 stimulated a negative inotropic effect, versus a positive inotropic effect with the nonselective alpha-1-agonist phenylephrine and the beta-agonist isoproterenol. Blood pressure assay in conscious rabbits using an indwelling aortic telemeter showed that A61603 by bolus intravenous dosing increased mean arterial pressure by 20 mm Hg at 0.14 μg/kg, 10-fold lower than norepinephrine, and chronic A61603 infusion by iPRECIO programmable micro Infusion pump did not increase BP at 22 μg/kg/d. A myocardial slice model useful in human myocardium and an anthracycline cardiotoxicity model useful in mouse were both problematic in rabbit. We conclude that alpha-1A mRNA is very low in rabbit heart, but the receptor is present by binding and mediates a negative inotropic response. Expression and function of the alpha-1A in rabbit heart differ from mouse and human, but the vasopressor response is similar to mouse.

  20. Structural determinants within residues 180-199 of the rodent. alpha. 5 nicotinic acetylcholine receptor subunit involved in. alpha. -bungarotoxin binding

    Energy Technology Data Exchange (ETDEWEB)

    McLane, K.E.; Xiadong Wu; Conti-Tronconi, B.M. (Univ. of Minnesota, St. Paul (United States))

    1991-11-05

    Synthetic peptides corresponding to sequence segments of the nicotinic acetylcholine receptor (nAChR) {alpha} subunits have been used to identify regions that contribute to formation of the binding sites for cholinergic ligands. The authors have previously defined {alpha}-bungarotoxin ({alpha}-BTX) binding sequences between residues 180 and 199 of a putative rat neuronal nAChR {alpha} subunit, designated {alpha}5, and between residues 181 and 200 of the chick neuronal {alpha}7 and {alpha}8 subunits. These sequences are relatively divergent compared with the Torpedo and muscle nAChR {alpha}1 {alpha}-BTX binding sites, which indicates a serious limitation of predicting functional domains of proteins based on homology in general. Given the highly divergent nature of the {alpha}5 sequence, they were interested in determining the critical amino acid residues for {alpha}-BTX binding. In the present study, the effects of single amino acid substitutions of Gly or Ala for each residue of the rat {alpha}(180-199) sequence were tested, using a competition assay, in which peptides compete for {sup 125}I-{alpha}-BTX binding with native Torpedo nAChR. These results indicate that a disulfide bridge between the vicinal cysteines at positions 191 and 192 of the {alpha}5 sequence is not an absolute requirement for {alpha}-BTX binding activity.

  1. Non random usage of T cell receptor alpha gene expression in atopy using anchored PCR.

    Science.gov (United States)

    Mansur, A H; Gelder, C M; Holland, D; Campell, D A; Griffin, A; Cunliffe, W; Markham, A F; Morrison, J F

    1996-01-01

    The T cell receptor (TCR) alpha beta heterodimer recognises antigenic peptide fragments presented by Class II MHC. This interaction initiates T cell activation and cytokine release with subsequent recruitment of inflammatory cells. Previous work from our group suggests a qualitative difference in variable alpha gene expression in atopy as compared to non atopic controls. In this study we examine TCR alpha repertoire using anchored PCR to provide a quantitative assessment of the V alpha and J alpha repertoire. One atopic (DRB1*0701,DRB1*15: DRB4*0101, DRB5*01: DQB1* 0303, DQB1*601/2) and one non-atopic (DRB1*0701,DRB1*03011/2: DRB4*01, DRB3*0x: DQB1* 0303, DQB1*0201/2) control were studied. Variable gene usage was markedly limited in the atopic individual. V alpha 1, 3, 8 accounted for 60% and J alpha 12, 31 30% of the gene usage. There was evidence of preferential V alpha-J alpha gene pairing and clonal expansion. We conclude that there is a marked non random TCR alpha gene distribution in atopy using both V alpha family and anchored PCR. This may be due in part to antigen driven clonal expansion. PMID:9095269

  2. Designer interface peptide grafts target estrogen receptor alpha dimerization.

    Science.gov (United States)

    Chakraborty, S; Asare, B K; Biswas, P K; Rajnarayanan, R V

    2016-09-01

    The nuclear transcription factor estrogen receptor alpha (ERα), triggered by its cognate ligand estrogen, regulates a variety of cellular signaling events. ERα is expressed in 70% of breast cancers and is a widely validated target for anti-breast cancer drug discovery. Administration of anti-estrogen to block estrogen receptor activation is still a viable anti-breast cancer treatment option but anti-estrogen resistance has been a significant bottle-neck. Dimerization of estrogen receptor is required for ER activation. Blocking ERα dimerization is therefore a complementary and alternative strategy to combat anti-estrogen resistance. Dimer interface peptide "I-box" derived from ER residues 503-518 specifically blocks ER dimerization. Recently using a comprehensive molecular simulation we studied the interaction dynamics of ERα LBDs in a homo-dimer. Based on this study, we identified three interface recognition peptide motifs LDKITDT (ERα residues 479-485), LQQQHQRLAQ (residues 497-506), and LSHIRHMSNK (residues 511-520) and reported the suitability of using LQQQHQRLAQ (ER 497-506) as a template to design inhibitors of ERα dimerization. Stability and self-aggregation of peptide based therapeutics poses a significant bottle-neck to proceed further. In this study utilizing peptide grafted to preserve their pharmacophoric recognition motif and assessed their stability and potential to block ERα mediated activity in silico and in vitro. The Grafted peptides blocked ERα mediated cell proliferation and viability of breast cancer cells but did not alter their apoptotic fate. We believe the structural clues identified in this study can be used to identify novel peptidometics and small molecules that specifically target ER dimer interface generating a new breed of anti-cancer agents. PMID:27462021

  3. Retinoic acid receptor alpha is associated with tamoxifen resistance in breast cancer

    OpenAIRE

    Johansson, Henrik J; Sanchez, Betzabe C.; Mundt, Filip; Forshed, Jenny; Kovacs, Aniko; Panizza, Elena; Hultin-Rosenberg, Lina; Lundgren, Bo; Martens, Ulf; Máthé, Gyöngyvér; Yakhini, Zohar; Helou, Khalil; Krawiec, Kamilla; Kanter, Lena; Hjerpe, Anders

    2013-01-01

    About one-third of oestrogen receptor alpha-positive breast cancer patients treated with tamoxifen relapse. Here we identify the nuclear receptor retinoic acid receptor alpha as a marker of tamoxifen resistance. Using quantitative mass spectrometry-based proteomics, we show that retinoic acid receptor alpha protein networks and levels differ in a tamoxifen-sensitive (MCF7) and a tamoxifen-resistant (LCC2) cell line. High intratumoural retinoic acid receptor alpha protein levels also correlate...

  4. Toll-Like Receptor 2- and 6-Mediated Stimulation by Macrophage-Activating Lipopeptide 2 Induces Lipopolysaccharide (LPS) Cross Tolerance in Mice, Which Results in Protection from Tumor Necrosis Factor Alpha but in Only Partial Protection from Lethal LPS Doses

    OpenAIRE

    Deiters, Ursula; Gumenscheimer, Marina; Galanos, Chris; Mühlradt, Peter F.

    2003-01-01

    Patients or experimental animals previously exposed to lipopolysaccharide (LPS) become tolerant to further LPS challenge. We investigated the potential of the macrophage-activating lipopeptide 2 (MALP-2) to induce in vivo cross tolerance to tumor necrosis factor alpha (TNF-α) and LPS. MALP-2-induced tolerance could be of practical interest, as MALP-2 proved much less pyrogenic in rabbits than LPS. Whereas LPS signals via Toll-like receptor 4 (TLR4), MALP-2 uses TLR2 and TLR6. LPS-mediated cyt...

  5. The pharmacology of spontaneously open alpha 1 beta 3 epsilon GABA A receptor-ionophores.

    Science.gov (United States)

    Maksay, Gábor; Thompson, Sally A; Wafford, Keith A

    2003-06-01

    Human alpha(1)beta(3) epsilon GABA(A) receptors were expressed in Xenopus oocytes and examined using the conventional two-electrode voltage-clamp technique and compared to alpha(1)beta(3)gamma(2) receptors. The effects of several GABA(A) agonists were studied, and the allosteric modulation of the channel by a number of GABAergic modulators investigated. The presence of the epsilon subunit increased the potency and efficacy of direct activation by partial GABA(A) agonists (piperidine-4-sulphonic acid and thio-4-PIOL), pentobarbital and neuro-steroids. Direct activation by 3-hydroxylated neurosteroids was restricted to 3alpha epimers, while chirality at C5 was indifferent. The 3beta-sulfate esters of pregnenolone and dehydroepiandrosterone inhibited the spontaneous currents with efficacies higher, while bicuculline methiodide and SR 95531 did so lower than picrotoxin and TBPS. Furosemide, fipronil, triphenylcyanoborate and Zn(2+) blocked the spontaneous currents of alpha(1)beta(3) epsilon receptors with different efficacies. Flunitrazepam and 4'-chlorodiazepam inhibited the spontaneous currents with micromolar potencies. In conclusion, spontaneously active alpha(1)beta(3) epsilon GABA(A) receptors can be potentiated and blocked by GABAergic agents within a broad range of efficacy.

  6. Estrogen receptor alpha polymorphisms and postmenopausal breast cancer risk.

    NARCIS (Netherlands)

    Ladd, AM Gonzalez-Zuloet; Vasquez, A.A.; Rivadeneira, F.; Siemes, C.; Hofman, A.; Stricker, B.H.; Pols, H.A.; Uitterlinden, A.G.; Duijn, C.M. van

    2008-01-01

    BACKGROUND: The estrogen receptor alpha (ESR1) is a mediator of estrogen response in the breast. The most studied variants in this gene are the PvuII and XbaI polymorphisms, which have been associated to lower sensitivity to estrogen. We evaluated whether these polymorphisms were associated with bre

  7. Schizophrenia and the alpha7 nicotinic acetylcholine receptor.

    Science.gov (United States)

    Martin, Laura F; Freedman, Robert

    2007-01-01

    In addition to the devastating symptoms of psychosis, many people with schizophrenia also suffer from cognitive impairment. These cognitive symptoms lead to marked dysfunction and can impact employability, treatment adherence, and social skills. Deficits in P50 auditory gating are associated with attentional impairment and may contribute to cognitive symptoms and perceptual disturbances. This nicotinic cholinergic-mediated inhibitory process represents a potential new target for therapeutic intervention in schizophrenia. This chapter will review evidence implicating the nicotinic cholinergic, and specifically, the alpha7 nicotinic receptor system in the pathology of schizophrenia. Impaired auditory sensory gating has been linked to the alpha7 nicotinic receptor gene on the chromosome 15q14 locus. A majority of persons with schizophrenia are heavy smokers. Although nicotine can acutely reverse diminished auditory sensory gating in people with schizophrenia, this effect is lost on a chronic basis due to receptor desensitization. The alpha7 nicotinic agonist 3-(2,4 dimethoxy)benzylidene-anabaseine (DMXBA) can also enhance auditory sensory gating in animal models. DMXBA is well tolerated in humans and a new study in persons with schizophrenia has found that DMXBA enhances both P50 auditory gating and cognition. alpha7 Nicotinic acetylcholine receptor agonists appear to be viable candidates for the treatment of cognitive disturbances in schizophrenia. PMID:17349863

  8. Schizophrenia and the alpha7 nicotinic acetylcholine receptor.

    Science.gov (United States)

    Martin, Laura F; Freedman, Robert

    2007-01-01

    In addition to the devastating symptoms of psychosis, many people with schizophrenia also suffer from cognitive impairment. These cognitive symptoms lead to marked dysfunction and can impact employability, treatment adherence, and social skills. Deficits in P50 auditory gating are associated with attentional impairment and may contribute to cognitive symptoms and perceptual disturbances. This nicotinic cholinergic-mediated inhibitory process represents a potential new target for therapeutic intervention in schizophrenia. This chapter will review evidence implicating the nicotinic cholinergic, and specifically, the alpha7 nicotinic receptor system in the pathology of schizophrenia. Impaired auditory sensory gating has been linked to the alpha7 nicotinic receptor gene on the chromosome 15q14 locus. A majority of persons with schizophrenia are heavy smokers. Although nicotine can acutely reverse diminished auditory sensory gating in people with schizophrenia, this effect is lost on a chronic basis due to receptor desensitization. The alpha7 nicotinic agonist 3-(2,4 dimethoxy)benzylidene-anabaseine (DMXBA) can also enhance auditory sensory gating in animal models. DMXBA is well tolerated in humans and a new study in persons with schizophrenia has found that DMXBA enhances both P50 auditory gating and cognition. alpha7 Nicotinic acetylcholine receptor agonists appear to be viable candidates for the treatment of cognitive disturbances in schizophrenia.

  9. Phorbol esters promote alpha 1-adrenergic receptor phosphorylation and receptor uncoupling from inositol phospholipid metabolism.

    OpenAIRE

    Leeb-Lundberg, L M; Cotecchia, S; Lomasney, J W; DeBernardis, J F; Lefkowitz, R J; Caron, M G

    1985-01-01

    DDT1 MF-2 cells, which are derived from hamster vas deferens smooth muscle, contain alpha 1-adrenergic receptors (54,800 +/- 2700 sites per cell) that are coupled to stimulation of inositol phospholipid metabolism. Incubation of these cells with tumor-promoting phorbol esters, which stimulate calcium- and phospholipid-dependent protein kinase, leads to a marked attenuation of the ability of alpha 1-receptor agonists such as norepinephrine to stimulate the turnover of inositol phospholipids. T...

  10. Biochemical and pharmacological studies of the hepatic alpha sub 1 -adrenergic receptor

    Energy Technology Data Exchange (ETDEWEB)

    Tchakarov, L.E.

    1988-01-01

    The structure and the regulation of the hepatic {alpha}{sub 1}-adrenergic receptors have been studied in the rat. The in vitro incubation of isolated liver cells in a serum-free buffer for 4 hr leads to the conversion of the adrenergic activation of glycogen phosphorylase from an {alpha}{sub 1}- to a {beta}-adrenoceptor-mediated event. This change is associated with no change in the glycogenolytic response to vasopressin and a reduction of the glycogenolytic response to glucagon. The time-dependent shift in the adrenergic control of glycogenolysis does not influence the density or the affinity of ({sup 3}H)prazosin-labeled {alpha}{sub 1}-receptors and ({sup 3}H)CGP-12177-labeled {beta}-receptors. The change in the adrenergic control of glycogenolysis is reversed by a 30-min incubation with 50 nM lipomodulin, whereas in freshly isolated cells lipomodulin doesn't affect the predominant {alpha}-receptor response. Conversely, exposure of freshly isolated cells to a monoclonal antibody to lipomodulin in the presence of 10 {mu}M phenylephrine, or to 2 {mu}g/ml mellitin, results in a shift in the adrenergic control of glycogenolysis from {alpha}{sub 1}- to {beta}-type within 30 min. The mechanism of activation of the Ca{sup 2+}-linked receptors for vasopressin and adrenaline was studied in isolated liver cells. A novel irreversible antagonist for the {alpha}{sub 1}-adrenergic receptors, I-phenyoxybenzamine (I-POB) has been synthesized and pharmacologically characterized.

  11. Receptor-like protein-tyrosine phosphatase alpha specifically inhibits insulin-increased prolactin gene expression

    DEFF Research Database (Denmark)

    Jacob, K K; Sap, J; Stanley, F M

    1998-01-01

    A physiologically relevant response to insulin, stimulation of prolactin promoter activity in GH4 pituitary cells, was used as an assay to study the specificity of protein-tyrosine phosphatase function. Receptor-like protein-tyrosine phosphatase alpha (RPTPalpha) blocks the effect of insulin to i...

  12. A functional Rev-erb alpha responsive element located in the human Rev-erb alpha promoter mediates a repressing activity.

    OpenAIRE

    Adelmant, G; Bègue, A. (Alain); Stéhelin, D; Laudet, V

    1996-01-01

    Rev-erb alpha belongs to the nuclear receptor superfamily, which contains receptors for steroids, thyroid hormones, retinoic acid, and vitamin D, as well as "orphan" receptors. No ligand has been found for Rev-erb alpha to date, making it one of these orphan receptors. Similar to some other orphan receptors, Rev-erb alpha has been shown to bind DNA as a monomer on a specific sequence called a Rev-erb alpah responsive element (RevRE), but its transcriptional activity remains unclear. In this p...

  13. SIP1/NHERF2 enhances estrogen receptor alpha transactivation in breast cancer cells

    OpenAIRE

    Meneses-Morales, Ivan; Tecalco-Cruz, Angeles C.; Barrios-García, Tonatiuh; Gómez-Romero, Vania; Trujillo-González, Isis; Reyes-Carmona, Sandra; García-Zepeda, Eduardo; Méndez-Enríquez, Erika; Cervantes-Roldán, Rafael; Pérez-Sánchez, Víctor; Recillas-Targa, Félix; Mohar-Betancourt, Alejandro; León-Del-Río, Alfonso

    2014-01-01

    The estrogen receptor alpha (ERα) is a ligand-activated transcription factor that possesses two activating domains designated AF-1 and AF-2 that mediate its transcriptional activity. The role of AF-2 is to recruit coregulator protein complexes capable of modifying chromatin condensation status. In contrast, the mechanism responsible for the ligand-independent AF-1 activity and for its synergistic functional interaction with AF-2 is unclear. In this study, we have identified the protein Na+/H+...

  14. Interaction between vitamin D receptor genotype and estrogen receptor alpha genotype influences vertebral fracture risk

    NARCIS (Netherlands)

    E.M. Colin; A.G. Uitterlinden (André); A.P. Bergink (Arjan); M. van de Klift (Marjolein); Y. Fang (Yue); P.P. Arp (Pascal); H.A.P. Pols (Huib); J.P.T.M. van Leeuwen (Hans); J.B.J. van Meurs (Joyce); A. Hofman (Albert)

    2003-01-01

    textabstractIn view of the interactions of vitamin D and the estrogen endocrine system, we studied the combined influence of polymorphisms in the estrogen receptor (ER) alpha gene and the vitamin D receptor (VDR) gene on the susceptibility to osteoporotic vertebral fractures in 634

  15. Alpha-adrenergic receptors in rat skeletal muscle

    DEFF Research Database (Denmark)

    Rattigan, S; Appleby, G J; Edwards, S J;

    1986-01-01

    Sarcolemma-enriched preparations from muscles rich in slow oxidative red fibres contained specific binding sites for the alpha 1 antagonist, prazosin (e.g. soleus Kd 0.13 nM, Bmax 29 fmol/mg protein). Binding sites for prazosin were almost absent from white muscle. Displacement of prazosin bindin...... adrenergic receptors are present on the sarcolemma of slow oxidative red fibres of rat skeletal muscle. The presence provides the mechanistic basis for apparent alpha-adrenergic effects to increase glucose and oxygen uptake in perfused rat hindquarter....

  16. In vitro inhibition of promyelocytic leukemia/retinoic acid receptor-alpha (PML/RARalpha) expression and leukemogenic activity by DNA/LNA chimeric antisense oligos.

    Science.gov (United States)

    Caprodossi, Sara; Galluzzi, Luca; Biagetti, Simona; Della Chiara, Giulia; Pelicci, Pier Giuseppe; Magnani, Mauro; Fanelli, Mirco

    2005-01-01

    Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by the chromosomal translocation t(15:17) that leads to the expression of promyelocytic leukemia/retinoic acid receptor-alpha (PML/ RARalpha) oncofusion protein. The block of differentiation at the promyelocytic stage of the blasts and their increased survival induced by PML/RARalpha are the principal biological features of the disease. Therapies based on pharmacological doses of retinoic acid (RA, 10(-6) M) are able to restore APL cell differentiation in most cases, but not to achieve complete hematological remission because retinoic acid resistance occurs in many patients. In order to elaborate alternative therapeutic approaches, we focused our attention on the use of antisense oligonucleotides as gene-specific drug directed to PML/RARalpha mRNA target. We used antisense molecules containing multiple locked nucleic acid (LNA) modifications. The LNAs are nucleotide analogues that are able to form duplexes with complementary DNA or RNA sequences with highly increased thermal stability and are resistant to 3'-exonuclease degradation in vitro. The DNA/LNA chimeric molecules were designed on the fusion sequence of PML and RARalpha genes to specifically target the oncofusion protein. Cell-free and in vitro experiments using U937-PR9-inducible cell line showed that DNA/LNA oligonucleotides were able to interfere with PML/RARalpha expression more efficiently than the corresponding unmodified DNA oligo. Moreover, the treatment of U937-PR9 cells with these chimeric antisense molecules was able to abrogate the block of differentiation induced by PML/RARalpha oncoprotein. These data suggest a possible application of oligonucleotides containing LNA in an antisense therapeutic strategy for APL.

  17. Genomic organization of the human thyroid hormone receptor alpha (c-erbA-1) gene.

    OpenAIRE

    Laudet, V; Begue, A; Henry-Duthoit, C; Joubel, A; P. Martin; Stehelin, D.; Saule, S.

    1991-01-01

    The thyroid hormone receptor alpha (THRA or c-erbA-1) gene belongs to a family of genes which encode nuclear receptors for various hydrophobic ligands such as steroids, vitamin D, retinoic acid and thyroid hormones. These receptors are composed of several domains important for hormone-binding, DNA-binding, dimerization and activation of transcription. We show here that the human THRA gene is organized in 10 exons distributed along 27 kbp of genomic DNA on chromosome 17. The position of the in...

  18. GTP synthases. Proton pumping and phosphorylation in ligand-receptor-G alpha-protein complexes.

    Science.gov (United States)

    Nederkoorn, P H; Timmerman, H; Donné-Op Den Kelder, G M; Timms, D; Wilkinson, A J; Kelly, D R; Broadley, K J; Davies, R H

    1996-01-01

    A structural model for a ligand-receptor-Gs alpha-protein complex to function as a GTP synthase is presented. The mechanism which is dependent on the movement and rotation of the G alpha-protein alpha 2-helix is seen to involve the delivery of, at least, one proton to the phosphorylation site in the rotation of this helix. The cycle is driven by a ligand-mediated proton pump through the alpha-helices of the receptor, attachment of the conserved Tyr-Arg-Tyr receptor proton shuttle being made to an aspartate group on the Gs alpha-protein terminal sidechain, which is itself linked to the Asn-Gln interaction known to control movement and rotation of the alpha 2-helix between .GDP and .GTP structures. The energetics of proton transfer through the shuttle mechanism and delivery of a proton to the aspartate group are shown to be sufficient to rupture this controlling interaction and its associated backbone bond. The complex leads to full spatial and energetic definition of the receptor proton shuttle mechanism, while there is a striking association of further Tyrosine and Arginine residues in the vicinity of the Gs alpha-protein Asn-Gln interaction. Calculations at the HF 6-31G** level confirm that a critical balance between ion pair and neutral forms of Tyr-Arg interactions under multiply hydrogen bonded conditions in a hydrophobic environment controls proton transfer and recovery mechanisms. The intrinsic preference of the neutral Tyr-Arg form over the ion-pair is 14.0 kcal/mol. Activation of the Tyrosine oxygen atom in the neutral form by single-NH or -OH groups reduces this difference by some 6.4-8.6 kcal/mol but the dominance of the neutral form is maintained. The expected slight overestimates are consistent with the maximum activation enthalpy of 11.0-12.0 kcal/ mol required to initiate proton transfer through the shuttle. The extended form of the shuttle with the Arginine acting competitively between the two Tyrosine residues allows interpretation of observed

  19. Megalin/LRP2 expression is induced by peroxisome proliferator-activated receptor -alpha and -gamma: implications for PPARs' roles in renal function.

    Directory of Open Access Journals (Sweden)

    Felipe Cabezas

    Full Text Available BACKGROUND: Megalin is a large endocytic receptor with relevant functions during development and adult life. It is expressed at the apical surface of several epithelial cell types, including proximal tubule cells (PTCs in the kidney, where it internalizes apolipoproteins, vitamins and hormones with their corresponding carrier proteins and signaling molecules. Despite the important physiological roles of megalin little is known about the regulation of its expression. By analyzing the human megalin promoter, we found three response elements for the peroxisomal proliferator-activated receptor (PPAR. The objective of this study was to test whether megalin expression is regulated by the PPARs. METHODOLOGY/PRINCIPAL FINDINGS: Treatment of epithelial cell lines with PPARα or PPARγ ligands increased megalin mRNA and protein expression. The stimulation of megalin mRNA expression was blocked by the addition of specific PPARα or PPARγ antagonists. Furthermore, PPAR bound to three PPAR response elements located in the megalin promoter, as shown by EMSA, and PPARα and its agonist activated a luciferase construct containing a portion of the megalin promoter and the first response element. Accordingly, the activation of PPARα and PPARγ enhanced megalin expression in mouse kidney. As previously observed, high concentrations of bovine serum albumin (BSA decreased megalin in PTCs in vitro; however, PTCs pretreated with PPARα and PPARγ agonists avoided this BSA-mediated reduction of megalin expression. Finally, we found that megalin expression was significantly inhibited in the PTCs of rats that were injected with BSA to induce tubulointerstitial damage and proteinuria. Treatment of these rats with PPARγ agonists counteracted the reduction in megalin expression and the proteinuria induced by BSA. CONCLUSIONS: PPARα/γ and their agonists positively control megalin expression. This regulation could have an important impact on several megalin

  20. Peroxisome proliferator-activated receptor alpha acts as a mediator of endoplasmic reticulum stress-induced hepatocyte apoptosis in acute liver failure

    Directory of Open Access Journals (Sweden)

    Li Zhang

    2016-07-01

    Full Text Available Peroxisome proliferator-activated receptor α (PPARα is a key regulator to ameliorate liver injury in cases of acute liver failure (ALF. However, its regulatory mechanisms remain largely undetermined. Endoplasmic reticulum stress (ER stress plays an important role in a number of liver diseases. This study aimed to investigate whether PPARα activation inhibits ER stress-induced hepatocyte apoptosis, thereby protecting against ALF. In a murine model of D-galactosamine (D-GalN- and lipopolysaccharide (LPS-induced ALF, Wy-14643 was administered to activate PPARα, and 4-phenylbutyric acid (4-PBA was administered to attenuate ER stress. PPARα activation ameliorated liver injury, because pre-administration of its specific inducer, Wy-14643, reduced the serum aminotransferase levels and preserved liver architecture compared with that of controls. The protective effect of PPARα activation resulted from the suppression of ER stress-induced hepatocyte apoptosis. Indeed, (1 PPARα activation decreased the expression of glucose-regulated protein 78 (Grp78, Grp94 and C/EBP-homologous protein (CHOP in vivo; (2 the liver protection by 4-PBA resulted from the induction of PPARα expression, as 4-PBA pre-treatment promoted upregulation of PPARα, and inhibition of PPARα by small interfering RNA (siRNA treatment reversed liver protection and increased hepatocyte apoptosis; (3 in vitro PPARα activation by Wy-14643 decreased hepatocyte apoptosis induced by severe ER stress, and PPARα inhibition by siRNA treatment decreased the hepatocyte survival induced by mild ER stress. Here, we demonstrate that PPARα activation contributes to liver protection and decreases hepatocyte apoptosis in ALF, particularly through regulating ER stress. Therefore, targeting PPARα could be a potential therapeutic strategy to ameliorate ALF.

  1. Peroxisome proliferator activator receptor gamma coactivator-1alpha (PGC-1α improves motor performance and survival in a mouse model of amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Cheng Alice

    2011-07-01

    Full Text Available Abstract Background Amyotrophic lateral sclerosis (ALS is a devastating neurodegenerative disease that affects spinal cord and cortical motor neurons. An increasing amount of evidence suggests that mitochondrial dysfunction contributes to motor neuron death in ALS. Peroxisome proliferator-activated receptor gamma co-activator-1α (PGC-1α is a principal regulator of mitochondrial biogenesis and oxidative metabolism. Results In this study, we examined whether PGC-1α plays a protective role in ALS by using a double transgenic mouse model where PGC-1α is over-expressed in an SOD1 transgenic mouse (TgSOD1-G93A/PGC-1α. Our results indicate that PGC-1α significantly improves motor function and survival of SOD1-G93A mice. The behavioral improvements were accompanied by reduced blood glucose level and by protection of motor neuron loss, restoration of mitochondrial electron transport chain activities and inhibition of stress signaling in the spinal cord. Conclusion Our results demonstrate that PGC-1α plays a beneficial role in a mouse model of ALS, suggesting that PGC-1α may be a potential therapeutic target for ALS therapy.

  2. Deletional rearrangement in the human T-cell receptor. cap alpha. -chain locus

    Energy Technology Data Exchange (ETDEWEB)

    de Villartay, J.P.; Lewis, D.; Hockett, R.; Waldmann, T.A.; Korsmeyer, S.J.; Cohen, D.I.

    1987-12-01

    The antigen-specific receptor on the surface of mature T lymphocytes is a heterodimer consisting of polypeptides termed ..cap alpha.. and ..beta... In the course of characterizing human T-cell tumors with an immature (CD4/sup -/, CD8/sup -/) surface phenotype, the authors detected a 2-kilobase ..cap alpha..-related transcript. Analysis of cDNA clones corresponding to this transcript established that a genetic element (which they call TEA, for T early ..cap alpha..) located between the ..cap alpha..-chain variable- and joining-region genes had been spliced to the ..cap alpha.. constant region. The TEA transcript is present early in thymocyte ontogeny, and its expression declines during T-cell maturation. More important, the TEA area functions as an active site for rearrangement within the ..cap alpha.. gene locus. Blot hybridization of restriction enzyme-digested DNA with a TEA probe revealed a narrowly limited pattern of rearrangement in polyclonal thymic DNA, surprisingly different from the pattern expected for the mature ..cap alpha.. gene with its complex diversity. These DNA blots also showed that TEA is generally present in the germ-line configuration in cells expressing the ..gamma..delta heterodimeric receptor and is deleted from mature (..cap alpha beta..-expressing) T-lymphocyte tumors and lines. Moreover, the TEA transcript lacked a long open reading frame for protein but instead possessed multiple copies of a repetitive element resembling those utilized in the heavy-chain class switch of the immunoglobulin genes. The temporal nature of the rearrangements and expression detected by TEA suggests that this recombination could mediate a transition between immature (..gamma..delta-expressing) T cells and mature (..cap alpha beta..-expressing) T cells.

  3. The orphan nuclear receptor SHP regulates PGC-1alpha expression and energy production in brown adipocytes.

    Science.gov (United States)

    Wang, Li; Liu, Jun; Saha, Pradip; Huang, Jiansheng; Chan, Lawrence; Spiegelman, Bruce; Moore, David D

    2005-10-01

    Brown adipocytes increase energy production in response to induction of PGC-1alpha, a dominant regulator of energy metabolism. We have found that the orphan nuclear receptor SHP (NR0B2) is a negative regulator of PGC-1alpha expression in brown adipocytes. Mice lacking SHP show increased basal expression of PGC-1alpha, increased energy expenditure, and resistance to diet-induced obesity. Increased PGC-1alpha expression in SHP null brown adipose tissue is not due to beta-adrenergic activation, since it is also observed in primary cultures of SHP(-/-) brown adipocytes that are not exposed to such stimuli. In addition, acute inhibition of SHP expression in cultured wild-type brown adipocytes increases basal PGC-1alpha expression, and SHP overexpression in SHP null brown adipocytes decreases it. The orphan nuclear receptor ERRgamma is expressed in BAT and its transactivation of the PGC-1alpha promoter is potently inhibited by SHP. We conclude that SHP functions as a negative regulator of energy production in BAT.

  4. ADD1/SREBP1c activates the PGC1-alpha promoter in brown adipocytes

    DEFF Research Database (Denmark)

    Hao, Qin; Hansen, Jacob B; Petersen, Rasmus K;

    2010-01-01

    regulatory element-binding protein-1c (SREBP1c) and peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC1alpha) in brown and inguinal white adipose tissues, but not in epididymal white adipose tissue. Using in vitro models of white and brown adipocytes we demonstrate that beta......Cold adaptation elicits a paradoxical simultaneous induction of fatty acid synthesis and beta-oxidation in brown adipose tissue. We show here that cold exposure coordinately induced liver X receptor alpha (LXRalpha), adipocyte determination and differentiation-dependent factor 1 (ADD1)/sterol...... as a regulator of PGC1alpha expression in brown adipose tissue....

  5. Peroxisome proliferator-activated receptors-alpha and gamma are targets to treat offspring from maternal diet-induced obesity in mice.

    Directory of Open Access Journals (Sweden)

    D'Angelo Carlo Magliano

    Full Text Available AIM: The aim of the present study was to evaluate whether activation of peroxisome proliferator-activated receptor (PPARalpha and PPARgamma by Bezafibrate (BZ could attenuate hepatic and white adipose tissue (WAT abnormalities in male offspring from diet-induced obese dams. MATERIALS AND METHODS: C57BL/6 female mice were fed a standard chow (SC; 10% lipids diet or a high-fat (HF; 49% lipids diet for 8 weeks before mating and during gestation and lactation periods. Male offspring received SC diet at weaning and were subdivided into four groups: SC, SC/BZ, HF and HF/BZ. Treatment with BZ (100 mg/Kg diet started at 12 weeks of age and was maintained for three weeks. RESULTS: The HF diet resulted in an overweight phenotype and an increase in oral glucose intolerance and fasting glucose of dams. The HF offspring showed increased body mass, higher levels of plasmatic and hepatic triglycerides, higher levels of pro-inflammatory and lower levels of anti-inflammatory adipokines, impairment of glucose metabolism, abnormal fat pad mass distribution, higher number of larger adipocytes, hepatic steatosis, higher expression of lipogenic proteins concomitant to decreased expression of PPARalpha and carnitine palmitoyltransferase I (CPT-1 in liver, and diminished expression of PPARgamma and adiponectin in WAT. Treatment with BZ ameliorated the hepatic and WAT abnormalities generated by diet-induced maternal obesity, with improvements observed in the structural, biochemical and molecular characteristics of the animals' livers and epididymal fat. CONCLUSION: Diet-induced maternal obesity lead to alterations in metabolism, hepatic lipotoxicity and adverse liver and WAT remodeling in the offspring. Targeting PPAR with Bezafibrate has beneficial effects reducing the alterations, mainly through reduction of WAT inflammatory state through PPARgamma activation and enhanced hepatic beta-oxidation due to increased PPARalpha/PPARgamma ratio in liver.

  6. TIF1alpha: a possible link between KRAB zinc finger proteins and nuclear receptors

    DEFF Research Database (Denmark)

    Le Douarin, B; You, J; Nielsen, Anders Lade;

    1998-01-01

    Ligand-induced gene activation by nuclear receptors (NRs) is thought to be mediated by transcriptional intermediary factors (TIFs), that interact with their ligand-dependent AF-2 activating domain. Included in the group of the putative AF-2 TIFs identified so far is TIF1alpha, a member of a new...... family of proteins which contains an N-terminal RBCC (RING finger-B boxes-coiled coil) motif and a C-terminal bromodomain preceded by a PHD finger. In addition to these conserved domains present in a number of transcriptional regulatory proteins, TIF1alpha was found to contain several protein......-protein interaction sites. Of these, one specifically interacts with NRs bound to their agonistic ligand and not with NR mutants that are defective in the AF-2 activity. Immediately adjacent to this 'NR box', TIF1alpha contains an interaction site for members of the chromatin organization modifier (chromo) family, HP...

  7. Alpha/sub 1/ receptor coupling events initiated by methoxy-substituted tolazoline partial agonists

    Energy Technology Data Exchange (ETDEWEB)

    Wick, P.; Keung, A.; Deth, R.

    1986-03-01

    A series of mono- and dimethyoxy substituted tolazoline derivatives, known to be partial agonists at the alpha/sub 1/ receptor, were compared with the ..cap alpha../sub 1/ selective full agonist phenylephrine (PE) on isolated strips of rabbit aorta Agonist activity was evaluated in contraction, /sup 45/Ca influx, /sup 45/Ca efflux, and /sup 32/P-Phospholipid labelling studies. Maximum contractile responses for the 2-, 3-, and 3, 5- methoxy substituted tolazoline derivatives (10/sup -5/M) were 53.8, 67.6 and 99.7% of the PE (10/sup -5/M) response respectively. These same partial agonists caused a stimulation of /sup 45/Ca influx to the extent of 64, 86, and 95% of the PE response respectively. In /sup 45/Ca efflux studies, (a measure of the intracellular Ca/sup +2/ release) the tolazolines caused: 30%, 63%, and 78% of the PE stimulated level. /sup 32/P-Phosphatidic acid (PA) labelling was measured as an index of PI turnover after ..cap alpha../sub 1/ receptor stimulation. Compared to PE, the 2-, 3-, and 3,5- methoxy substituted tolazoline derivatives caused 22, 46, and 72% PA labelling. The above values are all in reasonable accord with the rank order or agonist activity shown in maximum contractile responses. The results of this investigation suggest that partial agonists stimulate ..cap alpha.. receptor coupling events at a level which is quantitatively comparable to their potencies in causing contraction of arterial smooth muscle.

  8. In vitro anti-inflammatory activities of new steroidal antedrugs: [16alpha,17alpha-d] Isoxazoline and [16alpha,17alpha-d]-3'-hydroxy-iminoformyl isoxazoline derivatives of prednisolone and 9alpha-fluoroprednisolone.

    Science.gov (United States)

    Park, Kwan-K; Ko, Dong-H; You, Z; Khan, M Omar F; Lee, Henry J

    2006-03-01

    A series of new anti-inflammatory steroidal antedrugs with C-16,17-isoxazoline ring system were synthesized and their pharmacological activities were evaluated. We reported earlier that these compounds are promising antedrugs based on the results of 5-day rat croton oil ear edema assay. In the present study, most of these compounds showed high binding affinities to the glucocorticoid receptor of liver cytosol. 21-acetyloxy-9alpha-fluoro-11beta-hydroxy-3,20-dioxo-1,4-pregnadieno [16alpha,17alpha-d] isoxazoline (FP-ISO-21AC) and 11beta,21-dihydroxy-9alpha-fluoro-3,20-dioxo-1,4-pregnadieno [16alpha,17alpha-d] isoxazoline (FP-ISO-21OH) were found 5.0-, 5.3-fold more potent than prednisolone, respectively. Inhibitory effects of the antedrugs on the nitric oxide (NO) production were assessed using LPS-stimulated RAW 264.7 murine macrophage cells. All these steroidal antedrugs exhibited concentration-dependent inhibition of NO production, but their relative potencies were lower than prednisolone. In vitro metabolism study in rat plasma showed that FP-ISO-21AC and 21-acetyloxy-9alpha-fluoro-11beta-hydroxy-3,20-dioxo-1,4-pregnadieno [16alpha,17alpha-d]-3'-hydroxyiminoformyl isoxazoline (FP-OXIM-21AC) were hydrolyzed rapidly, with the half-lives of 2.1 and 4.2 min, respectively. The half-lives of FP-ISO-21OH and 11beta,21-dihydroxy-9alpha-fluoro-3,20-dioxo-1,4-pregnadieno [16alpha,17alpha-d]-3'-hydroxyiminoformyl isoxazoline (FP-OXIM-21OH) were 92.2 and 110.2 min, respectively. PMID:16309722

  9. The nicotinic alpha7 acetylcholine receptor agonist ssr180711 is unable to activate limbic neurons in mice overexpressing human amyloid-beta1-42

    DEFF Research Database (Denmark)

    Søderman, Andreas; Thomsen, Morten Skøtt; Hansen, Henrik H;

    2008-01-01

    systemic administration of the alpha7 nAChR agonist SSR180711 (10 mg/kg) result in a significant increase in Fos protein levels in the shell of nucleus accumbens in wild-type mice, but has no effect in the transgene mice. There were fewer cell bodies expressing Fos in the prefrontal cortex of transgene...

  10. TRIM32 promotes retinoic acid receptor {alpha}-mediated differentiation in human promyelogenous leukemic cell line HL60

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Tomonobu [Department of Biochemistry, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638 (Japan); Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo 060-8638 (Japan); Okumura, Fumihiko [Department of Biochemistry, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638 (Japan); Iguchi, Akihiro; Ariga, Tadashi [Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo 060-8638 (Japan); Hatakeyama, Shigetsugu, E-mail: hatas@med.hokudai.ac.jp [Department of Biochemistry, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638 (Japan)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer TRIM32 enhanced RAR{alpha}-mediated transcriptional activity even in the absence of RA. Black-Right-Pointing-Pointer TRIM32 stabilized RAR{alpha} in the human promyelogenous leukemic cell line HL60. Black-Right-Pointing-Pointer Overexpression of TRIM32 in HL60 cells induced granulocytic differentiation. Black-Right-Pointing-Pointer TRIM32 may function as a coactivator for RAR{alpha}-mediated transcription in APL cells. -- Abstract: Ubiquitination, one of the posttranslational modifications, appears to be involved in the transcriptional activity of nuclear receptors including retinoic acid receptor {alpha} (RAR{alpha}). We previously reported that an E3 ubiquitin ligase, TRIM32, interacts with several important proteins including RAR{alpha} and enhances transcriptional activity of RAR{alpha} in mouse neuroblastoma cells and embryonal carcinoma cells. Retinoic acid (RA), which acts as a ligand to nuclear receptors including RAR{alpha}, plays crucial roles in development, differentiation, cell cycles and apoptosis. In this study, we found that TRIM32 enhances RAR{alpha}-mediated transcriptional activity even in the absence of RA and stabilizes RAR{alpha} in the human promyelogenous leukemic cell line HL60. Moreover, we found that overexpression of TRIM32 in HL60 cells suppresses cellular proliferation and induces granulocytic differentiation even in the absence of RA. These findings suggest that TRIM32 functions as one of the coactivators for RAR{alpha}-mediated transcription in acute promyelogenous leukemia (APL) cells, and thus TRIM32 may become a potentially therapeutic target for APL.

  11. Development and validation of fluorescent receptor assays based on the human recombinant estrogen receptor subtypes alpha and beta

    NARCIS (Netherlands)

    de boer, T; Otjens, D; Muntendam, A; Meulman, E; van Oostijen, M; Ensing, K

    2004-01-01

    This article describes the development and validation of two fluorescent receptor assays for the hRec-estrogen receptor subtypes alpha and beta. As a labelled ligand an autofluorescent phyto-estrogen (coumestrol) has been used. The estrogen receptor (ER) belongs to the nuclear receptor family, a cla

  12. Effects of alpha-7 nicotinic acetylcholine receptor positive allosteric modulator on lipopolysaccharide-induced neuroinflammatory pain in mice.

    Science.gov (United States)

    Abbas, Muzaffar; Rahman, Shafiqur

    2016-07-15

    Evidence indicates that microglial activation contributes to the pathophysiology and maintenance of neuroinflammatory pain involving central nervous system alpha-7 nicotinic acetylcholine receptors. The objective of the present study was to determine the effects of 3a,4,5,9b-Tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS), an alpha-7 nicotinic acetylcholine receptor positive allosteric modulator (PAM), on tactile allodynia and thermal hyperalgesia following lipopolysaccharide (LPS)-induced microglial activation in hippocampus, a neuroinflammatory pain model in mice. In addition, we examined the effects of TQS on microglial activation marker, an ionized calcium-binding adapter molecule 1 (Iba-1), in the hippocampus may be associated with neuroinflammatory pain. Pretreatment of TQS (4mg/kg) significantly reduced LPS (1mg/kg)-induced tactile allodynia and thermal hyperalgesia. Moreover, pretreatment of methyllycaconitine (3mg/kg) significantly reversed TQS-induced antiallodynic and antihyperalgesic responses indicating the involvement of alpha-7 nicotinic acetylcholine receptor. Pretreatment of TQS significantly decreased LPS-induced increased in hippocampal Iba-1 expression. Overall, these results suggest that TQS reduces LPS-induced neuroinflammatory pain like symptoms via modulating microglial activation likely in the hippocampus and/or other brain region by targeting alpha-7 nicotinic acetylcholine receptor. Therefore, alpha-7 nicotinic acetylcholine receptor PAM such as TQS could be a potential drug candidate for the treatment of neuroinflammatory pain.

  13. Monoclonal antibodies to the human insulin receptor that activate glucose transport but not insulin receptor kinase activity

    Energy Technology Data Exchange (ETDEWEB)

    Forsayeth, J.R.; Caro, J.F.; Sinha, M.K.; Maddux, B.A.; Goldfine, I.D.

    1987-05-01

    Three mouse monoclonal antibodies were produced that reacted with the ..cap alpha.. subunit of the human insulin receptor. All three both immunoprecipitated /sup 125/I-labeled insulin receptors from IM-9 lymphocytes and competitively inhibited /sup 125/I-labeled insulin binding to its receptor. Unlike insulin, the antibodies failed to stimulate receptor autophosphorylation in both intact IM-9 lymphocytes and purified human placental insulin receptors. Moreover, unlike insulin, the antibodies failed to stimulate receptor-mediated phosphorylation of exogenous substrates. However, like insulin, two of the three antibodies stimulated glucose transport in isolated human adipocytes. One antibody, on a molar basis, was as potent as insulin. These studies indicate, therefore, that monoclonal antibodies to the insulin receptor can mimic a major function of insulin without activating receptor kinase activity. They also raise the possibility that certain actions of insulin such as stimulation of glucose transport may not require the activation of receptor kinase activity.

  14. A discrepancy between platelet alpha 2-receptor density and functional circulatory changes in hypertensives

    International Nuclear Information System (INIS)

    To investigate whether differences exist in peripheral alpha 2-adrenoceptors between normotensive and hypertensive subjects, we determined platelet alpha 2-adrenoceptor density in 10 (7 males) untreated essential hypertensives (mean age of 51.1 years, range of 44-59 years) and in 10 age- and sex-matched normotensive controls. Moreover, in hypertensive patients, we examined the relationship between receptor density and cardiovascular reactivity to mental arithmetic, static handgrip, and bicycle exercise, to verify the hypothesis that alpha 2-adrenoceptors might play a role in modulation of hemodynamic response to sympathetic stimuli. alpha 2-Adrenoceptor density, as calculated by binding of [3H]yohimbine to platelets, was significantly higher in essential hypertensives (314.8 +/- 38.7 fmol/mg) than in normotensive subjects (213.6 +/- 34.7 fmol/mg) (p less than 0.05), whereas receptor affinity was similar in both groups (4.0 +/- 0.5 nM hypertensives, 4.3 +/- 0.5 nM normotensives; p greater than 0.05). Mental arithmetic increased mean arterial pressure (MAP) by 21.5% from basal values and heart rate (HR) by 13.2%. During isometric exercise, MAP increased by 38.1% and HR by 24.7%, while during bicycle ergometry, mean increases in MAP and HR from baseline were of 27.2 and 54.3%, respectively. No correlation was found between platelet alpha 2-adrenoceptor density and percent changes in MAP induced by all tests, or between adrenoceptors and absolute basal and peak MAP values. Our findings suggest that in hypertensive patients, peripheral alpha 2-adrenoceptors are increased with respect to matched normotensives, but these receptors seem not to be involved in the modulation of cardiovascular adaptation to enhanced sympathetic activity

  15. Acute Myelogenous Leukemia without Maturation with a Retinoic Alpha-Receptor Deletion: A Case Report

    Directory of Open Access Journals (Sweden)

    Christopher Trosclair

    2014-06-01

    Full Text Available Acute promyelocytic leukemia (APL is characterized by a t(15;17 which fuses the 17q retinoic acid alpha-receptor sequence to the 15q PML gene sequence. The resulting fusion product plays a role in the development and maintenance of APL, and is very rarely found in other acute myeloid leukemia (AML subtypes. Rare complex APL genomic rearrangements have retinoic acid alpha-receptor sequence deletions. Here we report a retinoic acid alpha-receptor sequence deletion in a case of AML without differentiation. To our knowledge, this is the first example of a retinoic acid alpha-receptor sequence deletion in this AML subtype.

  16. Antiestrogenic activity of flavnoid phytochemicals mediated via c-Jun N-terminal protein kinase pathway. Cell-type specific regulation of estrogen receptor alpha

    Science.gov (United States)

    Flavonoid phytochemicals act as both agonists and antagonists of the human estrogen receptors (ERs). While a number of these compounds act by directly binding to the ER, certain phytochemicals, such as the flavonoid compounds chalcone and flavone, elicit antagonistic effects on estrogen signaling in...

  17. Inhibition of spontaneous receptor phosphorylation by residues in a putative alpha-helix in the KIT intracellular juxtamembrane region.

    Science.gov (United States)

    Ma, Y; Cunningham, M E; Wang, X; Ghosh, I; Regan, L; Longley, B J

    1999-05-01

    KIT receptor kinase activity is repressed, prior to stem cell factor binding, by unknown structural constraints. Using site-directed mutagenesis, we examined the role of KIT intracellular juxtamembrane residues Met-552 through Ile-563 in controlling receptor autophosphorylation. Alanine substitution for Tyr-553, Trp-557, Val-559, or Val-560, all sitting along the hydrophobic side of an amphipathic alpha-helix (Tyr-553-Ile-563) predicted by the Chou-Fasman algorithm, resulted in substantially increased spontaneous receptor phosphorylation, revealing inhibitory roles for these residues. Alanine substitution for other residues, most of which are on the hydrophilic side of the helix, caused no or slightly increased basal receptor phosphorylation. Converting Tyr-553 or Trp-557 to phenylalanine generated slight or no elevation, respectively, in basal KIT phosphorylation, indicating that the phenyl ring of Tyr-553 and the hydrophobicity of Trp-557 are critical for the inhibition. Although alanine substitution for Lys-558 had no effect on receptor phosphorylation, its substitution with proline produced high spontaneous receptor phosphorylation, suggesting that the predicted alpha-helical conformation is involved in the inhibition. A synthetic peptide comprising Tyr-553 through Ile-563 showed circular dichroism spectra characteristic of alpha-helix, supporting the structural prediction. Thus, the KIT intracellular juxtamembrane region contains important residues which, in a putative alpha-helical conformation, exert inhibitory control on the kinase activity of ligand-unoccupied receptor. PMID:10224103

  18. Proliferation of Estrogen Receptor alpha Positive Mammary Epithelial Cells is Restrained by TGFbeta1 in Adult Mice

    Energy Technology Data Exchange (ETDEWEB)

    Ewan, Kenneth B.R.; Oketch-Rabah, Hellen A.; Ravani, Shraddha A.; Shyamala, G.; Moses, Harold L.; Barcellos-Hoff, Mary Helen

    2005-03-03

    Transforming growth factor {beta}1 (TGF{beta}1) is a potent inhibitor of mammary epithelial proliferation. In human breast, estrogen receptor {alpha} (ER{alpha}) cells rarely co-localize with markers of proliferation, but their increased frequency correlates with breast cancer risk. To determine whether TGF{beta}1 is necessary for the quiescence of ER{alpha}-positive population, we examined mouse mammary epithelial gland at estrus. Approximately 35% of cells showed TGF{beta}1 activation, which co-localized with nuclear receptor-phosphorylated Smad 2/3, indicating that TGF{beta} signaling is autocrine. Furthermore, nuclear Smad co-localized with nuclear ER{alpha}. To test whether TGF{beta} was functional, we examined genetically engineered mice with different levels of TGF{beta}1. ER{alpha} co-localization with markers of proliferation (i.e. Ki-67 or BrdU) at estrus was significantly increased in the mammary glands of Tgf{beta}1 C57/bl/129SV heterozygote mice. This relationship was maintained following pregnancy, but was absent at puberty. Conversely, mammary epithelial expression of constitutively active TGF{beta}1 via the MMTV promoter suppressed proliferation of ER{alpha} positive cells. Thus, TGF{beta}1 activation functionally restrains ER{alpha} positive cells from proliferating in adult mammary gland. Accordingly, we propose that TGF{beta}1 dysregulation may promote proliferation of ER{alpha} positive cells associated with breast cancer risk in humans.

  19. Inhibition of MAP kinase promotes the recruitment of corepressor SMRT by tamoxifen-bound estrogen receptor alpha and potentiates tamoxifen action in MCF-7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Wei, E-mail: hongwei@tijmu.edu.cn [Department of Immunology, Tianjin Medical University, 300070 Tianjin (China); Department of Laboratory Medicine, Tianjin Medical University, 300070 Tianjin (China); Chen, Linfeng [Department of Medical Oncology, Harvard Medical School, Dana Farber Cancer Institute, Boston, 02115 MA (United States); Li, Juan [Department of Laboratory Medicine, Tianjin Medical University, 300070 Tianjin (China); Yao, Zhi [Department of Immunology, Tianjin Medical University, 300070 Tianjin (China)

    2010-05-28

    Estrogen receptor alpha (ER{alpha}), a ligand controlled transcription factor, plays an important role in breast cancer growth and endocrine therapy. Tamoxifen (TAM) antagonizes ER{alpha} activity and has been applied in breast cancer treatment. TAM-bound ER{alpha} associates with nuclear receptor-corepressors. Mitogen-activated protein kinase (MAPK) has been elucidated to result in cross-talk between growth factor and ER{alpha} mediated signaling. We show that activated MAPK represses interaction of TAM-bound ER{alpha} with silencing mediator for retinoid and thyroid hormone receptors (SMRT) and inhibits the recruitment of SMRT by ER{alpha} to certain estrogen target genes. Blockade of MAPK signaling cascade with MEK inhibitor U0126 promotes the interaction and subsequently inhibits ER{alpha} activity via enhanced recruitment of SMRT, leading to reduced expression of ER{alpha} target genes. The growth rate of MCF-7 cells was decelerated when treated with both TAM and U0126. Moreover, the growth of MCF-7 cells stably expressing SMRT showed a robust repression in the presence of TAM and U0126. These results suggest that activated MAPK signaling cascade attenuates antagonist-induced recruitment of SMRT to ER{alpha}, suggesting corepressor mediates inhibition of ER{alpha} transactivation and breast cancer cell growth by antagonist. Taken together, our finding indicates combination of antagonist and MAPK inhibitor could be a helpful approach for breast cancer therapy.

  20. Lucid dreaming and alpha activity: a preliminary report.

    Science.gov (United States)

    Ogilvie, R D; Hunt, H T; Tyson, P D; Lucescu, M L; Jeakins, D B

    1982-12-01

    10 good dream recallers spent 2 nights in the sleep lab during which they were awakened 4 times per night from REM sleep, twice during their highest alpha activity in REM, and twice during low REM alpha. 5 were given alpha feedback training prior to sleep onset. Arousals from high alpha REM sleep yielded significantly higher lucidity ratings. Alpha feedback had no effect upon lucidity or REM alpha levels. Similarities between lucid dreams and meditative phenomena are discussed.

  1. Lucid dreaming and alpha activity: a preliminary report.

    Science.gov (United States)

    Ogilvie, R D; Hunt, H T; Tyson, P D; Lucescu, M L; Jeakins, D B

    1982-12-01

    10 good dream recallers spent 2 nights in the sleep lab during which they were awakened 4 times per night from REM sleep, twice during their highest alpha activity in REM, and twice during low REM alpha. 5 were given alpha feedback training prior to sleep onset. Arousals from high alpha REM sleep yielded significantly higher lucidity ratings. Alpha feedback had no effect upon lucidity or REM alpha levels. Similarities between lucid dreams and meditative phenomena are discussed. PMID:7162915

  2. 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…

  3. Use of radioactive 7alpha, 17alpha-dimethyl-19-nortestosterone (mibolerone) in the assay of androgen receptors

    International Nuclear Information System (INIS)

    Tritiated 7alpha, 17alpha-dimethyl-19-nortestosterone (DMNT; mibolerone), a synthetic androgen stable to metabolic conversion in the rat ventral prostate, is an excellent radioactive ligand for the quantitation and characterization of androgen receptors in prostate, liver, and cultured cells. DMNT is more receptor-selective than 17alpha-methyl-17beta-hydroxy-estra-4,9,11-trien-3-one (R1881); DMNT interacts with glucocorticoid and progestin receptors much less strongly than R1881. Unlike 5alpha-dihydrotestosterone, DMNT does not bind tightly to testosterone-estradiol binding globulin of human serum. The hydroxylapatite-filter assay employed clearly distinguished between DMNT binding to androgen receptors of rat ventral prostate and interaction of DMNT with androgen binding protein of epididymides. The prostate cytosol (3H)DMNT-receptor complex sediments in two forms (4 and 8 S) in a low salt medium. In 0.4 M KCl, both the prostate cytosol and nuclear (3H)DMNT-receptor complexes migrated as 3-4 S components. The formation of both the cytosol and nuclear DMNT-receptor complexes is inhibited by antiandrogens and 17beta-estradiol

  4. Circulating sex hormones and gene expression of subcutaneous adipose tissue oestrogen and alpha-adrenergic receptors in HIV-lipodystrophy: implications for fat distribution

    DEFF Research Database (Denmark)

    Andersen, Ove; Pedersen, Steen B; Svenstrup, Birgit;

    2007-01-01

    of alpha2A-adrenergic-receptor correlated positively with expression of oestrogen-receptor-alpha. CONCLUSIONS: The results fit the hypothesis that sex hormones play a role in altered fat distribution and insulin sensitivity of male patients with HIV-lipodystrophy. The effect of oestradiol......OBJECTIVE: Circulating oestradiol and testosterone, which have been shown to increase in human immunodeficiency virus (HIV)-infected patients following highly active antiretroviral therapy (HAART), may influence fat distribution and insulin sensitivity. Oestradiol increases subcutaneous adipose...... tissue in humans possibly through binding to oestrogen-receptor-alpha, which in turn activates anti-lipolytic alpha2A-adrenergic-receptor. DESIGN AND METHODS: To address these issues circulating pituitary-gonadal-axis hormones and gene expression of receptors in subcutaneous adipose tissue were...

  5. Ligand-specific conformational changes in the alpha1 glycine receptor ligand-binding domain

    DEFF Research Database (Denmark)

    Pless, Stephan Alexander; Lynch, Joseph W

    2009-01-01

    indicate that channel opening is accompanied by conformational rearrangements in both beta-sheets. In an attempt to resolve ligand-dependent movements in the ligand-binding domain, we employed voltage-clamp fluorometry on alpha1 glycine receptors to compare changes mediated by the agonist, glycine...... in the inner beta-sheet and pre-M1 domain that may be important for activation, desensitization, or both. In contrast, most labeled residues in loops C and F yielded fluorescence changes identical in magnitude for glycine and strychnine. A notable exception was H201C in loop C. This labeled residue responded...... differently to glycine and strychnine, thus underlining the importance of loop C in ligand discrimination. These results provide an important step toward mapping the domains crucial for ligand discrimination in the ligand-binding domain of glycine receptors and possibly other Cys loop receptors....

  6. The origins of estrogen receptor alpha-positive and estrogen receptor alpha-negative human breast cancer

    International Nuclear Information System (INIS)

    Current hormonal therapies have benefited millions of patients with breast cancer. Their success, however, is often temporary and limited to a subset of patients whose tumors express estrogen receptor alpha (ER). The therapies are entirely ineffective in ER-negative disease. Recent studies suggest that there are many biological pathways and alterations involved in determining whether ER is expressed and how it is regulated during breast cancer evolution. Improving hormonal therapies, in addition to perfecting current strategies, will also target these newly discovered pathways and alterations, and others yet to be found. The present commentary will briefly highlight a few important observations and unanswered questions regarding ER status and growth regulation during breast cancer evolution, which hopefully will help to stimulate new thinking and progress in this important area of medial research

  7. PGC-1{beta} regulates mouse carnitine-acylcarnitine translocase through estrogen-related receptor {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Gacias, Mar; Perez-Marti, Albert; Pujol-Vidal, Magdalena; Marrero, Pedro F. [Department of Biochemistry and Molecular Biology, School of Pharmacy and the Institute of Biomedicine of the University of Barcelona (IBUB) (Spain); Haro, Diego, E-mail: dharo@ub.edu [Department of Biochemistry and Molecular Biology, School of Pharmacy and the Institute of Biomedicine of the University of Barcelona (IBUB) (Spain); Relat, Joana [Department of Biochemistry and Molecular Biology, School of Pharmacy and the Institute of Biomedicine of the University of Barcelona (IBUB) (Spain)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer The Cact gene is induced in mouse skeletal muscle after 24 h of fasting. Black-Right-Pointing-Pointer The Cact gene contains a functional consensus sequence for ERR. Black-Right-Pointing-Pointer This sequence binds ERR{alpha} both in vivo and in vitro. Black-Right-Pointing-Pointer This ERRE is required for the activation of Cact expression by the PGC-1/ERR axis. Black-Right-Pointing-Pointer Our results add Cact as a genuine gene target of these transcriptional regulators. -- Abstract: Carnitine/acylcarnitine translocase (CACT) is a mitochondrial-membrane carrier proteins that mediates the transport of acylcarnitines into the mitochondrial matrix for their oxidation by the mitochondrial fatty acid-oxidation pathway. CACT deficiency causes a variety of pathological conditions, such as hypoketotic hypoglycemia, cardiac arrest, hepatomegaly, hepatic dysfunction and muscle weakness, and it can be fatal in newborns and infants. Here we report that expression of the Cact gene is induced in mouse skeletal muscle after 24 h of fasting. To gain insight into the control of Cact gene expression, we examine the transcriptional regulation of the mouse Cact gene. We show that the 5 Prime -flanking region of this gene is transcriptionally active and contains a consensus sequence for the estrogen-related receptor (ERR), a member of the nuclear receptor family of transcription factors. This sequence binds ERR{alpha}in vivo and in vitro and is required for the activation of Cact expression by the peroxisome proliferator-activated receptor gamma coactivator (PGC)-1/ERR axis. We also demonstrate that XTC790, the inverse agonist of ERR{alpha}, specifically blocks Cact activation by PGC-1{beta} in C2C12 cells.

  8. Human cytomegalovirus infection inhibits tumor necrosis factor alpha (TNF-alpha) signaling by targeting the 55-kilodalton TNF-alpha receptor.

    Science.gov (United States)

    Baillie, J; Sahlender, D A; Sinclair, J H

    2003-06-01

    Infection with human cytomegalovirus (HCMV) results in complex interactions between viral and cellular factors which perturb many cellular functions. HCMV is known to target the cell cycle, cellular transcription, and immunoregulation, and it is believed that this optimizes the cellular environment for viral DNA replication during productive infection or during carriage in the latently infected host. Here, we show that HCMV infection also prevents external signaling to the cell by disrupting the function of TNFRI, the 55-kDa receptor for tumor necrosis factor alpha (TNF-alpha), one of the receptors for a potent cytokine involved in eliciting a wide spectrum of cellular responses, including antiviral responses. HCMV infection of fully permissive differentiated monocytic cell lines and U373 cells resulted in a reduction in cell surface expression of TNFRI. The reduction appeared to be due to relocalization of TNFRI from the cell surface and was reflected in the elimination of TNF-alpha-induced Jun kinase activity. Analysis of specific phases of infection suggested that viral early gene products were responsible for this relocalization. However, a mutant HCMV in which all viral gene products known to be involved in down-regulation of major histocompatibility complex (MHC) class I were deleted still resulted in relocalization of TNFRI. Consequently, TNFRI relocalization by HCMV appears to be mediated by a novel viral early function not involved in down-regulation of cell surface MHC class I expression. We suggest that upon infection, HCMV isolates the cell from host-mediated signals, forcing the cell to respond only to virus-specific signals which optimize the cell for virus production and effect proviral responses from bystander cells.

  9. Transient elevation of amygdala alpha 2 adrenergic receptor binding sites during the early stages of amygdala kindling.

    Science.gov (United States)

    Chen, M J; Vigil, A; Savage, D D; Weiss, G K

    1990-03-01

    Enhanced noradrenergic neurotransmission retards but does not prevent the development of kindling. We previously reported that locus coeruleus (LC) alpha 2 adrenergic receptor binding sites are transiently elevated during the early stages of kindling development. Since the firing activity of LC noradrenergic neurons is partially regulated via an alpha 2 receptor-mediated recurrent inhibition, the transient elevation in LC alpha 2 receptors could decrease LC activity and consequently facilitate the development of kindling. Transient elevation of alpha 2 receptor binding sites during early stages of kindling may also occur on noradrenergic axon terminals projecting to forebrain sites. Using in vitro neurotransmitter autoradiography techniques, we investigated this hypothesis by measuring specific [3H]idazoxan binding in 5 different areas of rat forebrain at 2 different stages of kindling development. After 2 class 1 kindled seizures, specific [3H]idazoxan binding was elevated significantly in the amygdala, but not in other forebrain regions. No differences in specific [3H]idazoxan binding were observed in any of the 5 brain regions in rats kindled to a single class 5 kindled motor seizure. Saturation of binding experiments indicated that the increase in amygdala [3H]idazoxan binding, following 2 class 1 kindled motor seizures, was due to an increase in the total number of alpha 2 receptor binding sites without a change in the affinity of the binding sites for [3H]idazoxan. Thus, the transient increase in alpha 2 receptors that occurs in the LC in the early stages of kindling also occurs in the forebrain region in which the kindled seizure originates.

  10. alpha-Toxin is a mediator of Staphylococcus aureus-induced cell death and activates caspases via the intrinsic death pathway independently of death receptor signaling

    NARCIS (Netherlands)

    Bantel, H; Sinha, B; Domschke, W; Peters, G; Schulze-Osthoff, K; Jänicke, R U

    2001-01-01

    Infections with Staphylococcus aureus, a common inducer of septic and toxic shock, often result in tissue damage and death of various cell types. Although S. aureus was suggested to induce apoptosis, the underlying signal transduction pathways remained elusive. We show that caspase activation and DN

  11. IL-4 function can be transferred to the IL-2 receptor by tyrosine containing sequences found in the IL-4 receptor alpha chain.

    Science.gov (United States)

    Wang, H Y; Paul, W E; Keegan, A D

    1996-02-01

    IL-4 binds to a cell surface receptor complex that consists of the IL-4 binding protein (IL-4R alpha) and the gamma chain of the IL-2 receptor complex (gamma c). The receptors for IL-4 and IL-2 have several features in common; both use the gamma c as a receptor component, and both activate the Janus kinases JAK-1 and JAK-3. In spite of these similarities, IL-4 evokes specific responses, including the tyrosine phosphorylation of 4PS/IRS-2 and the induction of CD23. To determine whether sequences within the cytoplasmic domain of the IL-4R alpha specify these IL-4-specific responses, we transplanted the insulin IL-4 receptor motif (I4R motif) of the huIL-4R alpha to the cytoplasmic domain of a truncated IL-2R beta. In addition, we transplanted a region that contains peptide sequences shown to block Stat6 binding to DNA. We analyzed the ability of cells expressing these IL-2R-IL-4R chimeric constructs to respond to IL-2. We found that IL-4 function could be transplanted to the IL-2 receptor by these regions and that proliferative and differentiative functions can be induced by different receptor sequences.

  12. Shared receptor components but distinct complexes for alpha and beta interferons.

    Science.gov (United States)

    Lewerenz, M; Mogensen, K E; Uzé, G

    1998-09-25

    The type I interferon family includes 13 alpha, one omega and one beta subtypes recognized by a complex containing the receptor subunits ifnar1 and ifnar2 and their associated Janus tyrosine kinases, Tyk2 and Jak1. To investigate the reported differences in the way that alpha and beta interferons signal through the receptor, we introduced alanine-substitutions in the ifnar2 extracellular domain, and expressed the mutants in U5A cells, lacking endogenous ifnar2. A selection, designed to recover mutants that responded preferentially to alpha or beta interferon yielded three groups: I, neutral; II, sensitive to alpha interferon, partially resistant to beta interferon; III, resistant to alpha interferon, partially sensitive to beta interferon. A mutant clone, TMK, fully resistant to alpha interferon with good sensitivity to beta interferon, was characterized in detail and compared with U5A cells complemented with wild-type ifnar2 and also with Tyk2-deficient 11.1 cells, which exhibit a similar alpha-unresponsive phenotype with a partial beta interferon response. Using anti-receptor antibodies and mutant forms of beta interferon, three distinct modes of ligand interaction could be discerned: (i) alpha interferon with ifnar1 and ifnar2; (ii) beta interferon with ifnar1 and ifnar2; (iii) beta interferon with ifnar2 alone. We conclude that alpha and beta interferons signal differently through their receptors because the two ligand subtypes interact with the receptor subunits ifnar 1 and ifnar2 in entirely different ways.

  13. Characterization of the interaction of lassa fever virus with its cellular receptor alpha-dystroglycan.

    Science.gov (United States)

    Kunz, Stefan; Rojek, Jillian M; Perez, Mar; Spiropoulou, Christina F; Oldstone, Michael B A

    2005-05-01

    The cellular receptor for the Old World arenaviruses Lassa fever virus (LFV) and lymphocytic choriomeningitis virus (LCMV) has recently been identified as alpha-dystroglycan (alpha-DG), a cell surface receptor that provides a molecular link between the extracellular matrix and the actin-based cytoskeleton. In the present study, we show that LFV binds to alpha-DG with high affinity in the low-nanomolar range. Recombinant vesicular stomatitis virus pseudotyped with LFV glycoprotein (GP) adopted the receptor binding characteristics of LFV and depended on alpha-DG for infection of cells. Mapping of the binding site of LFV on alpha-DG revealed that LFV binding required the same domains of alpha-DG that are involved in the binding of LCMV. Further, LFV was found to efficiently compete with laminin alpha1 and alpha2 chains for alpha-DG binding. Together with our previous studies on receptor binding of the prototypic immunosuppressive LCMV isolate LCMV clone 13, these findings indicate a high degree of conservation in the receptor binding characteristics between the highly human-pathogenic LFV and murine-immunosuppressive LCMV isolates. PMID:15857984

  14. Interaction between retinoid acid receptor-related orphan receptor alpha (RORA and neuropeptide S receptor 1 (NPSR1 in asthma.

    Directory of Open Access Journals (Sweden)

    Nathalie Acevedo

    Full Text Available Retinoid acid receptor-related Orphan Receptor Alpha (RORA was recently identified as a susceptibility gene for asthma in a genome-wide association study. To investigate the impact of RORA on asthma susceptibility, we performed a genetic association study between RORA single nucleotide polymorphisms (SNPs in the vicinity of the asthma-associated SNP (rs11071559 and asthma-related traits. Because the regulatory region of a previously implicated asthma susceptibility gene, Neuropeptide S receptor 1 (NPSR1, has predicted elements for RORA binding, we hypothesized that RORA may interact biologically and genetically with NPSR1. 37 RORA SNPs and eight NPSR1 SNPs were genotyped in the Swedish birth cohort BAMSE (2033 children and the European cross-sectional PARSIFAL study (1120 children. Seven RORA SNPs confined into a 49 kb region were significantly associated with physician-diagnosed childhood asthma. The most significant association with rs7164773 (T/C was driven by the CC genotype in asthma cases (OR = 2.0, 95%CI 1.36-2.93, p = 0.0003 in BAMSE; and 1.61, 1.18-2.19, p = 0.002 in the combined BAMSE-PARSIFAL datasets, respectively, and strikingly, the risk effect was dependent on the Gln344Arg mutation in NPSR1. In cell models, stimulation of NPSR1 activated a pathway including RORA and other circadian clock genes. Over-expression of RORA decreased NPSR1 promoter activity further suggesting a regulatory loop between these genes. In addition, Rora mRNA expression was lower in the lung tissue of Npsr1 deficient mice compared to wildtype littermates during the early hours of the light period. We conclude that RORA SNPs are associated with childhood asthma and show epistasis with NPSR1, and the interaction between RORA and NPSR1 may be of biological relevance. Combinations of common susceptibility alleles and less common functional polymorphisms may modify the joint risk effects on asthma susceptibility.

  15. Transcriptional targets shared by estrogen receptor- related receptors (ERRs) and estrogen receptor (ER) alpha, but not by ERbeta.

    OpenAIRE

    Vanacker, J M; K. Pettersson; Gustafsson, J.A.; Laudet, V

    1999-01-01

    The physiological activities of estrogens are thought to be mediated by specific nuclear receptors, ERalpha and ERbeta. However, certain tissues, such as the bone, that are highly responsive to estrogens only express a low level of these receptors. Starting from this apparent contradiction, we have evaluated the potentials of two related receptors ERRalpha and ERRbeta to intervene in estrogen signaling. ERalpha, ERRalpha and ERRbeta bind to and activate transcription through both the classica...

  16. Deorphanization of GPRC6A: a promiscuous L-alpha-amino acid receptor with preference for basic amino acids

    DEFF Research Database (Denmark)

    Wellendorph, Petrine; Hansen, Kasper B; Balsgaard, Anders;

    2005-01-01

    and was employed to rationally select potential ligands. Measurement of Ca2+-dependent chloride currents in Xenopus laevis oocytes facilitated the deorphanization of h6A/5.24 and identification of L-alpha-amino acids as agonists. The most active agonists were basic L-alpha-amino acids, L-Arg, L-Lys, and L......One of the most important tasks of molecular pharmacology is the deorphanization of the large number of G-protein-coupled receptors with unidentified endogenous agonists. We recently reported the cloning and analysis of expression of a novel human family C G-protein-coupled receptor, termed hGPRC6A....... To identify agonists at this orphan receptor, we faced the challenges of achieving surface expression in mammalian cell lines and establishing an appropriate functional assay. Generating a chimeric receptor construct, h6A/5.24, containing the ligand binding amino-terminal domain (ATD) of hGPRC6A...

  17. Ligands specify estrogen receptor alpha nuclear localization and degradation

    Directory of Open Access Journals (Sweden)

    Caze-Subra Stéphanie

    2010-12-01

    Full Text Available Abstract Background The estrogen receptor alpha (ERα is found predominately in the nucleus, both in hormone stimulated and untreated cells. Intracellular distribution of the ERα changes in the presence of agonists but the impact of different antiestrogens on the fate of ERα is a matter of debate. Results A MCF-7 cell line stably expressing GFP-tagged human ERα (SK19 cell line was created to examine the localization of ligand-bound GFP-ERα. We combined digitonin-based cell fractionation analyses with fluorescence and immuno-electron microscopy to determine the intracellular distribution of ligand-bound ERα and/or GFP-ERα. Using fluorescence- and electron microscopy we demonstrate that both endogenous ERα and GFP-ERα form numerous nuclear focal accumulations upon addition of agonist, 17β-estradiol (E2, and pure antagonists (selective estrogen regulator disruptor; SERD, ICI 182,780 or RU58,668, while in the presence of partial antagonists (selective estrogen regulator modulator; SERM, 4-hydroxytamoxifen (OHT or RU39,411, diffuse nuclear staining persisted. Digitonin based cell fractionation analyses confirmed that endogenous ERα and GFP-ERα predominantly reside in the nuclear fraction. Overall ERα protein levels were reduced after estradiol treatment. In the presence of SERMs ERα was stabilized in the nuclear soluble fraction, while in the presence of SERDs protein levels decreased drastically and the remaining ERα was largely found in a nuclear insoluble fraction. mRNA levels of ESR1 were reduced compared to untreated cells in the presence of all ligands tested, including E2. E2 and SERDs induced ERα degradation occurred in distinct nuclear foci composed of ERα and the proteasome providing a simple explanation for ERα sequestration in the nucleus. Conclusions Our results indicate that chemical structure of ligands directly affect the nuclear fate and protein turnover of the estrogen receptor alpha independently of their impact on

  18. Genome-wide identification of estrogen receptor alpha-binding sites in mouse liver

    DEFF Research Database (Denmark)

    Gao, Hui; Fält, Susann; Sandelin, Albin;

    2007-01-01

    We report the genome-wide identification of estrogen receptor alpha (ERalpha)-binding regions in mouse liver using a combination of chromatin immunoprecipitation and tiled microarrays that cover all nonrepetitive sequences in the mouse genome. This analysis identified 5568 ERalpha-binding regions...... genes. The majority of ERalpha-binding regions lie in regions that are evolutionarily conserved between human and mouse. Motif-finding algorithms identified the estrogen response element, and variants thereof, together with binding sites for activator protein 1, basic-helix-loop-helix proteins, ETS...... signaling in mouse liver, by characterizing the first step in this signaling cascade, the binding of ERalpha to DNA in intact chromatin....

  19. Whole-genome cartography of estrogen receptor alpha binding sites.

    Directory of Open Access Journals (Sweden)

    Chin-Yo Lin

    2007-06-01

    Full Text Available Using a chromatin immunoprecipitation-paired end diTag cloning and sequencing strategy, we mapped estrogen receptor alpha (ERalpha binding sites in MCF-7 breast cancer cells. We identified 1,234 high confidence binding clusters of which 94% are projected to be bona fide ERalpha binding regions. Only 5% of the mapped estrogen receptor binding sites are located within 5 kb upstream of the transcriptional start sites of adjacent genes, regions containing the proximal promoters, whereas vast majority of the sites are mapped to intronic or distal locations (>5 kb from 5' and 3' ends of adjacent transcript, suggesting transcriptional regulatory mechanisms over significant physical distances. Of all the identified sites, 71% harbored putative full estrogen response elements (EREs, 25% bore ERE half sites, and only 4% had no recognizable ERE sequences. Genes in the vicinity of ERalpha binding sites were enriched for regulation by estradiol in MCF-7 cells, and their expression profiles in patient samples segregate ERalpha-positive from ERalpha-negative breast tumors. The expression dynamics of the genes adjacent to ERalpha binding sites suggest a direct induction of gene expression through binding to ERE-like sequences, whereas transcriptional repression by ERalpha appears to be through indirect mechanisms. Our analysis also indicates a number of candidate transcription factor binding sites adjacent to occupied EREs at frequencies much greater than by chance, including the previously reported FOXA1 sites, and demonstrate the potential involvement of one such putative adjacent factor, Sp1, in the global regulation of ERalpha target genes. Unexpectedly, we found that only 22%-24% of the bona fide human ERalpha binding sites were overlapping conserved regions in whole genome vertebrate alignments, which suggest limited conservation of functional binding sites. Taken together, this genome-scale analysis suggests complex but definable rules governing ERalpha

  20. Stress-induced decrease of uterine blood flow in sheep is mediated by alpha 1-adrenergic receptors.

    Science.gov (United States)

    Dreiling, Michelle; Bischoff, Sabine; Schiffner, Rene; Rupprecht, Sven; Kiehntopf, Michael; Schubert, Harald; Witte, Otto W; Nathanielsz, Peter W; Schwab, Matthias; Rakers, Florian

    2016-09-01

    Prenatal maternal stress can be transferred to the fetus via a catecholamine-dependent decrease of uterine blood flow (UBF). However, it is unclear which group of adrenergic receptors mediates this mechanism of maternal-fetal stress transfer. We hypothesized that in sheep, alpha 1-adrenergic receptors may play a key role in catecholamine mediated UBF decrease, as these receptors are mainly involved in peripheral vasoconstriction and are present in significant number in the uterine vasculature. After chronic instrumentation at 125 ± 1 days of gestation (dGA; term 150 dGA), nine pregnant sheep were exposed at 130 ± 1 dGA to acute isolation stress for one hour without visual, tactile, or auditory contact with their flockmates. UBF, blood pressure (BP), heart rate (HR), stress hormones, and blood gases were determined before and during this isolation challenge. Twenty-four hours later, experiments were repeated during alpha 1-adrenergic receptor blockage induced by a continuous intravenous infusion of urapidil. In both experiments, ewes reacted to isolation with an increase in serum norepinephrine, cortisol, BP, and HR as typical signs of activation of sympatho-adrenal and the hypothalamic-pituitary-adrenal axis. Stress-induced UBF decrease was prevented by alpha 1-adrenergic receptor blockage. We conclude that UBF decrease induced by maternal stress in sheep is mediated by alpha 1-adrenergic receptors. Future studies investigating prevention strategies of impact of prenatal maternal stress on fetal health should consider selective blockage of alpha 1-receptors to interrupt maternal-fetal stress transfer mediated by utero-placental malperfusion.

  1. Inhibition of fatty acid amide hydrolase and cyclooxygenase-2 increases levels of endocannabinoid related molecules and produces analgesia via peroxisome proliferator-activated receptor-alpha in a model of inflammatory pain.

    Science.gov (United States)

    Jhaveri, Maulik D; Richardson, Denise; Robinson, Ian; Garle, Michael J; Patel, Annie; Sun, Yan; Sagar, Devi R; Bennett, Andrew J; Alexander, Stephen P H; Kendall, David A; Barrett, David A; Chapman, Victoria

    2008-07-01

    The antinociceptive effects of the endocannabinoids (ECs) are enhanced by inhibiting catabolic enzymes such as fatty acid amide hydrolase (FAAH). The physiological relevance of the metabolism of ECs by other pathways, such as cyclooxygenase-2 (COX2) is less clear. To address this question we compared the effects of local inhibition of FAAH versus COX2 (URB597 and nimesulide, respectively) on inflammatory hyperalgesia and levels of endocannabinoids and related molecules in the hindpaw. Inflammatory hyperalgesia was measured following intraplantar injection of carrageenan. Effects of intraplantar injection of URB597 (25 microg and 100 microg) or nimesulide (50 microg) on hyperalgesia and hindpaw levels of anandamide (AEA), 2-arachidonoylglycerol (2AG) and N-palmitoylethanolamine (PEA) were determined. Although both doses of URB597 increased levels of AEA and 2AG in the carrageenan inflamed hindpaw, only the lower dose of URB597 attenuated hyperalgesia (P<0.05). Nimesulide attenuated both hyperalgesia and hindpaw oedema (P<0.001, P<0.01, respectively) and increased levels of PEA (P<0.05) in the hindpaw. Since both AEA and PEA are ligands for peroxisome proliferator-activated receptor-alpha (PPARalpha), the effects of the PPARalpha antagonist GW6471 on nimesulide- and URB597-mediated effects were studied. GW6471, but not a PPARgamma antagonist, blocked the inhibitory effects of nimesulide and URB597 on hyperalgesia. Our data suggest that both COX2 and FAAH play a role in the metabolism of endocannabinoids and related molecules. The finding that PPARalpha antagonism blocked the inhibitory effects of nimesulide and URB597 suggests that PPARalpha contributes to their antinociceptive effects in the carrageenan model of inflammatory hyperalgesia.

  2. Expression of estrogen receptor alpha in preimplantation mice embryos

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective:To study the expression of estrogen receptor alpha (ERα) in preimplantation mice embryos.Methods:Mice zygotes were collected from superovulated Kunming mice and cultured in vitro.Embryos at different developmental stages were collected at 0,24,36,48,72 and 96hours after cultivation.The expression of ERα in early mice embryos was detected by reverse transcription-PCR (RT-PCR) and immunocytochemistry.Results:The expression of ERα mRNA was detected in all of the examined embryonic stages.The relative amount of ERα mRNA showed no significant difference between 1-cell stage embryos and 4-cell stage embryos (P>0.05).However,the relative level of ERα mRNA significantly decreased (P<0.05) at 2-cell stage and was the lowest at this stage.Over 2-cell stage,the ERα mRNA relative level would increase and achieve the peak level at blastocyst stage.The location of immunocytochemistry showed that ERα immunopositive cells could be firstly detected at 8-cell stage,after which they are consistently detected until blastocyst stage.In addition,the intensity of ERα positive staining was higher at blastocyst stage compared with that at 8-cell stage and morula stage.Conclusion:ERα is expressed in preimplantation mice embryos in a temporal and spatial pattern and may be involved in regulating the development of early mice embryos,which probably plays crucial roles in early embryonic development.

  3. RAINBOW TROUT ANDROGEN RECEPTOR ALPHA AND THE HUMAN ANDROGEN RECEPTOR: COMPARISONS IN THE COS WHOLE CELL BINDING ASSAY

    Science.gov (United States)

    Rainbow Trout Androgen Receptor Alpha And Human Androgen Receptor: Comparisons in the COS Whole Cell Binding Assay Mary C. Cardon, L. Earl Gray, Jr. and Vickie S. WilsonU.S. Environmental Protection Agency, ORD, NHEERL, Reproductive Toxicology Division, Research Triangle...

  4. Implication of platelet-derived growth factor receptor alpha in prostate cancer skeletal metastasis

    Institute of Scientific and Technical Information of China (English)

    Qingxin Liu; Danielle Jernigan; Yun Zhang; Alessandro Fatatis

    2011-01-01

    Metastasis represents by far the most feared complication of prostate carcinoma and is the main cause of death for patients.The skeleton is frequently targeted by disseminated cancer cells andrepresents the sole site of spread in more than 80% of prostate cancer cases.Compatibility between select malignant phenotypes and the microenvironment of colonized tissues is broadly recognized as the culprit for the organ-tropism of cancer cells.Here,we review our recent studies showing that the expression of platelet-derived growth factor receptor alpha (PDGFRα) supports the survival and growth of prostate cancer cells in the skeleton and that the soluble fraction of bone marrow activates PDGFRα in a ligand-independent fashion.Finally,we offer pre-clinical evidence that this receptor is a viable target for therapy.

  5. Relation of central alpha-adrenoceptor and other receptors to the control of renin secretion.

    Science.gov (United States)

    Ganong, W F

    1983-02-01

    The location and nature of the receptors in the brain on which clonidine acts to decrease renin secretion have been investigated in dogs. Clonidine was injected into the vertebral and carotid arteries, and its effects were compared with those of norepinephrine and epinephrine when injected into the third ventricle. It was also injected intravenously (IV) after transection of the brain stem and following treatment with intraventricular 6-hydroxydopamine. The results suggest that the renin-regulating receptors are located in the brain stem in a region different from the receptors mediating the depressor response, that they are alpha 2-adrenoceptors, and that they are postsynaptic in location. Central alpha 1-adrenoceptors appear to mediate increased renin secretion. Central serotonergic receptors also mediate increased renin secretion, but it is not known how the alpha 1- and alpha 2-adrenoceptors interact with the serotonergic systems.

  6. The estrogen receptor cooperates with the TGF alpha receptor (c-erbB) in regulation of chicken erythroid progenitor self-renewal.

    Science.gov (United States)

    Schroeder, C; Gibson, L; Nordström, C; Beug, H

    1993-03-01

    A unique combination of growth promoting factors is described that allows growth of large amounts (10(10)-10(11)) of normal erythroid progenitors from chick bone marrow. These erythroid progenitors express the estrogen receptor (ER) as well as the receptor tyrosine kinase TGF alpha R/c-erbB. They require both TGF alpha and estradiol for sustained self-renewal in vitro, but terminally differentiate upon withdrawal of TGF alpha and inactivation of the ER by an antagonist (ICI 164.384). Overexpression of the human ER in erythroblasts devoid of endogenous ER revealed that the hormone-activated ER alone arrested erythroid differentiation and repressed a large group of erythrocyte genes. When similarly overexpressed, TGF alpha R/c-erbB inhibited the expression of a distinct, but overlapping, set of genes. The endogenous ER and TGF alpha R/c-erbB affect erythrocyte gene expression in a similar, but less pronounced fashion. Surprisingly, suppression of ER function by antagonist efficiently inhibited erythroblast transformation by tyrosine kinase oncogenes, suggesting a role of the endogenous ER in leukemogenesis. We speculate that the oncogenes v-erbB and v-erbA cooperate in erythroleukemia induction by a mechanism that is employed by TGF alpha R/c-erbB and ER to regulate normal progenitor self-renewal in response to external signals. PMID:8458346

  7. Mouse egg integrin alpha 6 beta 1 functions as a sperm receptor.

    Science.gov (United States)

    Almeida, E A; Huovila, A P; Sutherland, A E; Stephens, L E; Calarco, P G; Shaw, L M; Mercurio, A M; Sonnenberg, A; Primakoff, P; Myles, D G; White, J M

    1995-06-30

    Binding between sperm and egg plasma membranes is an essential step in fertilization. Whereas fertilin, a mammalian sperm surface protein, is involved in this crucial interaction, sperm receptors on the egg plasma membrane have not been identified. Because fertilin contains a predicted integrin ligand domain, we investigated the expression and function of integrin subunits in unfertilized mouse eggs. Polymerase chain reactions detected mRNAs for alpha 5, alpha 6, alpha v, beta 1, beta 3, and beta 5. Immunofluorescence revealed alpha 6 beta 1 and alpha v beta 3 on the plasma membrane. GoH3, a function-blocking anti-alpha 6 monoclonal antibody, abolished sperm binding, but a nonfunction-blocking anti-alpha 6 monoclonal antibody, a function-blocking anti-alpha v beta 3 polyclonal antibody, and an RGD peptide had no effect. Somatic cells bound sperm avidly, but only if they expressed alpha 6 beta 1. A peptide analog of the fertilin integrin ligand domain inhibited sperm binding to eggs and alpha 6 beta 1+ cells and diminished GoH3 staining of eggs. Our results indicate a novel role for the integrin alpha 6 beta 1 as a cell-cell adhesion receptor that mediates sperm-egg binding. PMID:7600577

  8. Liver X receptors alpha and beta regulate renin expression in vivo

    NARCIS (Netherlands)

    Morello, Fulvio; de Boer, Rudolf A; Steffensen, Knut R; Gnecchi, Massimiliano; Chisholm, Jeffrey W; Boomsma, Frans; Anderson, Leonard M; Lawn, Richard M; Gustafsson, Jan-Ake; Lopez-Ilasaca, Marco; Pratt, Richard E; Dzau, Victor J

    2005-01-01

    The renin-angiotensin-aldosterone system controls blood pressure and salt-volume homeostasis. Renin, which is the first enzymatic step of the cascade, is critically regulated at the transcriptional level. In the present study, we investigated the role of liver X receptor alpha (LXR(alpha)) and LXR(b

  9. Thyroid Hormone Receptor alpha Modulates Lipopolysaccharide-Induced Changes in Peripheral Thyroid Hormone Metabolism

    NARCIS (Netherlands)

    J. Kwakkel; O. Chassande; H.C. van Beeren; E. Fliers; W.M. Wiersinga; A. Boelen

    2010-01-01

    Acute inflammation is characterized by low serum T-3 and T-4 levels accompanied by changes in liver type 1 deiodinase (D1), liver D3, muscle D2, and muscle D3 expression. It is unknown at present whether thyroid hormone receptor alpha (TR alpha) plays a role in altered peripheral thyroid hormone met

  10. Protection against myocardial ischaemia/reperfusion injury by PPAR-alpha activation is related to production of nitric oxide and endothelin-1

    DEFF Research Database (Denmark)

    Bulhak, A A; Sjöquist, P-O; Xu, C-B;

    2006-01-01

    BACKGROUND: Ligands of peroxisome proliferator-activated receptor alpha (PPAR-alpha) have been shown to reduce ischaemia/reperfusion injury. The mechanisms behind this effect are not well known. We hypothesized that activation of PPAR-alpha exerts cardioprotection via a mechanism related to nitri....... CONCLUSION: The results suggest that the PPAR-alpha activation protects the rat myocardium against ischaemia/ reperfusion injury via a mechanism related to production of NO, and possibly ET-1....

  11. Characterization of receptors for recombinant human tumor necrosis factor-alpha from human placental membranes

    International Nuclear Information System (INIS)

    High affinity receptors for recombinant human tumor necrosis factor-alpha (rhTNF-alpha) were identified on membranes prepared from full term human placenta. Highly purified rhTNF-alpha iodinated by the iodogen method was found to bind placental membranes in a displaceable manner with an approximate dissociation constant (KD) of 1.9 nM. The membrane bound TNF-alpha receptor could be solubilized by several detergents with optimum extraction being obtained with 1% Triton X-100. The binding of 125I-rhTNF-alpha to the solubilized receptor was found to be time and temperature dependent, yielding maximum binding within 1 h, 24 h and 48 h at 37 degrees C, 24 degrees C and 4 degrees C, respectively. However, the maximum binding obtainable at 4 degrees C was only 40% of that at 37 degrees C. The binding 125I-rhTNF-alpha to solubilized placental membrane extracts was displaceable by unlabeled rhTNF-alpha, but not by a related protein recombinant human tumor necrosis factor-beta (rhTNF-beta; previously called lymphotoxin). This is similar to the behavior of TNF-alpha receptors derived from detergent-solubilized cell extracts, although on intact cells, both rhTNF-alpha and rhTNF-beta bind with equal affinity to TNF receptors. The Scatchard analysis of the binding data of the solubilized receptor revealed high affinity binding sites with a KD of approximately 0.5 nM and a receptor concentration of about 1 pmole/mg protein. Gel filtration of the solubilized receptor-ligand complexes on Sephacryl S-300 revealed two different peaks of radioactivity at approximate molecular masses of 50,000 Da and 400,000 Da. The 400,000 dalton peak corresponded to the receptor-ligand complex. Overall, our results suggest that high affinity receptors for TNF-alpha are present on human placental membranes and provide evidence that these receptors may be different from that of rhTNF-beta

  12. A receptor-binding region in Escherichia coli alpha-haemolysin.

    Science.gov (United States)

    Cortajarena, Aitziber L; Goni, Félix M; Ostolaza, Helena

    2003-05-23

    Escherichia coli alpha-hemolysin (HlyA) is a 107-kDa protein toxin with a wide range of mammalian target cells. Previous work has shown that glycophorin is a specific receptor for HlyA in red blood cells (Cortajarena, A. L., Goñi, F. M., and Ostolaza, H. (2001) J. Biol. Chem. 276, 12513-12519). The present study was aimed at identifying the glycophorin-binding region in the toxin. Data in the literature pointed to a short amino acid sequence near the C terminus as a putative receptor-binding domain. Previous sequence analyses of several homologous toxins that belong, like HlyA, to the so-called RTX toxin family revealed a conserved region that corresponded to residues 914-936 of HlyA. We therefore prepared a deletion mutant lacking these residues (HlyA Delta 914-936) and found that its hemolytic activity was decreased by 10,000-fold with respect to the wild type. This deletion mutant was virtually unable to bind human and horse red blood cells or to bind pure glycophorin in an affinity column. The peptide Trp914-Arg936 had no lytic activity of its own, but it could bind glycophorin reconstituted in lipid vesicles. Moreover, the peptide Trp914-Arg936 protected red blood cells from hemolysis induced by wild type HlyA. It was concluded that amino acid residues 914-936 constitute a major receptor-binding region in alpha-hemolysin. PMID:12582172

  13. Nuclear receptor corepressor-dependent repression of peroxisome-proliferator-activated receptor delta-mediated transactivation

    DEFF Research Database (Denmark)

    Krogsdam, Anne-M; Nielsen, Curt A F; Neve, Søren;

    2002-01-01

    The nuclear receptor corepressor (NCoR) was isolated as a peroxisome-proliferator-activated receptor (PPAR) delta interacting protein using the yeast two-hybrid system. NCoR interacted strongly with the ligand-binding domain of PPAR delta, whereas interactions with the ligand-binding domains...... delta-RXR alpha heterodimer bound to an acyl-CoA oxidase (ACO)-type peroxisome-proliferator response element recruited a glutathione S-transferase-NCoR fusion protein in a ligand-independent manner. Contrasting with most other nuclear receptors, PPAR delta was found to interact equally well...

  14. Autoradiographic analysis of alpha 1-noradrenergic receptors in the human brain postmortem. Effect of suicide

    International Nuclear Information System (INIS)

    In vitro quantitative autoradiography of alpha 1-noradrenergic receptors, using tritiated prazosin as a ligand, was performed on 24 human brains postmortem. Twelve brains were obtained from suicide victims and 12 from matched controls. We found significant lower binding to alpha 1 receptors in several brain regions of the suicide group as compared with matched controls. This decrease in receptor density was evident in portions of the prefrontal cortex, as well as the temporal cortex and in the caudate nucleus. Age, sex, presence of alcohol, and time of death to autopsy did not affect prazosin binding, in our sample, as measured by autoradiography

  15. Alpha1 receptor coupling events initiated by methoxy-substituted tolazoline partial agonists

    International Nuclear Information System (INIS)

    A series of mono- and dimethyoxy substituted tolazoline derivatives, known to be partial agonists at the alpha1 receptor, were compared with the α1 selective full agonist phenylephrine (PE) on isolated strips of rabbit aorta Agonist activity was evaluated in contraction, 45Ca influx, 45Ca efflux, and 32P-Phospholipid labelling studies. Maximum contractile responses for the 2-, 3-, and 3, 5- methoxy substituted tolazoline derivatives (10-5M) were 53.8, 67.6 and 99.7% of the PE (10-5M) response respectively. These same partial agonists caused a stimulation of 45Ca influx to the extent of 64, 86, and 95% of the PE response respectively. In 45Ca efflux studies, (a measure of the intracellular Ca+2 release) the tolazolines caused: 30%, 63%, and 78% of the PE stimulated level. 32P-Phosphatidic acid (PA) labelling was measured as an index of PI turnover after α1 receptor stimulation. Compared to PE, the 2-, 3-, and 3,5- methoxy substituted tolazoline derivatives caused 22, 46, and 72% PA labelling. The above values are all in reasonable accord with the rank order or agonist activity shown in maximum contractile responses. The results of this investigation suggest that partial agonists stimulate α receptor coupling events at a level which is quantitatively comparable to their potencies in causing contraction of arterial smooth muscle

  16. Ligand-stimulated downregulation of the alpha interferon receptor: role of protein kinase D2.

    Science.gov (United States)

    Zheng, Hui; Qian, Juan; Varghese, Bentley; Baker, Darren P; Fuchs, Serge

    2011-02-01

    Alpha interferon (IFN-α) controls homeostasis of hematopoietic stem cells, regulates antiviral resistance, inhibits angiogenesis, and suppresses tumor growth. This cytokine is often used to treat cancers and chronic viral infections. The extent of cellular responses to IFN-α is limited by the IFN-induced ubiquitination and degradation of the IFN-α/β receptor chain 1 (IFNAR1) chain of the cognate receptor. IFNAR1 ubiquitination is facilitated by the βTrcp E3 ubiquitin ligase that is recruited to IFNAR1 upon its degron phosphorylation, which is induced by the ligand. Here we report identification of protein kinase D2 (PKD2) as a kinase that mediates the ligand-inducible phosphorylation of IFNAR1 degron and enables binding of βTrcp to the receptor. Treatment of cells with IFN-α induces catalytic activity of PKD2 and stimulates its interaction with IFNAR1. Expression and kinase activity of PKD2 are required for the ligand-inducible stimulation of IFNAR1 ubiquitination and endocytosis and for accelerated proteolytic turnover of IFNAR1. Furthermore, inhibition or knockdown of PKD2 robustly augments intracellular signaling induced by IFN-α and increases the efficacy of its antiviral effects. The mechanisms of the ligand-inducible elimination of IFNAR1 are discussed, along with the potential medical significance of this regulation. PMID:21173164

  17. Identification of a new isoform of the human estrogen receptor-alpha (hER-α) that is encoded by distinct transcripts and that is able to repress hER-α activation function 1

    OpenAIRE

    Flouriot, Gilles; Brand, Heike; Denger, Stefanie; Metivier, Raphaël; Kos, Martin; Reid, George; Sonntag-Buck, Vera; Gannon, Frank

    2000-01-01

    A new isoform of the human estrogen receptor-alpha (hER-α) has been identified and characterized. This 46 kDa isoform (hERα46) lacks the N-terminal 173 amino acids present in the previously characterized 66 kDa isoform (hERα66). hERα46 is encoded by a new class of hER-α transcript that lacks the first coding exon (exon 1A) of the ER-α gene. We demonstrated that these Δ1A hER-α transcripts originate from the E and F hER-α promoters and are produced by the splicing of exon 1E directly to exon 2...

  18. Ligand binding affinities of arctigenin and its demethylated metabolites to estrogen receptor alpha.

    Science.gov (United States)

    Jin, Jong-Sik; Lee, Jong-Hyun; Hattori, Masao

    2013-01-01

    Phytoestrogens are defined as plant-derived compounds with estrogen-like activities according to their chemical structures and activities. Plant lignans are generally categorized as phytoestrogens. It was reported that (-)-arctigenin, the aglycone of arctiin, was demethylated to (-)-dihydroxyenterolactone (DHENL) by Eubacterium (E.) sp. ARC-2. Through stepwise demethylation, E. sp. ARC-2 produced six intermediates, three mono-desmethylarctigenins and three di-desmethylarctigenins. In the present study, ligand binding affinities of (-)-arctigenin and its seven metabolites, including DHENL, were investigated for an estrogen receptor alpha, and found that demethylated metabolites had stronger binding affinities than (-)-arctigenin using a ligand binding screen assay method. The IC(50) value of (2R,3R)-2-(4-hydroxy-3-methoxybenzyl)-3-(3,4-dihydroxybenzyl)-butyrolactone was 7.9 × 10⁻⁴ M. PMID:23325100

  19. Ligand Binding Affinities of Arctigenin and Its Demethylated Metabolites to Estrogen Receptor Alpha

    Directory of Open Access Journals (Sweden)

    Masao Hattori

    2013-01-01

    Full Text Available Phytoestrogens are defined as plant-derived compounds with estrogen-like activities according to their chemical structures and activities. Plant lignans are generally categorized as phytoestrogens. It was reported that (−-arctigenin, the aglycone of arctiin, was demethylated to (−-dihydroxyenterolactone (DHENL by Eubacterium (E. sp. ARC-2. Through stepwise demethylation, E. sp. ARC-2 produced six intermediates, three mono-desmethylarctigenins and three di-desmethylarctigenins. In the present study, ligand binding affinities of (−-arctigenin and its seven metabolites, including DHENL, were investigated for an estrogen receptor alpha, and found that demethylated metabolites had stronger binding affinities than (−-arctigenin using a ligand binding screen assay method. The IC50 value of (2R,3R-2-(4-hydroxy-3-methoxybenzyl-3-(3,4-dihydroxybenzyl-butyrolactone was 7.9 × 10−4 M.

  20. The activity of granulocyte alpha-amylase in acute appendicitis.

    Science.gov (United States)

    Zakrzewska, I; Gajda, R

    1994-01-01

    The activity of alpha-amylase was measured in isolated granulocytes, serum and urine of 35 patients with acute appendicitis. The measurements were performed before operation and on the 7th day after operation. Slightly increased activity of alpha-amylase was found in the serum and urine of 15 patients. On the 7th day after operation the activity of this enzyme reached normal value. The activity of granulocyte alpha-amylase was elevated in 22 patients. In 2 of them the increased activity still maintained on the 7th day after operation. Positive correlation between the serum and granulocyte alpha-amylase activities was found. These observations allow to conclude that granulocytes are the source of increased alpha-amylase activity in the serum of patients with acute appendicitis.

  1. The activity of granulocyte alpha-amylase in acute appendicitis.

    Science.gov (United States)

    Zakrzewska, I; Gajda, R

    1994-01-01

    The activity of alpha-amylase was measured in isolated granulocytes, serum and urine of 35 patients with acute appendicitis. The measurements were performed before operation and on the 7th day after operation. Slightly increased activity of alpha-amylase was found in the serum and urine of 15 patients. On the 7th day after operation the activity of this enzyme reached normal value. The activity of granulocyte alpha-amylase was elevated in 22 patients. In 2 of them the increased activity still maintained on the 7th day after operation. Positive correlation between the serum and granulocyte alpha-amylase activities was found. These observations allow to conclude that granulocytes are the source of increased alpha-amylase activity in the serum of patients with acute appendicitis. PMID:7497089

  2. Stat2 binding to the interferon-alpha receptor 2 subunit is not required for interferon-alpha signaling.

    Science.gov (United States)

    Nguyen, Vinh-Phúc; Saleh, Abu Z M; Arch, Allison E; Yan, Hai; Piazza, Flavia; Kim, John; Krolewski, John J

    2002-03-22

    The interferon-alpha (IFNalpha) receptor consists of two subunits, the IFNalpha receptor 1 (IFNaR1) and 2 (IFNaR2) chains. Following ligand binding, IFNaR1 is phosphorylated on tyrosine 466, and this site recruits Stat2 via its SH2 domain. In contrast, IFNaR2 binds Stat2 constitutively. In this study we have characterized the Stat2-IFNaR2 interaction and examined its role in IFNalpha signaling. Stat2 binds the major IFNaR2 protein but not a variant containing a shorter cytoplasmic domain. The interaction does not require a STAT SH2 domain. Both tyrosine-phosphorylated and non-phosphorylated Stat2 bind IFNaR2 in vitro; however, relatively little phosphorylated Stat2 associates with IFNaR2 in vivo. In vitro binding assays defined IFNaR2 residues 418-444 as the minimal interaction domain and site-specific mutation of conserved acidic residues within this domain disrupted in vitro and in vivo binding. An IFNaR2 construct carrying these mutations was either (i) overexpressed in 293T cells or (ii) used to complement IFNaR2-deficient U5A cells. Unexpectedly, the activity of an IFNalpha-dependent reporter gene was not reduced but, instead, was enhanced up to 2-fold. This suggests that this particular IFNaR2-Stat2 interaction is not required for IFNalpha signaling, but might act to negatively inhibit signaling. Finally, a doubly truncated recombinant fragment of Stat2, spanning residues 136-702, associated with IFNaR2 in vitro, indicating that the interaction with IFNaR2 is direct and occurs in a central region of Stat2 marked by a hydrophobic core.

  3. 3-(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N-alkyl-N-arylbenzamides: potent, non-peptidic agonists of both the micro and delta opioid receptors.

    Science.gov (United States)

    Bishop, Michael J; Garrido, Dulce M; Boswell, G Evan; Collins, Mark A; Harris, Philip A; McNutt, Robert W; O'Neill, Scott J; Wei, Ke; Chang, Kwen-Jen

    2003-02-13

    Opioid analgesics with both micro and delta opioid receptor activation represent a new approach to the treatment of severe pain with an improved safety profile. Compounds with this profile may exhibit strong analgesic properties due to micro agonism, with a reduced side effect profile resulting from delta agonism. Replacing the p-diethylamide of the known potent delta opioid receptor selective agonist BW373U86 with a m-diethylamide resulted in a compound with agonist activity at both the micro and delta opioid receptors. Modifying the amide to an N-methyl-N-phenylamide increased agonist potency at both receptors. A series of 3-(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N-alkyl-N-arylbenzamides have been made to explore the structure-activity relationship (SAR) around the N-methyl-N-phenylamide. Several potent agonists of both the micro and delta opioid receptors have been identified, including (+)-3-((alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N-(4-fluorophenyl)-N-methylbenzamide (23), which has EC50 values of 0.67 and 1.1 nM at the micro (guinea pig ileum assay) and delta (mouse vas deferens assay) opioid receptors, respectively.

  4. EFFECTS OF INTEGRIN ALPHA ⅡbR995A MUTATION ON RECEPTOR AFFINITY AND pp 125 (FAK) PHOSPHORYLATION

    Institute of Scientific and Technical Information of China (English)

    Xue-yuan Tang; Zai-fu Jian; Guo-ping Wang; Hong-hui Yang; Wei Liu

    2004-01-01

    Objective To investigate the role of cytoplasmic domain of integrin alpha Ⅱb in platelet signal transduction.Methods Binding capacity of integrin alpha ⅡbR995Ato antibody platelet activation complex-1 (PAC-1) and pp125focal adhesion kinase (FAK) phosphorylation of cells were detected by flow cytometry, immune precipitation, and Western blotting.Results Without activation, wild-type alpha Ⅱ bbeta3 Chinese hamster ovary (CHO) cells failed to bind to PAC-1, but mutant chimera alpha ⅡbR995Aeta3 CHO cells were able to bind with PAC-1. Furthermore, phosphorylation of pp125 (FAK)in wild-type alpha Ⅱbbeta3 CHO cells occured only when cells were adhered to fibrinogen, but could not be detected in bovine serum albumin suspension. However in the mutant chimera group, it could be detected in both conditions.Conclusion The mutation in integrin alpha ⅡbR995Aalters its affinity state as a receptor, thus also mediating cytoplasmic signal transduction leading to the phosphorylation of pp125 (FAK) without ligand binding.

  5. Modeling Nonalcoholic Fatty Liver Disease with Human Pluripotent Stem Cell-Derived Immature Hepatocyte-Like Cells Reveals Activation of PLIN2 and Confirms Regulatory Functions of Peroxisome Proliferator-Activated Receptor Alpha

    Science.gov (United States)

    Graffmann, Nina; Ring, Sarah; Kawala, Marie-Ann; Wruck, Wasco; Ncube, Audrey; Trompeter, Hans-Ingo

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD/steatosis) is a metabolic disease characterized by the incorporation of fat into hepatocytes. In this study, we developed an in vitro model for NAFLD based on hepatocyte-like cells (HLCs) differentiated from human pluripotent stem cells. We induced fat storage in these HLCs and detected major expression changes of metabolism-associated genes, as well as an overall reduction of liver-related microRNAs. We observed an upregulation of the lipid droplet coating protein Perilipin 2 (PLIN2), as well as of numerous genes of the peroxisome proliferator-activated receptor (PPAR) pathway, which constitutes a regulatory hub for metabolic processes. Interference with PLIN2 and PPARα resulted in major alterations in gene expression, especially affecting lipid, glucose, and purine metabolism. Our model recapitulates many metabolic changes that are characteristic for NAFLD. It permits the dissection of disease-promoting molecular pathways and allows us to investigate the influences of distinct genetic backgrounds on disease progression. PMID:27308945

  6. Down-regulation of the alpha-2C adrenergic receptor: involvement of a serine/threonine motif in the third cytoplasmic loop

    OpenAIRE

    Deupree, Jean D; Borgeson, Claudia D.; Bylund, David B.

    2002-01-01

    Background The mechanisms by which alpha-2 adrenergic receptors are down-regulated following chronic exposure to agonist are not well understood. Interestingly, the human alpha-2C receptor does not down-regulate, whereas the opossum alpha-2C receptor does down-regulate. A comparison of the amino acid sequence of the third intracellular loop of these two receptors shows that the opossum alpha-2C receptor contains a potential G protein-coupled receptor kinase (GRK)phosphorylation motif (EESSTSE...

  7. Human alpha 2-adrenergic receptor subtype distribution: widespread and subtype-selective expression of alpha 2C10, alpha 2C4, and alpha 2C2 mRNA in multiple tissues.

    Science.gov (United States)

    Eason, M G; Liggett, S B

    1993-07-01

    At present, molecular cloning and pharmacological studies have delineated three human alpha 2-adrenergic receptor (alpha 2AR) subtypes, alpha 2C10, alpha 2C4, and alpha 2C2. Assignment of the alpha 2AR subtypes to specific functions has been limited by an unclear definition of tissue alpha 2AR expression outside of the central nervous system. It has been suggested that alpha 2C4 expression is confined to the brain, that alpha 2C2 expression is only in the liver and kidney, and that there is nearly ubiquitous expression of alpha 2C10. However, this is based on studies of a limited number of rat tissues or on studies using non-species-specific approaches. Therefore, to define alpha 2C10, alpha 2C4, and alpha 2C2 tissue expression, we used reverse transcription of total RNA isolated from 20 human tissues, followed by amplification of alpha 2AR cDNA using the polymerase chain reaction. This technique provided two advantages: high sensitivity and, with the use of subtype-specific oligonucleotide primers and probes, differentiation between the alpha 2AR subtypes. The tissues studied were aorta, vena cava, heart (epicardium and endocardium), lung, skeletal muscle, liver, pancreas (head and tail), fat (perinephric and subcutaneous), kidney (cortex and medulla), prostate, stomach, ileum, jejunum, colon, adrenal gland, and spleen. We found that the majority of these tissues expressed alpha 2C10, with the exceptions being the head of the pancreas, subcutaneous fat, colon, and spleen. In marked distinction to other studies, however, we found a prolific expression of the alpha 2C4 and alpha 2C2 subtypes. Expression of alpha 2C4 was found in all tissues with the exception of liver, fat, stomach, and colon, and a virtually ubiquitous expression of alpha 2C2 was found, with the exception of epicardium. Of all tissues studied, only colon and subcutaneous fat expressed a single alpha 2AR subtype, which was alpha 2C2. Thus, the alpha 2AR subtypes do not have a confined expression but

  8. Human alpha 2-adrenergic receptor subtype distribution: widespread and subtype-selective expression of alpha 2C10, alpha 2C4, and alpha 2C2 mRNA in multiple tissues.

    Science.gov (United States)

    Eason, M G; Liggett, S B

    1993-07-01

    At present, molecular cloning and pharmacological studies have delineated three human alpha 2-adrenergic receptor (alpha 2AR) subtypes, alpha 2C10, alpha 2C4, and alpha 2C2. Assignment of the alpha 2AR subtypes to specific functions has been limited by an unclear definition of tissue alpha 2AR expression outside of the central nervous system. It has been suggested that alpha 2C4 expression is confined to the brain, that alpha 2C2 expression is only in the liver and kidney, and that there is nearly ubiquitous expression of alpha 2C10. However, this is based on studies of a limited number of rat tissues or on studies using non-species-specific approaches. Therefore, to define alpha 2C10, alpha 2C4, and alpha 2C2 tissue expression, we used reverse transcription of total RNA isolated from 20 human tissues, followed by amplification of alpha 2AR cDNA using the polymerase chain reaction. This technique provided two advantages: high sensitivity and, with the use of subtype-specific oligonucleotide primers and probes, differentiation between the alpha 2AR subtypes. The tissues studied were aorta, vena cava, heart (epicardium and endocardium), lung, skeletal muscle, liver, pancreas (head and tail), fat (perinephric and subcutaneous), kidney (cortex and medulla), prostate, stomach, ileum, jejunum, colon, adrenal gland, and spleen. We found that the majority of these tissues expressed alpha 2C10, with the exceptions being the head of the pancreas, subcutaneous fat, colon, and spleen. In marked distinction to other studies, however, we found a prolific expression of the alpha 2C4 and alpha 2C2 subtypes. Expression of alpha 2C4 was found in all tissues with the exception of liver, fat, stomach, and colon, and a virtually ubiquitous expression of alpha 2C2 was found, with the exception of epicardium. Of all tissues studied, only colon and subcutaneous fat expressed a single alpha 2AR subtype, which was alpha 2C2. Thus, the alpha 2AR subtypes do not have a confined expression but

  9. DNA homologous recombination factor SFR1 physically and functionally interacts with estrogen receptor alpha.

    Directory of Open Access Journals (Sweden)

    Yuxin Feng

    Full Text Available Estrogen receptor alpha (ERα, a ligand-dependent transcription factor, mediates the expression of its target genes by interacting with corepressors and coactivators. Since the first cloning of SRC1, more than 280 nuclear receptor cofactors have been identified, which orchestrate target gene transcription. Aberrant activity of ER or its accessory proteins results in a number of diseases including breast cancer. Here we identified SFR1, a protein involved in DNA homologous recombination, as a novel binding partner of ERα. Initially isolated in a yeast two-hybrid screen, the interaction of SFR1 and ERα was confirmed in vivo by immunoprecipitation and mammalian one-hybrid assays. SFR1 co-localized with ERα in the nucleus, potentiated ER's ligand-dependent and ligand-independent transcriptional activity, and occupied the ER binding sites of its target gene promoters. Knockdown of SFR1 diminished ER's transcriptional activity. Manipulating SFR1 expression by knockdown and overexpression revealed a role for SFR1 in ER-dependent and -independent cancer cell proliferation. SFR1 differs from SRC1 by the lack of an intrinsic activation function. Taken together, we propose that SFR1 is a novel transcriptional modulator for ERα and a potential target in breast cancer therapy.

  10. Folate Receptor Targeted Alpha-Therapy Using Terbium-149

    CERN Document Server

    Müller, Cristina; Haller, Stephanie; Dorrer, Holger; Köster, Ulli; Johnston, Karl; Zhernosekov, Konstantin; Türler, Andreas; Schibli, Roger

    2014-01-01

    Terbium-149 is among the most interesting therapeutic nuclides for medical applications. It decays by emission of short-range α-particles (Eα = 3.967 MeV) with a half-life of 4.12 h. The goal of this study was to investigate the anticancer efficacy of a 149Tb-labeled DOTA-folate conjugate (cm09) using folate receptor (FR)-positive cancer cells in vitro and in tumor-bearing mice. 149Tb was produced at the ISOLDE facility at CERN. Radiolabeling of cm09 with purified 149Tb resulted in a specific activity of ~1.2 MBq/nmol. In vitro assays performed with 149Tb-cm09 revealed a reduced KB cell viability in a FR-specific and activity concentration-dependent manner. Tumor-bearing mice were injected with saline only (group A) or with 149Tb-cm09 (group B: 2.2 MBq; group C: 3.0 MBq). A significant tumor growth delay was found in treated animals resulting in an increased average survival time of mice which received 149Tb-cm09 (B: 30.5 d; C: 43 d) compared to untreated controls (A: 21 d). Analysis of blood parameters rev...

  11. Folate Receptor Targeted Alpha-Therapy Using Terbium-149

    Directory of Open Access Journals (Sweden)

    Cristina Müller

    2014-03-01

    Full Text Available Terbium-149 is among the most interesting therapeutic nuclides for medical applications. It decays by emission of short-range α-particles (Eα = 3.967 MeV with a half-life of 4.12 h. The goal of this study was to investigate the anticancer efficacy of a 149Tb-labeled DOTA-folate conjugate (cm09 using folate receptor (FR-positive cancer cells in vitro and in tumor-bearing mice. 149Tb was produced at the ISOLDE facility at CERN. Radiolabeling of cm09 with purified 149Tb resulted in a specific activity of ~1.2 MBq/nmol. In vitro assays performed with 149Tb-cm09 revealed a reduced KB cell viability in a FR-specific and activity concentration-dependent manner. Tumor-bearing mice were injected with saline only (group A or with 149Tb-cm09 (group B: 2.2 MBq; group C: 3.0 MBq. A significant tumor growth delay was found in treated animals resulting in an increased average survival time of mice which received 149Tb-cm09 (B: 30.5 d; C: 43 d compared to untreated controls (A: 21 d. Analysis of blood parameters revealed no signs of acute toxicity to the kidneys or liver in treated mice over the time of investigation. These results demonstrated the potential of folate-based α-radionuclide therapy in tumor-bearing mice.

  12. Integrin alphaVbeta6 is a high-affinity receptor for coxsackievirus A9.

    Science.gov (United States)

    Heikkilä, Outi; Susi, Petri; Stanway, Glyn; Hyypiä, Timo

    2009-01-01

    Coxsackievirus A9 (CAV9), a member of the genus Enterovirus in the family Picornaviridae, possesses an integrin-binding arginine-glycine-aspartic acid (RGD) motif in the C terminus of VP1 capsid protein. CAV9 has been shown to utilize integrins alphaVbeta3 and alphaVbeta6 as primary receptors for cell attachment. While CAV9 RGD-mutants (RGE and RGDdel) are capable of infecting rhabdomyosarcoma (RD) cell line, they grow very poorly in an epithelial lung carcinoma cell line (A549). In this study, the relationships between CAV9 infectivity in A549 and RD cells, receptor expression and integrin binding were analysed. A549 cells were shown to express both integrins alphaVbeta3 and alphaVbeta6, whereas alphaVbeta6 expression was not detected on the RD cells. Native CAV9 but not RGE and RGDdel mutants bound efficiently to immobilized alphaVbeta3 and alphaVbeta6. Adhesion of CAV9 but not RGE/RGDdel to A549 cells was also significantly higher than to RD cells. In contrast, no affinity or adhesion of bacterially produced VP1 proteins to the integrins or to the cells was detected. Function-blocking antibodies against alphaV-integrins blocked CAV9 but not CAV9-RGDdel infectivity, indicating that the viruses use different internalization routes; this may explain the differential infection kinetics of CAV9 and RGDdel. In an affinity assay, soluble alphaVbeta6, but not alphaVbeta3, bound to immobilized CAV9. Similarly, only soluble alphaVbeta6 blocked virus infectivity. These data suggest that CAV9 binding to alphaVbeta6 is a high-affinity interaction, which may indicate its importance in clinical infections; this remains to be determined.

  13. Intraperitoneal alpha-radioimmunotherapy in mice using different specific activities

    DEFF Research Database (Denmark)

    Elgqvist, Jörgen; Andersson, Håkan; Haglund, Elin;

    2009-01-01

    The aim of this study was to investigate the therapeutic efficacy of the alpha-radioimmunotherapy of ovarian cancer in mice, using different specific activities. This study was performed by using the monoclonal antibody, MX35 F(ab')(2), labeled with the alpha-particle-emitter, 211At.......The aim of this study was to investigate the therapeutic efficacy of the alpha-radioimmunotherapy of ovarian cancer in mice, using different specific activities. This study was performed by using the monoclonal antibody, MX35 F(ab')(2), labeled with the alpha-particle-emitter, 211At....

  14. Measurement of total alpha activity in water; Messung der Gesamt-Alpha-Aktivitaet in Wasser

    Energy Technology Data Exchange (ETDEWEB)

    Eikenberg, Jost [Paul Scherrer Institut (PSI), Villigen (Switzerland). Abt. fuer Strahlenschutz und Sicherheit; Florschuetz, Bernd [Hessisches Landesamt fuer Umwelt und Geologie, Kassel (Germany). Dezernat 15 - Strahlenschutz; Salvamoser, Josef [Institut fuer Angewandte Isotopen-, Gas- und Umweltuntersuchungen, Woerthsee (Germany); Steinkopff, Thomas [Deutscher Wetterdienst, Offenbach am Main (Germany); Wilhelm, Christoph [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Sicherheitsmanagement - Analytische Labore; Wisser, Sascha [FCI, Mainz (Germany)

    2014-04-01

    The article describes the measurement of the total alpha activity in an (evaporated) liquid sample, and the various sample preparation methods for measurements with proportional counters or LSC. (orig.)

  15. Distribution of alpha-amylase activity in selected broiler tissues.

    Science.gov (United States)

    Rodeheaver, D P; Wyatt, R D

    1986-02-01

    In an examination of broiler alpha-amylase, significant variation in the serum enzyme activity level was noted, adult levels were lower than those of young chicks. Analysis of alpha-amylase activity in various body fluids and tissues of 11-day and 7-week-old broilers indicated that the liver cannot be considered a source of alpha-amylase, although there was activity in both liver tissue and bile of 10 units/g wet weight and 35 units/100 ml, respectively. Fluid from the oral cavity had low levels of alpha-amylase activity, less than 100 units/100 ml, which decreased with age, indicating that the salivary glands may synthesize some alpha-amylase but are not a primary source. Sonication of the pancreatic homogenates was found to significantly increase the apparent activity of alpha-amylase 35-fold over unsonicated homogenates. The pancreas was the major source of alpha-amylase with activities ranging from 89 X 10(2) to 445 X 10(2) units/g wet weight. The level of activity increased with age of the bird. The electrophoretic zymograms of serum, liver, and pancreatic homogenates indicate a similar pancreatic origin for the alpha-amylase found in each tissue or fluid.

  16. Transcriptional co-activator PGC-1 alpha drives the formation of slow-twitch muscle fibres.

    Science.gov (United States)

    Lin, Jiandie; Wu, Hai; Tarr, Paul T; Zhang, Chen-Yu; Wu, Zhidan; Boss, Olivier; Michael, Laura F; Puigserver, Pere; Isotani, Eiji; Olson, Eric N; Lowell, Bradford B; Bassel-Duby, Rhonda; Spiegelman, Bruce M

    2002-08-15

    The biochemical basis for the regulation of fibre-type determination in skeletal muscle is not well understood. In addition to the expression of particular myofibrillar proteins, type I (slow-twitch) fibres are much higher in mitochondrial content and are more dependent on oxidative metabolism than type II (fast-twitch) fibres. We have previously identified a transcriptional co-activator, peroxisome-proliferator-activated receptor-gamma co-activator-1 (PGC-1 alpha), which is expressed in several tissues including brown fat and skeletal muscle, and that activates mitochondrial biogenesis and oxidative metabolism. We show here that PGC-1 alpha is expressed preferentially in muscle enriched in type I fibres. When PGC-1 alpha is expressed at physiological levels in transgenic mice driven by a muscle creatine kinase (MCK) promoter, a fibre type conversion is observed: muscles normally rich in type II fibres are redder and activate genes of mitochondrial oxidative metabolism. Notably, putative type II muscles from PGC-1 alpha transgenic mice also express proteins characteristic of type I fibres, such as troponin I (slow) and myoglobin, and show a much greater resistance to electrically stimulated fatigue. Using fibre-type-specific promoters, we show in cultured muscle cells that PGC-1 alpha activates transcription in cooperation with Mef2 proteins and serves as a target for calcineurin signalling, which has been implicated in slow fibre gene expression. These data indicate that PGC-1 alpha is a principal factor regulating muscle fibre type determination. PMID:12181572

  17. Identification of novel chicken estrogen receptor-alpha messenger ribonucleic acid isoforms generated by alternative splicing and promoter usage.

    Science.gov (United States)

    Griffin, C; Flouriot, G; Sonntag-Buck, V; Nestor, P; Gannon, F

    1998-11-01

    Using the rapid amplification of complementary DNA ends (RACE) methodology we have identified three new chicken estrogen receptor-alpha (cER alpha) messenger RNA (mRNA) variants in addition to the previously described form (isoform A). Whereas one of the new variants (isoform B) presents a 5'-extremity contiguous to the 5'-end of isoform A, the two other forms (isoforms C and D) are generated by alternative splicing of upstream exons (C and D) to a common site situated 70 nucleotides upstream of the translation start site in the previously assigned exon 1 (A). The 3'-end of exon 1C has been located at position -1334 upstream of the transcription start site of the A isoform (+1). Whereas the genomic location of exon 1D is unknown, 700 bp 5' to this exon were isolated by genomic walking, and their sequence was determined. The transcription start sites of the cER alpha mRNA isoforms were defined. In transfection experiments, the regions immediately upstream of the A-D cER alpha mRNA isoforms were shown to possess cell-specific promoter activities. Three of these promoters were down-regulated in the presence of estradiol and ER alpha protein. It is concluded, therefore, that the expression of the four different cER alpha mRNA isoforms is under the control of four different promoters. Finally, RT-PCR, S1 nuclease mapping, and primer extension analysis of these different cER alpha mRNA isoforms revealed a differential pattern of expression of the cER alpha gene in chicken tissues. Together, the results suggest that alternative 5'-splicing and promoter usage may be mechanisms used to modulate the levels of expression of the chicken ER alpha gene in a tissue-specific and/or developmental stage-specific manner. PMID:9794473

  18. The conjugated linoleic acid isomer trans-9,trans-11 is a dietary occurring agonist of liver X receptor {alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Ecker, Josef; Liebisch, Gerhard [Institute of Clinical Chemistry, University of Regensburg (Germany); Patsch, Wolfgang [Department of Laboratory Medicine, Hospital of Salzburg (Austria); Schmitz, Gerd, E-mail: gerd.schmitz@klinik.uni-regensburg.de [Institute of Clinical Chemistry, University of Regensburg (Germany)

    2009-10-30

    Conjugated linoleic acid (CLA) isomers are dietary fatty acids that modulate gene expression in many cell types. We have previously reported that specifically trans-9,trans-11 (t9,t11)-CLA induces expression of genes involved in lipid metabolism of human macrophages. To elucidate the molecular mechanism underlying this transcriptional activation, we asked whether t9,t11-CLA affects activity of liver X receptor (LXR) {alpha}, a major regulator of macrophage lipid metabolism. Here we show that t9,t11-CLA is a regulator of LXR{alpha}. We further demonstrate that the CLA isomer induces expression of direct LXR{alpha} target genes in human primary macrophages. Knockdown of LXR{alpha} with RNA interference in THP-1 cells inhibited t9,t11-CLA mediated activation of LXR{alpha} including its target genes. To evaluate the effective concentration range of t9,t11-CLA, human primary macrophages were treated with various doses of CLA and well known natural and synthetic LXR agonists and mRNA expression of ABCA1 and ABCG1 was analyzed. Incubation of human macrophages with 10 {mu}M t9,t11-CLA led to a significant modulation of ABCA1 and ABCG1 transcription and caused enhanced cholesterol efflux to high density lipoproteins and apolipoprotein AI. In summary, these data show that t9,t11-CLA is an agonist of LXR{alpha} in human macrophages and that its effects on macrophage lipid metabolism can be attributed to transcriptional regulations associated with this nuclear receptor.

  19. Evidence that the newly cloned low-density-lipoprotein receptor related protein (LRP) is the alpha 2-macroglobulin receptor

    DEFF Research Database (Denmark)

    Kristensen, T; Moestrup, Søren Kragh; Gliemann, Jørgen;

    1990-01-01

    these polypeptides, and analysis of a 1772 bp cDNA encoding part of the 500 kDa polypeptide provide evidence that the 500 kDa and 85 kDa chains are the alpha- and beta-subunits, respectively, of a recently cloned hepatic membrane protein, termed the low density lipoprotein receptor related protein (LRP) (Herz, J......The human placental receptor (alpha 2MR) for alpha 2-macroglobulin-proteinase complexes contains 3 polypeptides of approx. 500 kDa, 85 kDa, and 40 kDa. N-terminal sequence analysis of the 500 kDa and 85 kDa polypeptides, analysis of a random selection of peptides convering 536 residues from...

  20. Editing modifies the GABA(A) receptor subunit alpha3

    DEFF Research Database (Denmark)

    Ohlson, Johan; Pedersen, Jakob Skou; Haussler, David;

    2007-01-01

    to find selectively edited sites and combined it with bioinformatic techniques that find stem-loop structures suitable for editing. We present here the first verified editing candidate detected by this screening procedure. We show that Gabra-3, which codes for the alpha3 subunit of the GABA...

  1. The insulin receptor activation process involves localized conformational changes.

    Science.gov (United States)

    Baron, V; Kaliman, P; Gautier, N; Van Obberghen, E

    1992-11-15

    The molecular process by which insulin binding to the receptor alpha-subunit induces activation of the receptor beta-subunit with ensuing substrate phosphorylation remains unclear. In this study, we aimed at approaching this molecular mechanism of signal transduction and at delineating the cytoplasmic domains implied in this process. To do this, we used antipeptide antibodies to the following sequences of the receptor beta-subunit: (i) positions 962-972 in the juxtamembrane domain, (ii) positions 1247-1261 at the end of the kinase domain, and (iii) positions 1294-1317 and (iv) positions 1309-1326, both in the receptor C terminus. We have previously shown that insulin binding to its receptor induces a conformational change in the beta-subunit C terminus. Here, we demonstrate that receptor autophosphorylation induces an additional conformational change. This process appears to be distinct from the one produced by ligand binding and can be detected in at least three different beta-subunit regions: the juxtamembrane domain, the kinase domain, and the C terminus. Hence, the cytoplasmic part of the receptor beta-subunit appears to undergo an extended conformational change upon autophosphorylation. By contrast, the insulin-induced change does not affect the juxtamembrane domain 962-972 nor the kinase domain 1247-1261 and may be limited to the receptor C terminus. Further, we show that the hormone-dependent conformational change is maintained in a kinase-deficient receptor due to a mutation at lysine 1018. Therefore, during receptor activation, the ligand-induced change could precede ATP binding and receptor autophosphorylation. We propose that insulin binding leads to a transient receptor form that may allow ATP binding and, subsequently, autophosphorylation. The second conformational change could unmask substrate-binding sites and stabilize the receptor in an active conformation. PMID:1331080

  2. Ischemia- and agonist-induced changes in. alpha. - and. beta. -adrenergic receptor traffic in guinea pig hearts

    Energy Technology Data Exchange (ETDEWEB)

    Maisel, A.S.; Motulsky, H.J.; Ziegler, M.G.; Insel, P.A. (Univ. of California, La Jolla (USA))

    1987-11-01

    The authors have used radioligand binding techniques and subcellular fraction to assess whether changes in expression of myocardial {alpha}{sub 1}- and {beta}-adrenergic receptors are mediated by a redistribution of receptors between various membrane fractions. Three fractions were prepared from the left ventricles of guinea pigs that underwent either 1 h of ischemia or injection of epinephrine a crude membrane, a purified sarcolemma, and a light vesicle fraction. In control animals {alpha}{sub 1}-adrenergic receptors (({sup 3}H)prazosin binding) in light vesicles was only 25% of the total {alpha}{sub 1}-receptor density found in sarcolemmal and light vesicle fractions as compared with 50% for {beta}-adrenergic receptors (({sup 125}I)iodocyanopindolol binding sites). Although ischemia was associated with a 53% decrease in the number of light vesicle {beta}-adrenergic receptors and a 42% increase in the number of sarcolemma {beta}-receptors there was no change in the number of light vesicle {alpha}{sub 1}-receptors, even though the number of sarcolemmal {alpha}{sub 1}-receptors increased 34%. Epinephrine treatment promoted internalization of {beta}-adrenergic receptors. These results indicate that {alpha}{sub 1} and {beta}{sub 1}-adrenergic receptors may undergo a different cellular itinerary in guinea pig myocardium. Agonist and ischemia-induced changes in surface {beta}-receptors, but not {alpha}{sub 1}-receptors, appear to result from entry and exit of receptors from an intracellular pool that can be isolated in a light vesicle fraction. Changes in expression of {alpha}{sub 1}-adrenergic receptors may represent changes in the properties of receptors found in the sarcolemma or in a membrane fraction other than the light vesicle fraction that they have isolated.

  3. Effects of central imidazolinergic and alpha2-adrenergic activation on water intake

    Directory of Open Access Journals (Sweden)

    Sugawara A.M.

    2001-01-01

    Full Text Available Non-adrenergic ligands that bind to imidazoline receptors (I-R, a selective ligand that binds to alpha2-adrenoceptors (alpha2-AR and mixed ligands that bind to both receptors were tested for their action on water intake behavior of 24-h water-deprived rats. All drugs were injected into the third cerebral ventricle. Except for agmatine (80 nmol, mixed ligands binding to I-R/alpha2-AR such as guanabenz (40 nmol and UK 14304 (20 nmol inhibited water intake by 65% and up to 95%, respectively. The selective non-imidazoline alpha2-AR agonist, alpha-methylnoradrenaline, produced inhibition of water intake similar to that obtained with guanabenz, but at higher doses (80 nmol. The non-adrenergic I-R ligands histamine (160 nmol, mixed histaminergic and imidazoline ligand and imidazole-4-acetic acid (80 nmol, imidazoline ligand did not alter water intake. The results show that selective, non-imidazoline alpha2-AR activation suppresses water intake, and suggest that the action on imidazoline sites by non-adrenergic ligands is not sufficient to inhibit water intake.

  4. Ubiquitin/proteasome pathway regulates levels of retinoic acid receptor gamma and retinoid X receptor alpha in human keratinocytes.

    Science.gov (United States)

    Boudjelal, M; Wang, Z; Voorhees, J J; Fisher, G J

    2000-04-15

    Repeated exposure of human skin to solar UV radiation leads to premature aging (photoaging) and skin cancer. UV-induced skin damage can be ameliorated by all-trans retinoic acid treatment. The actions of retinoic acid in skin keratinocytes are mediated primarily by nuclear retinoic acid receptor gamma (RARgamma) and retinoid X receptor alpha (RXRalpha). We found that exposure of cultured primary human keratinocytes to UV irradiation (30 mJ/cm2) substantially reduced (50-90%) RARgamma and RXRalpha mRNA and protein within 8 h. The rates of disappearance of RARgamma and RXRalpha proteins after UV exposure or treatment with the protein synthesis inhibitor cycloheximide were similar. UV irradiation did not increase the rate of breakdown of RARgamma or RXRalpha but rather reduced their rate of synthesis. The addition of proteasome inhibitors MG132 and LLvL, but not the lysosomal inhibitor E64, prevented loss of RARgamma and RXRalpha proteins after exposure of keratinocytes to either UV radiation or cycloheximide. Soluble extracts from nonirradiated or UV-irradiated keratinocytes possessed similar levels of proteasome activity that degraded RARgamma and RXRalpha proteins in vitro. Furthermore, RARgamma and RXRalpha were polyubiquitinated in intact cells. RXRalpha was found to contain two proline, glutamate/aspartate, serine, and threonine (PEST) motifs, which confer rapid turnover of many short-lived regulatory proteins that are degraded by the ubiquitin/proteasome pathway. However, the PEST motifs in RXRalpha did not function to regulate its stability, because deletion of the PEST motifs individually or together did not alter ubiquitination or proteasome-mediated degradation of RXRalpha. These results demonstrate that loss of RARgamma and RXRalpha proteins after UV irradiation results from degradation via the ubiquitin/proteasome pathway. Taken together, the data here indicate that ubiquitin/proteasome-mediated breakdown is an important mechanism regulating the levels of

  5. Affinity purification of human granulocyte macrophage colony-stimulating factor receptor alpha-chain. Demonstration of binding by photoaffinity labeling

    International Nuclear Information System (INIS)

    The human granulocyte macrophage colony-stimulating factor (GM-CSF) receptor alpha-chain, a low affinity component of the receptor, was solubilized and affinity-purified from human placenta using biotinylated GM-CSF. Scatchard analysis of 125I-GM-CSF binding to the placental membrane extract disclosed that the GM-CSF receptor had a dissociation constant (Kd) of 0.5-0.8 nM, corresponding to the Kd value of the GM-CSF receptor alpha-chain on the intact placental membrane. Affinity labeling of the solubilized protein using a photoreactive cross-linking agent, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB), demonstrated a single specific band of 70-95 kDa representing a ligand-receptor complex. Approximately 2 g of the placental membrane extract was subjected to a biotinylated GM-CSF-fixed streptavidin-agarose column, resulting in a single major band at 70 kDa on a silver-stained sodium dodecyl sulfate gel. The radioiodination for the purified material disclosed that the purified protein had an approximate molecular mass of 70 kDa and a pI of 6.6. Binding activity of the purified material was demonstrated by photoaffinity labeling using HSAB-125I-GM-CSF, producing a similar specific band at 70-95 kDa as was demonstrated for the crude protein

  6. Affinity purification of human granulocyte macrophage colony-stimulating factor receptor alpha-chain. Demonstration of binding by photoaffinity labeling

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, S.; Shibuya, K.; Miyazono, K.; Tojo, A.; Oka, Y.; Miyagawa, K.; Takaku, F. (Univ. of Tokyo (Japan))

    1990-11-15

    The human granulocyte macrophage colony-stimulating factor (GM-CSF) receptor alpha-chain, a low affinity component of the receptor, was solubilized and affinity-purified from human placenta using biotinylated GM-CSF. Scatchard analysis of {sup 125}I-GM-CSF binding to the placental membrane extract disclosed that the GM-CSF receptor had a dissociation constant (Kd) of 0.5-0.8 nM, corresponding to the Kd value of the GM-CSF receptor alpha-chain on the intact placental membrane. Affinity labeling of the solubilized protein using a photoreactive cross-linking agent, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB), demonstrated a single specific band of 70-95 kDa representing a ligand-receptor complex. Approximately 2 g of the placental membrane extract was subjected to a biotinylated GM-CSF-fixed streptavidin-agarose column, resulting in a single major band at 70 kDa on a silver-stained sodium dodecyl sulfate gel. The radioiodination for the purified material disclosed that the purified protein had an approximate molecular mass of 70 kDa and a pI of 6.6. Binding activity of the purified material was demonstrated by photoaffinity labeling using HSAB-{sup 125}I-GM-CSF, producing a similar specific band at 70-95 kDa as was demonstrated for the crude protein.

  7. Preliminary Molecular Dynamic Simulations of the Estrogen Receptor Alpha Ligand Binding Domain from Antagonist to Apo

    Directory of Open Access Journals (Sweden)

    Adrian E. Roitberg

    2008-06-01

    Full Text Available Estrogen receptors (ER are known as nuclear receptors. They exist in the cytoplasm of human cells and serves as a DNA binding transcription factor that regulates gene expression. However the estrogen receptor also has additional functions independent of DNA binding. The human estrogen receptor comes in two forms, alpha and beta. This work focuses on the alpha form of the estrogen receptor. The ERα is found in breast cancer cells, ovarian stroma cells, endometrium, and the hypothalamus. It has been suggested that exposure to DDE, a metabolite of DDT, and other pesticides causes conformational changes in the estrogen receptor. Before examining these factors, this work examines the protein unfolding from the antagonist form found in the 3ERT PDB crystal structure. The 3ERT PDB crystal structure has the estrogen receptor bound to the cancer drug 4-hydroxytamoxifen. The 4-hydroxytamoxifen ligand was extracted before the simulation, resulting in new conformational freedom due to absence of van der Waals contacts between the ligand and the receptor. The conformational changes that result expose the binding clef of the co peptide beside Helix 12 of the receptor forming an apo conformation. Two key conformations in the loops at either end of the H12 are produced resulting in the antagonist to apo conformation transformation. The results were produced over a 42ns Molecular Dynamics simulation using the AMBER FF99SB force field.

  8. Altered hepatic vasopressin and alpha 1-adrenergic receptors after chronic endotoxin infusion

    Energy Technology Data Exchange (ETDEWEB)

    Roth, B.L.; Spitzer, J.A.

    1987-05-01

    Sepsis and septic shock are complicated by a number of hemodynamic and metabolic aberrations. These include catecholamine refractoriness and altered glucose metabolism. Recently, a nonshock rat model of continuous endotoxin infusion via an implanted osmotic pump was developed that reproduces some of the metabolic and cardiovascular findings of human sepsis. By using this model, we have found a decreased number of hepatic plasma membrane alpha 1-adrenergic and (Arg8)vasopressin receptors in rats continuously infused with endotoxin. There was a significant decrease in (/sup 3/H)prazosin (35 +/- 7%) and (/sup 3/H) (Arg8)vasopressin (43 +/- 8%) receptors after 30 h of continuous endotoxin infusion with no change in affinity. The ability of norepinephrine to form the high-affinity complex with alpha 1-adrenergic receptors was not altered after chronic endotoxin infusion. The results are consistent with the concept that alterations in receptor number might underlie certain of the metabolic consequences of chronic sepsis.

  9. Dioxin increases the interaction between aryl hydrocarbon receptor and estrogen receptor alpha at human promoters

    DEFF Research Database (Denmark)

    Ahmed, Shaaima; Valen, Eivind; Sandelin, Albin Gustav;

    2009-01-01

    genes with little knowledge of what was occurring at other genomic regions. In this study, we showed using chromatin immunoprecipitation followed by hybridization to promoter focused microarrays (ChIP-chip) that 2,3,7,8-tetrachlorodibenzo-p-dioxin treatment significantly increased the overlap of genomic......Recent studies have shown that activated aryl hydrocarbon receptor (AHR) induced the recruitment of estrogen receptor- (ER ) to AHR-regulated genes and that AHR is recruited to ER -regulated genes. However, these findings were limited to a small number of well-characterized AHR- or ER -responsive...... of ER to AHR target genes but also that AHR is recruited to estrogen-responsive regions in a gene-specific manner, suggesting that AHR utilizes both of these mechanisms to modulate estrogen-dependent signaling....

  10. Evaluation of 7 {alpha}-O-IADPN as a new potential SPECT opioid receptor imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R.F.; Mao, S.Y. [Fujian Medical College, Fuzhou (China). Dept. of Nuclear Medicine; Tafani, J.A.M.; Coulais, Y.; Guiraud, R. [Hospital Purpan, Toulouse (France). Service Central de medicine Nucleaire; Zajac, J.M. [LPTF-CNRS, Toulouse (France)

    1998-03-01

    Full text: A new iodinated diprenorphine antagonist analogue, [{sup 123}I]7 {alpha}.-O-IADPN, [E] - 17-(cyclopropylmethyl) -4,5 (x-epoxy- 18,19-dihydro-3-hydroxy-6-methoxy-7 {alpha}-[1-(3-iodoallyl)oxy-1-methylethyl]-6,14-endo-ethenomorphinan for in vivo and in vitro studies as a potential central nervous system (CNS) opioid receptor imaging agent was developed. In vivo biodistribution and metabolism of 7 {alpha}-O-lADPN in rat demonstrated that 0.16% of the iodinated compound was presented in mouse brain with a degradation-resistant at the first 60 min, and that 36% of the total cerebral radioactivity and 63% of its specific binding to opioid receptors were observed 20 min after i.v. injection. The cerebral radioactivity in mouse brain concentrated in the basal ganglion and cortex, and displayed a remarkably high target-to-non-target ratio (cortex/cerebellum = 60 min post-injection). The in vitro binding studies showed that [{sup 123}I]7 {alpha}-O-IADPN binds non selectively to multiple opioid receptors {mu} = 8 K) with a very high affinity (Ki = 0.4 + 0.2 nM). Ex vivo autoradiography results in mouse further confirmed the high uptake and retention of this agent in basal ganglion region and cortex. The planar imaging of monkey brains after i.v. injection of [{sup 123}I]7 {alpha}-O-IADPN clearly displayed that multiple opioid receptors can be visualized. With the excellent in vitro affinity and in vivo stability to deiodination and high target-to-nontarget ratio, [{sup 123}I]7 {alpha}- O-IADPN appears to be useful as a CNS opioid receptor imaging probe for SPECT in primate and non-primate.

  11. Dynamic expression of alpha 1 beta 1 and alpha 2 beta 1 integrin receptors by human vascular smooth muscle cells. Alpha 2 beta 1 integrin is required for chemotaxis across type I collagen-coated membranes.

    OpenAIRE

    Skinner, M P; Raines, E W; Ross, R.

    1994-01-01

    Vascular smooth muscle cells (SMCs) in the media of normal arteries express alpha 1 beta 1 integrin with no detectable alpha 2 beta 1 as determined by immunocytochemistry. In contrast, immunoprecipitation of integrins expressed by human SMCs cultured from medial explants shows strong expression of alpha 2 beta 1 and no expression of alpha 1 beta 1. The apparent reciprocal expression of these two collagen and laminin receptors was confirmed by flow cytometric analysis of fluorescent labeled ce...

  12. Suppression of estrogen receptor-alpha transactivation by thyroid transcription factor-2 in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eunsook; Gong, Eun-Yeung [Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Romanelli, Maria Grazia [Department of Life and Reproduction Sciences, University of Verona, Strada le Grazie 8, 37134 Verona (Italy); Lee, Keesook, E-mail: klee@chonnam.ac.kr [Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757 (Korea, Republic of)

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer TTF-2 was expressed in mammary glands and breast cancer cells. Black-Right-Pointing-Pointer TTF-2 repressed ER{alpha} transactivation. Black-Right-Pointing-Pointer TTF-2 inhibited the proliferation of breast cancer cells. -- Abstract: Estrogen receptors (ERs), which mediate estrogen actions, regulate cell growth and differentiation of a variety of normal tissues and hormone-responsive tumors through interaction with cellular factors. In this study, we show that thyroid transcription factor-2 (TTF-2) is expressed in mammary gland and acts as ER{alpha} co-repressor. TTF-2 inhibited ER{alpha} transactivation in a dose-dependent manner in MCF-7 breast cancer cells. In addition, TTF-2 directly bound to and formed a complex with ER{alpha}, colocalizing with ER{alpha} in the nucleus. In MCF-7/TTF-2 stable cell lines, TTF-2 repressed the expression of endogenous ER{alpha} target genes such as pS2 and cyclin D1 by interrupting ER{alpha} binding to target promoters and also significantly decreased cell proliferation. Taken together, these data suggest that TTF-2 may modulate the function of ER{alpha} as a corepressor and play a role in ER-dependent proliferation of mammary cells.

  13. Interactions between the cyclic AMP receptor protein and the alpha subunit of RNA polymerase at the Escherichia coli galactose operon P1 promoter.

    Science.gov (United States)

    Attey, A; Belyaeva, T; Savery, N; Hoggett, J; Fujita, N; Ishihama, A; Busby, S

    1994-10-25

    DNAase I footprinting has been used to study open complexes between Escherichia coli RNA polymerase and the galactose operon P1 promoter, both in the absence and the presence of CRP (the cyclic AMP receptor protein, a transcription activator). From the effects of deletion of the C-terminal part of the RNA polymerase alpha subunit, we deduce that alpha binds at the upstream end of both the binary RNA polymerase-galP1 and ternary RNA polymerase-CRP-galP1 complexes. Disruption of the alpha-upstream contact suppresses open complex formation at galP1 at lower temperatures. In ternary RNA polymerase-CRP-galP1 complexes, alpha appears to make direct contact with Activating Region 1 in CRP. DNAase I footprinting has been used to detect and quantify interactions between purified alpha and CRP bound at galP1. PMID:7971267

  14. Molecular cloning, characterisation, and tissue distribution of oestrogen receptor alpha in eelpout (Zoarces viviparus)

    DEFF Research Database (Denmark)

    Andreassen, Thomas K; Skjødt, Karsten; Anglade, Isabelle;

    2003-01-01

    A cDNA encoding the eelpout (Zoarces viviparus) oestrogen receptor alpha (eERalpha) has been isolated from eelpout liver, cloned and sequenced. The cDNA contains a complete open reading frame encoding 570 amino acid residues (mw: 63.0 kDa). The amino acid sequence of eERalpha showed a high degree...

  15. Estrogen receptor-alpha-immunoreactive neurons in the periaqueductal gray of the adult ovariectomized female cat

    NARCIS (Netherlands)

    VanderHorst, Veronique G.J.M.; Meijer, Ellie; Schasfoort, Fabienne C.; Leeuwen, Fred van; Holstege, Gert

    1998-01-01

    Anatomical and physiological studies in rodent and cat have shown that distinct parts of the midbrain periaqueductal gray (FAG) are important for the estrogen dependent, female reproductive behavior. The present study gives a detailed overview of the estrogen receptor-alpha-immunoreactive (ER-IR) ne

  16. Height in pre- and postmenopausal women is influenced by estrogen receptor alpha gene polymorphisms

    NARCIS (Netherlands)

    J.B.J. van Meurs (Joyce); A.P. Bergink (Arjan); M. van de Klift (Marjolein); Y. Fang (Yue); G. Leusink (Geraline); A.G. Uitterlinden (André); H.A.P. Pols (Huib); J.P.T.M. van Leeuwen (Hans); S.C.E. Schuit (Stephanie); A. Hofman (Albert)

    2004-01-01

    textabstractThe estrogen receptor alpha gene (ESR1) is known to be involved in metabolic pathways influencing growth. We have performed two population-based association studies using three common polymorphisms within this candidate gene to determine whether these are associated with variation in adu

  17. Blood pressure in patients with primary aldosteronism is influenced by bradykinin B(2) receptor and alpha-adducin gene polymorphisms.

    Science.gov (United States)

    Mulatero, Paolo; Williams, Tracy A; Milan, Alberto; Paglieri, Cristina; Rabbia, Franco; Fallo, Francesco; Veglio, Franco

    2002-07-01

    Primary aldosteronism (PA) is the most common cause of endocrine hypertension. PA is most frequently presented as moderate to severe hypertension, but the clinical and biochemical features vary widely. The aim of our study was to identify genetic variants that influence the phenotype of patients with PA. We hypothesized that genetic variants potentially affecting aldosterone production (aldosterone synthase, CYP11B2), renal proximal tubule reabsorption (alpha-adducin), or the mechanisms of counterbalance leading to vasodilatation and sodium excretion (bradykinin B(2)-receptor, B(2)R) could influence the clinical and biochemical characteristics of patients with PA. We studied three polymorphisms of these genes (C-344T of CYP11B2, G460W of alpha-adducin, and C-58T of B(2)R) in 167 primary aldosteronism patients (56 with aldosterone-producing adenoma and 111 with idiopathic hyperaldosteronism). B(2)R and alpha-adducin genotypes were strong independent predictors of both systolic and diastolic blood pressure levels; plasma renin activity and aldosterone also play a marginal role on BP levels. Body mass index, age, sex, and CYP11B2 genotype displayed no significant effect on the clinical parameters of our population. In particular, alpha-adducin and B(2)R polymorphisms accounted for 13.2% and 11.0% of the systolic and diastolic blood pressure variance, respectively. These data suggest that genetic variants of alpha-adducin and the bradykinin B(2)-R influence the blood pressure levels in patients with primary aldosteronism. PMID:12107246

  18. Genomics of signaling crosstalk of estrogen receptor alpha in breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Peter Dudek

    Full Text Available BACKGROUND: The estrogen receptor alpha (ERalpha is a ligand-regulated transcription factor. However, a wide variety of other extracellular signals can activate ERalpha in the absence of estrogen. The impact of these alternate modes of activation on gene expression profiles has not been characterized. METHODOLOGY/PRINCIPAL FINDINGS: We show that estrogen, growth factors and cAMP elicit surprisingly distinct ERalpha-dependent transcriptional responses in human MCF7 breast cancer cells. In response to growth factors and cAMP, ERalpha primarily activates and represses genes, respectively. The combined treatments with the anti-estrogen tamoxifen and cAMP or growth factors regulate yet other sets of genes. In many cases, tamoxifen is perverted to an agonist, potentially mimicking what is happening in certain tamoxifen-resistant breast tumors and emphasizing the importance of the cellular signaling environment. Using a computational analysis, we predicted that a Hox protein might be involved in mediating such combinatorial effects, and then confirmed it experimentally. Although both tamoxifen and cAMP block the proliferation of MCF7 cells, their combined application stimulates it, and this can be blocked with a dominant-negative Hox mutant. CONCLUSIONS/SIGNIFICANCE: The activating signal dictates both target gene selection and regulation by ERalpha, and this has consequences on global gene expression patterns that may be relevant to understanding the progression of ERalpha-dependent carcinomas.

  19. Omega-3 fatty acid deficient male rats exhibit abnormal behavioral activation in the forced swim test following chronic fluoxetine treatment: association with altered 5-HT1A and alpha2A adrenergic receptor expression.

    Science.gov (United States)

    Able, Jessica A; Liu, Yanhong; Jandacek, Ronald; Rider, Therese; Tso, Patrick; McNamara, Robert K

    2014-03-01

    Omega-3 fatty acid deficiency during development leads to enduing alterations in central monoamine neurotransmission in rat brain. Here we investigated the effects of omega-3 fatty acid deficiency on behavioral and neurochemical responses to chronic fluoxetine (FLX) treatment. Male rats were fed diets with (CON, n = 34) or without (DEF, n = 30) the omega-3 fatty acid precursor alpha-linolenic acid (ALA) during peri-adolescent development (P21-P90). A subset of CON (n = 14) and DEF (n = 12) rats were administered FLX (10 mg/kg/d) through their drinking water for 30 d beginning on P60. The forced swimming test (FST) was initiated on P90, and regional brain mRNA markers of serotonin and noradrenaline neurotransmission were determined. Dietary ALA depletion led to significant reductions in frontal cortex docosahexaenoic acid (DHA, 22:6n-3) composition in DEF (-26%, p = 0.0001) and DEF + FLX (-32%, p = 0.0001) rats. Plasma FLX and norfluoxetine concentrations did not different between FLX-treated DEF and CON rats. During the 15-min FST pretest, DEF + FLX rats exhibited significantly greater climbing behavior compared with CON + FLX rats. During the 5-min test trial, FLX treatment reduced immobility and increased swimming in CON and DEF rats, and only DEF + FLX rats exhibited significant elevations in climbing behavior. DEF + FLX rats exhibited greater midbrain, and lower frontal cortex, 5-HT1A mRNA expression compared with all groups including CON + FLX rats. DEF + FLX rats also exhibited greater midbrain alpha2A adrenergic receptor mRNA expression which was positively correlated with climbing behavior in the FST. These preclinical data demonstrate that low omega-3 fatty acid status leads to abnormal behavioral and neurochemical responses to chronic FLX treatment in male rats.

  20. Chapter 8. Activation mechanisms of chemokine receptors

    DEFF Research Database (Denmark)

    Jensen, Pia C; Rosenkilde, Mette M

    2009-01-01

    Chemokine receptors belong to the large family of 7-transmembrane (7TM) G-protein-coupled receptors. These receptors are targeted and activated by a variety of different ligands, indicating that activation is a result of similar molecular mechanisms but not necessarily similar modes of ligand bin...

  1. Mechanism for the activation of glutamate receptors

    Science.gov (United States)

    Scientists at the NIH have used a technique called cryo-electron microscopy to determine a molecular mechanism for the activation and desensitization of ionotropic glutamate receptors, a prominent class of neurotransmitter receptors in the brain and spina

  2. Interactions between the cyclic AMP receptor protein and the alpha subunit of RNA polymerase at the Escherichia coli galactose operon P1 promoter.

    OpenAIRE

    Attey, A; Belyaeva, T; Savery, N; Hoggett, J; Fujita, N; Ishihama, A; Busby, S

    1994-01-01

    DNAase I footprinting has been used to study open complexes between Escherichia coli RNA polymerase and the galactose operon P1 promoter, both in the absence and the presence of CRP (the cyclic AMP receptor protein, a transcription activator). From the effects of deletion of the C-terminal part of the RNA polymerase alpha subunit, we deduce that alpha binds at the upstream end of both the binary RNA polymerase-galP1 and ternary RNA polymerase-CRP-galP1 complexes. Disruption of the alpha-upstr...

  3. Induction of experimental autoimmune encephalomyelitis in C57BL/6 mice deficient in either the chemokine macrophage inflammatory protein-1alpha or its CCR5 receptor

    DEFF Research Database (Denmark)

    Tran, E H; Kuziel, W A; Owens, T

    2000-01-01

    and its CCR5 receptor in the induction of EAE by immunizing C57BL / 6 mice deficient in either MIP-1alpha or CCR5 with myelin oligodendrocyte glycoprotein (MOG). We found that MIP-1alpha-deficient mice were fully susceptible to MOG-induced EAE. These knockout animals were indistinguishable from wild...... chemoattractant protein-1, MIP-1beta, MIP-2, lymphotactin and T cell activation gene-3 during the course of the disease. CCR5-deficient mice were also susceptible to disease induction by MOG. The dispensability of MIP-1alpha and CCR5 for MOG-induced EAE in C57BL / 6 mice supports the idea that differential...

  4. The association between the melanocyte-stimulating hormone receptor and the alpha 2-adrenoceptor on the Anolis melanophore.

    OpenAIRE

    Carter, R J; Shuster, S.

    1982-01-01

    1 The primary effect of catecholamines was to lighten Anolis skin previously darkened by alpha-melanocyte-stimulating hormone (alpha-MSH). In concentrations above 10(-7) M noradrenaline, 10(-6) M adrenaline and 10(-5) dopamine, darkening of subpopulations of melanophores occurred. Subsequent experiments were concerned with the effect of low catecholamine concentrations on alpha-MSH action. 2 The relationship between MSH receptors and alpha-adrenoceptors on the Anolis melanophore was studied b...

  5. An angiotensin II type 1 receptor activation switch patch revealed through evolutionary trace analysis

    DEFF Research Database (Denmark)

    Bonde, Marie Mi; Yao, Rong; Ma, Jian-Nong;

    2010-01-01

    Seven transmembrane (7TM) or G protein-coupled receptors constitute a large superfamily of cell surface receptors sharing a structural motif of seven transmembrane spanning alpha helices. Their activation mechanism most likely involves concerted movements of the transmembrane helices, but remains...

  6. An Angiotensin II type 1 receptor activation switch patch revealed through Evolutionary Trace analysis

    DEFF Research Database (Denmark)

    Bonde, Marie Mi; Yao, Rong; Ma, Jian-Nong;

    2010-01-01

    Seven transmembrane (7TM) or G protein-coupled receptors constitute a large superfamily of cell surface receptors sharing a structural motif of seven transmembrane spanning alpha helices. Their activation mechanism most likely involves concerted movements of the transmembrane helices, but remains...

  7. 8-[2-(2-pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid stimulates GABA release from interneurons projecting to CA1 pyramidal neurons in the rat hippocampus via pre-synaptic alpha7 acetylcholine receptors.

    Science.gov (United States)

    Kanno, Takeshi; Yaguchi, Takahiro; Yamamoto, Satoshi; Yamamoto, Hideyuki; Fujikawa, Hirokazu; Nagata, Tetsu; Tanaka, Akito; Nishizaki, Tomoyuki

    2005-11-01

    Nicotinic acetylcholine (ACh) receptors, such as alpha7, alpha3beta4 and alpha4beta2 receptors in the hippocampus, are suggested to modulate neurotransmitter release. 8-[2-(2-Pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA) (100 nM), a linoleic acid derivative, potentiated responses of alpha7, alpha3beta4 and alpha4beta2 ACh receptors expressed in Xenopus oocytes that are blocked by 3-(1-[dimethylaminopropyl] indol-3-yl)-4-[indol-3-yl] maleimide (GF109203X), a selective inhibitor of protein kinase C (PKC), except for alpha3beta4 ACh receptors. DCP-LA enhanced the nicotine-triggered release of GABA from rat hippocampal slices in the presence of tetrodotoxin in a bell-shaped dose-dependent manner at concentrations ranging from 10 nM to 10 microM, although DCP-LA by itself had no effect on GABA release. The DCP-LA action was inhibited by GF109203X or alpha-bungarotoxin, an inhibitor of alpha7 ACh receptors, but not by mecamylamine or dihydro-beta-erithroidine, an inhibitor of alpha3beta4 and alpha4beta2 ACh receptors. A similar effect on GABA release was obtained with 12-O-tetradecanoylphorbol 13-acetate, a PKC activator. DCP-LA (100 nM) also enhanced GABA release triggered by choline, an agonist of alpha7 ACh receptors, but not 3-[2(s)-azetidinylmethoxy] pyridine, an agonist of alpha4beta2 ACh receptors. In addition, DCP-LA (100 nM) increased the rate of nicotine-triggered GABA(A) receptor-mediated miniature inhibitory post-synaptic currents, monitored from CA1 pyramidal neurons of rat hippocampal slices, and the effect was also inhibited by GF109203X or alpha-bungarotoxin but not by mecamylamine. Thus, the results of the present study indicate that DCP-LA stimulates GABA release by enhancing activity of pre-synaptic alpha7 ACh receptors present on the GABAergic terminals of interneurons that transmit to CA1 pyramidal neurons via a PKC pathway. PMID:16248884

  8. Characterization of the retina in the alpha7 nicotinic acetylcholine receptor knockout mouse

    Science.gov (United States)

    Smith, Marci L.

    Acetylcholine receptors (AChRs) are involved in visual processing and are expressed by inner retinal neurons in all species studied to date (Keyser et al., 2000; Dmitrieva et al., 2007; Liu et al., 2009), but their distribution in the mouse retina remains unknown. Reductions in alpha7 nicotinic AChRs (nAChRs) are thought to contribute to memory and visual deficits observed in Alzheimer's and schizophrenia (Coyle et al., 1983; Nordberg et al., 1999; Leonard et al., 2006). However, the alpha7 nAChR knockout (KO) mouse has a mild phenotype (Paylor et al., 1998; Fernandes et al., 2006; Young et al., 2007; Origlia et al., 2012). The purpose of this study was to determine the expression of AChRs in wildtype (WT) mouse retina and to assess whether up-regulation of other AChRs in the alpha7 nAChR KO retina may explain the minimal deficits described in the KO mouse. Reverse-transcriptase PCR (RT-PCR) showed that mRNA transcripts for alpha2-7, alpha 9, alpha10, beta2-4 nAChR subunits and m1-m5 muscarinic AChR (mAChR) subtypes were present in WT murine retina. Western blot analysis confirmed the presence of alpha3-5, alpha9, and m1-m5 AChR proteins and immunohistochemical analysis demonstrated nAChR and mAChR proteins expressed by subsets of bipolar, amacrine and ganglion cells. This is the first reported expression of alpha9 and alpha10 nAChR transcripts and alpha9 nAChR proteins in the retina of any species. Quantitative RT-PCR (qPCR) showed changes in AChR transcript expression in the alpha7 nAChR KO mouse retina relative to WT. Within whole retina alpha2, alpha9, alpha10, beta4, m1 and m4 AChR transcripts were up-regulated, while alpha5 nAChR transcripts were down-regulated. However, cell populations showed subtle differences; m4 mAChR transcripts were up-regulated in the ganglion cell layer and outer portion of the inner nuclear layer (oINL),while beta4 nAChR transcript up-regulation was limited to the oINL. Surprisingly, alpha2, alpha9, beta4, m2 and m4 transcripts were

  9. Effect of extracellular pH on recombinant alpha1beta2gamma2 and alpha1beta2 GABAA receptors.

    Science.gov (United States)

    Mercik, Katarzyna; Pytel, Maria; Cherubini, Enrico; Mozrzymas, Jerzy W

    2006-08-01

    Recently, we have reported that extracellular protons allosterically modulated neuronal GABA(A) receptors [Mozrzymas, J.W., Zarnowska, E.D., Pytel, M., Mercik, K., 2003a. Modulation of GABA(A) receptors by hydrogen ions reveals synaptic GABA transient and a crucial role of desensitiztion process. Journal of Neuroscience 23, 7981-7992]. However, GABAARs in neurons are heterogeneous and the effect of hydrogen ions depends on the receptor subtype. In particular, gamma2 subunit sets the receptor sensibility to several modulators including protons. However, the mechanisms whereby protons modulate gamma2-containing and gamma2-free GABAARs have not been fully elucidated. To this end, current responses to ultrafast GABA applications were recorded for alpha1beta2gamma2 and alpha1beta2 receptors at different pH values. For both receptor types, increase in pH induced a decrease in amplitudes of currents elicited by saturating [GABA] but this effect was stronger for alpha1beta2 receptors. In the case of alpha1beta2gamma2 receptors, protons strongly affected the current time course due to a down regulation of binding and desensitization rates. This effect was qualitatively similar to that described in neurons. Protons strongly influenced the amplitude of alpha1beta2 receptor-mediated currents but the effect on their kinetics was weak suggesting a predominant direct non-competitive inhibition with a minor allosteric modulation. In conclusion, we provide evidence that extracellular protons strongly affect GABAA receptors and that, depending on the presence of the gamma2 subunit, the modulatory mechanisms show profound quantitative and qualitative differences.

  10. Identification of COUP-TFII Orphan Nuclear Receptor as a Retinoic Acid-Activated Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Kruse, Schoen W; Suino-Powell, Kelly; Zhou, X Edward; Kretschman, Jennifer E; Reynolds, Ross; Vonrhein, Clemens; Xu, Yong; Wang, Liliang; Tsai, Sophia Y; Tsai, Ming-Jer; Xu, H Eric [Baylor; (Van Andel); (Globel Phasing); (Grand Valley)

    2010-01-12

    The chicken ovalbumin upstream promoter-transcription factors (COUP-TFI and II) make up the most conserved subfamily of nuclear receptors that play key roles in angiogenesis, neuronal development, organogenesis, cell fate determination, and metabolic homeostasis. Although the biological functions of COUP-TFs have been studied extensively, little is known of their structural features or aspects of ligand regulation. Here we report the ligand-free 1.48 {angstrom} crystal structure of the human COUP-TFII ligand-binding domain. The structure reveals an autorepressed conformation of the receptor, where helix {alpha}10 is bent into the ligand-binding pocket and the activation function-2 helix is folded into the cofactor binding site, thus preventing the recruitment of coactivators. In contrast, in multiple cell lines, COUP-TFII exhibits constitutive transcriptional activity, which can be further potentiated by nuclear receptor coactivators. Mutations designed to disrupt cofactor binding, dimerization, and ligand binding, substantially reduce the COUP-TFII transcriptional activity. Importantly, retinoid acids are able to promote COUP-TFII to recruit coactivators and activate a COUP-TF reporter construct. Although the concentration needed is higher than the physiological levels of retinoic acids, these findings demonstrate that COUP-TFII is a ligand-regulated nuclear receptor, in which ligands activate the receptor by releasing it from the autorepressed conformation.

  11. Interleukin-4 receptor alpha gene variants and allergic disease

    Directory of Open Access Journals (Sweden)

    Hall Ian P

    2000-06-01

    Full Text Available Abstract The interleukin-4 (IL-4 signalling cascade has been identified as a pathway potentially important in the development of asthma. Genetic variants within this signalling pathway might contribute to the risk of developing asthma in a given individual. A number of polymorphisms have been described within the IL-4 receptor α (IL-4Rα gene. In addition polymorphism occurs in the promoter for the IL-4 gene itself. This commentary accompanies a paper by C Ober et al describing the contribution of IL-4Rα polymorphism to susceptibility to asthma and atopy in the Hutterite population and other outbred populations collected during the collaborative studies on the genetics of asthma (CSGA programme.

  12. Gamma power is phase-locked to posterior alpha activity.

    Directory of Open Access Journals (Sweden)

    Daria Osipova

    Full Text Available Neuronal oscillations in various frequency bands have been reported in numerous studies in both humans and animals. While it is obvious that these oscillations play an important role in cognitive processing, it remains unclear how oscillations in various frequency bands interact. In this study we have investigated phase to power locking in MEG activity of healthy human subjects at rest with their eyes closed. To examine cross-frequency coupling, we have computed coherence between the time course of the power in a given frequency band and the signal itself within every channel. The time-course of the power was calculated using a sliding tapered time window followed by a Fourier transform. Our findings show that high-frequency gamma power (30-70 Hz is phase-locked to alpha oscillations (8-13 Hz in the ongoing MEG signals. The topography of the coupling was similar to the topography of the alpha power and was strongest over occipital areas. Interestingly, gamma activity per se was not evident in the power spectra and only became detectable when studied in relation to the alpha phase. Intracranial data from an epileptic subject confirmed these findings albeit there was slowing in both the alpha and gamma band. A tentative explanation for this phenomenon is that the visual system is inhibited during most of the alpha cycle whereas a burst of gamma activity at a specific alpha phase (e.g. at troughs reflects a window of excitability.

  13. Functional discrepancies between tumor necrosis factor and lymphotoxin alpha explained by trimer stability and distinct receptor interactions

    DEFF Research Database (Denmark)

    Schuchmann, M; Hess, S; Bufler, P;

    1995-01-01

    interaction with the human p55TNFR. This was demonstrated in NIH 3T3 cells transfected with the human p55TNFR, where cytotoxicity is mediated exclusively by the transfected receptor. Although the p55ATNFR had virtually identical affinities for TNF and LT alpha, as defined by Scatchard analysis......Tumor necrosis factor (TNF) and lymphotoxin alpha (LT alpha) are closely related cytokines which bind with nearly identical affinities to the same pair of cell surface receptors, p55 and p75TNFR. Therefore it is assumed that TNF and LT alpha are redundant cytokines. This study, however...

  14. The estrogen receptor alpha nuclear localization sequence is critical for fulvestrant-induced degradation of the receptor.

    Science.gov (United States)

    Casa, Angelo J; Hochbaum, Daniel; Sreekumar, Sreeja; Oesterreich, Steffi; Lee, Adrian V

    2015-11-01

    Fulvestrant, a selective estrogen receptor down-regulator (SERD) is a pure competitive antagonist of estrogen receptor alpha (ERα). Fulvestrant binds ERα and reduces the receptor's half-life by increasing protein turnover, however, its mechanism of action is not fully understood. In this study, we show that removal of the ERα nuclear localization sequence (ERΔNLS) resulted in a predominantly cytoplasmic ERα that was degraded in response to 17-β-estradiol (E2) but was resistant to degradation by fulvestrant. ERΔNLS bound the ligands and exhibited receptor interaction similar to ERα, indicating that the lack of degradation was not due to disruption of these processes. Forcing ERΔNLS into the nucleus with a heterologous SV40-NLS did not restore degradation, suggesting that the NLS domain itself, and not merely receptor localization, is critical for fulvestrant-induced ERα degradation. Indeed, cloning of the endogenous ERα NLS onto the N-terminus of ERΔNLS significantly restored both its nuclear localization and turnover in response to fulvestrant. Moreover, mutation of the sumoylation targets K266 and K268 within the NLS impaired fulvestrant-induced ERα degradation. In conclusion, our study provides evidence for the unique role of the ERα NLS in fulvestrant-induced degradation of the receptor.

  15. CERAPP: Collaborative Estrogen Receptor Activity Prediction Project

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data from a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project) demonstrating using predictive computational...

  16. Adsorption behavior of alpha -cypermethrin on cork and activated carbon.

    Science.gov (United States)

    Domingues, Valentina F; Priolo, Giuseppe; Alves, Arminda C; Cabral, Miguel F; Delerue-Matos, Cristina

    2007-08-01

    Studies were undertaken to determine the adsorption behavior of alpha -cypermethrin [R)-alpha -cyano-3-phenoxybenzyl(1S)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, and (S)-alpha-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] in solutions on granules of cork and activated carbon (GAC). The adsorption studies were carried out using a batch equilibrium technique. A gas chromatograph with an electron capture detector (GC-ECD) was used to analyze alpha -cypermethrin after solid phase extraction with C18 disks. Physical properties including real density, pore volume, surface area and pore diameter of cork were evaluated by mercury porosimetry. Characterization of cork particles showed variations thereby indicating the highly heterogeneous structure of the material. The average surface area of cork particles was lower than that of GAC. Kinetics adsorption studies allowed the determination of the equilibrium time - 24 hours for both cork (1-2 mm and 3-4 mm) and GAC. For the studied alpha -cypermethrin concentration range, GAC revealed to be a better sorbent. However, adsorption parameters for equilibrium concentrations, obtained through the Langmuir and Freundlich models, showed that granulated cork 1-2 mm have the maximum amount of adsorbed alpha-cypermethrin (q(m)) (303 microg/g); followed by GAC (186 microg/g) and cork 3-4 mm (136 microg/g). The standard deviation (SD) values, demonstrate that Freundlich model better describes the alpha -cypermethrin adsorption phenomena on GAC, while alpha -cypermethrin adsorption on cork (1-2 mm and 3-4 mm) is better described by the Langmuir. In view of the adsorption results obtained in this study it appears that granulated cork may be a better and a cheaper alternative to GAC for removing alpha -cypermethrin from water.

  17. Alpha-conotoxins as pharmacological probes of nicotinic acetylcholine receptors

    Institute of Scientific and Technical Information of China (English)

    Layla AZAM; J Michael MCINTOSH

    2009-01-01

    Cysteine-rich peptides from the venom of cone snails (Conus) target a wide variety of different ion channels. One family of conopeptides, the a-conotoxins, specifically target different isoforms of nicotinic acetylcholine receptors (nAChRs) found both in the neuromuscular junction and central nervous system. This family is further divided into subfamilies based on the number of amino acids between cysteine residues. The exquisite subtype selectivity of certain a-conotoxins has been key to the characterization of native nAChR isoforms involved in modulation of neurotransmitter release, the pathophysiol-ogy of Parkinson's disease and nociception. Structure/function characterization of a-conotoxins has led to the development of analogs with improved potency and/or subtype selectivity. Cyclization of the backbone structure and addition of lipo-philic moieties has led to improved stability and bioavailability of a-conotoxins, thus paving the way for orally available therapeutics. The recent advances in phylogeny, exogenomics and molecular modeling promises the discovery of an even greater number of a-conotoxins and analogs with improved selectivity for specific subtypes of nAChRs.

  18. Retinoid X receptor alpha controls innate inflammatory responses through the up-regulation of chemokine expression.

    Science.gov (United States)

    Núñez, Vanessa; Alameda, Daniel; Rico, Daniel; Mota, Rubén; Gonzalo, Pilar; Cedenilla, Marta; Fischer, Thierry; Boscá, Lisardo; Glass, Christopher K; Arroyo, Alicia G; Ricote, Mercedes

    2010-06-01

    The retinoid X receptor alpha (RXRalpha) plays a central role in the regulation of many intracellular receptor signaling pathways and can mediate ligand-dependent transcription by forming homodimers or heterodimers with other nuclear receptors. Although several members of the nuclear hormone receptor superfamily have emerged as important regulators of macrophage gene expression, the existence in vivo of an RXR signaling pathway in macrophages has not been established. Here, we provide evidence that RXRalpha regulates the transcription of the chemokines Ccl6 and Ccl9 in macrophages independently of heterodimeric partners. Mice lacking RXRalpha in myeloid cells exhibit reduced levels of CCL6 and CCL9, impaired recruitment of leukocytes to sites of inflammation, and lower susceptibility to sepsis. These studies demonstrate that macrophage RXRalpha plays key roles in the regulation of innate immunity and represents a potential target for immunotherapy of sepsis.

  19. Receptor protein tyrosine phosphatase alpha is essential for hippocampal neuronal migration and long-term potentiation

    DEFF Research Database (Denmark)

    Petrone, Angiola; Battaglia, Fortunato; Wang, Cheng;

    2003-01-01

    (RPTPalpha) regulates SRC family kinases, potassium channels and NMDA receptors. Here, we report that absence of RPTPalpha compromises correct positioning of pyramidal neurons during development of mouse hippocampus. Thus, RPTPalpha is a novel member of the functional class of genes that control radial......Despite clear indications of their importance in lower organisms, the contributions of protein tyrosine phosphatases (PTPs) to development or function of the mammalian nervous system have been poorly explored. In vitro studies have indicated that receptor protein tyrosine phosphatase alpha...

  20. Evidence that the newly cloned low-density-lipoprotein receptor related protein (LRP) is the alpha 2-macroglobulin receptor

    DEFF Research Database (Denmark)

    Kristensen, T; Moestrup, Søren Kragh; Gliemann, Jørgen;

    1990-01-01

    The human placental receptor (alpha 2MR) for alpha 2-macroglobulin-proteinase complexes contains 3 polypeptides of approx. 500 kDa, 85 kDa, and 40 kDa. N-terminal sequence analysis of the 500 kDa and 85 kDa polypeptides, analysis of a random selection of peptides convering 536 residues from...... these polypeptides, and analysis of a 1772 bp cDNA encoding part of the 500 kDa polypeptide provide evidence that the 500 kDa and 85 kDa chains are the alpha- and beta-subunits, respectively, of a recently cloned hepatic membrane protein, termed the low density lipoprotein receptor related protein (LRP) (Herz, J......., Hamann, U., Rogne, S., Myklebost, O., Gausepohl, H. and Stanley, K.K. (1988) EMBO J. 7, 4119-4127; Herz, J., Kowal, R.C., Goldstein, J.L. and Brown, M.S. (1990) EMBO J. 9, 1769-1776). N-terminal sequence analysis of the 40 kDa polypeptide shows that it is of distinct genetic origin. It is suggested...

  1. Pharmacological differentiation of presynaptic inhibitory alpha-adrenoceptors and opiate receptors in the cat nictitating membrane.

    OpenAIRE

    Dubocovich, M. L.; Langer, S. Z.

    1980-01-01

    1 The action of morphine, naturally occurring and synthetic opiate peptides on [3H]-noradrenaline release induced by nerve stimulation was studied in the isolated nerve muscle preparation of the cat nictitating membrane under experimental conditions in which the alpha-presynaptic receptors were blocked by phentolamine 1 microM. 2 Morphine and the naturally occurring peptides: [Met5]-enkephalin, [Leu5]-enkephalin and beta-endorphin reduced 3H-transmitter overflow and responses to nerve stimula...

  2. Platelet-derived growth factor receptor alpha in glioma: a bad seed

    Institute of Scientific and Technical Information of China (English)

    Kun-Wei Liu; Bo Hu; Shi-Yuan Cheng

    2011-01-01

    Recent collaborative,large-scale genomic profiling of the most common and aggressive brain tumor glioblastoma multiforme(GBM) has significantly advanced our understanding of this disease.The gene encoding platelet-derived growth factor receptor alpha (PDGFRα) was identified as the third of the top 11 amplified genes in clinical GBM specimens.The important roles of PDGFRα signaling during normal brain development also implicate the possible pathologic consequences of PDGFRα over-activation in glioma.Although the initial clinical trials using PDGFR kinase inhibitors have been predominantly disappointing,diagnostic and treatment modalities involving genomic profiling and personalized medicine are expected to improve the therapy targeting PDGFRα signaling.In this review,we discuss the roles of PDGFRα signaling during development of the normal central nervous system (CNS) and in pathologic conditions such as malignant glioma.We further compare various animal models of PDGF-induced gliomagenesis and their potential as a novel platform of pre-clinical drug testing.We then summarize our recent publication and how these findings will likely impact treatments for gliomas driven by PDGFRα overexpression.A better understanding of PDGFRα signaling in glioma and their microenvironment,through the use of human or mouse models,is necessary to design a more effective therapeutic strategy against gliomas harboring the aberrant PDGFRα signaling.

  3. Platelet-derived growth factor receptor alpha in glioma: a bad seed.

    Science.gov (United States)

    Liu, Kun-Wei; Hu, Bo; Cheng, Shi-Yuan

    2011-09-01

    Recent collaborative, large-scale genomic profiling of the most common and aggressive brain tumor glioblastoma multiforme(GBM) has significantly advanced our understanding of this disease. The gene encoding platelet-derived growth factor receptor alpha(PDGFRα) was identified as the third of the top 11 amplified genes in clinical GBM specimens. The important roles of PDGFRα signaling during normal brain development also implicate the possible pathologic consequences of PDGFRα over-activation in glioma. Although the initial clinical trials using PDGFR kinase inhibitors have been predominantly disappointing, diagnostic and treatment modalities involving genomic profiling and personalized medicine are expected to improve the therapy targeting PDGFRα signaling. In this review, we discuss the roles of PDGFRαsignaling during development of the normal central nervous system(CNS) and in pathologic conditions such as malignant glioma. We further compare various animal models of PDGF-induced gliomagenesis and their potential as a novel platform of pre-clinical drug testing. We then summarize our recent publication and how these findings will likely impact treatments for gliomas driven by PDGFRα overexpression. A better understanding of PDGFRα signaling in glioma and their microenvironment, through the use of human or mouse models, is necessary to design a more effective therapeutic strategy against gliomas harboring the aberrant PDGFRα signaling. PMID:21880180

  4. The role of alpha-7 nicotinic receptors in food intake behaviors

    Directory of Open Access Journals (Sweden)

    Kristina L. McFadden

    2014-06-01

    Full Text Available Nicotine alters appetite and energy expenditure, leading to changes in body weight. While the exact mechanisms underlying these effects are not fully established, both central and peripheral involvement of the alpha-7 nicotinic acetylcholine receptor (α7nAChR has been suggested. Centrally, the α7nAChR modulates activity of hypothalamic neurons involved in food intake regulation, including proopiomelanocortin (POMC and neuropeptide Y (NPY. α7nAChRs also modulate glutamatergic and dopaminergic systems controlling reward processes that affect food intake. Additionally, α7nAChRs are important peripheral mediators of chronic inflammation, a key contributor to health problems in obesity. This review focuses on nicotinic cholinergic effects on eating behaviors, specifically those involving the α7nAChR, with the hypothesis that α7nAChR agonism leads to appetite suppression. Recent studies are highlighted that identify links between α7nAChR expression and obesity, insulin resistance, and diabetes and describe early findings showing an α7nAChR agonist to be associated with reduced weight gain in a mouse model of diabetes. Given these effects, the α7nAChR may be a useful therapeutic target for strategies to treat and manage obesity.

  5. Itai-itai disease is not associated with polymorphisms of the estrogen receptor {alpha} gene

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, Hisahide; Hayashi, Chiyo; Lee, Myeongjin; Ayaki, Hitoshi; Sumino, Kimiaki [Kobe Univ. School of Medicine (Japan). Dept. of Public Health; Yamamoto, Ryoji; Ninomiya, Ruriko; Koizumi, Naoko [Hyogo College of Medicine (Japan). Dept. of Public Health

    1999-11-01

    Itai-itai (or ouch-ouch) disease is a syndrome accompanied by bone mineral disorders, and which may be related to oral cadmium exposure. Itai-itai predominantly affects postmenopausal women with a history of multiple childbirths. Recently, it has been reported that polymorphisms of the estrogen receptor {alpha} (ER{alpha}) gene are associated with postmenopausal reduction of bone mineral density in Japanese women. However, estrogen receptors have never been studied in itai-itai disease. In this study, we examined the genotypic distributions of PvuII and XbaI restriction fragment length polymorphisms (RFLPs) of the ER{alpha} gene in patients with itai-itai disease and compared them with those of control subjects. The RFLPs are represented here as P{sub p} (PvuII) and Xx (XbaI); the capital and small letters signify the absence and presence of restriction sites, respectively. The genotypic distributions of the patient group were: PP, 14.8%; Pp, 55.6%; pp, 29.6%; XX, 7.4%; Xx, 29.6%; and xx, 63.0%. These distributions were similar to those observed for the control groups, hence no pattern of genotypic distribution was observed that could be related to itai-itai disease. We conclude that RFLPs of the ER{alpha} gene may not be associated with itai-itai disease. (orig.)

  6. Estrogen receptor alpha as a key target of red wine polyphenols action on the endothelium.

    Directory of Open Access Journals (Sweden)

    Matthieu Chalopin

    Full Text Available BACKGROUND: A greater reduction in cardiovascular risk and vascular protection associated with diet rich in polyphenols are generally accepted; however, the molecular targets for polyphenols effects remain unknown. Meanwhile evidences in the literature have enlightened, not only structural similarities between estrogens and polyphenols known as phytoestrogens, but also in their vascular effects. We hypothesized that alpha isoform of estrogen receptor (ERalpha could be involved in the transduction of the vascular benefits of polyphenols. METHODOLOGY/PRINCIPAL FINDINGS: Here, we used ERalpha deficient mice to show that endothelium-dependent vasorelaxation induced either by red wine polyphenol extract, Provinols, or delphinidin, an anthocyanin that possesses similar pharmacological profile, is mediated by ERalpha. Indeed, Provinols, delphinidin and ERalpha agonists, 17-beta-estradiol and PPT, are able to induce endothelial vasodilatation in aorta from ERalpha Wild-Type but not from Knock-Out mice, by activation of nitric oxide (NO pathway in endothelial cells. Besides, silencing the effects of ERalpha completely prevented the effects of Provinols and delphinidin to activate NO pathway (Src, ERK 1/2, eNOS, caveolin-1 leading to NO production. Furthermore, direct interaction between delphinidin and ERalpha activator site is demonstrated using both binding assay and docking. Most interestingly, the ability of short term oral administration of Provinols to decrease response to serotonin and to enhance sensitivity of the endothelium-dependent relaxation to acetylcholine, associated with concomitant increased NO production and decreased superoxide anions, was completely blunted in ERalpha deficient mice. CONCLUSIONS/SIGNIFICANCE: This study provides evidence that red wine polyphenols, especially delphinidin, exert their endothelial benefits via ERalpha activation. It is a major breakthrough bringing new insights of the potential therapeutic of

  7. Alpha9 alpha10 nicotinic acetylcholine receptors as target for the treatment of chronic pain.

    Science.gov (United States)

    Del Bufalo, Alessandra; Cesario, Alfredo; Salinaro, Gianluca; Fini, Massimo; Russo, Patrizia

    2014-01-01

    Chronic pain is a widespread healthcare problem affecting not only the patient but in many ways all the society. Chronic pain is a disease itself that endures for a long period of time and it is resistant to the majority of medical treatments that provide modest improvements in pain and minimum improvements in physical and emotional functioning. More co-existing chronic pain conditions may be present in the same individual (patient). The α9α10 nicotinic acetylcholine receptor (nAChR) may be a potential target in the pathophysiology of chronic pain, as well in the development of breast and lung cancers. α-conotoxins (α-CNT) are small peptides used offensively by carnivorous marine snails known as Conus that target nAChR. Among α-CNT there are potent and selective antagonists of α9α10 nAChR such as RgIA and Vc1.1 that produces both acute and long lasting analgesia. Moreover, these peptides accelerate the recovery of nerve function after injury, likely through immune/inflammatory-mediated mechanisms. We review the background, findings, implications and problems in using compounds that act on α9α10 nAChR. PMID:24641230

  8. Interaction between AVP and sympathetic system in subtotal nephrectomy-saline hypertension: role of alpha and V1 receptors.

    Science.gov (United States)

    Ozaykan, B; Doğan, A

    2000-01-14

    The development process of subtotal nephrectomy-salt hypertension is still unclear. The aim of the present study was to determine the role of the interaction between vasopressin and sympathetic system in the development of this hypertension by using AVP V1 antagonist and alpha blocker phentolamine under anesthesia condition. For this purpose, we carried out about 73% subtotal nephrectomy on male Wistar rats. One group of these rats (normotensive group) was given a low-salt diet and the other group (hypertensive group) was given a high-salt diet for 4 weeks. Finally, eight groups of rats were formed according to the kind(s) of the injected drug(s): (1) normotensive and hypertensive groups injected only V1 antagonist, (2) normotensive and hypertensive groups injected only phentolamine, (3) normotensive and hypertensive groups injected first V1 antagonist and then phentolamine, (4) normotensive and hypertensive groups injected first phentolamine and then V1 antagonist. Either V1 or alpha blockage separately led to a higher reduction in the mean blood pressure (MAP) of the hypertensives than, of the normotensives (p < 0.05). The combined blockage of V1 and alpha receptors, also caused a higher decrease in the MAP of hypertensive group than, of normotensive group, not depending on the order of the injections (p < 0.01). The heart rate increase recorded as a response to the phentolamine injection in normotensive group, did not develop in hypertensive group (p < 0.05). There was no significant difference between the two groups with regard to plasma electrolytes and osmolality. A positive correlation was found between systolic blood pressure and plasma osmolality in hypertensive group (r = 0.40, p < 0.05), but not in normotensive group. We conclude that the increase in V1 and alpha pressor activities contributes to the subtotal nephrectomy-saline hypertension and the augmentation of alpha pressor activity by vasopressin may participate in this contribution.

  9. Effect of chemicals on fungal alpha-amylase activity.

    Science.gov (United States)

    Ali, F S; Abdel-Moneim, A A

    1989-01-01

    The effect of 8 growth regulators at concentrations of 1,000, 5,000 and 10,000 ppm on the activity of fungal (Aspergillus flavus var. columnaris) alpha-amylase was studied. Indol acetic acid (IAA) and naphthalene acetic acid (NAA) inhibited alpha-amylase activity by 2% and 7% at 1,000 ppm. The other 6 growth regulators, indol butyric acid (IBA), gibberellic acid, cumarin, cycocel (CCC), atonik-G and kylar, did not inhibit but stimulated alpha-amylase activity (0 to 9%) at 1,000 ppm. All growth regulators studied inhibited alpha-amylase activity at 5,000 and 10,000 ppm concentration except kylar. The effect of organic acids and formaldehyde at 0.01, 0.005, and 0.001 M was studied. Acetic acid stimulated alpha-amylase at all concentrations, but formic acid, oxalic acid, lactic acid and citric acid inhibited alpha-amylase activity by 91, 100, 100 and 79%, respectively, at a concentration of 0.01 M, while by 31, 100, 15 and 20%, respectively, at 0.005 M. Formaldehyde induced 7, 3 and 2% inhibition at 0.01, 0.005 and 0.001 M, respectively. At 0.01 M either sorbitol or fructose inhibited alpha-amylase by 8%, Maltose 7%, sucrose 6%, phenol, glucose and galactose each by 5%, ethanol, glycerol, arabinose and sodium benzoate each by 4%, isopropanol and mannitol 1%, but methanol and ammonium citrate dibasic did not inhibit alpha-amylase. The results indicate that CuCl2, SnCl2, AgNO3 and Fe2(SO4)3 were the strongest inhibitors, followed by Cd(C2H3O2), HgCl2, Na2-EDTA, Na2HPO4, and CaCl2 in decreasing order. NaCl, NaBr and Mn SO4 did not inhibit alpha-amylase at concentrations from 10 mM to 0.01 mM. PMID:2515680

  10. Are different stoichiometries feasible for complexes between lymphotoxin-alpha and tumor necrosis factor receptor 1?

    OpenAIRE

    Mascarenhas Nahren; Kästner Johannes

    2012-01-01

    Abstract Background Tumor necrosis factors, TNF and lymphotoxin-α (LT), are cytokines that bind to two receptors, TNFR1 and TNFR2 (TNF-receptor 1 and 2) to trigger their signaling cascades. The exact mechanism of ligand-induced receptor activation is still unclear. It is generally assumed that three receptors bind to the homotrimeric ligand to trigger a signaling event. Recent evidence, though, has raised doubts if the ligand:receptor stoichiometry should indeed be 3:3 for ligand-induced cell...

  11. Measurement of biologically active interleukin-1 by a soluble receptor binding assay

    International Nuclear Information System (INIS)

    A soluble receptor binding assay has been developed for measuring human interleukin-1 alpha (IL-1 alpha), human IL-1 beta, and mouse IL-1 alpha. The assay is based on a competition between unlabeled IL-1 and 125I-labeled mouse recombinant IL-1 alpha for binding to soluble IL-1 receptor prepared from mouse EL-4 cells. The assay measures only biologically active IL-1 folded in its native conformation. The ratio of human IL-1 alpha to human IL-1 beta can be measured in the same sample by a pretreatment step which removes human IL-1 beta from samples prior to assay. This technique has been used to monitor the purification of recombinant IL-1, and may be utilized to specifically and accurately measure bioactive IL-1 in human serum and cell culture supernatants

  12. Alpha activity in Indian thermal springs

    International Nuclear Information System (INIS)

    Background: Dissolved radon is contained in natural water due to primordial uranium in rocks and soils with which it comes in contact. There is dual exposure from radon in water i.e. due to inhalation of the radon released from the water into the ambient air and through ingestion when water is used for drinking. As radon contaminated water adversely affects the health, it is therefore fundamental from health and hygiene point of view to measure radium concentration and radon exhalation rates in water.Materials and Methods: LR-115, Type-II plastic track detectors were used to measure the radium concentration and radon exhalation rate in water samples collected from various thermal springs. The alpha tracks registered were counted by optical microscope at suitable magnification and converted into radium concentration and subsequently radon exhalation rates were measured. Results: The radon concentration emanated from water samples(air borne) varied from 84 Bqm-3 to 827 Bqm-3 with an average of 429± 12.72 Bqm-3 and the dissolved radon concentration varied from 5.65 Bq 1-1 to 55.66 Bq 1-1 with an average of 28.88± 0.85 Bq 1-1. The radon mass exhalation rates varied from 2.37 m Bq kg-1 hr-1 to 23.39 mBq kg-1 hr-1 with an average of 12.14 ±0.36 mBq kg-1 hr-1 and surface exhalation rates from 52.34 mBq m-2 hr-1 to 515.29 mBq m-2 hr-1 with an average of 267.36 ± 7.93 from different thermal spring water samples. The radium concentration varied from 0.3 0 Bq 1-1 to 2.93 Bq 1-1 with an average of 1.52 ± 0.045 Bq 1-1. Results indicate that the thermal spring water, which is also being used for drinking, is safe as far as radium concentration is concerned with the exception of a few isolated thermal spring sources

  13. Characterization of a stable, major DNA polymerase alpha species devoid of DNA primase activity.

    OpenAIRE

    Kaiserman, H B; Benbow, R. M.

    1987-01-01

    We have purified from Xenopus laevis ovaries a major DNA polymerase alpha species that lacked DNA primase activity. This primase-devoid DNA polymerase alpha species exhibited the same sensitivity as the DNA polymerase DNA primase alpha to BuAdATP and BuPdGTP, nucleotide analogs capable of distinguishing between DNA polymerase delta and DNA polymerase DNA primase alpha. The primase-devoid DNA polymerase alpha species also lacked significant nuclease activity indicative of the alpha-like (rathe...

  14. Disruption of retinoic acid receptor alpha reveals the growth promoter face of retinoic acid.

    Directory of Open Access Journals (Sweden)

    Giulia Somenzi

    Full Text Available BACKGROUND: Retinoic acid (RA, the bioactive derivative of Vitamin A, by epigenetically controlling transcription through the RA-receptors (RARs, exerts a potent antiproliferative effect on human cells. However, a number of studies show that RA can also promote cell survival and growth. In the course of one of our studies we observed that disruption of RA-receptor alpha, RARalpha, abrogates the RA-mediated growth-inhibitory effects and unmasks the growth-promoting face of RA (Ren et al., Mol. Cell. Biol., 2005, 25:10591. The objective of this study was to investigate whether RA can differentially govern cell growth, in the presence and absence of RARalpha, through differential regulation of the "rheostat" comprising ceramide (CER, the sphingolipid with growth-inhibitory activity, and sphingosine-1-phosphate (S1P, the sphingolipid with prosurvival activity. METHODOLOGY/PRINCIPAL FINDINGS: We found that functional inhibition of endogenous RARalpha in breast cancer cells by using either RARalpha specific antagonists or a dominant negative RARalpha mutant hampers on one hand the RA-induced upregulation of neutral sphingomyelinase (nSMase-mediated CER synthesis, and on the other hand the RA-induced downregulation of sphingosine kinase 1, SK1, pivotal for S1P synthesis. In association with RA inability to regulate the sphingolipid rheostat, cells not only survive, but also grow more in response to RA both in vitro and in vivo. By combining genetic, pharmacological and biochemical approaches, we mechanistically demonstrated that RA-induced growth is, at least in part, due to non-RAR-mediated activation of the SK1-S1P signaling. CONCLUSIONS/SIGNIFICANCE: In the presence of functional RARalpha, RA inhibits cell growth by concertedly, and inversely, modulating the CER and S1P synthetic pathways. In the absence of a functional RARalpha, RA-in a non-RAR-mediated fashion-promotes cell growth by activating the prosurvival S1P signaling. These two distinct

  15. Hormone activation of baculovirus expressed progesterone receptors.

    Science.gov (United States)

    Elliston, J F; Beekman, J M; Tsai, S Y; O'Malley, B W; Tsai, M J

    1992-03-15

    Human and chicken progesterone receptors (A form) were overproduced in a baculovirus expression system. These recombinant progesterone receptors were full-length bound progesterone specifically and were recognized by monoclonal antibodies, AB52 and PR22, specific for human and chicken progesterone receptor, respectively. In gel retardation studies, binding of recombinant human and chicken progesterone receptors to their progesterone response element (PRE) was specific and was enhanced in the presence of progesterone. Binding of human progesterone receptor to the PRE was also enhanced in the presence of the antiprogestin, RU486, but very little effect was observed in the presence of estradiol, dexamethasone, testosterone, and vitamin D. In our cell-free transcription system, human progesterone receptor induced transcription in a receptor-dependent and hormone-activable manner. Receptor-stimulated transcription required the presence of the PRE in the test template and could be specifically inhibited by excess PRE oligonucleotides. Furthermore, chicken progesterone receptor also induced in vitro transcription in a hormone-activable manner. These results demonstrate that steroid receptors overexpressed in a baculovirus expression system are functional and exhibit steroid-responsive binding and transcription. These observations support our present understanding of the mechanism of steroid receptor-regulated gene expression and provide a technological format for studies of the role of hormone and antihormone in altering gene expression. PMID:1544902

  16. Risk factors for breast cancer characterized by the estrogen receptor alpha A908G (K303R) mutation

    OpenAIRE

    Conway, Kathleen; Parrish, Eloise; Edmiston, Sharon N; Tolbert, Dawn; Tse, Chiu-Kit; Moorman, Patricia; Newman, Beth; Millikan, Robert C.

    2007-01-01

    Introduction Estrogen is important in the development of breast cancer, and its biological effects are mediated primarily through the two estrogen receptors alpha and beta. A point mutation in the estrogen receptor alpha gene, ESR1, referred to as A908G or K303R, was originally identified in breast hyperplasias and was reported to be hypersensitive to estrogen. We recently detected this mutation at a low frequency of 6% in invasive breast tumors of the Carolina Breast Cancer Study (CBCS). Met...

  17. Expression and prognostic value of platelet-derived growth factor-AA and its receptor alpha in nephroblastoma

    NARCIS (Netherlands)

    Ghanem, Mazen; Nijman, Rien; Safan, Manal; van der Kwast, Theodorus; Vansteenbrugge, Gert

    2010-01-01

    OBJECTIVE To investigate the potential role of platelet-derived growth factor-AA (PDGF-AA) and the PDGF-alpha receptor as prognostic markers in Wilms' tumour. PATIENTS AND METHODS The expression of PDGF-AA and PDGF-alpha were investigated using immunohistochemical analysis of 62 Wilms' tumours. Pati

  18. Autocrine regulation of cell proliferation by estrogen receptor-alpha in estrogen receptor-alpha-positive breast cancer cell lines

    Directory of Open Access Journals (Sweden)

    Pan Zhongzong

    2009-01-01

    Full Text Available Abstract Background Estrogen receptor-α (ERα is essential for mammary gland development and is a major oncogene in breast cancer. Since ERα is not colocalized with the cell proliferation marker Ki-67 in the normal mammary glands and the majority of primary breast tumors, it is generally believed that paracrine regulation is involved in ERα mediated cell proliferation. In the paracrine model, ERα-positive cells don't proliferate but will release some paracrine growth factors to stimulate the neighboring cells to proliferate. In a subpopulation of cancer cells in some primary breast tumors, however, ERα does colocalize with the cell proliferation marker Ki-67, suggesting an autocrine regulation by ERα in some primary breast tumors. Methods Colocalization of ERα with Ki-67 in ERα-positive breast cancer cell lines (MCF-7, T47D, and ZR75-1 was evaluated by immunofluorescent staining. Cell cycle phase dependent expression of ERα was determined by co-immunofluorescent staining of ERα and the major cyclins (D, E, A, B, and by flow cytometry analysis of ERαhigh cells. To further confirm the autocrine action of ERα, MCF-7 cells were growth arrested by ICI182780 treatment, followed by treatment with EGFR inhibitor, before estrogen stimulation and analyses for colocalization of Ki-67 and ERα and cell cycle progression. Results Colocalization of ERα with Ki-67 was present in all three ERα-positive breast cancer cell lines. Unlike that in the normal mammary glands and the majority of primary breast tumors, ERα is highly expressed throughout the cell cycle in MCF-7 cells. Without E2 stimulation, MCF-7 cells released from ICI182780 treatment remain at G1 phase. E2 stimulation of ICI182780 treated cells, however, promotes the expression and colocalization of ERα and Ki-67 as well as the cell cycle progressing through the S and G2/M phases. Inhibition of EGFR signaling does not inhibit the autocrine action of ERα. Conclusion Our data indicate

  19. PDGFR alpha signaling in the primary cilium regulates NHE1-dependent fibroblast migration via coordinated differential activity of MEK1/2-ERK1/2-p90(RSK) and AKT signaling pathways

    DEFF Research Database (Denmark)

    Clement, Ditte L.; Mally, Sabine; Stock, Christian;

    2013-01-01

    In fibroblasts, platelet-derived growth factor receptor alpha (PDGFR alpha) is upregulated during growth arrest and compartmentalized to the primary cilium. PDGF-AA mediated activation of the dimerized ciliary receptor produces a phosphorylation cascade through the PI3K-AKT and MEK1/2-ERK1/2 path...

  20. The Novel, Nicotinic Alpha7 Receptor Partial Agonist, BMS-933043, Improves Cognition and Sensory Processing in Preclinical Models of Schizophrenia

    Science.gov (United States)

    Bristow, Linda J.; Easton, Amy E.; Li, Yu-Wen; Sivarao, Digavalli V.; Lidge, Regina; Jones, Kelli M.; Post-Munson, Debra; Daly, Christopher; Lodge, Nicholas J.; Gallagher, Lizbeth; Molski, Thaddeus; Pieschl, Richard; Chen, Ping; Hendricson, Adam; Westphal, Ryan; Cook, James; Iwuagwu, Christiana; Morgan, Daniel; Benitex, Yulia; King, Dalton; Macor, John E.; Zaczek, Robert; Olson, Richard

    2016-01-01

    The development of alpha7 nicotinic acetylcholine receptor agonists is considered a promising approach for the treatment of cognitive symptoms in schizophrenia patients. In the present studies we characterized the novel agent, (2R)-N-(6-(1H-imidazol-1-yl)-4-pyrimidinyl)-4'H-spiro[4-azabicyclo[2.2.2]octane-2,5'-[1,3]oxazol]-2'-amine (BMS-933043), in vitro and in rodent models of schizophrenia-like deficits in cognition and sensory processing. BMS-933043 showed potent binding affinity to native rat (Ki = 3.3 nM) and recombinant human alpha7 nicotinic acetylcholine receptors (Ki = 8.1 nM) and agonist activity in a calcium fluorescence assay (EC50 = 23.4 nM) and whole cell voltage clamp electrophysiology (EC50 = 0.14 micromolar (rat) and 0.29 micromolar (human)). BMS-933043 exhibited a partial agonist profile relative to acetylcholine; the relative efficacy for net charge crossing the cell membrane was 67% and 78% at rat and human alpha7 nicotinic acetylcholine receptors respectively. BMS-933043 showed no agonist or antagonist activity at other nicotinic acetylcholine receptor subtypes and was at least 300 fold weaker at binding to and antagonizing human 5-HT3A receptors (Ki = 2,451 nM; IC50 = 8,066 nM). BMS-933043 treatment i) improved 24 hour novel object recognition memory in mice (0.1–10 mg/kg, sc), ii) reversed MK-801-induced deficits in Y maze performance in mice (1–10 mg/kg, sc) and set shift performance in rats (1–10 mg/kg, po) and iii) reduced the number of trials required to complete the extradimensional shift discrimination in neonatal PCP treated rats performing the intra-dimensional/extradimensional set shifting task (0.1–3 mg/kg, po). BMS-933043 also improved auditory gating (0.56–3 mg/kg, sc) and mismatch negativity (0.03–3 mg/kg, sc) in rats treated with S(+)ketamine or neonatal phencyclidine respectively. Given this favorable preclinical profile BMS-933043 was selected for further development to support clinical evaluation in humans. PMID

  1. Alpha/sub 2/-adrenergic receptors on a platelet precursor cell line, HEL

    Energy Technology Data Exchange (ETDEWEB)

    McKernan, R.M.; Motulsky, H.J.; Rozansky, D.; Insel, P.A.

    1986-03-01

    The authors have identified ..cap alpha../sub 2/-adrenergic receptors on human erythroleukemia HEL cells, a suspension-growing, bone-marrow-derived cell line related to human platelets. Intact HEL cells were studied using radioligand binding and cAMP accumulation assays. The authors identified saturable specific binding of the ..cap alpha../sub 2/-antagonist (/sup 3/H)yohimbine (yoh) in cells incubated at 37/sup 0/C for 1 hr (B/sub max/ 5900 +/- 2100 sites/cell, K/sub d/ 3.6 +/- 0.9 nM, n = 7). Competition for (/sup 3/H)yoh binding sites with antagonists confirmed that these sites were similar to human ..cap alpha../sub 2/-adrenoceptors from platelets and other resources, as typified by their high affinity for WY-26392, yohimbine and idazoxan, and very low affinity for prazosin. Studies at 37/sup 0/C revealed a low affinity of these sites for catecholamines (K/sub i/ for (-)-epinephrine, 21 ..mu..M; (-)-norepinephrine, 45 ..mu..M, (+)-epinephrine, 80 ..mu..M). When experiments were conducted at 4 /sup 0/C, (-)-epinephrine was able to compete for only 50-60% of the sites specifically labelled by (/sup 3/H)yoh at 37/sup 0/, but (-)-epinephrine had an approximately 10-fold greater affinity for these sites (K/sub i/ at 4 /sup 0/C = 2.4 ..mu..M). In addition, epinephrine inhibited cAMP accumulation stimulated by forskolin and PGE/sub 1/ in HEL cells; this response was inhibited by pertussis toxin. The authors conclude that HEL cells possess ..cap alpha../sub 2/-adrenergic receptors linked to G/sub i/ and thus should serve as a useful model to explore metabolism and regulation of these receptors in human cells.

  2. Alpha-activities in environmental samples

    International Nuclear Information System (INIS)

    Determination of 239Pu(240Pu) in human lungs from autopsies show for the period 1961 - 1965 lung burdens between 150 - 600 fCi and about 50 fCi/organ for the years 1978/79. In some cases also 241Am and 234U/238U contents were analyzed. Air concentration measurements concerning 239Pu(240Pu) and uranium isotopes were carried out using air filters taken between 1962 - 1979 at a sampling station in Vienna. Additionally performed investigations about the α-activity of typical food stuffs allow a rough estimation of the intake for the general population. Based on statistical data and the results of activity measurements especially of 210Po, 226Ra, 232Th and U(nat) in coals and the ashes, emissions from coal fired stationary sources are discussed. (Author)

  3. Human ADAM 12 (meltrin alpha) is an active metalloprotease

    DEFF Research Database (Denmark)

    Loechel, F; Gilpin, B J; Engvall, E;

    1998-01-01

    The ADAMs (a disintegrin and metalloprotease) are a family of multidomain proteins with structural homology to snake venom metalloproteases. We recently described the cloning and sequencing of human ADAM 12 (meltrin alpha). In this report we provide evidence that the metalloprotease domain of ADAM...... 12 is catalytically active. We used the trapping mechanism of alpha2-macroglobulin to assay for protease activity of wild-type and mutant ADAM 12 proteins produced in a COS cell transfection system. We found that ADAM 12 is synthesized as a zymogen, with the prodomain maintaining the metalloprotease...... in a latent form, probably by means of a cysteine switch. The zymogen could be activated chemically by alkylation with N-ethylmaleimide. Cleavage of the prodomain at a site for a furin-like endopeptidase resulted in an ADAM 12 protein with proteolytic activity. The protease activity was sensitive...

  4. Estrogen and the selective estrogen receptor modulator (SERM) protection against cell death in estrogen receptor alpha and beta expressing U2OS cells

    OpenAIRE

    Kallio, Anu; Guo, Tao; Lamminen, Elisa; Seppänen, Jani; Kangas, Lauri; Väänänen, H Kalervo; Härkönen, Pirkko

    2008-01-01

    Estrogen and the selective estrogen receptor modulator (SERM) protection against cell death in estrogen receptor alpha and beta expressing U2OS cells SWEDEN (Kallio, Anu) SWEDEN Received: 2007-12-01 Revised: 2008-03-12 Accepted: 2008-03-12

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

    DEFF Research Database (Denmark)

    Onda, Masamitsu; Li, Daisy; Suzuki, Shinichi;

    2002-01-01

    PURPOSE: The purpose of this study was to determine whether the length of the THRA1 microsatellite, which resides in a noncoding portion of the thyroid hormone receptor-alpha1 gene, affects receptor expression and is linked to clinicopathological parameters in thyroid cancer. EXPERIMENTAL DESIGN:...

  6. A Gly482Ser missense mutation in the peroxisome proliferator-activated receptor gamma coactivator-1 is associated with altered lipid oxidation and early insulin secretion in Pima Indians

    DEFF Research Database (Denmark)

    Muller, Yunhua Li; Bogardus, Clifton; Pedersen, Oluf;

    2003-01-01

    Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) is a transcriptional coactivator of peroxisome proliferator-activated receptor gamma and alpha, which play important roles in adipogenesis and lipid metabolism. A single nucleotide polymorphism within the coding region...

  7. TNF-alpha-induced mitochondrial alterations in human T cells requires FADD and caspase-8 activation but not RIP and caspase-3 activation.

    Science.gov (United States)

    Shakibaei, Mehdi; Sung, Bokyung; Sethi, Gautam; Aggarwal, Bharat B

    2010-09-15

    Although much is known about how TNF-alpha induces apoptosis in the presence of inhibitors of protein synthesis, little is known about how it induces apoptosis without these inhibitors. In this report we investigated temporal sequence of events induced by TNF-alpha in the absence of protein synthesis. Regardless of whether we measured the effects by plasma membrane phosphotidylserine accumulation, by DNA strand breaks, or activation of caspases, significant changes were observed only between 12-24 h of TNF-alpha treatment. One of the earliest changes observed after TNF-alpha treatment was mitochondrial swelling at 10 min; followed by cytochrome c and Smac release at 10-30 min, and then heterochromatin clumping occurred at 60 min. While genetic deletion of receptor-interaction protein (RIP) had no effect on TNF-alpha-induced mitochondrial damage, deletion of Fas-associated death domain (FADD) abolished the TNF-induced mitochondrial swelling. Since pan-caspase inhibitor z-VAD-fmk abolished the TNF-alpha-induced mitochondrial changes, z-DEVD-fmk, an inhibitor of caspase-3 had no effect, suggesting that TNF-alpha-induced mitochondrial changes or cytochrome c and Smac release requires caspase-8 but not caspase-3 activation. Overall, our results indicated that mitochondrial changes are early events in TNF-alpha-induced apoptosis and that these mitochondrial changes require recruitment of FADD and caspase-8 activation, but not caspase-3 activation or RIP recruitment. PMID:20136500

  8. Monoclonal antibodies to the human insulin receptor that activate glucose transport but not insulin receptor kinase activity.

    OpenAIRE

    Forsayeth, J R; Caro, J F; Sinha, M K; Maddux, B A; Goldfine, I D

    1987-01-01

    Three mouse monoclonal antibodies were produced that reacted with the alpha subunit of the human insulin receptor. All three both immunoprecipitated 125I-labeled insulin receptors from IM-9 lymphocytes and competitively inhibited 125I-labeled insulin binding to its receptor. Unlike insulin, the antibodies failed to stimulate receptor autophosphorylation in both intact IM-9 lymphocytes and purified human placental insulin receptors. Moreover, unlike insulin, the antibodies failed to stimulate ...

  9. Effect of TNF{alpha} on activities of different promoters of human apolipoprotein A-I gene

    Energy Technology Data Exchange (ETDEWEB)

    Orlov, Sergey V., E-mail: serge@iem.sp.ru [Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, 197376 St. Petersburg (Russian Federation); Department of Embryology, St. Petersburg State University, 199034 St. Petersburg (Russian Federation); Mogilenko, Denis A. [Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, 197376 St. Petersburg (Russian Federation); Department of Embryology, St. Petersburg State University, 199034 St. Petersburg (Russian Federation); Shavva, Vladimir S. [Department of Embryology, St. Petersburg State University, 199034 St. Petersburg (Russian Federation); Dizhe, Ella B.; Ignatovich, Irina A. [Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, 197376 St. Petersburg (Russian Federation); Perevozchikov, Andrej P., E-mail: app@iem.sp.ru [Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, 197376 St. Petersburg (Russian Federation); Department of Embryology, St. Petersburg State University, 199034 St. Petersburg (Russian Federation)

    2010-07-23

    Research highlights: {yields} TNF{alpha} stimulates the distal alternative promoter of human apoA-I gene. {yields} TNF{alpha} acts by weakening of promoter competition within apoA-I gene (promoter switching). {yields} MEK1/2 and nuclear receptors PPAR{alpha} and LXRs take part in apoA-I promoter switching. -- Abstract: Human apolipoprotein A-I (ApoA-I) is a major structural and functional protein component of high-density lipoproteins. The expression of the apolipoprotein A-I gene (apoA-I) in hepatocytes is repressed by pro-inflammatory cytokines such as IL-1{beta} and TNF{alpha}. Recently, two novel additional (alternative) promoters for human apoA-I gene have been identified. Nothing is known about the role of alternative promoters in TNF{alpha}-mediated downregulation of apoA-I gene. In this article we report for the first time about the different effects of TNF{alpha} on two alternative promoters of human apoA-I gene. Stimulation of HepG2 cells by TNF{alpha} leads to activation of the distal alternative apoA-I promoter and downregulation of the proximal alternative and the canonical apoA-I promoters. This effect is mediated by weakening of the promoter competition within human apoA-I 5'-regulatory region (apoA-I promoter switching) in the cells treated by TNF{alpha}. The MEK1/2-ERK1/2 cascade and nuclear receptors PPAR{alpha} and LXRs are important for TNF{alpha}-mediated apoA-I promoter switching.

  10. Estrogen/estrogen receptor alpha signaling in mouse posterofrontal cranial suture fusion.

    Directory of Open Access Journals (Sweden)

    Aaron W James

    Full Text Available BACKGROUND: While premature suture fusion, or craniosynostosis, is a relatively common condition, the cause is often unknown. Estrogens are associated with growth plate fusion of endochondral bones. In the following study, we explore the previously unknown significance of estrogen/estrogen receptor signaling in cranial suture biology. METHODOLOGY/PRINCIPAL FINDINGS: Firstly, estrogen receptor (ER expression was examined in physiologically fusing (posterofrontal and patent (sagittal mouse cranial sutures by quantitative RT-PCR. Next, the cranial suture phenotype of ER alpha and ER beta knockout (alphaERKO, betaERKO mice was studied. Subsequently, mouse suture-derived mesenchymal cells (SMCs were isolated; the effects of 17-beta estradiol or the estrogen antagonist Fulvestrant on gene expression, osteogenic and chondrogenic differentiation were examined in vitro. Finally, in vivo experiments were performed in which Fulvestrant was administered subcutaneously to the mouse calvaria. Results showed that increased ERalpha but not ERbeta transcript abundance temporally coincided with posterofrontal suture fusion. The alphaERKO but not betaERKO mouse exhibited delayed posterofrontal suture fusion. In vitro, addition of 17-beta estradiol enhanced both osteogenic and chondrogenic differentiation in suture-derived mesenchymal cells, effects reversible by Fulvestrant. Finally, in vivo application of Fulvestrant significantly diminished calvarial osteogenesis, inhibiting suture fusion. CONCLUSIONS/SIGNIFICANCE: Estrogen signaling through ERalpha but not ERbeta is associated with and necessary for normal mouse posterofrontal suture fusion. In vitro studies suggest that estrogens may play a role in osteoblast and/or chondrocyte differentiation within the cranial suture complex.

  11. Identification of alpha beta and gamma delta T cell receptor-positive cells

    DEFF Research Database (Denmark)

    Geisler, C; Larsen, J K; Plesner, T

    1988-01-01

    distribution and function of these different T cells. In immunofluorescence studies gamma delta TCR+ cells have been identified as CD3+WT-31- or CD3+CD4-CD8- cells. However, this may not be the optimal procedure because gamma delta TCR+ cells are weakly WT-31+, and some are CD8+. The aim of this study......Two lineages of T lymphocytes bearing the CD3 antigen can be defined on the basis of the nature of the heterodimeric receptor chain (alpha beta or gamma delta T cell receptor (TCR) expressed. Precise identification of alpha beta and gamma delta TCR+ cells is essential when studying the tissue...... was to evaluate a panel of monoclonal antibodies (MoAb) directed against different chains of the TCR-T3 complex for a more precise identification of alpha beta+ and gamma delta TCR+ cells in flow cytometric studies. We found that the MoAb anti-Ti-gamma A and delta-TCS-1, recognizing the TCR-gamma and the TCR...

  12. Localization of peroxisome proliferator-activated receptor alpha (PPARα) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD) in cells expressing the Ca2+-binding proteins calbindin, calretinin, and parvalbumin in the adult rat hippocampus

    Science.gov (United States)

    Rivera, Patricia; Arrabal, Sergio; Vargas, Antonio; Blanco, Eduardo; Serrano, Antonia; Pavón, Francisco J.; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2014-01-01

    The N-acylethanolamines (NAEs), oleoylethanolamide (OEA) and palmithylethanolamide (PEA) are known to be endogenous ligands of PPARα receptors, and their presence requires the activation of a specific phospholipase D (NAPE-PLD) associated with intracellular Ca2+ fluxes. Thus, the identification of a specific population of NAPE-PLD/PPARα-containing neurons that express selective Ca2+-binding proteins (CaBPs) may provide a neuroanatomical basis to better understand the PPARα system in the brain. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the co-existence of NAPE-PLD/PPARα and the CaBPs calbindin D28k, calretinin and parvalbumin in the rat hippocampus. PPARα expression was specifically localized in the cell nucleus and, occasionally, in the cytoplasm of the principal cells (dentate granular and CA pyramidal cells) and some non-principal cells of the hippocampus. PPARα was expressed in the calbindin-containing cells of the granular cell layer of the dentate gyrus (DG) and the SP of CA1. These principal PPARα+/calbindin+ cells were closely surrounded by NAPE-PLD+ fiber varicosities. No pyramidal PPARα+/calbindin+ cells were detected in CA3. Most cells containing parvalbumin expressed both NAPE-PLD and PPARα in the principal layers of the DG and CA1/3. A small number of cells containing PPARα and calretinin was found along the hippocampus. Scattered NAPE-PLD+/calretinin+ cells were specifically detected in CA3. NAPE-PLD+ puncta surrounded the calretinin+ cells localized in the principal cells of the DG and CA1. The identification of the hippocampal subpopulations of NAPE-PLD/PPARα-containing neurons that express selective CaBPs should be considered when analyzing the role of NAEs/PPARα-signaling system in the regulation of hippocampal functions. PMID:24672435

  13. Genetic analysis of the estrogen-related receptor alpha and studies of association with obesity and type 2 diabetes

    DEFF Research Database (Denmark)

    Larsen, L H; Rose, C S; Sparsø, T;

    2007-01-01

    The estrogen-related receptor alpha (ERRalpha or NR3B1) is a transcription factor from the nuclear receptor super-family, group III. The gene encoding ERRalpha (ESRRA) is located on chromosome 11q13, a region showing genetic linkage to body mass index and fat percentage. Through interaction...

  14. Estrogen inhibits RANKL-stimulated osteoclastic differentiation of human monocytes through estrogen and RANKL-regulated interaction of estrogen receptor-{alpha} with BCAR1 and Traf6

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Lisa J., E-mail: robinsonlj@msx.upmc.edu [Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Yaroslavskiy, Beatrice B.; Griswold, Reed D.; Zadorozny, Eva V.; Guo, Lida; Tourkova, Irina L. [Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Blair, Harry C. [Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Veteran' s Affairs Medical Center, Pittsburgh, PA 15243 (United States)

    2009-04-15

    The effects of estrogen on osteoclast survival and differentiation were studied using CD14-selected mononuclear osteoclast precursors from peripheral blood. Estradiol at {approx} 1 nM reduced RANKL-dependent osteoclast differentiation by 40-50%. Osteoclast differentiation was suppressed 14 days after addition of RANKL even when estradiol was withdrawn after 18 h. In CD14+ cells apoptosis was rare and was not augmented by RANKL or by 17-{beta}-estradiol. Estrogen receptor-{alpha} (ER{alpha}) expression was strongly down-regulated by RANKL, whether or not estradiol was present. Mature human osteoclasts thus cannot respond to estrogen via ER{alpha}. However, ER{alpha} was present in CD14+ osteoclast progenitors, and a scaffolding protein, BCAR1, which binds ER{alpha} in the presence of estrogen, was abundant. Immunoprecipitation showed rapid ({approx} 5 min) estrogen-dependent formation of ER{alpha}-BCAR1 complexes, which were increased by RANKL co-treatment. The RANKL-signaling intermediate Traf6, which regulates NF-{kappa}B activity, precipitated with this complex. Reduction of NF-{kappa}B nuclear localization occurred within 30 min of RANKL stimulation, and estradiol inhibited the phosphorylation of I{kappa}B in response to RANKL. Inhibition by estradiol was abolished by siRNA knockdown of BCAR1. We conclude that estrogen directly, but only partially, curtails human osteoclast formation. This effect requires BCAR1 and involves a non-genomic interaction with ER{alpha}.

  15. The lack of gonadotrophin-releasing hormone (GnRH) receptor desensitisation in alphaT3-1 cells is not due to GnRH receptor reserve or phosphatidylinositol 4,5-bis-phosphate pool size.

    Science.gov (United States)

    Forrest-Owen, W; Willars, G B; Nahorski, S R; Assefa, D; Davidson, J S; Hislop, J; McArdle, C A

    1999-01-25

    The phospholipase C (PLC)-activating gonadotrophin-releasing hormone (GnRH) receptor is thought not to rapidly desensitise in alphaT3-1 cells. This extremely unusual characteristic raises the concern that it might be a feature of the cell type, rather than the receptor per se. Here we have used video imaging to establish whether the effects of endogenous PLC-activating G-protein coupled receptors (GPCRs) on Ca2+ ion concentration [Ca2+]i desensitise in these cells. Oxytocin, endothelin-1, methacholine, and UTP all caused [Ca2+]i increases which underwent rapid homologous desensitisation in that they were transient and responses to repeat stimuli were attenuated whereas subsequent responses to GnRH were not. To test whether receptor reserve obscures functional desensitisation of GnRH receptors, a photoaffinity antagonist (Pant-1), was used to effect a partial and irreversible receptor blockade. UV crosslinking in medium with 1000 nM Pant-1 reduced GnRH receptor number to 20 +/- 5% and reduced maximal buserelin-stimulated [3H]IP(X) accumulation to 57 +/- 5%, demonstrating removal of receptor reserve. In control alphaT3-1 cells the initial rate of GnRH-stimulated [3H]IP(X) accumulation was maintained for at least 5 min and GnRH caused a sustained increase in Ins(1,4,5)P3 mass (confirming the resistance of GnRH receptors to desensitisation) and Pant-1 pre-treatment reduced the magnitude of these responses without altering their temporal profiles. In alphaT3-1 cells stably transfected with recombinant human muscarinic receptors (alphaT3-1/M3), responses to methacholine were characteristic of desensitising GPCRs (transient Ins(1,4,5)P3 and curvilinear [3H]IP(X) responses) and were unaltered by Pant-1. To test the relevance of phospholipid pool size, alphaT3-1/M3 cells were pre-treated with GnRH or methacholine in medium with LiCl (to deplete PtdIns(4,5)P2 pools). These pre-treatments reduced subsequent responses to methacholine and GnRH comparably, indicating access to a

  16. Association of estrogen receptor-alpha and vitamin D receptor genotypes with therapeutic response to calcium in postmenopausal Chinese women

    Institute of Scientific and Technical Information of China (English)

    Zhen-lin ZHANG; Yue-juan QIN; Qi-ren HUANG; Jin-wei HE; Miao LI; Qi ZHOU; Yun-qiu HU; Yu-juan LIU

    2004-01-01

    AIM: To investigate the correlation between calcium treatment in postmenopausal women and estrogen receptoralpha (ER-alpha) Xba Ⅰ and Pvu Ⅱ genotype and vitamin D receptor (VDR) Apa Ⅰ genotype. METHODS: One hundred fifteen postmenopausal Chinese women of Han population were enrolled and treated with calcichew-D3(1000 mg calcium and 400 U vitamin D3) daily for 1 year. At entry and after 1 year treatment, the bone mineral density (BMD), serum and urinary bone turnover biochemical markers were evaluated. ER-alpha and VDR genotype were analyzed using PCR-restriction fragment length polymorphism. RESULTS: After 1 year of calcium supplementation, a significant increase of BMD and a marked reduction in serum ALP and PTH levels, and a significant increase of serum 25-(OH) vitamin D level were observed (P<0.01 or P<0.05). At entry and after 1 year of treatment, no significant association was found between Xba Ⅰ, Pvu Ⅱ, and Apa Ⅰ genotypes and BMD in L1-4,Neck, and Troch, and all bone turnover marker levels. However, the percentage of change (median, QR) in Neck BMD was significantly different in homozygous XX [-4.14 (from -6.54 to -1.34)] in comparison with Xx [1.72(from -1.12 to 3.20)] (P<0.001) or xx [1.22 (from -1.74 to 3.06)] Xba Ⅰ ER-alpha genotype (P=0.001).CONCLUSION: Women with ER-α Xba Ⅰ genotype XX may have a higher risk of relatively fast bone mass loss in femoral neck after menopause and that they may have a poor responsiveness to calcium supplementation. The changes in BMD are not associated with ER-alpha Pvu Ⅱ genotype and VDR Apa Ⅰ genotype after 1 year of calcium supplementation.

  17. Estrogen receptor alpha augments changes in hemostatic gene expression in HepG2 cells treated with estradiol and phytoestrogens.

    Science.gov (United States)

    Kelly, Lynne A; Seidlova-Wuttke, Dana; Wuttke, Wolfgang; O'Leary, John J; Norris, Lucy A

    2014-01-15

    Phytoestrogens are popular alternatives to estrogen therapy however their effects on hemostasis in post-menopausal women are unknown. The aim of this study was to determine the effect of the phytoestrogens, genistein, daidzein and equol on the expression of key genes from the hemostatic system in human hepatocyte cell models and to determine the role of estrogen receptors in mediating any response seen. HepG2 cells and Hep89 cells (expressing estrogen receptor alpha (ERα)) were incubated for 24 h with 50 nM 17β-estradiol, genistein, daidzein or equol. Tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), Factor VII, fibrinogen γ, protein C and protein S mRNA expression were determined using TaqMan PCR. Genistein and equol increased tPA and PAI-1 expression in Hep89 cells with fold changes greater than those observed for estradiol. In HepG2 cells (which do not express ERα), PAI-1 and tPA expression were unchanged. Increased expression of Factor VII was observed in phytoestrogen treated Hep89 cells but not in similarly treated HepG2s. Prothrombin gene expression was increased in equol and daidzein treated HepG2 cells in the absence of the classical estrogen receptors. These data suggest that phytoestrogens can regulate the expression of coagulation and fibrinolytic genes in a human hepatocyte cell line; an effect which is augmented by ERα.

  18. Nitric oxide enhances the sensitivity of alpaca melanocytes to respond to {alpha}-melanocyte-stimulating hormone by up-regulating melanocortin-1 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yanjun; Cao, Jing; Wang, Haidong; Zhang, Jie; Zhu, Zhiwei; Bai, Rui; Hao, HuanQing; He, Xiaoyan; Fan, Ruiwen [College of Animal Science and Technology, Shanxi Agricultural University, 030801 Taigu, Shanxi (China); Dong, Changsheng, E-mail: cs_dong@sxau.edu.cn [College of Animal Science and Technology, Shanxi Agricultural University, 030801 Taigu, Shanxi (China)

    2010-06-11

    Nitric oxide (NO) and {alpha}-melanocyte-stimulating hormone ({alpha}-MSH) have been correlated with the synthesis of melanin. The NO-dependent signaling of cellular response to activate the hypothalamopituitary proopiomelanocortin system, thereby enhances the hypophysial secretion of {alpha}-MSH to stimulate {alpha}-MSH-receptor responsive cells. In this study we investigated whether an NO-induced pathway can enhance the ability of the melanocyte to respond to {alpha}-MSH on melanogenesis in alpaca skin melanocytes in vitro. It is important for us to know how to enhance the coat color of alpaca. We set up three groups for experiments using the third passage number of alpaca melanocytes: the control cultures were allowed a total of 5 days growth; the UV group cultures like the control group but the melanocytes were then irradiated everyday (once) with 312 mJ/cm{sup 2} of UVB; the UV + L-NAME group is the same as group UV but has the addition of 300 {mu}M L-NAME (every 6 h). To determine the inhibited effect of NO produce, NO produces were measured. To determine the effect of the NO to the key protein and gene of {alpha}-MSH pathway on melanogenesis, the key gene and protein of the {alpha}-MSH pathway were measured by quantitative real-time PCR and Western immunoblotting. The results provide exciting new evidence that NO can enhance {alpha}-MSH pathway in alpaca skin melanocytes by elevated MC1R. And we suggest that the NO pathway may more rapidly cause the synthesis of melanin in alpaca skin under UV, which at that time elevates the expression of MC1R and stimulates the keratinocytes to secrete {alpha}-MSH to enhance the {alpha}-MSH pathway on melanogenesis. This process will be of considerable interest in future studies.

  19. The role of estrogen receptor alpha in mediating chemoresistance in breast cancer cells

    Directory of Open Access Journals (Sweden)

    Jiang Zhinong

    2012-05-01

    Full Text Available Abstract Introduction Previous studies suggested that estrogen receptor alpha (ERα plays an important role in the chemoresistance of breast cancers. However, large random trials failed to demonstrate any benefit of the concurrent estrogen antagonist tamoxifen on the chemotherapy efficacy. Thus, in the present study, the importance of the role of ERα in the chemoresistance of breast cancer cells was investigated. Methods The ERα-transfected Bcap37 cells and natural ERα-positive T47D breast cancer cells were treated using chemotherapeutic agents with or without 17-beta estradiol (E2 pretreatment. Their viabilities were assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assays. The dead cell rates were determined using propidium iodide dye exclusion tests, and the expression levels of Bcl-2 and Bax were detected through Western blot analysis. The effects of E2 on the growth of breast cancer cells were also determined via cell growth curve and cell cycle analysis. Results ERα activation by E2 increased the sensitivity of natural ERα-positive T47D breast cancer cells to chemotherapeutic agents. However, the increase in ERα expression in ERα-negative Bcap37 breast cancer cells also significantly increased their resistance. These phenomena cannot be explained by asserting that ERα mediated the chemoresistance of breast cancer cells by regulating the expression of Bcl-2 and Bax. Our findings show that ERα activation upregulated the expression of Bcl-2 in natural ERα-positive T47D breast cancer cells, whereas ERα activation by E2 downregulated and upregulated the Bcl-2 and Bax expression levels, respectively, in ERα-transfected Bcap37 cells. This phenomenon was due to the influence of ERα on the growth of breast cancer cells. Specifically, ERα activation enhanced the growth of natural ERα-positive breast cancer cells and thus increased their sensitivity to chemotherapeutic agents. However, ERα activation also

  20. Estrogen Receptor Alpha Distribution and Expression in the Social Neural Network of Monogamous and Polygynous Peromyscus.

    Science.gov (United States)

    Cushing, Bruce S

    2016-01-01

    In microtine and dwarf hamsters low levels of estrogen receptor alpha (ERα) in the bed nucleus of the stria terminalis (BST) and medial amygdala (MeA) play a critical role in the expression of social monogamy in males, which is characterized by high levels of affiliation and low levels of aggression. In contrast, monogamous Peromyscus males display high levels of aggression and affiliative behavior with high levels of testosterone and aromatase activity. Suggesting the hypothesis that in Peromyscus ERα expression will be positively correlated with high levels of male prosocial behavior and aggression. ERα expression was compared within the social neural network, including the posterior medial BST, MeA posterodorsal, medial preoptic area (MPOA), ventromedial hypothalamus (VMH), and arcuate nucleus in two monogamous species, P. californicus and P. polionotus, and two polygynous species, P. leucopus and P. maniculatus. The results supported the prediction, with male P. polionotus and P. californicus expressing higher levels of ERα in the BST than their polygynous counter parts, and ERα expression was sexually dimorphic in the polygynous species, with females expressing significantly more than males in the BST in both polygynous species and in the MeA in P. leucopus. Peromyscus ERα expression also differed from rats, mice and microtines as in neither the MPOA nor the VMH was ERα sexually dimorphic. The results supported the hypothesis that higher levels of ERα are associated with monogamy in Peromyscus and that differential expression of ERα occurs in the same regions of the brains regardless of whether high or low expression is associated with social monogamy. Also discussed are possible mechanisms regulating this differential relationship.

  1. Functional oestrogen receptor {alpha} imaging in endometrial carcinoma using 16{alpha}-[{sup 18}F]fluoro-17{beta}-oestradiol PET

    Energy Technology Data Exchange (ETDEWEB)

    Tsujikawa, Tetsuya; Kiyono, Yasushi; Kudo, Takashi; Fujibayashi, Yasuhisa [University of Fukui, Biomedical Imaging Research Center, Fukui (Japan); Yoshida, Yoshio; Kurokawa, Tetsuji; Kotsuji, Fumikazu [University of Fukui, Department of Gynecology, Faculty of Medical Sciences, Fukui (Japan); Okazawa, Hidehiko [University of Fukui, Biomedical Imaging Research Center, Fukui (Japan); University of Fukui, Research and Education Program for Life Science, Fukui (Japan)

    2011-01-15

    To investigate the correlation between uptake of 16{alpha}-[{sup 18}F]fluoro-17{beta}-oestradiol (FES) and expression of oestrogen receptors as well as other related immunohistochemistry markers, positron emission tomography (PET) was performed in patients with endometrial carcinoma before surgery. Nineteen patients with endometrioid adenocarcinoma underwent preoperative PET studies with FES and 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (FDG). Standardized uptake values (SUVs) for each tracer and the regional FDG to FES SUV ratio were calculated using images after coregistration. PET values were compared with postoperative stage, differentiation grade and immunohistochemical scores including oestrogen receptor subtypes (ER{alpha}, ER{beta}), progesterone receptor B (PR-B), Ki-67 and glucose transporter 1 (GLUT1). FES uptake showed a significantly positive correlation with expression of ER{alpha}. The FDG to FES ratio showed a significantly negative correlation with expression of ER{alpha} and PR-B. The FES uptake and FDG to FES ratio did not correlate with expression of ER{beta}, Ki-67 or GLUT1. FDG uptake was not correlated with any of the immunohistochemical scores. The PR-B score was strongly correlated with the ER{alpha} score. Well-differentiated carcinoma (grade 1) showed a significantly higher FES uptake and significantly lower FDG to FES ratio than moderately or poorly differentiated carcinoma (grade 2-3). None of the PET parameters were significantly different between advanced-stage carcinoma ({>=} stage IB) and early-stage carcinoma (IA) based on the Federation International de Gynecologie et d'Obstetrique (FIGO) staging classification. Differentiation grade was the most closely correlated parameter to FES uptake and FDG to FES ratio by multivariate analyses. FES PET combined with FDG would be useful for non-invasive evaluation of ER{alpha} distribution, as well as ER{alpha} function, which reflects differentiation grade in endometrial carcinoma. (orig.)

  2. Antiviral activity of bacteria-derived human alpha interferons against encephalomyocarditis virus infection of mice.

    OpenAIRE

    Weck, P K; Rinderknecht, E; Estell, D A; Stebbing, N

    1982-01-01

    Bacteria-derived human leukocyte interferon (IFN) subtypes, IFN-alpha A, -alpha B, and -alpha D, and two hybrid IFNs, IFN-alpha AD and -alpha DA, were examined for both in vitro and in vivo antiviral activity. Two of these materials in highly purified form (IFN-alpha D and -alpha D) protect mice against lethal doses of encephalomyocarditis virus infection. A single dose of 1 microgram of protein of IFN-alpha D 3 h before infection conferred protection in both BDF1 and CD-1 mice against enceph...

  3. Highly Potent, Water Soluble Benzimidazole Antagonist for Activated (alpha)4(beta)1 Integrin

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, R D; Andrei, M; Lau, E Y; Lightstone, F C; Liu, R; Lam, K S; Kurth, M J

    2007-08-29

    The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin, activated constitutively in lymphoma, can be targeted with the bisaryl urea peptidomimetic antagonist 1 (LLP2A). However, concerns on its preliminary pharmacokinetic (PK) profile provided an impetus to change the pharmacophore from a bisaryl urea to a 2-arylaminobenzimidazole moiety resulting in improved solubility while maintaining picomolar potency [5 (KLCA4); IC{sub 50} = 305 pM]. With exceptional solubility, this finding has potential for improving PK to help diagnose and treat lymphomas.

  4. Direct interaction of the kringle domain of urokinase-type plasminogen activator (uPA) and integrin alpha v beta 3 induces signal transduction and enhances plasminogen activation.

    Science.gov (United States)

    Tarui, Takehiko; Akakura, Nobuaki; Majumdar, Mousumi; Andronicos, Nicholas; Takagi, Junichi; Mazar, Andrew P; Bdeir, Khalil; Kuo, Alice; Yarovoi, Serge V; Cines, Douglas B; Takada, Yoshikazu

    2006-03-01

    It has been questioned whether there are receptors for urokinase-type plasminogen activator (uPA) that facilitate plasminogen activation other than the high affinity uPA receptor (uPAR/CD87) since studies of uPAR knockout mice did not support a major role of uPAR in plasminogen activation. uPA also promotes cell adhesion, chemotaxis, and proliferation besides plasminogen activation. These uPA-induced signaling events are not mediated by uPAR, but mediated by unidentified, lower-affinity receptors for the uPA kringle. We found that uPA binds specifically to integrin alpha v beta 3 on CHO cells depleted of uPAR. The binding of uPA to alpha v beta 3 required the uPA kringle domain. The isolated uPA kringle domain binds specifically to purified, recombinant soluble, and cell surface alpha v beta 3, and other integrins (alpha 4 beta 1 and alpha 9 beta 1), and induced migration of CHO cells in an alpha v beta 3-dependent manner. The binding of the uPA kringle to alpha v beta 3 and uPA kringle-induced alpha v beta 3-dependent cell migration were blocked by homologous plasminogen kringles 1-3 or 1-4 (angiostatin), a known integrin antagonist. We studied whether the binding of uPA to integrin alpha v beta 3 through the kringle domain plays a role in plasminogen activation. On CHO cell depleted of uPAR, uPA enhanced plasminogen activation in a kringle and alpha v beta 3-dependent manner. Endothelial cells bound to and migrated on uPA and uPA kringle in an alpha v beta 3-dependent manner. These results suggest that uPA binding to integrins through the kringle domain plays an important role in both plasminogen activation and uPA-induced intracellular signaling. The uPA kringle-integrin interaction may represent a novel therapeutic target for cancer, inflammation, and vascular remodeling. PMID:16525582

  5. Serum interleukin-1 alpha and soluble interleukin-2 receptor concentrations in cystic fibrosis.

    OpenAIRE

    Greally, P; Hussain, M J; Vergani, D.; Price, J F

    1993-01-01

    Interleukin (IL)-1 and IL-2 may participate in the systemic inflammatory response and hypergammaglobulinaemia observed in patients with cystic fibrosis. Thirty seven patients with cystic fibrosis were compared with 25 normal controls. High IgG and IgM concentrations were associated with more severe pulmonary disease. IL-1 alpha and soluble IL-2 receptor concentrations were higher in the cystic fibrosis group than in the controls and also correlated with concentrations of IgG and IgM. These re...

  6. Epicardial retinoid X receptor alpha is required for myocardial growth and coronary artery formation.

    Science.gov (United States)

    Merki, Esther; Zamora, Mónica; Raya, Angel; Kawakami, Yasuhiko; Wang, Jianming; Zhang, Xiaoxue; Burch, John; Kubalak, Steven W; Kaliman, Perla; Izpisua Belmonte, Juan Carlos; Chien, Kenneth R; Ruiz-Lozano, Pilar

    2005-12-20

    Vitamin A signals play critical roles during embryonic development. In particular, heart morphogenesis depends on vitamin A signals mediated by the retinoid X receptor alpha (RXRalpha), as the systemic mutation of this receptor results in thinning of the myocardium and embryonic lethality. However, the molecular and cellular mechanisms controlled by RXRalpha signaling in this process are unclear, because a myocardium-restricted RXRalpha mutation does not perturb heart morphogenesis. Here, we analyze a series of tissue-restricted mutations of the RXRalpha gene in the cardiac neural crest, endothelial, and epicardial lineages, and we show that RXRalpha signaling in the epicardium is required for proper cardiac morphogenesis. Moreover, we detect an additional phenotype of defective coronary arteriogenesis associated with RXRalpha deficiency and identify a retinoid-dependent Wnt signaling pathway that cooperates in epicardial epithelial-to-mesenchymal transformation. PMID:16352730

  7. Identification and characterization of estrogen receptor-related receptor alpha and gamma in human glioma and astrocytoma cells.

    Science.gov (United States)

    Gandhari, Mukesh K; Frazier, Chester R; Hartenstein, Julia S; Cloix, Jean-Francois; Bernier, Michel; Wainer, Irving W

    2010-02-01

    The purpose of this study was to examine expression and function of estrogen receptor-related receptors (ERRs) in human glioma and astrocytoma cell lines. These estrogen receptor-negative cell lines expressed ERRalpha and ERRgamma proteins to varying degree in a cell context dependent manner, with U87MG glioma cells expressing both orphan nuclear receptors. Cell proliferation assays were performed in the presence of ERR isoform-specific agonists and antagonists, and the calculated EC(50) and IC(50) values were consistent with previous reported values determined in other types of cancer cell lines. Induction of luciferase expression under the control of ERR isoform-specific promoters was also observed in these cells. These results indicate that ERRalpha and ERRgamma are differentially expressed in these tumor cell lines and likely contribute to agonist-dependent ERR transcriptional activity. PMID:19822186

  8. HIF-1alpha and HIF-2alpha are differentially activated in distinct cell populations in retinal ischaemia.

    Directory of Open Access Journals (Sweden)

    Freya M Mowat

    Full Text Available BACKGROUND: Hypoxia plays a key role in ischaemic and neovascular disorders of the retina. Cellular responses to oxygen are mediated by hypoxia-inducible transcription factors (HIFs that are stabilised in hypoxia and induce the expression of a diverse range of genes. The purpose of this study was to define the cellular specificities of HIF-1alpha and HIF-2alpha in retinal ischaemia, and to determine their correlation with the pattern of retinal hypoxia and the expression profiles of induced molecular mediators. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the tissue distribution of retinal hypoxia during oxygen-induced retinopathy (OIR in mice using the bio-reductive drug pimonidazole. We measured the levels of HIF-1alpha and HIF-2alpha proteins by Western blotting and determined their cellular distribution by immunohistochemistry during the development of OIR. We measured the temporal expression profiles of two downstream mediators, vascular endothelial growth factor (VEGF and erythropoietin (Epo by ELISA. Pimonidazole labelling was evident specifically in the inner retina. Labelling peaked at 2 hours after the onset of hypoxia and gradually declined thereafter. Marked binding to Müller glia was evident during the early hypoxic stages of OIR. Both HIF-1alpha and HIF-2alpha protein levels were significantly increased during retinal hypoxia but were evident in distinct cellular distributions; HIF-1alpha stabilisation was evident in neuronal cells throughout the inner retinal layers whereas HIF-2alpha was restricted to Müller glia and astrocytes. Hypoxia and HIF-alpha stabilisation in the retina were closely followed by upregulated expression of the downstream mediators VEGF and EPO. CONCLUSIONS/SIGNIFICANCE: Both HIF-1alpha and HIF-2alpha are activated in close correlation with retinal hypoxia but have contrasting cell specificities, consistent with differential roles in retinal ischaemia. Our findings suggest that HIF-2alpha activation

  9. Characterization of a novel small molecule subtype specific estrogen-related receptor alpha antagonist in MCF-7 breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Michael J Chisamore

    Full Text Available BACKGROUND: The orphan nuclear receptor estrogen-related receptor alpha (ERRalpha is a member of the nuclear receptor superfamily. It was identified through a search for genes encoding proteins related to estrogen receptor alpha (ERalpha. An endogenous ligand has not been found. Novel ERRalpha antagonists that are highly specific for binding to the ligand binding domain (LBD of ERRalpha have been recently reported. Research suggests that ERRalpha may be a novel drug target to treat breast cancer and/or metabolic disorders and this has led to an effort to characterize the mechanisms of action of N-[(2Z-3-(4,5-dihydro-1,3-thiazol-2-yl-1,3-thiazolidin-2-yl idene]-5H dibenzo[a,d][7]annulen-5-amine, a novel ERRalpha specific antagonist. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate this ERRalpha ligand inhibits ERRalpha transcriptional activity in MCF-7 cells by luciferase assay but does not affect mRNA levels measured by real-time RT-PCR. Also, ERalpha (ESR1 mRNA levels were not affected upon treatment with the ERRalpha antagonist, but other ERRalpha (ESRRA target genes such as pS2 (TFF1, osteopontin (SPP1, and aromatase (CYP19A1 mRNA levels decreased. In vitro, the ERRalpha antagonist prevents the constitutive interaction between ERRalpha and nuclear receptor coactivators. Furthermore, we use Western blots to demonstrate ERRalpha protein degradation via the ubiquitin proteasome pathway is increased by the ERRalpha-subtype specific antagonist. We demonstrate by chromatin immunoprecipitation (ChIP that the interaction between ACADM, ESRRA, and TFF1 endogenous gene promoters and ERRalpha protein is decreased when cells are treated with the ligand. Knocking-down ERRalpha (shRNA led to similar genomic effects seen when MCF-7 cells were treated with our ERRalpha antagonist. CONCLUSIONS/SIGNIFICANCE: We report the mechanism of action of a novel ERRalpha specific antagonist that inhibits transcriptional activity of ERRalpha, disrupts the constitutive

  10. Topological dispositions of lysine. alpha. 380 and lysine. gamma. 486 in the acetylcholine receptor from Torpedo californica

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, B.P. (Univ. of California, San Diego, La Jolla (USA))

    1991-04-23

    The locations have been determined, with respect to the plasma membrane, of lysine {alpha}380 and lysine {gamma}486 in the {alpha} subunit and the {gamma} subunit, respectively, of the nicotinic acetylcholine receptor from Torpedo californica. Immunoadsorbents were constructed that recognize the carboxy terminus of the peptide GVKYIAE released by proteolytic digestion from positions 378-384 in the amino acid sequence of the {alpha} subunit of the acetylcholine receptor and the carboxy terminus of the peptide KYVP released by proteolytic digestion from positions 486-489 in the amino acid sequence of the {gamma} subunit. They were used to isolate these peptides from proteolytic digests of polypeptides from the acetylcholine receptor. Sealed vesicles containing the native acetylcholine receptor were labeled with pyridoxal phosphate and sodium ({sup 3}H)-borohydride. The effect of saponin on the incorporation of pyridoxamine phosphate into lysine {alpha}380 and lysine {gamma}486 from the acetylcholine receptor in these vesicles was assessed with the immunoadsorbents. The conclusions that follow from these results are that lysine {alpha}380 is on the inside surface of a vesicle and lysine {gamma}486 is on the outside surface. Because a majority (85%) of the total binding sites for {alpha}-bungarotoxin bind the toxin in the absence of saponin, the majority of the vesicles are right side out with the inside of the vesicle corresponding to the cytoplasmic surface and the outside of the vesicle corresponding to the extracytoplasmic, synaptic surface. Because lysine {alpha}380 and lysine {gamma}486 lie on opposite sides of the membrane, a membrane-spanning segment must be located between the two positions occupied by these two amino acids in the common sequence of a polypeptide of the acetylcholine receptor.

  11. Role of interleukin-15 receptor alpha polymorphisms in normal weight obese syndrome.

    Science.gov (United States)

    Di Renzo, L; Gloria-Bottini, F; Saccucci, P; Bigioni, M; Abenavoli, L; Gasbarrini, G; De Lorenzo, A

    2009-01-01

    Previous published studies have identified a class of women, Normal Weight Obese women (NWO) with normal BMI and high fat content. An important role of Interleukin-15 (IL-15) has been documented in facilitating muscle proliferation and promoting fat depletion. Indeed the presence of three types of IL-15 receptor subunits in fat tissue suggests a direct effect on adipose tissue. We studied three single nucleotide polymorphisms (SNP) of IL-15R-alpha receptor gene and investigated their relationship with NWO phenotype. We considered two classes of women according to their BMI and percent fat mass (percent FAT), class 1: including 72 overweight-obese women (high BMI-high fat mass) and class 2: including 36 NWO (normal BMI, high fat mass). Three sites of Interleukin-15 receptor subunit á gene were examined, located respectively in exon4, exon5 intron-exon border and exon7. Genotyping of the identified polymorphisms was performed by restriction fragment length polymorphism. Haplotype frequency estimation was performed by using the Mendel-University of Chicago program. Odds ratio analyses were calculated by EPISTAT program. Highly significant differences were observed for exon 7- exon5 intron-exon border and exon 4-exon 7 haplotype distribution between class 1 and class 2 women. These results strongly support the hypothesis that genetic variability of the IL-15 receptor has an important role in body fat composition. Our data underscore previous findings that suggest a potential role of IL-15 cytokine in NWO syndrome. PMID:19309557

  12. Activation of podocytes by mesangial-derived TNF-alpha: glomerulo-podocytic communication in IgA nephropathy.

    Science.gov (United States)

    Lai, Kar Neng; Leung, Joseph C K; Chan, Loretta Y Y; Saleem, Moin A; Mathieson, Peter W; Lai, Fernand M; Tang, Sydney C W

    2008-04-01

    We have previously documented that human mesangial cell (HMC)-derived TNF-alpha is an important mediator involved in the glomerulo-tubular communication in the development of interstitial damage in IgA nephropathy (IgAN). With the strategic position of podocytes, we further examined the role of mesangial cells in the activation of podocytes in IgAN. There was no binding of IgA from patients with IgAN to podocytes. Podocytes cultured with IgA from patients with IgAN did not induce the release of growth factors or cytokines. Furthermore, podocytes did not express mRNA of known IgA receptors. In contrast, IgA-conditioned medium (IgA-HMC medium) prepared by culturing HMC with IgA from patients with IgAN for 48 h significantly increased the gene expression and protein synthesis of TNF-alpha by podocytes with a 17-fold concentration above that of IgA-HMC medium. The upregulation of TNF-alpha expression by podocyte was only abolished by a neutralizing antibody against TNF-alpha but not by other antibodies. Exogenous TNF-alpha upregulated the synthesis of TNF-alpha by podocytes in an autocrine fashion. IgA-HMC medium prepared with IgA from patients with IgAN also significantly upregulated the expression of both TNF-alpha receptor 1 and 2 in podocytes. Our in vitro finding suggests podocytes may play a contributory role in the development of interstitial damage in IgAN by amplifying the activation of tubular epithelial cells with enhanced TNF-alpha synthesis after inflammatory changes of HMC.

  13. Androgen insensitivity syndrome: gonadal androgen receptor activity

    International Nuclear Information System (INIS)

    To determine whether abnormalities of the androgen receptor previously observed in skin fibroblasts from patients with androgen insensitivity syndrome also occur in the gonads of affected individuals, androgen receptor activity in the gonads of a patient with testicular feminization syndrome was investigated. Using conditions for optimal recovery of androgen receptor from human testes established by previous studies, we detected the presence of a high-affinity (dissociation constant . 3.2 X 10(-10) mol/L), low-capacity (4.2 X 10(-12) mol/mg DNA), androgen-binding protein when tritium-labeled R1881 was incubated at 4 degrees C with nuclear extracts from the gonads of control patients or from a patient with testicular feminization syndrome but not when incubated at 37 degrees C. Thus this patient has an androgen receptor with a temperature lability similar to that of receptors from normal persons

  14. Increased sensitivity of estrogen receptor alpha overexpressing antral follicles to methoxychlor and its metabolites.

    Science.gov (United States)

    Paulose, Tessie; Hernández-Ochoa, Isabel; Basavarajappa, Mallikarjuna S; Peretz, Jackye; Flaws, Jodi A

    2011-04-01

    Methoxychlor (MXC), an organochlorine pesticide, and its metabolites, mono-hydroxy MXC (MOH) and bis-hydroxy MXC (HPTE) are known ovarian toxicants and can cause inhibition of antral follicle growth. Since these chemicals bind to estrogen receptor alpha (ESR1), we hypothesized that ovaries overexpressing ESR1 (ESR1 OE) would be more susceptible to toxicity induced by MXC and its metabolites because the chemicals can bind to more ESR1 in the antral follicles. We cultured antral follicles from controls and ESR1 OE mouse ovaries with either the vehicle dimethylsulfoxide (DMSO), MXC, MOH, or HPTE. The data show that at 96 h, the cultured antral follicles from ESR1 OE antral follicles are more susceptible to toxicity induced by MXC, MOH, and HPTE because low doses of these chemicals cause follicle growth inhibition in ESR1 OE mice but not in control mice. On comparing gene expression levels of nuclear receptors in the cultured antral follicles of ESR1 OE and control follicles, we found differential messenger RNA (mRNA) expression of Esr1, estrogen receptor beta (Esr2), androgen receptor (Ar), progesterone receptor (Pr), and aryl hydrocarbon receptor (Ahr) between the genotypes. We also analyzed mRNA levels of Cyp3a41a, the enzyme metabolizing MOH and HPTE, in the cultured follicles and found that Cyp3a41a was significantly lower in DMSO-treated ESR1 OE follicles compared with controls. In ESR1 OE livers, we found that Cyp3a41a levels were significantly lower compared with control livers. Collectively, these data suggest that MXC and its metabolites cause differential gene expression in ESR1 OE mice compared with controls. The results also suggest that the increased sensitivity of ESR1 OE mouse ovaries to toxicity induced by MXC and its metabolites is due to low clearance of the metabolites by the liver and ovary.

  15. DMPD: What is disrupting IFN-alpha's antiviral activity? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15283983 What is disrupting IFN-alpha's antiviral activity? Mbow ML, Sarisky RT. Tr...ends Biotechnol. 2004 Aug;22(8):395-9. (.png) (.svg) (.html) (.csml) Show What is disrupting IFN-alpha's antiviral activity...? PubmedID 15283983 Title What is disrupting IFN-alpha's antiviral activity? Authors Mbow ML,

  16. Structure and diversity of the T-cell receptor alpha chain in the Mexican axolotl.

    Science.gov (United States)

    Fellah, J S; Kerfourn, F; Dumay, A M; Aubet, G; Charlemagne, J

    1997-01-01

    Polymerase chain reaction was used to isolate cDNA clones encoding putative T-cell receptor (TCR) alpha chains in an amphibian, the Mexican axolotl (Ambystoma mexicanum). Five TCRalpha-V chain-encoding segments were identified, each belonging to a separate family. The best identity scores for these axolotl TCRalpha-V segments were all provided by sequences belonging to the human TCRalpha-V1 family and the mouse TCRalpha-V3 and TCRalpha-V8 families. A total of 14 different TCRA-J segments were identified from 44 TCRA-V/TCRA-J regions sequenced, suggesting that a large repertoire of TCRA-J segments is a characteristic of most vertebrates. The structure of the axolotl CDR3 alpha chain loop is in good agreement with that of mammals, including a majority of small hydrophobic residues at position 92 and of charged, hydrophilic, or polar residues at positions 93 and 94, which are highly variable and correspond to the TCRA-V/J junction. This suggests that some positions of the axolotl CDR3 alpha chain loop are positively selected during T-cell differentiation, particularly around residue 93 that could be selected for its ability to makes contacts with major histocompatibility complex-associated antigenic peptides, as in mammals. The axolotl Calpha domain had the typical structure of mammalian and avian Calpha domains, including the charged residues in the TM segment that are thought to interact with other proteins in the membrane, as well as most of the residues forming the conserved antigen receptor transmembrane motif. PMID:9002443

  17. Activating STAT3 Alpha for Promoting Healing of Neurons

    Science.gov (United States)

    Conway, Greg

    2008-01-01

    A method of promoting healing of injured or diseased neurons involves pharmacological activation of the STAT3 alpha protein. Usually, injured or diseased neurons heal incompletely or not at all for two reasons: (1) they are susceptible to apoptosis (cell death); and (2) they fail to engage in axogenesis that is, they fail to re-extend their axons to their original targets (e.g., muscles or other neurons) because of insufficiency of compounds, denoted neurotrophic factors, needed to stimulate such extension. The present method (see figure) of treatment takes advantage of prior research findings to the effect that the STAT3 alpha protein has anti-apoptotic and pro-axogenic properties.

  18. Ockham's razor and selective androgen receptor modulators (SARMs): are we overlooking the role of 5alpha-reductase?

    Science.gov (United States)

    Gao, Wenqing; Dalton, James T

    2007-02-01

    Selective Androgen Receptor Modulators (SARMs) are a novel class of AR ligands that possess tissue-selective pharmacological activities. SARMs of various chemical structures have been discovered and characterized, and lead compounds with much improved specificity for AR, in vivo pharmacokinetic profiles, and higher degree of tissue selectivity have entered clinical development, and are expected to dramatically expand the clinical applications of androgens. With the rapid progress in SARM discovery and increasing demand for mechanism-based drug design, more and more research efforts have been devoted to the mechanisms of action of the observed tissue selectivity of SARMs. There is increasing enthusiasm in adapting the molecular mechanisms of action from SERM research to the SARM field; however, is the SARM story really so complicated? The tissue-specific expression of 5alpha-reductase might provide a simple explanation for this puzzle.

  19. Receptor tyrosine phosphatase R-PTP-alpha is tyrosine-phosphorylated and associated with the adaptor protein Grb2

    DEFF Research Database (Denmark)

    Su, J; Batzer, A; Sap, J

    1994-01-01

    -phosphorylated and associated in vivo with the Grb2 protein. This association can be reproduced in stably and transiently transfected cells, as well as in vitro using recombinant Grb2 protein. Association requires the presence of an intact SH2 domain in Grb2, as well as tyrosine phosphorylation of R-PTP-alpha. This observation......Receptor tyrosine phosphatases (R-PTPases) have generated interest because of their suspected involvement in cellular signal transduction. The adaptor protein Grb2 has been implicated in coupling receptor tyrosine kinases to Ras. We report that a ubiquitous R-PTPase, R-PTP-alpha, is tyrosine...... links a receptor tyrosine phosphatase with a key component of a central cellular signalling pathway and provides a basis for addressing R-PTP-alpha function....

  20. Effects of local alpha2-adrenergic receptor blockade on adipose tissue lipolysis during prolonged systemic adrenaline infusion in normal man

    DEFF Research Database (Denmark)

    Simonsen, Lene; Enevoldsen, Lotte H; Stallknecht, Bente;

    2008-01-01

    During prolonged adrenaline infusion, lipolysis peaks within 30 min and thereafter tends to decline, and we hypothesized that the stimulation of local adipose tissue alpha2-adrenergic receptors accounts for this decline. The lipolytic effect of a prolonged intravenous adrenaline infusion combined....... Regional adipose tissue blood flow was measured by the (133)Xe clearance technique. Regional glycerol output (lipolytic rate) was calculated from these measurements and simultaneous measurements of arterial glycerol concentrations. Adrenaline infusion increased lipolysis in all three depots (data...... circulating adrenaline concentrations, and the decrease in lipolysis in subcutaneous adipose tissue under prolonged adrenaline stimulation is thus not attributed to alpha2-adrenergic receptor inhibition of lipolysis. However, in the preperitoneal adipose tissue depot, alpha2-adrenergic receptor tone plays...

  1. Lectin-like receptor for alpha 1-acid glycoprotein in the epithelium of the rat prostate gland and seminal vesicles

    DEFF Research Database (Denmark)

    Andersen, U O; Bøg-Hansen, T C; Kirkeby, S

    1996-01-01

    BACKGROUND: A receptor for alpha 1-acid glycoprotein glycoforms AGP-B and AGP-C in the epithelium of the rat prostate gland and seminal vesicles is described. METHODS: The interaction between AGP-glycoforms and their receptor is a lectin-like interaction confirmed by inhibition of the binding...... in rat prostate and seminal vesicles. The localization of the AGP lectin receptor is compared to the localization of glycoprotein AGP, and small differences are found. CONCLUSIONS: It is proposed the AGP receptors in the prostate and seminal vesicles belong to a group of lectins in the control...

  2. Pharmacology and toxicology of fibrates as hypolipidemic drugs mediated by nuclear receptor peroxisome proliferator—activated receptor

    Institute of Scientific and Technical Information of China (English)

    SugaT

    2002-01-01

    PPAR(peroxisome proliferator-activated receptor) is a family of nuclear receptor.In recent years,it has been focused for the discovery and development of new drugs which are mediated by PPARs.Fibrate hypolipidemic drugs are the specific and potent ligands to PPAR alpha and have been widely used for the treatment of hyperlipidemia.But these drugs induce hepatocarcinogenesis in rodent animals after the long-term administration.However,there are species differences on these phenomena which are not seen in mammals ioncluding human.To clarify the mechanism of carcinogenesis by these drugs in important for the evaluation of safety of these drugs in human.

  3. Chemokine stromal cell-derived factor 1alpha activates basophils by means of CXCR4

    DEFF Research Database (Denmark)

    Jinquan, T; Jacobi, H H; Jing, C;

    2000-01-01

    The CXC chemokine receptor 4 (CXCR4) is predominantly expressed on inactivated naive T lymphocytes, B lymphocytes, dendritic cells, and endothelial cells. CXC chemokine stromal cell-derived factor 1alpha (SDF-1alpha) is the only known ligand for CXCR4. To date, the CXCR4 expression and function o...

  4. The atrophy and changes in the cellular compositions of the thymus and spleen observed in mice subjected to short-term exposure to perfluorooctanesulfonate are high-dose phenomena mediated in part by peroxisome proliferator-activated receptor-alpha (PPARα)

    International Nuclear Information System (INIS)

    We have previously shown that short-term, high-dose exposure of mice to the environmentally persistent perfluorooctanoate (PFOA) results in thymic and splenic atrophy and the attenuation of specific humoral immune responses. Here we characterize the effects of a 10-day treatment with different dietary doses (1-0.001%, w/w) of perfluorooctanesulfonate (PFOS), a similar fluorochemical, on the immune system of male C57BL/6 mice. At doses greater than 0.02%, PFOS induced clinical signs of toxicity in the animals, whereas at the concentration of 0.02%, this compound caused weight loss, hepatomegaly and atrophy of the thymus, spleen and adipose tissue without toxicity. With this latter dose, histopathological and flow-cytometric analysis revealed that (i) the thymic cortex was virtually depleted of cells; (ii) the total numbers of thymocytes and splenocytes were reduced by 84 and 43%, respectively; (iii) although all populations of thymocytes and splenocytes were smaller, the thymic CD4+CD8+ cells and the splenic B-lymphocytes were most decreased. These alterations resembled those evoked by analogous exposure to PFOA, but were less pronounced. At lower doses (less than 0.02%), PFOS induced hepatomegaly without affecting the thymus or spleen. Finally, comparison of male wild-type 129/Sv mice and the corresponding knock-outs lacking peroxisome proliferator-activated receptor-alpha (PPARα) indicated that these effects of PFOS are not strain-dependent. More importantly, hepatomegaly is independent of PPARα, the thymic changes are partially dependent on this receptor, and splenic responses are largely eliminated in its absence. Thus, immunomodulation caused by PFOS is a high-dose phenomenon partially dependent on PPARα.

  5. Agonist-promoted desensitization and phosphorylation of. cap alpha. /sub 1/-adrenergic receptors coupled to stimulation of phosphatidylinositol metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Leeb-Lundberg, L.M.F.; Cotecchia, S.; Caron, M.G.; Lefkowitz, R.J.

    1986-03-05

    In the DDT/sub 1/ MF-2 hamster vas deferens smooth muscle cell line the ..cap alpha../sub 1/-adrenergic receptor (..cap alpha../sub 1/-AR) agonist norepinephrine (NE) promotes rapid attenuation of ..cap alpha../sub 1/-AR-mediated phosphatidylinositol (PI) metabolism which is paralleled by rapid phosphorylation of the ..cap alpha../sub 1/-AR. Cells were labeled by incubation with /sup 32/P/sub i/. Coincubation with NE (100 ..mu..M) significantly increases the rate of /sup 32/P-labeling of both PI and phosphatidic acid. Pretreatment of cells with 100 ..mu..M NE (in the presence of 1 ..mu..M propranolol to prevent ..beta..-AR interactions) results in a drastic attenuation of the NE response on PI metabolism. ..cap alpha../sub 1/-AR from labeled cells can be solubilized and purified by affinity chromatography on Affigel-A55414 and wheat germ agglutinin agarose chromatography. SDS-PAGE of purified ..cap alpha../sub 1/-AR shows a NE-promoted increase in phosphorylation of the M/sub r/ 80K ligand binding peptide. Stoichiometry of phosphorylation increases from approx. 1 mol phosphate/mol ..cap alpha../sub 1/-AR in the basal condition to approx. 2.5 after NE treatment. Both desensitization and phosphorylation are rapid being maximal within 10-20 min of agonist exposure. These results together with previous findings that phorbol esters promote rapid ..cap alpha../sub 1/-AR uncoupling and phosphorylation suggest that receptor phosphorylation is an important mechanism of regulation of ..cap alpha../sub 1/-AR receptor responsiveness.

  6. Evaluation of [{sup 125}I]7{alpha}-O-iodoally diprenophine as a new potential SPECT opioid receptor imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R.F.; Tafani, J.A.M.; Frances, B.; Bergon, M.; Coulais, Y.; Zajac, J. M.; Guiraud, R

    1997-08-01

    A new iodinated diprenorphine analog, [{sup 125}I]7{alpha}-O-iodoallyl diprenorphine ([{sup 125}I]7{alpha}-O-IA-DPN), was prepared by iododestannylation and characterized. As an opioid antagonist, this agent showed very high affinity (K{sub i} = 0.4 {+-} 0.2 nM) and 63% of specific binding by in vitro and in vivo binding studies. Inhibition curves indicated that this tracer labeled with the same affinities to three opioid receptors ({mu} = {delta} = {kappa}). The findings demonstrate that this proposed compound appears to be a potential radioprobe for future study of opioid receptors by in vivo SPECT.

  7. Molecular cloning, characterisation, and tissue distribution of oestrogen receptor alpha in eelpout (Zoarces viviparus).

    Science.gov (United States)

    Andreassen, Thomas K; Skjoedt, Karsten; Anglade, Isabelle; Kah, Olivier; Korsgaard, Bodil

    2003-07-01

    A cDNA encoding the eelpout (Zoarces viviparus) oestrogen receptor alpha (eERalpha) has been isolated from eelpout liver, cloned and sequenced. The cDNA contains a complete open reading frame encoding 570 amino acid residues (mw: 63.0 kDa). The amino acid sequence of eERalpha showed a high degree of identity to ERalpha of other teleost species. The tissue distribution of eERalpha mRNA was examined using Northern blotting, RT-PCR and in situ hybridisation (ISH). All three methods identified a pronounced expression of eERalpha in liver, pituitary, testis and ovary. In the brain ISH experiments showed that ERalpha mRNA was highly expressed in distinct regions of the preoptic area and the mediobasal hypothalamus. We have provided evidence that the receptor is auto-regulated by 17beta-oestradiol (E(2)) not only in liver but also in the testis, indicating an important role for E(2) during spermatogenesis in male eelpout. RT-PCR analysis showed a broader expression pattern including significant expression in the brain, kidney, heart, and gut of adult eelpout. In eelpout embryos eERalpha expression has also been identified, indicating a possible role for the receptor in early development. This study contributes to the accumulating evidence that in fish E(2) is not only involved in the regulation of liver specific proteins, but has a much broader range of targets.

  8. NMDA receptor activity in neuropsychiatric disorders

    Directory of Open Access Journals (Sweden)

    Shaheen E Lakhan

    2013-06-01

    Full Text Available N-Methyl-D-aspartate (NMDA receptors play a variety of physiologic roles and their proper signaling is essential for cellular homeostasis. Any disruption in this pathway, leading to either enhanced or decreased activity, may result in the manifestation of neuropsychiatric pathologies such as schizophrenia, mood disorders, substance induced psychosis, Huntington's disease, Alzheimer's disease, and neuropsychiatric systemic lupus erythematosus. Here, we explore the notion that the overlap in activity of at least one biochemical pathway, the NMDA receptor pathway, may be the link to understanding the overlap in psychotic symptoms between diseases. This review intends to present a broad overview of those neuropsychiatric disorders for which alternations in NMDA receptor activity is prominent thus suggesting that continued direction of pharmaceutical intervention to this pathway may present a viable option for managing symptoms.

  9. Are different stoichiometries feasible for complexes between lymphotoxin-alpha and tumor necrosis factor receptor 1?

    Directory of Open Access Journals (Sweden)

    Mascarenhas Nahren

    2012-05-01

    Full Text Available Abstract Background Tumor necrosis factors, TNF and lymphotoxin-α (LT, are cytokines that bind to two receptors, TNFR1 and TNFR2 (TNF-receptor 1 and 2 to trigger their signaling cascades. The exact mechanism of ligand-induced receptor activation is still unclear. It is generally assumed that three receptors bind to the homotrimeric ligand to trigger a signaling event. Recent evidence, though, has raised doubts if the ligand:receptor stoichiometry should indeed be 3:3 for ligand-induced cellular response. We used molecular dynamics simulations, elastic network models, as well as MM/PBSA to analyze this question. Results Applying MM/PBSA methodology to different stoichiometric complexes of human LT-(TNFR1n=1,2,3 the free energy of binding in these complexes has been estimated by single-trajectory and separate-trajectory methods. Simulation studies rationalized the favorable binding energy in the LT-(TNFR11 complex, as evaluated from single-trajectory analysis to be an outcome of the interaction of cysteine-rich domain 4 (CRD4 and the ligand. Elastic network models (ENMs help to associate the difference in the global fluctuation of the receptors in these complexes. Functionally relevant transformation associated with these complexes reveal the difference in the dynamics of the receptor when free and in complex with LT. Conclusions MM/PBSA predicts complexes with a ligand-receptor molar ratio of 3:1 and 3:2 to be energetically favorable. The high affinity associated with LT-(TNFR11 is due to the interaction between the CRD4 domain with LT. The global dynamics ascertained from ENMs have highlighted the differential dynamics of the receptor in different states.

  10. Estrogen receptors alpha and beta in rat placenta: detection by RT-PCR, real time PCR and Western blotting

    Directory of Open Access Journals (Sweden)

    Al-Bader Maie D

    2006-03-01

    Full Text Available Abstract Background High levels of estrogens during pregnancy not only retard placental and fetal growth but can lead to reproductive tract abnormalities in male progeny. Estrogens act through estrogen receptors (ER to modulate the transcription of target genes. These ER exist in two isoforms, ER alpha and ER beta and recently several variants of these isoforms have been identified. Methods The expressions of ER isoforms and variants have been studied in rat placenta at 16, 19 and 21 days gestation (dg. Gene expression was assessed using RT-PCR and real time PCR while protein expression was studied using Western blotting followed by immunodetection. Placental homogenates were probed with: a monoclonal antibody raised against the steroid binding domain of the ER alpha (ER alpha -S, a monoclonal antibody raised against the hinge region of ER alpha (ER alpha -H and a polyclonal antibody raised against the amino terminus of ER beta. Results ER alpha and ER beta mRNA and protein were detected from as early as 16 dg. Two PCR products were detected for ER alpha, one for the wild type ER alpha, and a smaller variant. Real time PCR results suggested the presence of a single product for ER beta. The antibodies used for detection of ER alpha protein both identified a single 67 kDa isoform; however a second 54 kDa band, which may be an ER alpha variant, was identified when using the ER alpha -H antibody. The abundance of both ER alpha bands decreased significantly between 16 and 19 dg. As for ER beta, four bands (76, 59, 54 and 41 kDa were detected. The abundance of the 59 and 54 kDa bands decreased significantly between 16 and 19 dg. Conclusion This study shows that both ER protein isoforms and their variants are present in rat placenta. The decrease in their expression near parturition suggests that the placenta may be relatively unresponsive to estrogens at this stage.

  11. The contraction induced increase in gene expression of peroxisome proliferator-activated receptor (PPAR)-gamma coactivator 1alpha (PGC-1alpha), mitochondrial uncoupling protein 3 (UCP3) and hexokinase II (HKII) in primary rat skeletal muscle cells is dependent on reactive oxygen species

    DEFF Research Database (Denmark)

    Silveira, Leonardo R.; Pilegaard, Henriette; Kusuhara, Keiko;

    2006-01-01

    We evaluated the role of reactive oxygen species (ROS) for the contraction induced increase in expression of PGC-1alpha, HKII and UCP3 mRNA. Rat skeletal muscle cells were subjected to acute or repeated electrostimulation in the presence and absence of antioxidants. Contraction of muscle cells lead...

  12. Inhibition of Toll-like receptor 2-mediated interleukin-8 production in Cystic Fibrosis airway epithelial cells via the alpha7-nicotinic acetylcholine receptor.

    LENUS (Irish Health Repository)

    Greene, Catherine M

    2010-01-01

    Cystic Fibrosis (CF) is an inherited disorder characterised by chronic inflammation of the airways. The lung manifestations of CF include colonization with Pseudomonas aeruginosa and Staphylococcus aureus leading to neutrophil-dominated airway inflammation and tissue damage. Inflammation in the CF lung is initiated by microbial components which activate the innate immune response via Toll-like receptors (TLRs), increasing airway epithelial cell production of proinflammatory mediators such as the neutrophil chemokine interleukin-8 (IL-8). Thus modulation of TLR function represents a therapeutic approach for CF. Nicotine is a naturally occurring plant alkaloid. Although it is negatively associated with cigarette smoking and cardiovascular damage, nicotine also has anti-inflammatory properties. Here we investigate the inhibitory capacity of nicotine against TLR2- and TLR4-induced IL-8 production by CFTE29o- airway epithelial cells, determine the role of alpha7-nAChR (nicotinic acetylcholine receptor) in these events, and provide data to support the potential use of safe nicotine analogues as anti-inflammatories for CF.

  13. Anti-interleukin-1 alpha autoantibodies in humans: Characterization, isotype distribution, and receptor-binding inhibition--higher frequency in Schnitzler's syndrome (urticaria and macroglobulinemia)

    Energy Technology Data Exchange (ETDEWEB)

    Saurat, J.H.; Schifferli, J.; Steiger, G.; Dayer, J.M.; Didierjean, L. (Department of Dermatology, University Hospital, Geneva (Switzerland))

    1991-08-01

    Since autoantibodies (Abs) to cytokines may modify their biologic activities, high-affinity binding factors for interleukin-1 alpha (IL-1 alpha BF) were characterized in human sera. IL-1 alpha BF was identified as IgG (1) by sucrose density-gradient centrifugation followed by immunodiffusion autoradiography, (2) by ligand-blotting method, (3) by ligand binding to affinity-immobilized serum IgG, and (4) by IgG affinity purification followed by sucrose density-gradient centrifugation. IL-1 alpha binding activity resided in the F(ab)2 fragment. The apparent equilibrium constant was in the range of IgG found after immunization with conventional antigens (i.e., 10(-9) to 10(-10) mol/L). Anti-IL-1 alpha IgG auto-Abs represented only an extremely small fraction of total IgG (less than 1/10(-5)). Some sera with IL-1 alpha BF and purified IgG thereof were able to inhibit by 96% to 98% the binding of human recombinant IL-1 alpha to its receptor on murine thymoma EL4-6.1 cells, whereas other sera did not. When 125I-labeled anti-IL-1 alpha IgG complexes were injected into rats, they prolonged the plasma half-life of 125I-labeled IL-1 alpha several fold and altered its tissue distribution. The predominant class was IgG (12/19), mainly IgG4 (9/19), but in five of the sera, anti-IL-1 alpha IgA was also detected. In a screening of 271 sera, IL-1 alpha BF was detected in 17/98 normal subjects and was not more frequent in several control groups of patients, except in patients with Schnitzler's syndrome (fever, chronic urticaria, bone pain, and monoclonal IgM paraprotein) (6/9; p less than 0.005). The pathologic significance of these auto-Abs remains to be determined.

  14. Anti-interleukin-1 alpha autoantibodies in humans: Characterization, isotype distribution, and receptor-binding inhibition--higher frequency in Schnitzler's syndrome (urticaria and macroglobulinemia)

    International Nuclear Information System (INIS)

    Since autoantibodies (Abs) to cytokines may modify their biologic activities, high-affinity binding factors for interleukin-1 alpha (IL-1 alpha BF) were characterized in human sera. IL-1 alpha BF was identified as IgG (1) by sucrose density-gradient centrifugation followed by immunodiffusion autoradiography, (2) by ligand-blotting method, (3) by ligand binding to affinity-immobilized serum IgG, and (4) by IgG affinity purification followed by sucrose density-gradient centrifugation. IL-1 alpha binding activity resided in the F(ab)2 fragment. The apparent equilibrium constant was in the range of IgG found after immunization with conventional antigens (i.e., 10(-9) to 10(-10) mol/L). Anti-IL-1 alpha IgG auto-Abs represented only an extremely small fraction of total IgG (less than 1/10(-5)). Some sera with IL-1 alpha BF and purified IgG thereof were able to inhibit by 96% to 98% the binding of human recombinant IL-1 alpha to its receptor on murine thymoma EL4-6.1 cells, whereas other sera did not. When 125I-labeled anti-IL-1 alpha IgG complexes were injected into rats, they prolonged the plasma half-life of 125I-labeled IL-1 alpha several fold and altered its tissue distribution. The predominant class was IgG (12/19), mainly IgG4 (9/19), but in five of the sera, anti-IL-1 alpha IgA was also detected. In a screening of 271 sera, IL-1 alpha BF was detected in 17/98 normal subjects and was not more frequent in several control groups of patients, except in patients with Schnitzler's syndrome (fever, chronic urticaria, bone pain, and monoclonal IgM paraprotein) (6/9; p less than 0.005). The pathologic significance of these auto-Abs remains to be determined

  15. Transcriptional activation of the mouse obese (ob) gene by CCAAT/enhancer binding protein alpha

    DEFF Research Database (Denmark)

    Hwang, C S; Mandrup, S; MacDougald, O A;

    1996-01-01

    Like other adipocyte genes that are transcriptionally activated by CCAAT/enhancer binding protein alpha (C/EBP alpha) during preadipocyte differentiation, expression of the mouse obese (ob) gene is immediately preceded by the expression of C/EBP alpha. While the 5' flanking region of the mouse ob......, these findings implicate C/EBP alpha as a transcriptional activator of the ob gene promoter and identify the functional C/EBP binding site in the promoter....

  16. Reduced number of alpha- and beta-adrenergic receptors in the myocardium of rats exposed to tobacco smoke

    Energy Technology Data Exchange (ETDEWEB)

    Larue, D.; Kato, G.

    1981-04-09

    The concentration of alpha- and beta-adrenergic receptors--as measured by specific (/sup 3/H)WB-4101 and (-)-(/sup 3/H)dihydroalprenolol binding--was diminished by 60% below control values in the hearts of rats exposed to tobacco smoke. These changes in receptor numbers took place almost immediately after tobacco smoke exposure and were rapidly reversible after termination of the exposure. The dissociation constant, KD, for (/sup 3/H)WB-4101 was identical in exposed (KD . 0.34 +/- 0.09 nM) and control (KD . 0.35 +/- 0.07 nM) hearts but was significantly different in the case of (-)-(3H)dihydroalprenolol binding (exposed, KD . 2.83 +/- 0.30 mM vs. control KD . 5.22 +/- 0.61 nM). For beta-receptor binding there was no significant difference between exposed and control animals in the Ki values for (-)-epinephrine, (-)-norepinephrine, (-)-alprenolol, (+/-)-propranolol or timolol. (-)-Isoproterenol, however, was found to bind with lower affinity in exposed compared with control hearts. For alpha-receptor binding there was no significant difference between control and 'smoked' animals in the Ki values for (-)-epinephrine, (-0)-norepinephrine or phentolamine. The decrease in alpha- and beta-adrenergic receptor concentration may be related to the phenomenon of receptor desensitization resulting from a release of catecholamines in rats exposed to tobacco smoke.

  17. Estrogen receptor alpha and risk for cognitive impairment in postmenopausal women

    DEFF Research Database (Denmark)

    Olsen, Line; Rasmussen, Henrik B; Hansen, Thomas;

    2006-01-01

    The estrogen receptor alpha (ESR1) gene has been implicated in the process of cognitive impairment in elderly women. In a paired case-control study, we tested whether two ESR1 gene polymorphisms (the XbaI and PvuII sites) are risk factors for cognitive impairment as measured by the six......-item Orientation-Memory-Concentration test in postmenopausal Danish women. Hormone replacement therapy, age and executive cognitive ability were examined as covariates for ESR1 gene effects on cognitive impairment. The XbaI polymorphism showed a marginal effect on cognitive abilities (P=0.054) when adjusted...... cognitive ability. These data support that the ESR1 gene variants affect cognitive functioning in postmenopausal women....

  18. Behavioral Disturbances in Estrogen-Related Receptor alpha-Null Mice

    Directory of Open Access Journals (Sweden)

    Huxing Cui

    2015-04-01

    Full Text Available Eating disorders, such as anorexia nervosa and bulimia nervosa, are common and severe mental illnesses of unknown etiology. Recently, we identified a rare missense mutation in the transcription factor estrogen-related receptor alpha (ESRRA that is associated with the development of eating disorders. However, little is known about ESRRA function in the brain. Here, we report that Esrra is expressed in the mouse brain and demonstrate that Esrra levels are regulated by energy reserves. Esrra-null female mice display a reduced operant response to a high-fat diet, compulsivity/behavioral rigidity, and social deficits. Selective Esrra knockdown in the prefrontal and orbitofrontal cortices of adult female mice recapitulates reduced operant response and increased compulsivity, respectively. These results indicate that Esrra deficiency in the mouse brain impairs behavioral responses in multiple functional domains.

  19. Behavioral disturbances in estrogen-related receptor alpha-null mice.

    Science.gov (United States)

    Cui, Huxing; Lu, Yuan; Khan, Michael Z; Anderson, Rachel M; McDaniel, Latisha; Wilson, Hannah E; Yin, Terry C; Radley, Jason J; Pieper, Andrew A; Lutter, Michael

    2015-04-21

    Eating disorders, such as anorexia nervosa and bulimia nervosa, are common and severe mental illnesses of unknown etiology. Recently, we identified a rare missense mutation in the transcription factor estrogen-related receptor alpha (ESRRA) that is associated with the development of eating disorders. However, little is known about ESRRA function in the brain. Here, we report that Esrra is expressed in the mouse brain and demonstrate that Esrra levels are regulated by energy reserves. Esrra-null female mice display a reduced operant response to a high-fat diet, compulsivity/behavioral rigidity, and social deficits. Selective Esrra knockdown in the prefrontal and orbitofrontal cortices of adult female mice recapitulates reduced operant response and increased compulsivity, respectively. These results indicate that Esrra deficiency in the mouse brain impairs behavioral responses in multiple functional domains.

  20. Structure of the T cell receptor in a Ti alpha V beta 2, alpha V beta 8-positive T cell line

    DEFF Research Database (Denmark)

    Hou, X; Dietrich, J; Kuhlmann, J;

    1994-01-01

    not known; however, it has been suggested that each TcR contains two Ti dimers. To gain insight into the structure of the TcR we constructed a Ti alpha V beta 2, alpha V beta 8-positive T cell line which expressed the endogenous human TiV beta 8 and the transfected mouse TiV beta 2 both in association......The T cell receptor (TcR) is composed of at least six different polypeptide chains consisting of the clonotypic Ti heterodimer (Ti alpha beta or Ti gamma delta) and the noncovalently associated CD3 chains (CD3 gamma delta epsilon zeta). The exact number of subunits constituting the TcR is still...... with the endogenous Ti alpha and CD3 chains at the cell surface. Preclearing experiments with radioiodinated cell lysate prepared with digitonin lysis buffer demonstrated that depleting the lysate of Ti alpha V beta 8 by immunoprecipitation with anti V beta 8 monoclonal antibody (mAb) did not reduce the amount of Ti...

  1. Role of the cholinergic nervous system in rheumatoid arthritis: aggravation of arthritis in nicotinic acetylcholine receptor alpha7 subunit gene knockout mice

    NARCIS (Netherlands)

    M.A. van Maanen; S.P. Stoof; G.J. Larosa; M.J. Vervoordeldonk; P.P. Tak

    2010-01-01

    BACKGROUND: The alpha7 subunit of nicotinic acetylcholine receptors (alpha7nAChR) can negatively regulate the synthesis and release of proinflammatory cytokines by macrophages and fibroblast-like synoviocytes in vitro. In addition, stimulation of the alpha7nAChR can reduce the severity of arthritis

  2. Elf-1 and Stat5 bind to a critical element in a new enhancer of the human interleukin-2 receptor alpha gene

    OpenAIRE

    Lécine, P; Algarté, M; Rameil, P; Beadling, C; Bucher, P.; Nabholz, M; Imbert, J

    1997-01-01

    The interleukin 2 receptor alpha-chain (IL-2R alpha) gene is a key regulator of lymphocyte proliferation. IL-2R alpha is rapidly and potently induced in T cells in response to mitogenic stimuli. Interleukin 2 (IL-2) stimulates IL-2R alpha. transcription, thereby amplifying expression of its own high-affinity receptor. IL-2R alpha transcription is at least in part controlled by two positive regulatory regions, PRRI and PRRII. PRRI is an inducible proximal enhancer, located between nucleotides ...

  3. Potentiation of excitatory transmission in substantia gelatinosa neurons of rat spinal cord by inhibition of estrogen receptor alpha

    Directory of Open Access Journals (Sweden)

    Li Kai-Cheng

    2010-12-01

    Full Text Available Abstract Background It has been shown that estrogen is synthesized in the spinal dorsal horn and plays a role in modulating pain transmission. One of the estrogen receptor (ER subtypes, estrogen receptor alpha (ERα, is expressed in the spinal laminae I-V, including substantia gelatinosa (SG, lamina II. However, it is unclear how ERs are involved in the modulation of nociceptive transmission. Results In the present study, a selective ERα antagonist, methyl-piperidino-pyrazole (MPP, was used to test the potential functional roles of spinal ERα in the nociceptive transmission. Using the whole-cell patch-clamp technique, we examined the effects of MPP on SG neurons in the dorsal root-attached spinal cord slice prepared from adult rats. We found that MPP increased glutamatergic excitatory postsynaptic currents (EPSCs evoked by the stimulation of either Aδ- or C-afferent fibers. Further studies showed that MPP treatment dose-dependently increased spontaneous EPSCs frequency in SG neurons, while not affecting the amplitude. In addition, the PKC was involved in the MPP-induced enhancement of synaptic transmission. Conclusions These results suggest that the selective ERα antagonist MPP pre-synaptically facilitates the excitatory synaptic transmission to SG neurons. The nociceptive transmission evoked by Aδ- and C-fiber stimulation could be potentiated by blocking ERα in the spinal neurons. Thus, the spinal estrogen may negatively regulate the nociceptive transmission through the activation of ERα.

  4. Evidence that 17alpha-estradiol is biologically active in the uterine tissue: Antiuterotonic and antiuterotrophic action

    Directory of Open Access Journals (Sweden)

    Navarrete Erika

    2005-07-01

    Full Text Available Abstract Background 17alpha-Estradiol has been considered as the hormonally inactive isomer of 17beta-estradiol. Recently, nongenomic (smooth muscle relaxation and genomic (light estrogenic activity effects of 17alpha-estradiol have been reported, but no reports have yet determined its possible antiestrogenic activity. Therefore, this study investigated: the nongenomic action of 17alpha-estradiol on uterine contractile activity and its potential agonist-antagonist activity on uterine growth. Methods Uterine rings from rats were isometrically recorded. Different concentrations (0.2–200 microM of 17alpha-estradiol were tested on spontaneous contraction and equimolarly compared with 17beta-estradiol. To examine the mechanism of 17alpha-estradiol action, its effect was studied in presence of beta2-antagonist (propranolol, antiestrogens (tamoxifen and ICI 182,780 or inhibitors of protein synthesis (cycloheximide and transcription (actinomycin D. Moreover, contractions induced by high potassium (KCl solution or calcium in depolarized tissues by KCl-calcium free solution were exposed to 17alpha-estradiol. Collaterally, we performed an uterotrophic assay in adult ovariectomized rats measuring the uterine wet weight. The administration for three days of 0.3 microM/day/Kg 17beta-estradiol was equimolarly compared with the response produced by 17alpha-estradiol. Antiuterotrophic activity was assayed by administration of 0.3 microM/day/Kg 17beta-estradiol and various doses ratios (1:1, 1:3, 1:5, and 1:100 of 17alpha-estradiol. Results The estradiol isomers elicited an immediate relaxation, concentration-dependent and reversible on spontaneous contraction. 17alpha-Estradiol presented lower potency than 17beta-estradiol although it did not antagonize 17beta-estradiol-induced relaxation. Relaxation to 17alpha-estradiol was not inhibited by propranolol, tamoxifen, ICI 182,780, cycloheximide or actinomycin D. The KCl contractions were also sensitive to 17alpha

  5. INTERACTION OF PAH-RELATED COMPOUNDS WITH THE ALPHA AND BETA ISOFORMS OF ESTROGEN RECEPTOR. (R826192)

    Science.gov (United States)

    The ability of several 4- and 5-ring polycyclic aromatic hydrocarbons (PAHs), heterocyclic PAHs, and their monohydroxy derivatives to interact with the estrogen receptor (ER) alpha and beta isoforms was examined. Only compounds possessing a hydroxyl group were able to compete wit...

  6. Genetic variation in liver x receptor alpha and risk of ischemic vascular disease in the general population

    DEFF Research Database (Denmark)

    Stender, Stefan; Frikke-Schmidt, Ruth; Anestis, Aristomenis;

    2011-01-01

    Although animal studies indicate that liver X receptor alpha (LXRα) might influence risk of atherosclerosis, data in humans remain scarce. We tested the hypothesis that genetic variation in LXRα associates with risk of ischemic vascular disease and/or plasma lipid and lipoprotein levels in the ge...

  7. Genetic variation in liver x receptor alpha and risk of ischemic vascular disease in the general population

    DEFF Research Database (Denmark)

    Stender, Stefan; Frikke-Schmidt, Ruth; Anestis, Aristomenis;

    2011-01-01

    Although animal studies indicate that liver X receptor alpha (LXRa) might influence risk of atherosclerosis, data in humans remain scarce. We tested the hypothesis that genetic variation in LXRa associates with risk of ischemic vascular disease and/or plasma lipid and lipoprotein levels in the ge...

  8. BINDING OF STEROIDS AND ENVIRONMENTAL CHEMICALS TO THE RAINBOW TROUT ANDROGEN RECEPTOR ALPHA EXPRESSED IN COS CELLS

    Science.gov (United States)

    Binding of Steroids and Environmental Chemicals to the Rainbow Trout Androgen Receptor Alpha Expressed in COS Cells. Mary C. Cardon, L. Earl Gray. Jr., Phillip C. Hartig and Vickie S. Wilson U.S. Environmental Protection Agency, ORD, NHEERL, Reproductive Toxicology...

  9. Association of 5' estrogen receptor alpha gene polymorphisms with bone mineral density, vertebral bone area and fracture risk

    NARCIS (Netherlands)

    J.B.J. van Meurs (Joyce); A.G. Uitterlinden (André); H.A.P. Pols (Huib); A.E.A.M. Weel (Angelique); M. van de Klift (Marjolein); A.P. Bergink (Arjan); P.P. Arp (Pascal); Y. Fang (Yue); C.M. van Duijn (Cock); J.P.T.M. van Leeuwen (Hans); S.C.E. Schuit (Stephanie); A. Hofman (Albert)

    2003-01-01

    textabstractThis study investigates the influence of genetic variation of the estrogen receptor alpha (ESR1) gene locus on several bone parameters in 2042 individuals of The Rotterdam Study, a prospective population-based cohort study of elderly subjects. We analysed three polymorphic sites in the 5

  10. Steroid and G Protein Binding Characteristics of the Seatrout and Human Progestin Membrane Receptor Alpha Subtypes and Their Evolutionary Origins

    NARCIS (Netherlands)

    Thomas, P.; Pang, Y.; Dong, J.; Groenen, P.; Kelder, J.; Vlieg, J. de; Zhu, Y.; Tubbs, C.

    2006-01-01

    A novel progestin receptor (mPR) with seven-transmembrane domains was recently discovered in spotted seatrout and homologous genes were identified in other vertebrates. Here we show that cDNAs for the mPR alpha subtypes from spotted seatrout (st-mPRalpha) and humans (hu-mPRalpha) encode progestin re

  11. Using Nuclear Receptor Activity to Stratify Hepatocarcinogens

    Science.gov (United States)

    Nuclear receptors (NR) are a superfamily of ligand-activated transcription factors that control a range of cellular processes. Persistent stimulation of some NR is a non-genotoxic mechanism of rodent liver cancer with unclear relevance to humans. Here we report on a systematic an...

  12. Functional characterisation of the human alpha1 glycine receptor in a fluorescence-based membrane potential assay

    DEFF Research Database (Denmark)

    Jensen, Anders A.; Kristiansen, Uffe

    2004-01-01

    In the present study, we have created a stable HEK293 cell line expressing the human homomeric alpha1 glycine receptor (GlyR) and characterised its functional pharmacology in a conventional patch-clamp assay and in the FLIPR Membrane Potential (FMP) assay, a fluorescence-based high throughput...... and RU 5135>strychnine>brucine>PMBA=picrotoxin>atropine for the antagonists. The actions of three allosteric modulators at the alpha1 GlyR cell line were also characterised in the FMP assay. Micromolar concentrations of Zn2+ inhibited alpha1 GlyR signalling but in contrast to previous reports the metal...... not be suited for sophisticated studies of GlyR pharmacology and kinetics. However, the assay offers several advantages in studies of ligand-receptor interactions. Furthermore, the assay could be highly useful in the search for structurally novel ligands acting at GlyRs....

  13. Evaluation of estrogen receptor alpha and beta and progesterone receptor expression and correlation with clinicopathologic factors and proliferative marker Ki-67 in breast cancers

    DEFF Research Database (Denmark)

    Rosa, Fabíola E; Caldeira, José R F; Felipes, Joice;

    2008-01-01

    To elucidate the molecular profile of hormonal steroid receptor status, we analyzed ER-alpha, ER-beta, and PGR mRNA and protein expression in 80 breast carcinomas using reverse transcriptase polymerase chain reaction (RT-PCR), quantitative RT-PCR, and immunohistochemical analysis. Qualitative...... analysis revealed positive expression of ER-alpha, ER-beta, and PGR mRNA in 48%, 59%, and 48% of the breast carcinomas, respectively. ER-alpha, ER-beta, and PGR transcript overexpression was observed in 51%, 0%, and 12% of the cases, respectively, whereas moderate or strong protein expression was detected...... in 68%, 78%, and 49% of the cases, respectively. Tumor grade was negatively correlated with transcript and protein levels of ER-alpha (P = .0169 and P = .0006, respectively) and PGR (P = .0034 and P = .0005, respectively). Similarly, proliferative index Ki-67 was negatively associated with transcript...

  14. Estrogen receptor alpha single nucleotide polymorphism as predictor of diabetes type 2 risk in hypogonadal men.

    Science.gov (United States)

    Linnér, Carl; Svartberg, Johan; Giwercman, Aleksander; Giwercman, Yvonne Lundberg

    2013-06-01

    Estradiol (E2) is, apart from its role as a reproductive hormone, also important for cardiac function and bone maturation in both genders. It has also been shown to play a role in insulin production, energy expenditure and in inducing lipolysis. The aim of the study was to investigate if low circulating testosterone or E2 levels in combination with variants in the estrogen receptor alpha (ESR1) and estrogen receptor beta (ESR2) genes were of importance for the risk of type-2 diabetes. The single nucleotide polymorphisms rs2207396 and rs1256049, in ESR1 and ESR2, respectively, were analysed by allele specific PCR in 172 elderly men from the population-based Tromsø study. The results were adjusted for age. In individuals with low total (≤11 nmol/L) or free testosterone (≤0.18 nmol/L) being carriers of the variant A-allele in ESR1 was associated with 7.3 and 15.9 times, respectively, increased odds ratio of being diagnosed with diabetes mellitus type 2 (p = 0.025 and p = 0.018, respectively). Lower concentrations of E2 did not seem to increase the risk of being diagnosed with diabetes. In conclusion, in hypogonadal men, the rs2207396 variant in ESR1 predicts the risk of type 2 diabetes.

  15. Mice lacking the alpha4 nicotinic receptor subunit fail to modulate dopaminergic neuronal arbors and possess impaired dopamine transporter function.

    Science.gov (United States)

    Parish, C L; Nunan, J; Finkelstein, D I; McNamara, F N; Wong, J Y; Waddington, J L; Brown, R M; Lawrence, A J; Horne, M K; Drago, J

    2005-11-01

    Neuronal nicotinic acetylcholine receptors (nAChRs) at presynaptic sites can modulate dopaminergic synaptic transmission by regulating dopamine (DA) release and uptake. Dopaminergic transmission in nigrostriatal and mesolimbic pathways is vital for the coordination of movement and is associated with learning and behavioral reinforcement. We reported recently that the D2 DA receptor plays a central role in regulating the arbor size of substantia nigra dopaminergic neurons. Given the known effects of nAChRs on dopaminergic neurotransmission, we assessed the ability of the alpha4 nAChR subunit to regulate arbor size of dopaminergic neurons by comparing responses of wild-type and alpha4 nAChR subunit knockout [alpha4(-/-)] mice to long-term exposure to cocaine, amphetamine, nicotine, and haloperidol, and after substantia nigra neurotoxic lesioning. We found that dopaminergic neurons in adult drug-naive alpha4(-/-) mice had significantly larger terminal arbors, and despite normal short-term behavioral responses to drugs acting on pre- and postsynaptic D2 DA receptors, they were unable to modulate their terminal arbor in response to pharmacological manipulation or after lesioning. In addition, although synaptosome DA uptake studies showed that the interaction of the D2 DA receptor and the dopamine transporter (DAT) was preserved in alpha4(-/-) mice, DAT function was found to be impaired. These findings suggest that the alpha4 subunit of the nAChR is an independent regulator of terminal arbor size of nigrostriatal dopaminergic neurons and that reduced functionality of presynaptic DAT may contribute to this effect by impairing DA uptake. PMID:16077034

  16. Alpha-synuclein promotes clathrin-mediated endocytosis of NMDA receptors in dopaminergic cells

    Institute of Scientific and Technical Information of China (English)

    Shun Yu; Furong Cheng; Xin Li; Yaohua Li; Tao Wang; Guangwei Liu; Andrius Baskys

    2012-01-01

    Loss of dopaminergic i a compensatory increase in nput to the striatum associated with Parkinson' s disease brings about glutamate release onto the dopaminergic cell bodies in the substantia nigra pars compacta (SNpc)[1] Glutamate over-activation of NMDA receptors on these cells can cause excitotoxicity and contribute to their further loss. NMDA receptor-mediated neuronal death is reduced by group I mGluR-mediated up-regulation of endocytosis protein RAB5B[2.3] Among proteins shown to interact with RAB5 proteins is a-synuclein

  17. Spongian diterpenoids inhibit androgen receptor activity

    OpenAIRE

    Yang, Yu Chi; Labros G Meimetis; Tien, Amy H; Mawji, Nasrin R.; Carr, Gavin; Wang, Jun; Andersen, Raymond J.; Sadar, Marianne D.

    2013-01-01

    Androgen receptor (AR) is a ligand-activated transcription factor and a validated drug target for all stages of prostate cancer. Antiandrogens compete with physiological ligands for AR ligand-binding domain (LBD). High-throughput screening of a marine natural product library for small molecules that inhibit AR transcriptional activity yielded the furanoditerpenoid spongia-13(16),-14-dien-19-oic acid, designated terpene 1 (T1). Characterization of T1 and the structurally related semi-synthetic...

  18. Effect of the feeding system on the fatty acid composition, expression of the Δ9-desaturase, Peroxisome Proliferator-Activated Receptor Alpha, Gamma, and Sterol Regulatory Element Binding Protein 1 genes in the semitendinous muscle of light lambs of the Rasa Aragonesa breed

    Directory of Open Access Journals (Sweden)

    Rodellar Clementina

    2010-07-01

    Full Text Available Abstract Background Conjugated linoleic acids (CLAs are receiving increasing attention because of their beneficial effects on human health, with milk and meat products derived from ruminants as important sources of CLA in the human diet. SCD gene is responsible for some of the variation in CLA concentration in adipose tissues, and PPARγ, PPARα and SREBP1 genes are regulator of SCD gene. The aim of this work was to evaluate the effect of the feeding system on fatty acid composition, CLA content and relative gene expression of Δ9-desaturase (SCD, Peroxisome Proliferator-Activated Receptor Gamma (PPARγ, Peroxisome Proliferator-Activated Receptor Alpha, (PPARα and Sterol Regulatory Element Binding Protein (SREBP1 in Rasa Aragonesa light lambs in semitendinous muscle. Forty-four single-born male lambs were used to evaluate the effect of the feeding system, varying on an intensity gradient according to the use of concentrates: 1. grazing alfalfa, 2. grazing alfalfa with a supplement for lambs, 3. indoor lambs with grazing ewes and 4. drylot. Results Both grazing systems resulted in a higher concentration of vaccenic acid (VA, CLA, CLA/VA acid ratio, and a lower oleic content, oleic acid (C18:1/stearic acid (C18:0 ratio, PUFA n-6/n-3 ratio and SCD expression compared to other diets. In addition feeding system affected the fatty acid composition and SCD expression, possibly due to CLA concentration or the PUFA n-6/n-3 ratio. Both expression of the SCD gene and the feeding system were important factors affecting CLA concentration in the animal's semitendinous muscle. PPARγ, PPARα and SREBP1 expression seemed to be unaffected by the feeding system. Although no significant results were found, PPARγ, PPARα and SREBP1 showed similar expression pattern as SCD. Moreover, the correlation results between SCD expression and PPARγ (p SREBP1 (p SCD expression in a different way. Conclusions The data indicated that the feeding system is the main factor

  19. Nicotine acts on growth plate chondrocytes to delay skeletal growth through the alpha7 neuronal nicotinic acetylcholine receptor.

    Directory of Open Access Journals (Sweden)

    Atsuo Kawakita

    Full Text Available BACKGROUND: Cigarette smoking adversely affects endochondral ossification during the course of skeletal growth. Among a plethora of cigarette chemicals, nicotine is one of the primary candidate compounds responsible for the cause of smoking-induced delayed skeletal growth. However, the possible mechanism of delayed skeletal growth caused by nicotine remains unclarified. In the last decade, localization of neuronal nicotinic acetylcholine receptor (nAChR, a specific receptor of nicotine, has been widely detected in non-excitable cells. Therefore, we hypothesized that nicotine affect growth plate chondrocytes directly and specifically through nAChR to delay skeletal growth. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the effect of nicotine on human growth plate chondrocytes, a major component of endochondral ossification. The chondrocytes were derived from extra human fingers. Nicotine inhibited matrix synthesis and hypertrophic differentiation in human growth plate chondrocytes in suspension culture in a concentration-dependent manner. Both human and murine growth plate chondrocytes expressed alpha7 nAChR, which constitutes functional homopentameric receptors. Methyllycaconitine (MLA, a specific antagonist of alpha7 nAChR, reversed the inhibition of matrix synthesis and functional calcium signal by nicotine in human growth plate chondrocytes in vitro. To study the effect of nicotine on growth plate in vivo, ovulation-controlled pregnant alpha7 nAChR +/- mice were given drinking water with or without nicotine during pregnancy, and skeletal growth of their fetuses was observed. Maternal nicotine exposure resulted in delayed skeletal growth of alpha7 nAChR +/+ fetuses but not in alpha7 nAChR -/- fetuses, implying that skeletal growth retardation by nicotine is specifically mediated via fetal alpha7 nAChR. CONCLUSIONS/SIGNIFICANCE: These results suggest that nicotine, from cigarette smoking, acts directly on growth plate chondrocytes to decrease

  20. Alpha1A-adrenergic receptor-directed autoimmunity induces left ventricular damage and diastolic dysfunction in rats.

    Directory of Open Access Journals (Sweden)

    Katrin Wenzel

    Full Text Available BACKGROUND: Agonistic autoantibodies to the alpha(1-adrenergic receptor occur in nearly half of patients with refractory hypertension; however, their relevance is uncertain. METHODS/PRINCIPAL FINDINGS: We immunized Lewis rats with the second extracellular-loop peptides of the human alpha(1A-adrenergic receptor and maintained them for one year. Alpha(1A-adrenergic antibodies (alpha(1A-AR-AB were monitored with a neonatal cardiomyocyte contraction assay by ELISA, and by ERK1/2 phosphorylation in human alpha(1A-adrenergic receptor transfected Chinese hamster ovary cells. The rats were followed with radiotelemetric blood pressure measurements and echocardiography. At 12 months, the left ventricles of immunized rats had greater wall thickness than control rats. The fractional shortening and dp/dt(max demonstrated preserved systolic function. A decreased E/A ratio in immunized rats indicated a diastolic dysfunction. Invasive hemodynamics revealed increased left ventricular end-diastolic pressures and decreased dp/dt(min. Mean diameter of cardiomyocytes showed hypertrophy in immunized rats. Long-term blood pressure values and heart rates were not different. Genes encoding sarcomeric proteins, collagens, extracellular matrix proteins, calcium regulating proteins, and proteins of energy metabolism in immunized rat hearts were upregulated, compared to controls. Furthermore, fibrosis was present in immunized hearts, but not in control hearts. A subset of immunized and control rats was infused with angiotensin (Ang II. The stressor raised blood pressure to a greater degree and led to more cardiac fibrosis in immunized, than in control rats. CONCLUSIONS/SIGNIFICANCE: We show that alpha(1A-AR-AB cause diastolic dysfunction independent of hypertension, and can increase the sensitivity to Ang II. We suggest that alpha(1A-AR-AB could contribute to cardiovascular endorgan damage.

  1. Alpha-amylase activity in blood increases after pharmacological, but not psychological, activation of the adrenergic system

    OpenAIRE

    Nater, Urs M.; Roberto La Marca; Katja Erni; Ulrike Ehlert

    2015-01-01

    BACKGROUND & AIM: Alpha-amylase in both blood and saliva has been used as a diagnostic parameter. While studies examining alpha-amylase activity in saliva have shown that it is sensitive to physiological and psychological challenge of the adrenergic system, no challenge studies have attempted to elucidate the role of the adrenergic system in alpha-amylase activity in blood. We set out to examine the impact of psychological and pharmacological challenge on alpha-amylase in blood in two separat...

  2. Stress affects salivary alpha-Amylase activity in bonobos.

    Science.gov (United States)

    Behringer, Verena; Deschner, Tobias; Möstl, Erich; Selzer, Dieter; Hohmann, Gottfried

    2012-01-18

    Salivary alpha-Amylase (sAA) is a starch digesting enzyme. In addition to its function in the context of nutrition, sAA has also turned out to be useful for monitoring sympathetic nervous system activity. Recent studies on humans have found a relationship between intra-individual changes in sAA activity and physical and psychological stress. In studies on primates and other vertebrates, non-invasive monitoring of short-term stress responses is usually based on measurements of cortisol levels, which are indicative of hypothalamic-pituitary-adrenal activity. The few studies that have used both cortisol levels and sAA activity indicate that these two markers may respond differently and independently to different types of stress such that variation in the degree of the activation of different stress response systems might reflect alternative coping mechanisms or individual traits. Here, we present the first data on intra- and inter-individual variation of sAA activity in captive bonobos and compare the results with information from other ape species and humans. Our results indicate that sAA activity in the bonobo samples was significantly lower than in the human samples but within the range of other great ape species. In addition, sAA activity was significantly higher in samples collected at times when subjects had been exposed to stressors (judged by changes in behavioral patterns and cortisol levels) than in samples collected at other times. Our results indicate that bonobos possess functioning sAA and, as in other species, sAA activity is influenced by autonomic nervous system activity. Monitoring sAA activity could therefore be a useful tool for evaluating stress in bonobos. PMID:21945369

  3. Roles of oestrogen receptors alpha and beta in behavioural neuroendocrinology: beyond Yin/Yang.

    Science.gov (United States)

    Rissman, E F

    2008-06-01

    Oestrogen receptor beta (ERbeta) was discovered more than 10 years ago. It is widely distributed in the brain. In some areas, such as the entorhinal cortex, it is present as the only ER, whereas in other regions, such as the bed nucleus of the stria terminalis and preoptic area, it can be found co-expressed with ERalpha, often within the same neurones. These ERs share ligands, and there are several complex relationships between the two receptors. Initially, the relationship between them was labelled as 'yin/yang', meaning that the actions of each complemented those of the other, but now, years later, other relationships have been described. Based on evidence from neuroendocrine and behavioural studies, three types of interactions between the two oestrogen receptors are described in this review. The first relationship is antagonistic; this is evident from studies on the role of oestrogen in spatial learning. When oestradiol is given in a high, chronic dose, spatial learning is impaired. This action of oestradiol requires ERalpha, and when ERbeta is not functional, lower doses of oestradiol have this negative effect on behaviour. The second relationship between the two receptors is one that is synergistic, and this is illustrated in the combined effects of the two receptors on the production of the neuropeptide oxytocin and its receptor. The third relationship is sequential; separate actions of the two receptors are postulated in activation and organisation of sexually dimorphic reproductive behaviours. Future studies on all of these topics will inform us about how ER selective ligands might affect oestrogen functions at the organismal level.

  4. Real-time MEG neurofeedback training of posterior alpha activity modulates subsequent visual detection performance

    NARCIS (Netherlands)

    Okazaki, Y.O.; Horschig, J.; Luther, L.M.; Oostenveld, R.; Murakami, I.; Jensen, O.

    2015-01-01

    It has been demonstrated that alpha activity is lateralized when attention is directed to the left or right visual hemifield. We investigated whether real-time neurofeedback training of the alpha lateralization enhances participants' ability to modulate posterior alpha lateralization and causes subs

  5. Characterization of the ligand binding site of the bovine IgA Fc receptor (bFc alpha R).

    Science.gov (United States)

    Morton, H Craig; Pleass, Richard J; Woof, Jenny M; Brandtzaeg, Per

    2004-12-24

    Recently, we identified a bovine IgA Fc receptor (bFc alpha R), which shows high homology to the human myeloid Fc alpha R, CD89. IgA binding has previously been shown to depend on several specific residues located in the B-C and F-G loops of the membrane-distal extracellular domain 1 of CD89. To compare the ligand binding properties of these two Fc alpha Rs, we have mapped the IgA binding site of bFc alpha R. We show that, in common with CD89, Tyr-35 in the B-C loop is essential for IgA binding. However, in contrast to earlier observations on CD89, mutation of residues in the F-G loop did not significantly inhibit IgA binding.

  6. Random length assortment of human and mouse T cell receptor for antigen alpha and beta chain CDR3.

    Science.gov (United States)

    Johnson, G; Wu, T T

    1999-10-01

    In view of the recently determined three-dimensional structures of complexes formed by the T cell receptor for antigen (TCR), the processed peptide and the MHC class I molecule, it is expected that the combined configuration formed by the third complementarity determining regions (CDR3) of TCR alpha and beta chains will be very restricted in size and shape due to the limited length variations of the processed peptides. Thus, the combined TCR alpha and beta chain CDR3 lengths should have a fairly narrow distribution. This feature can be due to the selective association of long alpha chain CDR3 with short beta chain CDR3 and vice versa or due to random assortment of alpha and beta chain CDR3 of even narrower length distribution. Based on existing translated amino acid sequence data, it has been found that the latter mechanism is responsible.

  7. Characterization of the ligand binding site of the bovine IgA Fc receptor (bFc alpha R).

    Science.gov (United States)

    Morton, H Craig; Pleass, Richard J; Woof, Jenny M; Brandtzaeg, Per

    2004-12-24

    Recently, we identified a bovine IgA Fc receptor (bFc alpha R), which shows high homology to the human myeloid Fc alpha R, CD89. IgA binding has previously been shown to depend on several specific residues located in the B-C and F-G loops of the membrane-distal extracellular domain 1 of CD89. To compare the ligand binding properties of these two Fc alpha Rs, we have mapped the IgA binding site of bFc alpha R. We show that, in common with CD89, Tyr-35 in the B-C loop is essential for IgA binding. However, in contrast to earlier observations on CD89, mutation of residues in the F-G loop did not significantly inhibit IgA binding. PMID:15485844

  8. Evidence of balanced diversity at the chicken interleukin 4 receptor alpha chain locus

    Directory of Open Access Journals (Sweden)

    Podisi Baitsi

    2009-06-01

    Full Text Available Abstract Background The comparative analysis of genome sequences emerging for several avian species with the fully sequenced chicken genome enables the genome-wide investigation of selective processes in functionally important chicken genes. In particular, because of pathogenic challenges it is expected that genes involved in the chicken immune system are subject to particularly strong adaptive pressure. Signatures of selection detected by inter-species comparison may then be investigated at the population level in global chicken populations to highlight potentially relevant functional polymorphisms. Results Comparative evolutionary analysis of chicken (Gallus gallus and zebra finch (Taeniopygia guttata genes identified interleukin 4 receptor alpha-chain (IL-4Rα, a key cytokine receptor as a candidate with a significant excess of substitutions at nonsynonymous sites, suggestive of adaptive evolution. Resequencing and detailed population genetic analysis of this gene in diverse village chickens from Asia and Africa, commercial broilers, and in outgroup species red jungle fowl (JF, grey JF, Ceylon JF, green JF, grey francolin and bamboo partridge, suggested elevated and balanced diversity across all populations at this gene, acting to preserve different high-frequency alleles at two nonsynonymous sites. Conclusion Haplotype networks indicate that red JF is the primary contributor of diversity at chicken IL-4Rα: the signature of variation observed here may be due to the effects of domestication, admixture and introgression, which produce high diversity. However, this gene is a key cytokine-binding receptor in the immune system, so balancing selection related to the host response to pathogens cannot be excluded.

  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. Phenobarbital and Insulin Reciprocate Activation of the Nuclear Receptor Constitutive Androstane Receptor through the Insulin Receptor.

    Science.gov (United States)

    Yasujima, Tomoya; Saito, Kosuke; Moore, Rick; Negishi, Masahiko

    2016-05-01

    Phenobarbital (PB) antagonized insulin to inactivate the insulin receptor and attenuated the insulin receptor downstream protein kinase B (AKT)-forkhead box protein O1 and extracellular signal-regulated kinase 1/2 signals in mouse primary hepatocytes and HepG2 cells. Hepatic AKT began dephosphorylation in an early stage of PB treatment, and blood glucose levels transiently increased in both wild-type and constitutive androstane receptor (CAR) knockout (KO) mice. On the other hand, blood glucose levels increased in wild-type mice, but not KO mice, in later stages of PB treatment. As a result, PB, acting as an insulin receptor antagonist, elicited CAR-independent increases and CAR-dependent decreases of blood glucose levels at these different stages of treatment, respectively. Reciprocally, insulin activation of the insulin receptor repressed CAR activation and induction of its target CYP2B6 gene in HepG2 cells. Thus, PB and insulin cross-talk through the insulin receptor to regulate glucose and drug metabolism reciprocally.

  11. Molecular determinants of desensitization and assembly of the chimeric GABA(A) receptor subunits (alpha1/gamma2) and (gamma2/alpha1) in combinations with beta2 and gamma2

    DEFF Research Database (Denmark)

    Elster, L; Kristiansen, U; Pickering, D S;

    2001-01-01

    )beta2gamma2 subunit combinations formed functional receptor complexes as shown by whole-cell patch-clamp recordings and [3H]muscimol and [3H]flunitrazepam binding. Moreover, the surface immunofluorescence staining of Sf-9 cells expressing the (alpha1/gamma2)-containing receptors was pronounced......Two gamma-aminobutyric acid(A) (GABA(A)) receptor chimeras were designed in order to elucidate the structural requirements for GABA(A) receptor desensitization and assembly. The (alpha1/gamma2) and (gamma2/alpha1) chimeric subunits representing the extracellular N-terminal domain of alpha1 or gamma......2 and the remainder of the gamma2 or alpha1 subunits, respectively, were expressed with beta2 and beta2gamma2 in Spodoptera frugiperda (Sf-9) cells using the baculovirus expression system. The (alpha1/gamma2)beta2 and (alpha1/gamma2)beta2gamma2 but not the (gamma2/alpha1)beta2 and (gamma2/alpha1...

  12. Fatty acids activate a chimera of the clofibric acid-activated receptor and the glucocorticoid receptor.

    OpenAIRE

    Göttlicher, M; Widmark, E; Q. Li; Gustafsson, J.A.

    1992-01-01

    Peroxisome proliferators such as clofibric acid, nafenopin, and WY-14,643 have been shown to activate PPAR (peroxisome proliferator-activated receptor), a member of the steroid nuclear receptor superfamily. We have cloned the cDNA from the rat that is homologous to that from the mouse [Issemann, I. & Green, S. (1990) Nature (London) 347, 645-650], which encodes a 97% similar protein with a particularly well-conserved putative ligand-binding domain. To search for physiologically occurring acti...

  13. Synthesis and evaluation of new imaging agent for central nicotinic acetylcholine receptor {alpha}{sub 7} subtype

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Mikako [Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu (Japan); Nishiyama, Shingo; Tsukada, Hideo [PET Center, Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu (Japan); Hatano, Kentaro [National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu (Japan); Fuchigami, Takeshi [Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu (Japan); Yamaguchi, Hiroshi [National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu (Japan); Molecular Imaging Frontier Research Center, Hamamatsu University School of Medicine, Hamamatsu (Japan); Matsushima, Yoshitaka [Department of Chemistry, Hamamatsu University School of Medicine, Hamamatsu (Japan); Ito, Kengo [National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu (Japan); Magata, Yasuhiro [Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu (Japan); Molecular Imaging Frontier Research Center, Hamamatsu University School of Medicine, Hamamatsu (Japan)], E-mail: magata@hama-med.ac.jp

    2010-04-15

    Introduction: The nicotinic acetylcholine receptor (nAChR) {alpha}7 subtype ({alpha}{sub 7} nAChR) is one of the major nAChR subtypes in the brain. We synthesized C-11 labeled {alpha}{sub 7} nAChR ligands, (R)-2-[{sup 11}C]methylamino-benzoic acid 1-aza-bicyclo[2.2.2]oct-3-yl ester ([{sup 11}C](R)-MeQAA) and its isomer (S)-[{sup 11}C]MeQAA, for in vivo investigation with positron emission tomography (PET). Then, the potential of (R)- and (S)-[{sup 11}C]MeQAA for in vivo imaging of {alpha}{sub 7} nAChR in the brain was evaluated in mice and monkeys. Methods: The binding affinity for {alpha}{sub 7} nAChR was measured using rat brain. Biodistribution and in vivo receptor blocking studies were undertaken in mice. Dynamic PET scans were performed in conscious monkeys. Results: The affinity for {alpha}{sub 7} nAChR was 41 and 182 nM for (R)- and (S)-MeQAA, respectively. The initial uptake in the mouse brain was high ([{sup 11}C](R)-MeQAA: 7.68 and [{sup 11}C](S)-MeQAA: 6.65 %dose/g at 5 min). The clearance of [{sup 11}C](R)-MeQAA was slow in the hippocampus ({alpha}{sub 7} nAChR-rich region) but was rapid in the cerebellum ({alpha}{sub 7} nAChR-poor region). On the other hand, the clearance was fast for [{sup 11}C](S)-MeQAA in all regions. The brain uptake of [{sup 11}C](R)-MeQAA was decreased by methyllycaconitine ({alpha}{sub 7} nAChR antagonist) treatment. In monkeys, {alpha}{sub 7} nAChRs were highly distributed in the thalamus and cortex but poorly distributed in the cerebellum. The high accumulation was observed in the cortex and thalamus for [{sup 11}C](R)-MeQAA, while the uptake was rather homogeneous for [{sup 11}C](S)-MeQAA. Conclusions: [{sup 11}C](R)-MeQAA was successfully synthesized and showed high uptake to the brain. However, since the in vivo selectivity for {alpha}{sub 7} nAChR was not enough, further PET kinetic analysis or structure optimization is needed for specific visualization of brain {alpha}{sub 7} nAChRs in vivo.

  14. Human Receptor Activation by Aroclor 1260, a Polychlorinated Biphenyl Mixture

    OpenAIRE

    Wahlang, Banrida; Falkner, K. Cameron; Clair, Heather B.; Al-Eryani, Laila; Prough, Russell A.; States, J. Christopher; Coslo, Denise M.; Omiecinski, Curtis J.; Cave, Matthew C.

    2014-01-01

    Polychlorinated biphenyls (PCBs) are persistent environmental toxicants, present in 100% of U.S. adults and dose-dependently associated with obesity and non-alcoholic fatty liver disease (NAFLD). PCBs are predicted to interact with receptors previously implicated in xenobiotic/energy metabolism and NAFLD. These receptors include the aryl hydrocarbon receptor (AhR), pregnane xenobiotic receptor (PXR), constitutive androstane receptor (CAR), peroxisome proliferator-activated receptors (PPARs), ...

  15. Mode of action and functional significance of 7alpha-hydroxypregnenolone stimulating locomotor activity

    Directory of Open Access Journals (Sweden)

    Shogo eHaraguchi

    2011-08-01

    Full Text Available Previous studies over the past two decades have demonstrated that the brain and other nervous systems possess key steroidogenic enzymes and produces pregnenolone and other various neurosteroids in vertebrates in general. Recently, 7alpha-hydroxypregnenolone, a novel bioactive neurosteroid, was identified in the brain of newts and quail. Importantly, this novel neurosteroid is produced from pregnenolone through the enzymatic activity of cytochrome P4507alpha and acts on brain tissue as a neuronal modulator to stimulate locomotor activity in these vertebrates. Subsequently, the mode of action of 7alpha-hydroxypregnenolone was demonstrated. 7alpha-Hydroxypregnenolone stimulates locomotor activity through activation of the dopaminergic system. To understand the functional significance of 7alpha-hydroxypregnenolone in the regulation of locomotor activity, diurnal and seasonal changes in 7alpha-hydroxypregnenolone synthesis were further characterized. Melatonin derived from the pineal gland and eyes regulates 7alpha-hydroxypregnenolone synthesis in the brain, thus inducing diurnal locomotor changes. Prolactin, an adenohypophyseal hormone, regulates 7alpha-hydroxypregnenolone synthesis in the brain, and also induces seasonal locomotor changes. In addition, 7alpha-hydroxypregnenolone mediates corticosterone action to modulate locomotor activity under stress. This review summarizes the current knowledge regarding the mode of action and functional significance of 7alpha-hydroxypregnenolone, a newly identified bioactive neurosteroid stimulating locomotor activity.

  16. Radiolabeled high affinity peptidomimetic antagonist selectively targets {alpha}{sub v}{beta}{sub 3} receptor-positive tumor in mice

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Beom-Su [Department of Nuclear Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Lim, Esther [Department of Radiology, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Hee Park, Seung [Department of Nuclear Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Shin, In Soo [Department of Nuclear Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Danthi, S. Narasimhan [Department of Radiology, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Hwang, In Sook [Department of Nuclear Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Le, Nhat [Department of Nuclear Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Yu, Sarah [Department of Nuclear Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Xie Jianwu [Department of Radiology, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Li, King C.P. [Department of Radiology, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Carrasquillo, Jorge A. [Department of Nuclear Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Paik, Chang H. [Department of Nuclear Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States)]. E-mail: cpaik@mail.nih.gov

    2007-05-15

    Objectives: The aim of this research was to synthesize radiolabeled peptidomimetic integrin {alpha}{sub v}{beta}{sub 3} antagonists that selectively target integrin {alpha}{sub v}{beta}{sub 3} receptor and clear rapidly from the whole body. Methods: Integrin {alpha}{sub v}{beta}{sub 3} antagonists, 4-[2-(3,4,5,6-tetrahydropyrimidine-2-ylamino) ethyloxy]benzoyl-2-(S)-aminoethylsulfonyl-amino-{beta}-alanine (IA) and 4-[2-(3,4,5,6-tetrahydro-pyrimidin-2-ylamino)-ethyloxy]benzoyl-2-(S)-[N- (3-amino-neopenta-1-carbamyl)]-aminoethylsulfonylamino-{beta}-alanine hydrochloride (IAC), a hydrophobic carbamate derivative of IA, were conjugated with 2-p-isothiocyanatobenzyl-DOTA at the amino terminus and labeled with {sup 111}In. The {sup 111}In labeled IA and IAC were subjected to in vitro receptor binding, biodistribution and imaging studies using nude mice bearing the receptor-positive M21 human melanoma xenografts. Results: The {sup 111}In-labeled IA (40%) and -IAC (72%) specifically bound in vitro to {alpha}{sub v}{beta}{sub 3} (0.8 {mu}M) at a molar excess. This receptor binding was completely blocked by a molar excess of cold IA to {alpha}{sub v}{beta}{sub 3}. The higher receptor-binding affinity of the {sup 111}In-labeled IAC was reflected in higher tumor uptake and retention: 5.6{+-}1.4 and 4.5{+-}0.7 %ID/g vs. 3.8{+-}0.9 and 2.0{+-}0.3 %ID/g for the {sup 111}In-labeled IA at 0.33 and 2 h. The tumor uptakes were inhibited by the co-injection of 200 {mu}g of IA, indicating that the uptake was receptor mediated. These antagonists were excreted primarily via the renal system. The {sup 111}In activity retained in the whole body was quite comparable between the {sup 111}In-labeled IA (24% ID) and the {sup 111}In-labeled IAC (33% ID) at 2 h. The higher peak tumor uptake and longer retention resulted in higher tumor-to-background ratios for the {sup 111}In-labeled IAC at 2 h with 9.7, 2.3, 0.8, 1.9, 7.1, 2.2, 0.9, 3.7 and 9.9 for blood, liver, kidney, lung, heart, stomach

  17. RELAXIN ACTIVATES PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA

    OpenAIRE

    Singh, Sudhir; Bennett, Robert G

    2009-01-01

    Relaxin is a polypeptide hormone that triggers multiple signaling pathways through its receptor RXFP1. Many of relaxin’s functions, including vascular and antifibrotic effects, are similar to those induced by activation of PPARγ. In this study, we tested the hypothesis that relaxin signaling through RXFP1 would activate PPARγ activity. In cells overexpressing RXFP1 (HEK-RXFP1), relaxin increased transcriptional activity through a PPAR response element (PPRE) in a concentration-dependent manne...

  18. Glutathione transferase classes alpha, pi, and mu: GSH activation mechanism.

    Science.gov (United States)

    Dourado, Daniel F A R; Fernandes, Pedro Alexandrino; Ramos, Maria João

    2010-10-14

    Since the early 1960s, glutathione transferases (GSTs) have been described as detoxification enzymes. In fact, GSTs are the most important enzymes involved in the metabolism of electrophilic xenobiotic/endobiotic compounds. These enzymes are able to catalyze the nucleophilic addition of glutathione (GSH) sulfur thiolate to a wide range of electrophilic substrates, building up a less toxic and more soluble compound. Cytosolic classes alpha, pi, and mu are the most extensively studied GSTs. However, many of the catalytic events are still poorly understood. In the present work, we have resorted to density functional theory (DFT) and to potential of mean force (PMF) calculations to determine the GSH activation mechanism of GSTP1-1 and GSTM1-1 isoenzymes. For the GSTP1-1 enzyme, we have demonstrated that a water molecule, after an initial conformational rearrangement of GSH, can assist a proton transfer between the GSH cysteine thiol (GSH-SH) and the GSH glutamate alpha carboxylate (GSH-COO(-)) groups. The energy barrier associated with the proton transfer is 11.36 kcal·mol(-1). The GSTM1-1 enzyme shows a completely different behavior from the previous isoenzyme. In this case, two water molecules, positioned between the GSH-SH and the ξ N atom of His107, working like a bridge, are able to promote the proton transfer between these two active groups with an energy barrier of 7.98 kcal·mol(-1). All our results are consistent with all the enzymes kinetics and mutagenesis experimental studies.

  19. Exogenous Alpha-Synuclein Alters Pre- and Post-Synaptic Activity by Fragmenting Lipid Rafts.

    Science.gov (United States)

    Emanuele, Marco; Esposito, Alessandro; Camerini, Serena; Antonucci, Flavia; Ferrara, Silvia; Seghezza, Silvia; Catelani, Tiziano; Crescenzi, Marco; Marotta, Roberto; Canale, Claudio; Matteoli, Michela; Menna, Elisabetta; Chieregatti, Evelina

    2016-05-01

    Alpha-synuclein (αSyn) interferes with multiple steps of synaptic activity at pre-and post-synaptic terminals, however the mechanism/s by which αSyn alters neurotransmitter release and synaptic potentiation is unclear. By atomic force microscopy we show that human αSyn, when incubated with reconstituted membrane bilayer, induces lipid rafts' fragmentation. As a consequence, ion channels and receptors are displaced from lipid rafts with consequent changes in their activity. The enhanced calcium entry leads to acute mobilization of synaptic vesicles, and exhaustion of neurotransmission at later stages. At the post-synaptic terminal, an acute increase in glutamatergic transmission, with increased density of PSD-95 puncta, is followed by disruption of the interaction between N-methyl-d-aspartate receptor (NMDAR) and PSD-95 with ensuing decrease of long term potentiation. While cholesterol loading prevents the acute effect of αSyn at the presynapse; inhibition of casein kinase 2, which appears activated by reduction of cholesterol, restores the correct localization and clustering of NMDARs.

  20. Exogenous Alpha-Synuclein Alters Pre- and Post-Synaptic Activity by Fragmenting Lipid Rafts

    Directory of Open Access Journals (Sweden)

    Marco Emanuele

    2016-05-01

    Full Text Available Alpha-synuclein (αSyn interferes with multiple steps of synaptic activity at pre-and post-synaptic terminals, however the mechanism/s by which αSyn alters neurotransmitter release and synaptic potentiation is unclear. By atomic force microscopy we show that human αSyn, when incubated with reconstituted membrane bilayer, induces lipid rafts' fragmentation. As a consequence, ion channels and receptors are displaced from lipid rafts with consequent changes in their activity. The enhanced calcium entry leads to acute mobilization of synaptic vesicles, and exhaustion of neurotransmission at later stages. At the post-synaptic terminal, an acute increase in glutamatergic transmission, with increased density of PSD-95 puncta, is followed by disruption of the interaction between N-methyl-d-aspartate receptor (NMDAR and PSD-95 with ensuing decrease of long term potentiation. While cholesterol loading prevents the acute effect of αSyn at the presynapse; inhibition of casein kinase 2, which appears activated by reduction of cholesterol, restores the correct localization and clustering of NMDARs.

  1. Hispolon inhibits the growth of estrogen receptor positive human breast cancer cells through modulation of estrogen receptor alpha

    International Nuclear Information System (INIS)

    Human estrogen receptor α (ERα) is a nuclear transcription factor that is a major therapeutic target in breast cancer. The transcriptional activity of ERα is regulated by certain estrogen-receptor modulators. Hispolon, isolated from Phellinus linteus, a traditional medicinal mushroom called Sanghwang in Korea, has been used to treat various pathologies, such as inflammation, gastroenteric disorders, lymphatic diseases, and cancers. In this latter context, Hispolon has been reported to exhibit therapeutic efficacy against various cancer cells, including melanoma, leukemia, hepatocarcinoma, bladder cancer, and gastric cancer cells. However, ERα regulation by Hispolon has not been reported. In this study, we investigated the effects of Hispolon on the growth of breast cancer cells. We found that Hispolon decreased expression of ERα at both mRNA and the protein levels in MCF7 and T47D human breast cancer cells. Luciferase reporter assays showed that Hispolon decreased the transcriptional activity of ERα. Hispolon treatment also inhibited expression of the ERα target gene pS2. We propose that Hispolon, an anticancer drug extracted from natural sources, inhibits cell growth through modulation of ERα in estrogen-positive breast cancer cells and is a candidate for use in human breast cancer chemotherapy. - Highlights: • Hispolon decreased ERα expression at both mRNA and protein levels. • Hispolon decreased ERα transcriptional activity. • Hispolon treatment inhibited expression of ERα target gene pS2. • Shikonin is a candidate chemotherapeutic target in the treatment of human breast cancer

  2. Hispolon inhibits the growth of estrogen receptor positive human breast cancer cells through modulation of estrogen receptor alpha

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Eun Hyang; Jang, Soon Young; Cho, In-Hye [Department of Pharmacy, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Hong, Darong [Department of Life and Nanopharmaceutical Science, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Jung, Bom; Park, Min-Ju [Department of Pharmacy, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Kim, Jong-Ho, E-mail: jonghokim@khu.ac.kr [Department of Pharmacy, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

    2015-08-07

    Human estrogen receptor α (ERα) is a nuclear transcription factor that is a major therapeutic target in breast cancer. The transcriptional activity of ERα is regulated by certain estrogen-receptor modulators. Hispolon, isolated from Phellinus linteus, a traditional medicinal mushroom called Sanghwang in Korea, has been used to treat various pathologies, such as inflammation, gastroenteric disorders, lymphatic diseases, and cancers. In this latter context, Hispolon has been reported to exhibit therapeutic efficacy against various cancer cells, including melanoma, leukemia, hepatocarcinoma, bladder cancer, and gastric cancer cells. However, ERα regulation by Hispolon has not been reported. In this study, we investigated the effects of Hispolon on the growth of breast cancer cells. We found that Hispolon decreased expression of ERα at both mRNA and the protein levels in MCF7 and T47D human breast cancer cells. Luciferase reporter assays showed that Hispolon decreased the transcriptional activity of ERα. Hispolon treatment also inhibited expression of the ERα target gene pS2. We propose that Hispolon, an anticancer drug extracted from natural sources, inhibits cell growth through modulation of ERα in estrogen-positive breast cancer cells and is a candidate for use in human breast cancer chemotherapy. - Highlights: • Hispolon decreased ERα expression at both mRNA and protein levels. • Hispolon decreased ERα transcriptional activity. • Hispolon treatment inhibited expression of ERα target gene pS2. • Shikonin is a candidate chemotherapeutic target in the treatment of human breast cancer.

  3. CERAPP: Collaborative estrogen receptor activity prediction project

    DEFF Research Database (Denmark)

    Mansouri, Kamel; Abdelaziz, Ahmed; Rybacka, Aleksandra;

    2016-01-01

    Background: Humans are exposed to thousands of man-made chemicals in the environment. Some chemicals mimic natural endocrine hormones and, thus, have the potential to be endocrine disruptors. Most of these chemicals have never been tested for their ability to interact with the estrogen receptor (ER......). Risk assessors need tools to prioritize chemicals for evaluation in costly in vivo tests, for instance, within the U.S. EPA Endocrine Disruptor Screening Program. oBjectives: We describe a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project......) and demonstrate the efficacy of using predictive computational models trained on high-throughput screening data to evaluate thousands of chemicals for ER-related activity and prioritize them for further testing. Methods: CERAPP combined multiple models developed in collaboration with 17 groups in the United...

  4. Recent advances in the discovery of alpha1-adrenoceptor agonists.

    Science.gov (United States)

    Bishop, Michael J

    2007-01-01

    The alpha(1) adrenoceptors are three of nine well-characterized receptors that are activated by epinephrine and norepinephrine. Agonists acting at the alpha(1) adrenoceptors produce numerous physiological effects, and are used therapeutically for several indications. Many known alpha(1) adrenoceptor agonists are alpha(1A) selective, but the discovery of highly selective alpha(1B) and alpha(1D) adrenoceptor agonists has proven to be an extremely difficult goal to achieve. This review will focus on recent advances in the discovery, development and clinical utility of subtype-specific alpha(1) agonists as well as contributions to our understanding of agonist-receptor interactions.

  5. Activation of NTS A2a adenosine receptors differentially resets baroreflex control of renal vs. adrenal sympathetic nerve activity.

    Science.gov (United States)

    Ichinose, Tomoko K; O'Leary, Donal S; Scislo, Tadeusz J

    2009-04-01

    The role of nucleus of solitary tract (NTS) A(2a) adenosine receptors in baroreflex mechanisms is controversial. Stimulation of these receptors releases glutamate within the NTS and elicits baroreflex-like decreases in mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA), whereas inhibition of these receptors attenuates HR baroreflex responses. In contrast, stimulation of NTS A(2a) adenosine receptors increases preganglionic adrenal sympathetic nerve activity (pre-ASNA), and the depressor and sympathoinhibitory responses are not markedly affected by sinoaortic denervation and blockade of NTS glutamatergic transmission. To elucidate the role of NTS A(2a) adenosine receptors in baroreflex function, we compared full baroreflex stimulus-response curves for HR, RSNA, and pre-ASNA (intravenous nitroprusside/phenylephrine) before and after bilateral NTS microinjections of selective adenosine A(2a) receptor agonist (CGS-21680; 2.0, 20 pmol/50 nl), selective A(2a) receptor antagonist (ZM-241385; 40 pmol/100 nl), and nonselective A(1) + A(2a) receptor antagonist (8-SPT; 1 nmol/100 nl) in urethane/alpha-chloralose anesthetized rats. Activation of A(2a) receptors decreased the range, upper plateau, and gain of baroreflex-response curves for RSNA, whereas these parameters all increased for pre-ASNA, consistent with direct effects of the agonist on regional sympathetic activity. However, no resetting of baroreflex-response curves along the MAP axis occurred despite the marked decreases in baseline MAP. The antagonists had no marked effects on baseline variables or baroreflex-response functions. We conclude that the activation of NTS A(2a) adenosine receptors differentially alters baroreflex control of HR, RSNA, and pre-ASNA mostly via non-baroreflex mechanism(s), and these receptors have virtually no tonic action on baroreflex control of these sympathetic outputs.

  6. In vivo Regulation of the Allergic Response by the Interleukin 4 Receptor Alpha Chain Immunoreceptor Tyrosine-based Inhibitory Motif

    Science.gov (United States)

    Tachdjian, Raffi; Khatib, Shadi Al; Schwinglshackl, Andreas; Kim, Hong Sook; Chen, Andrew; Blasioli, Julie; Mathias, Clinton; Kim, Hye-Young; Umetsu, Dale T.; Oettgen, Hans C.; Chatila, Talal A.

    2010-01-01

    Background Signaling by IL-4 and IL-13 via the IL-4 receptor alpha chain (IL-4Rα) plays a critical role in the pathology of allergic diseases. The IL-4Rα is endowed with an immunoreceptor tyrosine-based inhibitory motif (ITIM), centered on tyrosine 709 (Y709) in the cytoplasmic domain, that binds a number of regulatory phosphatases. The function of the ITIM in the in vivo regulation of IL-4R signaling remains unknown. Objective To determine the in vivo function of the IL-4Rα ITIM using mice in which the ITIM was inactivated by mutagenesis of the tyrosine Y709 residue into phenylalanine (F709). Methods F709 ITIM mutant mice were derived by knockin mutagenesis. Activation of intracellular signaling cascades by IL-4 and IL-13 was assessed by intracellular staining of phosphorylated signaling intermediates and by gene expression analysis. In vivo responses to allergic sensitization were assessed using models of allergic airway inflammation. Results The F709 mutation increased STAT6 phosphorylation by IL-4 and, disproportionately, by IL-13. This was associated with exaggerated Th2 polarization, enhanced alternative macrophage activation by IL-13, augmented basal and antigen-induced IgE responses and intensified allergen-induced eosinophilic airway inflammation and hyperreactivity. Conclusions These results point to a physiologic negative regulatory role for the Y709 ITIM in signaling via IL-4Rα, especially by IL-13. PMID:20392476

  7. The involvement of hypoxia-inducible factor 1 alpha in Toll-like receptor 7/8-mediated inflammatory response

    Institute of Scientific and Technical Information of China (English)

    Sally A Nicholas; Vadim V Sumbayev

    2009-01-01

    Toll-like receptors (TLRs) 7 and 8 are crucial in host defence against single-stranded RNA (ssRNA) viruses. Such viruses cause severe illnesses, which remain a serious medical burden in both industrialised and developing countries. TLR7/8 downstream signaling leads to a dramatic cellular stress associated with energy consumption. However, the molecular mechanisms of cell survival and adaptation to TLR7/8-induced stress, which give the cells an opportunity to initiate proper inflammatory reactions, are not clear at all. Here we report for the first time that ligand-induced ac-tivation of TLR7/8 leads to the accumulation of hypoxia-inducible factor 1 alpha (HIF-1α) protein in THP-1 human myeloid macrophages via redox-and reactive nitrogen species-dependent mechanisms. MAP kinases and phosphoi-nositol-3K are not involved in TLR7/8-mediated HIF-1α accumulation. Experiments with HIF-la knockdown THP-1 cells have clearly demonstrated that HIF-1α is important for the protection of these cells against TLR7/8-induced depletion of ATP. Thus, HIF-1α might support both cell survival and the production of pro-inflammatory cytokines upon TLR7/8 activation.

  8. Activation of group III metabotropic glutamate receptors is neuroprotective in cortical cultures.

    Science.gov (United States)

    Bruno, V; Copani, A; Bonanno, L; Knoepfel, T; Kuhn, R; Roberts, P J; Nicoletti, F

    1996-08-22

    (RS)-alpha-Methyl-4-phosphonophenylglycine (MPPG) and (S)-alpha-methyl-3-carboxyphenylalanine (M3CPA), two novel preferential antagonists of group III metabotropic glutamate (mGlu) receptors, antagonized the neuroprotective activity of L-2-amino-4-phosphono-butanoate (L-AP4) or L-serine-O-phosphate in mice cultured cortical cells exposed to a toxic pulse of N-methyl-D-aspartate. In contrast, MPPG did not influence the neuroprotective activity of the selective group II mGlu receptor agonist, (2S,1'R,2'R,3'R)-2-(2,3-dicarboxy-cyclopropyl) glycine (DCG-IV). These results indicate that activation of group III mGu receptors exerts neuroprotective activity against excitotoxic neuronal death. At least one of the two major group III mGlu receptor subtypes, i.e. mGlu4 receptor, is expressed by cultured cortical neurons, as shown by immunocytochemical analysis with specific polyclonal antibodies. PMID:8880068

  9. A Review of the Updated Pharmacophore for the Alpha 5 GABA(A Benzodiazepine Receptor Model

    Directory of Open Access Journals (Sweden)

    Terry Clayton

    2015-01-01

    Full Text Available An updated model of the GABA(A benzodiazepine receptor pharmacophore of the α5-BzR/GABA(A subtype has been constructed prompted by the synthesis of subtype selective ligands in light of the recent developments in both ligand synthesis, behavioral studies, and molecular modeling studies of the binding site itself. A number of BzR/GABA(A α5 subtype selective compounds were synthesized, notably α5-subtype selective inverse agonist PWZ-029 (1 which is active in enhancing cognition in both rodents and primates. In addition, a chiral positive allosteric modulator (PAM, SH-053-2′F-R-CH3 (2, has been shown to reverse the deleterious effects in the MAM-model of schizophrenia as well as alleviate constriction in airway smooth muscle. Presented here is an updated model of the pharmacophore for α5β2γ2 Bz/GABA(A receptors, including a rendering of PWZ-029 docked within the α5-binding pocket showing specific interactions of the molecule with the receptor. Differences in the included volume as compared to α1β2γ2, α2β2γ2, and α3β2γ2 will be illustrated for clarity. These new models enhance the ability to understand structural characteristics of ligands which act as agonists, antagonists, or inverse agonists at the Bz BS of GABA(A receptors.

  10. Estrogen and inflammation modulate estrogen receptor alpha expression in specific tissues of the temporomandibular joint

    Directory of Open Access Journals (Sweden)

    Bellinger Larry L

    2009-12-01

    Full Text Available Abstract Background Estrogen is known to play role in temporomandibular joint (TMJ disorders and estrogen effects can be mediated by estrogen receptor (ER alpha present in the TMJ. Cells expressing the estrogen receptor ERalpha are present in the temporomandibular joint (TMJ but changes in expression due to estrogen and inflammation have not been characterized. In this study, ERalpha protein content and the number of cells expressing ERalpha was measured in 17 beta-estradiol-treated rats after inflammation was induced in the TMJ. Methods Sixteen ovariectomized female rats were divided into two groups such that one group received 17 beta estradiol (E2 and the other was given vehicle (VEH. Groups were then subdivided further, one received injections of saline and the other received Complete Freund's adjuvant (CFA within the superior joint space of the TMJ. Thus the four groups include no E2/saline, E2/saline, no E2/CFA and E2/CFA. After treatment, the rats were sacrificed, and the TMJ anterior, disc, retrodiscal and synovial tissues were analyzed by western blot and immunocytochemistry. Positive stained cells were counted using a Nikon epifluorescent microscope. Results The western blot showed that ERalpha protein significantly decreased with inflammation. The number of ERalpha-positive cells in the TMJ was not affected by inflammation or 17 beta-estradiol with exception of the retrodiscal tissue. In the retrodiscal tissue 17 beta-estradiol significantly decreased the number of ERalpha-positive cells but only in a non-inflamed joint. Conclusions In conclusion, inflammation and 17 beta-estradiol can modulate ERalpha expression in the TMJ but the effects are tissue specific.

  11. Tryptic mapping and membrane topology of the benzodiazepine receptor alpha-subunit

    Energy Technology Data Exchange (ETDEWEB)

    Lentes, K.U.; Venter, J.C.

    1986-05-01

    Rat brain membrane benzodiazepine receptors (BZR) were photoaffinity labelled specifically (in presence or absence of 6 ..mu..M clonazepam) with 10 nM /sup 3/H-flunitrazepam (FNZ). Digestion of the FNZ-labelled, membrane-bound BZR with 200 ..mu..g trypsin/mg membrane protein yielded H/sub 2/O-soluble BZR-fragments of molecular mass (M/sub r/) 34, 31, 28, 24, 21, 18, 16, 12, 10 and 7kDa. Because the 34kDa-peptide is the largest fragment containing a FNZ-binding site they conclude that this represents the extracellular domain of the BZR. In the remaining pellet two labelled peptides with M/sub r/ of 44kDa and 28kDa were found that required the use of detergents for their solubilization; they therefore contain the membrane anchoring domain. Digestion of the 0.5% Na-deoxycholate solubilized, intact BZR (M/sub r/ 51kDa) resulted in the same tryptic pattern as the membrane form of the receptor plus two larger fragments of M/sub r/ 45kDa and 40kDa. Arrangement of all tryptic fragments with reference to the FNZ binding site reveals a membrane topology of the BZR alpha-subunit with 67% (34kDa) for the extracellular domain, 21% (11kDa) for the membrane anchoring domain and 12% (6kDa) for a putative cytoplasmic domain. The overlap between some of the labelled fragments suggest that the BZ binding site must be located near the membrane surface of the extracellular domain.

  12. Tryptic mapping and membrane topology of the benzodiazepine receptor alpha-subunit

    International Nuclear Information System (INIS)

    Rat brain membrane benzodiazepine receptors (BZR) were photoaffinity labelled specifically (in presence or absence of 6 μM clonazepam) with 10 nM 3H-flunitrazepam (FNZ). Digestion of the FNZ-labelled, membrane-bound BZR with 200 μg trypsin/mg membrane protein yielded H2O-soluble BZR-fragments of molecular mass (M/sub r/) 34, 31, 28, 24, 21, 18, 16, 12, 10 and 7kDa. Because the 34kDa-peptide is the largest fragment containing a FNZ-binding site they conclude that this represents the extracellular domain of the BZR. In the remaining pellet two labelled peptides with M/sub r/ of 44kDa and 28kDa were found that required the use of detergents for their solubilization; they therefore contain the membrane anchoring domain. Digestion of the 0.5% Na-deoxycholate solubilized, intact BZR (M/sub r/ 51kDa) resulted in the same tryptic pattern as the membrane form of the receptor plus two larger fragments of M/sub r/ 45kDa and 40kDa. Arrangement of all tryptic fragments with reference to the FNZ binding site reveals a membrane topology of the BZR alpha-subunit with 67% (34kDa) for the extracellular domain, 21% (11kDa) for the membrane anchoring domain and 12% (6kDa) for a putative cytoplasmic domain. The overlap between some of the labelled fragments suggest that the BZ binding site must be located near the membrane surface of the extracellular domain

  13. Peroxisome proliferator-activated receptors for hypertension

    Institute of Scientific and Technical Information of China (English)

    Daisuke; Usuda; Tsugiyasu; Kanda

    2014-01-01

    Peroxisome proliferator-activated receptors(PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily, which is composed of four members encoded by distinct genes(α, β, γ, and δ). The genes undergo transactivation or transrepression under specific mechanisms that lead to the induction or repression of target gene expression. As is the case with other nuclear receptors, all four PPAR isoforms contain five or six structural regions in four functional domains; namely, A/B, C, D, and E/F. PPARs have many functions, particularly functions involving control of vascular tone, inflammation, and energy homeostasis, and are, therefore, important targets for hypertension, obesity, obesity-induced inflammation, and metabolic syndrome in general. Hence, PPARs also represent drug targets, and PPARα and PPARγ agonists are used clinically in the treatment of dyslipidemia and type 2 diabetes mellitus, respectively. Because of their pleiotropic effects, they have been identified as active in a number of diseases and are targets for the development of a broad range of therapies for a variety of diseases. It is likely that the range of PPARγ agonist therapeutic actions will result in novel approaches to lifestyle and other diseases. The combination of PPARs with reagents or with other cardiovascular drugs, such as diuretics and angiotensin Ⅱ receptor blockers, should be studied.This article provides a review of PPAR isoform characteristics, a discussion of progress in our understanding of the biological actions of PPARs, and a summary of PPAR agonist development for patient management. We also include a summary of the experimental and clinical evidence obtained from animal studies and clinical trials conducted to evaluate the usefulness and effectiveness of PPAR agonists in the treatment of lifestyle-related diseases.

  14. Alpha7 Nicotinic Acetylcholine Receptor Is a Target in Pharmacology and Toxicology

    Directory of Open Access Journals (Sweden)

    Miroslav Pohanka

    2012-02-01

    Full Text Available Alpha7 nicotinic acetylcholine receptor (α7 nAChR is an important part of the cholinergic nerve system in the brain. Moreover, it is associated with a cholinergic anti-inflammatory pathway in the termination of the parasympathetic nervous system. Antagonists of α7 nAChR are a wide group represented by conotoxin and bungarotoxin. Even Alzheimer’s disease drug memantine acting as an antagonist in its side pathway belongs in this group. Agonists of α7 nAChR are suitable for treatment of multiple cognitive dysfunctions such as Alzheimer’s disease or schizophrenia. Inflammation or even sepsis can be ameliorated by the agonistic acting compounds. Preparations RG3487, SEN34625/WYE-103914, SEN12333, ABT-107, Clozapine, GTS-21, CNI-1493, and AR-R17779 are representative examples of the novel compounds with affinity toward the α7 nAChR. Pharmacological, toxicological, and medicinal significance of α7 nAChR are discussed throughout this paper.

  15. Loss of estrogen-related receptor alpha disrupts ventral-striatal synaptic function in female mice.

    Science.gov (United States)

    De Jesús-Cortés, Héctor; Lu, Yuan; Anderson, Rachel M; Khan, Michael Z; Nath, Varun; McDaniel, Latisha; Lutter, Michael; Radley, Jason J; Pieper, Andrew A; Cui, Huxing

    2016-08-01

    Eating disorders (EDs), including anorexia nervosa, bulimia nervosa and binge-ED, are mental illnesses characterized by high morbidity and mortality. While several studies have identified neural deficits in patients with EDs, the cellular and molecular basis of the underlying dysfunction has remained poorly understood. We previously identified a rare missense mutation in the transcription factor estrogen-related receptor alpha (ESRRA) associated with development of EDs. Because ventral-striatal signaling is related to the reward and motivation circuitry thought to underlie EDs, we performed functional and structural analysis of ventral-striatal synapses in Esrra-null mice. Esrra-null female, but not male, mice exhibit altered miniature excitatory postsynaptic currents on medium spiny neurons (MSNs) in the ventral striatum, including increased frequency, increased amplitude, and decreased paired pulse ratio. These electrophysiological measures are associated with structural and molecular changes in synapses of MSNs in the ventral striatum, including fewer pre-synaptic glutamatergic vesicles and enhanced GluR1 function. Neuronal Esrra is thus required for maintaining normal synaptic function in the ventral striatum, which may offer mechanistic insights into the behavioral deficits observed in Esrra-null mice. PMID:27155145

  16. Loss of estrogen-related receptor alpha disrupts ventral-striatal synaptic function in female mice.

    Science.gov (United States)

    De Jesús-Cortés, Héctor; Lu, Yuan; Anderson, Rachel M; Khan, Michael Z; Nath, Varun; McDaniel, Latisha; Lutter, Michael; Radley, Jason J; Pieper, Andrew A; Cui, Huxing

    2016-08-01

    Eating disorders (EDs), including anorexia nervosa, bulimia nervosa and binge-ED, are mental illnesses characterized by high morbidity and mortality. While several studies have identified neural deficits in patients with EDs, the cellular and molecular basis of the underlying dysfunction has remained poorly understood. We previously identified a rare missense mutation in the transcription factor estrogen-related receptor alpha (ESRRA) associated with development of EDs. Because ventral-striatal signaling is related to the reward and motivation circuitry thought to underlie EDs, we performed functional and structural analysis of ventral-striatal synapses in Esrra-null mice. Esrra-null female, but not male, mice exhibit altered miniature excitatory postsynaptic currents on medium spiny neurons (MSNs) in the ventral striatum, including increased frequency, increased amplitude, and decreased paired pulse ratio. These electrophysiological measures are associated with structural and molecular changes in synapses of MSNs in the ventral striatum, including fewer pre-synaptic glutamatergic vesicles and enhanced GluR1 function. Neuronal Esrra is thus required for maintaining normal synaptic function in the ventral striatum, which may offer mechanistic insights into the behavioral deficits observed in Esrra-null mice.

  17. The orphan nuclear receptor Rev-Erbalpha is a peroxisome proliferator-activated receptor (PPAR) gamma target gene and promotes PPARgamma-induced adipocyte differentiation

    DEFF Research Database (Denmark)

    Fontaine, Coralie; Dubois, Guillaume; Duguay, Yannick;

    2003-01-01

    Rev-Erbalpha (NR1D1) is an orphan nuclear receptor encoded on the opposite strand of the thyroid receptor alpha gene. Rev-Erbalpha mRNA is induced during adipocyte differentiation of 3T3-L1 cells, and its expression is abundant in rat adipose tissue. Peroxisome proliferator-activated receptor gamma...... (PPARgamma) (NR1C3) is a nuclear receptor controlling adipocyte differentiation and insulin sensitivity. Here we show that Rev-Erbalpha expression is induced by PPARgamma activation with rosiglitazone in rat epididymal and perirenal adipose tissues in vivo as well as in 3T3-L1 adipocytes in vitro...... for this nuclear receptor as a promoter of adipocyte differentiation....

  18. Ligand-Stimulated Downregulation of the Alpha Interferon Receptor: Role of Protein Kinase D2▿ §

    OpenAIRE

    Zheng, Hui; Qian, Juan; Varghese, Bentley; Baker, Darren P.; Fuchs, Serge

    2010-01-01

    Alpha interferon (IFN-α) controls homeostasis of hematopoietic stem cells, regulates antiviral resistance, inhibits angiogenesis, and suppresses tumor growth. This cytokine is often used to treat cancers and chronic viral infections. The extent of cellular responses to IFN-α is limited by the IFN-induced ubiquitination and degradation of the IFN-α/β receptor chain 1 (IFNAR1) chain of the cognate receptor. IFNAR1 ubiquitination is facilitated by the βTrcp E3 ubiquitin ligase that is recruited ...

  19. 64Cu-Labeled Alpha-Melanocyte-Stimulating Hormone Analog for MicroPET Imaging of Melanocortin 1 Receptor Expression

    OpenAIRE

    CHENG Zhen; Xiong, Zhengming; Subbarayan, Murugesan; Chen, Xiaoyuan; Gambhir, Sanjiv Sam

    2007-01-01

    The alpha-melanocyte-stimulating hormone (α-MSH) receptor (melanocortin type 1 receptor, or MC1R) plays an important role in the development and growth of melanoma cells. It was found that MC1R was overexpressed on most murine and human melanoma, making it a promising molecular target for melanoma imaging and therapy. Radiolabeled α-MSH peptide and its analogs that can specifically bind with MC1R have been extensively explored for developing novel agents for melanoma detection and radionuclid...

  20. 5-HT2A Receptor Binding in the Frontal Cortex of Parkinson's Disease Patients and Alpha-Synuclein Overexpressing Mice

    DEFF Research Database (Denmark)

    Rasmussen, Nadja Bredo; Olesen, Mikkel Vestergaard; Brudek, Tomasz;

    2016-01-01

    The 5-HT2A receptor is highly involved in aspects of cognition and executive function and seen to be affected in neurodegenerative diseases like Alzheimer's disease and related to the disease pathology. Even though Parkinson's disease (PD) is primarily a motor disorder, reports of impaired...... executive function are also steadily being associated with this disease. Not much is known about the pathophysiology behind this. The aim of this study was thereby twofold: (1) to investigate 5-HT2A receptor binding levels in Parkinson's brains and (2) to investigate whether PD associated pathology, alpha...

  1. Activation of the epidermal growth factor receptor (EGFR) by a novel metalloprotease pathway.

    LENUS (Irish Health Repository)

    Bergin, David A

    2008-11-14

    Neutrophil Elastase (NE) is a pro-inflammatory protease present at higher than normal levels in the lung during inflammatory disease. NE regulates IL-8 production from airway epithelial cells and can activate both EGFR and TLR4. TACE\\/ADAM17 has been reported to trans-activate EGFR in response to NE. Here, using 16HBE14o-human bronchial epithelial cells we demonstrate a new mechanism by which NE regulates both of these events. A high molecular weight soluble metalloprotease activity detectable only in supernatants from NE-treated cells by gelatin and casein zymography was confirmed to be meprin alpha by Western immunoblotting. In vitro studies demonstrated the ability of NE to activate meprin alpha, which in turn could release soluble TGFalpha and induce IL-8 production from 16HBE14o- cells. These effects were abrogated by actinonin, a specific meprin inhibitor. NE-induced IL-8 expression was also inhibited by meprin alpha siRNA. Immunoprecipitation studies detected EGFR\\/TLR4 complexes in NE-stimulated cells overexpressing these receptors. Confocal studies confirmed colocalization of EGFR and TLR4 in 16HBE14o- cells stimulated with meprin alpha. NFkappaB was also activated via MyD88 in these cells by meprin alpha. In bronchoalveolar lavage fluid from NE knock-out mice infected intra-tracheally with Pseudomonas aeruginosa meprin alpha was significantly decreased compared with control mice, and was significantly increased and correlated with NE activity, in bronchoalveolar lavage fluid from individuals with cystic fibrosis but not healthy controls. The data describe a previously unidentified lung metalloprotease meprin alpha, and its role in NE-induced EGFR and TLR4 activation and IL-8 production.

  2. Relaxin Family Peptide Receptor 1 (RXFP1) Activation Stimulates the Peroxisome Proliferator-Activated Receptor Gamma

    OpenAIRE

    Singh, Sudhir; Bennett, Robert G

    2009-01-01

    Relaxin (Rlx) has antifibrotic effects in a number of tissues. Many of these effects are similar to those induced by the activators of peroxisome proliferator-activated receptor γ (PPARγ), raising the possibility that a mechanism for Rlx’s antifibrotic effects may involve activation of the PPARγ pathway. This study investigates the effect of Rlx on PPARs and their mechanism of upregulation. It shows that Rlx stimulates ligand-independent PPAR activation in a dose-dependent manner. The combine...

  3. Augmentation of glycine receptor alpha3 currents suggests a mechanism for glucose-mediated analgesia.

    Science.gov (United States)

    Breitinger, Ulrike; Breitinger, Hans-Georg

    2016-01-26

    The inhibitory glycine receptor (GlyR) mediates rapid synaptic inhibition in the mammalian central nervous system. Recently, glucose was identified as a positive modulator of α1 GlyRs. Here, recombinant human α3GlyRs with and without glucose treatment were studied using patch clamp methods. Similar to α1GlyRs, receptor variants α3L and α3K were potentiated by sugar. Glucose treatment reduced EC50 values of GlyR α3L and α3K by a factor of 4.5 and 3.3, respectively, without affecting maximum currents or desensitization. The high-activity mutant α3L(P185L) was not further potentiated by glucose. Potentiation of glycinergic signalling may underlie some of the analgetic effects of glucose. PMID:26656729

  4. EEG alpha activity reflects motor preparation rather than the mode of action selection

    Directory of Open Access Journals (Sweden)

    Marie-Pierre eDeiber

    2012-08-01

    Full Text Available Alpha-band activity (8-13 Hz is suppressed by sensory stimulation and movements, modulated by attention, working memory and mental tasks and may be sensitive to higher motor control functions. The aim of the present study was to examine alpha oscillatory activity during the preparation of simple left or right finger movements, contrasting the external and internal mode of action selection. Three preparation conditions were examined using a precueing paradigm with S1 as the preparatory and S2 as the imperative cue: Full, laterality instructed by S1; Free, laterality freely selected and None, laterality instructed by S2. Time-frequency analysis was performed in the alpha frequency range during the S1-S2 interval, and alpha motor-related amplitude asymmetries (MRAA were also calculated. The significant MRAA during the Full and Free conditions indicated effective external and internal motor response preparation. In the absence of specific motor preparation (None, a posterior alpha power decrease (event-related desynchronization, ERD dominated, reflecting the main engagement of attentional resources. In Full and Free motor preparation, posterior alpha ERD was accompanied by a midparietal alpha power increase (event-related synchronization, ERS, suggesting a concomitant inhibition of task-irrelevant visual activity. In both Full and Free motor preparation, analysis of alpha power according to MRAA amplitude revealed two types of functional activation patterns: 1 a motor alpha pattern, with predominantly midparietal alpha ERS and large MRAA corresponding to lateralized motor activation/visual inhibition and 2 an attentional alpha pattern, with dominating right posterior alpha ERD and small MRAA reflecting visuospatial attention. The present results suggest that alpha oscillatory patterns do not resolve the selection mode of action, but rather distinguish separate functional strategies of motor preparation. 

  5. Estrogen receptor alpha overexpressing mouse antral follicles are sensitive to atresia induced by methoxychlor and its metabolites.

    Science.gov (United States)

    Paulose, Tessie; Hannon, Patrick R; Peretz, Jackye; Craig, Zelieann R; Flaws, Jodi A

    2012-06-01

    Methoxychlor (MXC) and its metabolites bind to estrogen receptors (ESRs) and increase ovarian atresia. To test whether ESR alpha (ESR1) overexpressing (ESR1 OE) antral follicles are more sensitive to atresia compared to controls, we cultured antral follicles with vehicle, MXC (1-100 μg/ml) or metabolites (0.1-10 μg/ml). Results indicate that MXC and its metabolites significantly increase atresia in ESR1 OE antral follicles at lower doses compared to controls. Activity of pro-apoptotic factor caspase-3/7 was significantly higher in ESR1 OE treated antral follicles compared to controls. ESR1 OE mice dosed with MXC 64 mg/kg/day had an increased percentage of atretic antral follicles compared to controls. Furthermore, pro-caspase-3 levels were found to be significantly lower in ESR1 OE ovaries than controls dosed with MXC 64 mg/kg/day. These data suggest that ESR1 OE ovaries are more sensitive to atresia induced by MXC and its metabolites in vitro and in vivo compared to controls.

  6. Virtual screening studies of Chinese medicine Coptidis Rhizoma as alpha7 nicotinic acetylcholine receptor agonists for treatment of Alzheimer's disease

    Science.gov (United States)

    Xiang, Li; Xu, Youdong; Zhang, Yan; Meng, Xianli; Wang, Ping

    2015-04-01

    Alzheimer's disease (AD) is an age-related neurodegenerative disease. Extensive in vitro and in vivo experiments have proved that the decreased activity of the cholinergic neuron is responsible for the memory and cognition deterioration. The alpha7 nicotinic acetylcholine receptor (α7-nAChR) is proposed to a drug target of AD, and compounds which acting as α7-nAChR agonists are considered as candidates in AD treatment. Chinese medicine CoptidisRhizoma and its compounds are reported in various anti-AD effects. In this study, virtual screening, docking approaches and hydrogen bond analyses were applied to screen potential α7-nAChR agonists from CoptidisRhizome. The 3D structure of the protein was obtained from PDB database. 87 reported compounds were included in this research and their structures were accessed by NCBI Pubchem. Docking analysis of the compounds was performed using AutoDock 4.2 and AutoDock Vina. The images of the binding modes hydrogen bonds and the hydrophobic interaction were rendered with PyMOL1.5.0.4. and LigPlot+ respectively. Finally, N-tran-feruloyltyramine, isolariciresinol, flavanone, secoisolariciresinol, (+)-lariciresinol and dihydrochalcone, exhibited the lowest docking energy of protein-ligand complex. The results indicate these 6 compounds are potential α7 nAChR agonists, and expected to be effective in AD treatment.

  7. Evolution of nuclear retinoic acid receptor alpha (RARα) phosphorylation sites. Serine gain provides fine-tuned regulation.

    Science.gov (United States)

    Samarut, Eric; Amal, Ismail; Markov, Gabriel V; Stote, Roland; Dejaegere, Annick; Laudet, Vincent; Rochette-Egly, Cécile

    2011-07-01

    The human nuclear retinoic acid (RA) receptor alpha (hRARα) is a ligand-dependent transcriptional regulator, which is controlled by a phosphorylation cascade. The cascade starts with the RA-induced phosphorylation of a serine residue located in the ligand-binding domain, S(LBD), allowing the recruitment of the cdk7/cyclin H/MAT1 subcomplex of TFIIH through the docking of cyclin H. It ends by the subsequent phosphorylation by cdk7 of an other serine located in the N-terminal domain, S(NTD). Here, we show that this cascade relies on an increase in the flexibility of the domain involved in cyclin H binding, subsequently to the phosphorylation of S(LBD). Owing to the functional importance of RARα in several vertebrate species, we investigated whether the phosphorylation cascade was conserved in zebrafish (Danio rerio), which expresses two RARα genes: RARα-A and RARα-B. We found that in zebrafish RARαs, S(LBD) is absent, whereas S(NTD) is conserved and phosphorylated. Therefore, we analyzed the pattern of conservation of the phosphorylation sites and traced back their evolution. We found that S(LBD) is most often absent outside mammalian RARα and appears late during vertebrate evolution. In contrast, S(NTD) is conserved, indicating that the phosphorylation of this functional site has been under ancient high selection constraint. This suggests that, during evolution, different regulatory circuits control RARα activity. PMID:21297158

  8. Monoclonal antibodies to the human insulin receptor that activate glucose transport but not insulin receptor kinase activity

    International Nuclear Information System (INIS)

    Three mouse monoclonal antibodies were produced that reacted with the α subunit of the human insulin receptor. All three both immunoprecipitated 125I-labeled insulin receptors from IM-9 lymphocytes and competitively inhibited 125I-labeled insulin binding to its receptor. Unlike insulin, the antibodies failed to stimulate receptor autophosphorylation in both intact IM-9 lymphocytes and purified human placental insulin receptors. Moreover, unlike insulin, the antibodies failed to stimulate receptor-mediated phosphorylation of exogenous substrates. However, like insulin, two of the three antibodies stimulated glucose transport in isolated human adipocytes. One antibody, on a molar basis, was as potent as insulin. These studies indicate, therefore, that monoclonal antibodies to the insulin receptor can mimic a major function of insulin without activating receptor kinase activity. They also raise the possibility that certain actions of insulin such as stimulation of glucose transport may not require the activation of receptor kinase activity

  9. The gene encoding the Acyl-CoA-binding protein is activated by peroxisome proliferator-activated receptor gamma through an intronic response element functionally conserved between humans and rodents

    DEFF Research Database (Denmark)

    Helledie, Torben; Grøntved, Lars; Jensen, Søren S;

    2002-01-01

    have remained largely unknown. Here we report that ACBP is a novel peroxisome proliferator-activated receptor (PPAR)gamma target gene. The rat ACBP gene is directly activated by PPARgamma/retinoid X receptor alpha (RXRalpha) and PPARalpha/RXRalpha, but not by PPARdelta/RXRalpha, through a PPAR...

  10. Interferon alpha bioactivity critically depends on Scavenger receptor class B type I function.

    Science.gov (United States)

    Vasquez, Marcos; Fioravanti, Jessica; Aranda, Fernando; Paredes, Vladimir; Gomar, Celia; Ardaiz, Nuria; Fernandez-Ruiz, Veronica; Méndez, Miriam; Nistal-Villan, Estanislao; Larrea, Esther; Gao, Qinshan; Gonzalez-Aseguinolaza, Gloria; Prieto, Jesus; Berraondo, Pedro

    2016-08-01

    Scavenger receptor class B type I (SR-B1) binds pathogen-associated molecular patterns participating in the regulation of the inflammatory reaction but there is no information regarding potential interactions between SR-B1 and the interferon system. Herein, we report that SR-B1 ligands strongly regulate the transcriptional response to interferon α (IFNα) and enhance its antiviral and antitumor activity. This effect was mediated by the activation of TLR2 and TLR4 as it was annulled by the addition of anti-TLR2 or anti-TLR4 blocking antibodies. In vivo, we maximized the antitumor activity of IFNα co-expressing in the liver a SR-B1 ligand and IFNα by adeno-associated viruses. This gene therapy strategy eradicated liver metastases from colon cancer with reduced toxicity. On the other hand, genetic and pharmacological inhibition of SR-B1 blocks the clathrin-dependent interferon receptor recycling pathway with a concomitant reduction in IFNα signaling and bioactivity. This effect can be applied to enhance cancer immunotherapy with oncolytic viruses. Indeed, SR-B1 antagonists facilitate replication of oncolytic viruses amplifying their tumoricidal potential. In conclusion, SR-B1 agonists behave as IFNα enhancers while SR-B1 inhibitors dampen IFNα activity. These results demonstrate that SR-B1 is a suitable pharmacology target to enhance cancer immunotherapy based on IFNα and oncolytic viruses. PMID:27622065

  11. Toll-like receptor 3 regulates angiogenesis and apoptosis in prostate cancer cell lines through hypoxia-inducible factor 1 alpha.

    Science.gov (United States)

    Paone, Alessio; Galli, Roberta; Gabellini, Chiara; Lukashev, Dmitriy; Starace, Donatella; Gorlach, Agnes; De Cesaris, Paola; Ziparo, Elio; Del Bufalo, Donatella; Sitkovsky, Michail V; Filippini, Antonio; Riccioli, Anna

    2010-07-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible factor 1 (HIF-1) regulates several cellular processes, including apoptosis, in response to hypoxia and to other stimuli also in normoxic conditions. Here we describe a novel protumor machinery triggered by TLR3 activation in PC3 cells consisting of increased expression of the specific I.3 isoform of HIF-1 alpha and nuclear accumulation of HIF-1 complex in normoxia, resulting in reduced apoptosis and in secretion of functional vascular endothelial growth factor (VEGF). Moreover, we report that, in the less aggressive LNCaP cells, TLR3 activation fails to induce nuclear accumulation of HIF-1 alpha. However, the transfection of I.3 isoform of hif-1 alpha in LNCaP cells allows poly(I:C)-induced HIF-1 activation, resulting in apoptosis protection and VEGF secretion. Altogether, our findings demonstrate that differences in the basal level of HIF-1 alpha expression in different prostate cancer cell lines underlie their differential response to TLR3 activation, suggesting a correlation between different stages of malignancy, hypoxic gene expression, and beneficial responsiveness to TLR agonists. PMID:20651983

  12. Repeated administration of alpha7 nicotinic acetylcholine receptor (nAChR) agonists, but not positive allosteric modulators, increases alpha7 nAChR levels in the brain

    DEFF Research Database (Denmark)

    Christensen, Ditte Z; Mikkelsen, Jens D; Hansen, Henrik H;

    2010-01-01

    The alpha7 nicotinic acetylcholine receptor (nAChR) is an important target for treatment of cognitive deficits in schizophrenia and Alzheimer's disease. However, the receptor desensitizes rapidly in vitro, which has led to concern regarding its applicability as a clinically relevant drug target...

  13. Left temporal alpha band activity increases during working memory retention of pitches

    NARCIS (Netherlands)

    Van Dijk, H.; Nieuwenhuis, I.L.C.; Jensen, O.

    2010-01-01

    The functional role and regional specificity of similar to 10 Hz alpha band activity remains of debate. Alpha band activity is strongly modulated in visual working memory tasks and it has been proposed to subserve resource allocation by disengaging task-irrelevant regions. It remains unknown if alph

  14. AMP-activated protein kinase-regulated activation of the PGC-1alpha promoter in skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Isabella Irrcher

    Full Text Available The mechanisms by which PGC-1alpha gene expression is controlled in skeletal muscle remains largely undefined. Thus, we sought to investigate the transcriptional regulation of PGC-1alpha using AICAR, an activator of AMPK, that is known to increase PGC-1alpha expression. A 2.2 kb fragment of the human PGC-1alpha promoter was cloned and sequence analysis revealed that this TATA-less sequence houses putative consensus sites including a GC-box, a CRE, several IRSs, a SRE, binding sites for GATA, MEF2, p 53, NF-kappaB, and EBox binding proteins. AMPK activation for 24 hours increased PGC-1alpha promoter activity with concomitant increases in mRNA expression. The effect of AICAR on transcriptional activation was mediated by an overlapping GATA/EBox binding site at -495 within the PGC-1alpha promoter based on gel shift analyses that revealed increases in GATA/EBox DNA binding. Mutation of the EBox within the GATA/EBox binding site in the promoter reduced basal promoter activity and completely abolished the AICAR effect. Supershift analyses identified USF-1 as a DNA binding transcription factor potentially involved in regulating PGC-1alpha promoter activity, which was confirmed in vivo by ChIP. Overexpression of either GATA-4 or USF-1 alone increased the p851 PGC-1alpha promoter activity by 1.7- and 2.0-fold respectively, while co-expression of GATA-4 and USF-1 led to an additive increase in PGC-1alpha promoter activity. The USF-1-mediated increase in PGC-1alpha promoter activation led to similar increases at the mRNA level. Our data identify a novel AMPK-mediated regulatory pathway that regulates PGC-1alpha gene expression. This could represent a potential therapeutic target to control PGC-1alpha expression in skeletal muscle.

  15. Interplanetary Lyman $\\alpha$ line profiles: variations with solar activity cycle

    CERN Document Server

    Quemerais, E; Bertaux, J L; Koutroumpa, D; Clarke, J; Kyrola, E; Schmidt, W; Qu\\'emerais, Eric; Lallement, Rosine; Bertaux, Jean-Loup; Koutroumpa, Dimitra; Clarke, John; Kyrola, Erkki; Schmidt, Walter

    2006-01-01

    Interplanetary Lyman alpha line profiles are derived from the SWAN H cell data measurements. The measurements cover a 6-year period from solar minimum (1996) to after the solar maximum of 2001. This allows us to study the variations of the line profiles with solar activity. These line profiles were used to derive line shifts and line widths in the interplanetary medium for various angles of the LOS with the interstellar flow direction. The SWAN data results were then compared to an interplanetary background upwind spectrum obtained by STIS/HST in March 2001. We find that the LOS upwind velocity associated with the mean line shift of the IP \\lya line varies from 25.7 km/s to 21.4 km/s from solar minimum to solar maximum. Most of this change is linked with variations in the radiation pressure. LOS kinetic temperatures derived from IP line widths do not vary monotonically with the upwind angle of the LOS. This is not compatible with calculations of IP line profiles based on hot model distributions of interplanet...

  16. Discoidin domain receptor 1 is activated independently of beta(1) integrin

    DEFF Research Database (Denmark)

    Vogel, W; Brakebusch, C; Fässler, R;

    2000-01-01

    Various types of collagen have been identified as potential ligands for the two mammalian discoidin domain receptor (DDR) tyrosine kinases, DDR1 and DDR2. It is presently unclear whether collagen-induced DDR receptor activation, which occurs with very slow kinetics, involves additional proteins...... blocking antibodies for alpha(2)beta(1) integrin or in cells with a targeted deletion of the beta(1) integrin gene. Finally, we show that overexpression of dominant negative DDR1 in the myoblast cell line C2C12 blocks cellular differentiation and the formation of myofibers....

  17. Single amino acid changes that render human IFN-alpha 2 biologically active on mouse cells.

    OpenAIRE

    Weber, H.; Valenzuela, D; Lujber, G; Gubler, M; Weissmann, C

    1987-01-01

    Human IFN-alpha 1 and IFN-alpha 2 differ in 28 of 166 amino acids and show very different specific antiviral activities on human and murine cells. We have identified, by hybrid scanning and site-directed mutagenesis, three residues in IFN-alpha 2, in positions 121, 125 and 132 which, when replaced individually or jointly by their IFN-alpha 1 counterparts, modify its activity on mouse cells by up to 400-fold. We argue that these residues are involved in direct contacts with the mouse interfero...

  18. In Vivo Assessment of the Regulation of Transforming Growth Factor Alpha, Epidermal Growth Factor (EGF), and EGF Receptor in the Human Endometrium by Medroxyprogesterone Acetate

    OpenAIRE

    Fernando M. Reis; Lhullier, Cintia; Edelweiss, Maria Isabel; Spritzer, Poli Mara

    2005-01-01

    Purpose: The present study evaluated the in vivo effect of medroxyprogesterone acetate (MPA) on the localization of immunoreactive transforming growth factor alpha (TGFα), epidermal growth factor (EGF), and their common receptor (EGF-R) in the human endometrium.

  19. Protease activated receptors (PARS) mediation in gyroxin biological activity

    International Nuclear Information System (INIS)

    Gyroxin is a serine protease enzyme from the South American rattlesnake (Crotalus durissus terrificus) venom; it is only partially characterized and has multiple activities. Gyroxin induces blood coagulation, blood pressure decrease and a neurotoxic behavior named barrel rotation. The mechanisms involved in this neurotoxic activity are not known. Whereas gyroxin is a member of enzymes with high potential to become a new drug with clinical applications such as thrombin, batroxobin, ancrod, tripsyn and kalicrein, it is important to find out how gyroxin works. The analysis on agarose gel electrophoresis and circular dichroism confirmed the molecules' integrity and purity. The gyroxin intravenous administration in mice proved its neurotoxicity (barrel rotation). In vivo studies employing intravital microscopy proved that gyroxin induces vasodilation with the participation of protease activated receptors (PARs), nitric oxide and Na+K+ATPase. The leukocytes' adherence and rolling counting indicated that gyroxin has no pro inflammatory activity. Gyroxin induced platelet aggregation, which was blocked by inhibitors of PAR1 and PAR4 receptors (SCH 79797 and tcY-NH2, respectively). Finally, it was proved that the gyroxin temporarily alter the permeability of the blood brain barrier (BBB). Our study has shown that both the protease-activated receptors and nitric oxide are mediators involved in the biological activities of gyroxin. (author)

  20. Relationship between peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1α)with body energy metabolism and obesity in central obese mice%PGC-1α与中枢性肥胖小鼠的机体能量代谢和肥胖发生的相关性

    Institute of Scientific and Technical Information of China (English)

    杨美子; 孙倩; 刘欣; 孙雪华; 栾海云; 金勇君

    2012-01-01

    目的 通过观察过氧化物酶体增殖物活化受体γ共激活因子-1α(PGC-1α)在中枢性肥胖小鼠中的表达水平研究PGC-1α与能量代谢和肥胖的相关性.方法 皮下注射谷氨酸钠建立小鼠中枢性肥胖的病理模型,比较各组小鼠的BMI、摄食量及测定体温的变化;检测PGC-1α在棕与白色脂肪、肝脏、肺脏、心脏和脑中的表达水平.结果 PGC-1α在上述组织中都有不同程度的表达;而模型组PGC-1α的表达下调.PGC-1α在棕色脂肪的表达始终高于白色脂肪;寒冷刺激可诱导脂肪组织中PGC-1α表达增加,且在棕色脂肪中尤为显著.结论 PGC-1α可能与机体能量代谢和肥胖的发生密切相关.%Objective To investigate the level of peroxisome proliferator - activated receptor gamma coactivator 1 alpha ( PGC -lα) expression in the central obese mice in order to get the relationship between PGC -1 α with energy metabolism and obesity. Methods To create the obese mod-els, the glutamic sodium was injected by subcutaneous. The body mass index, body temperature, food intake were examined. Besides, the level of PGC - 1α expression in brown adipose, white adipose, liver, lung, heart and brain were detected through RT - PCR. Results The expres-sion of PGC - la in brown adipose, white fat, liver, heart, lung and brain were different. Compared with the normal group, the expression of PGC - 1α was basically reduced in the model group. In addition, the PGC - lα expression in white and brown adipose were up regulated in cold stimulation and more significantly increased in brown adipose. Con-clusion It's likely that PGC - la was associated closely with body ener-gy metabolism and obesity.

  1. Mutant U5A cells are complemented by an interferon-alpha beta receptor subunit generated by alternative processing of a new member of a cytokine receptor gene cluster.

    Science.gov (United States)

    Lutfalla, G; Holland, S J; Cinato, E; Monneron, D; Reboul, J; Rogers, N C; Smith, J M; Stark, G R; Gardiner, K; Mogensen, K E

    1995-10-16

    The cellular receptor for the alpha/beta interferons contains at least two components that interact with interferon. The ifnar1 component is well characterized and a putative ifnar2 cDNA has recently been identified. We have cloned the gene for ifnar2 and show that it produces four different transcripts encoding three different polypeptides that are generated by exon skipping, alternative splicing and differential use of polyadenylation sites. One polypeptide is likely to be secreted and two are transmembrane proteins with identical extracellular and transmembrane domains but divergent cytoplasmic tails of 67 and 251 amino acids. A mutant cell line U5A, completely defective in IFN-alpha beta binding and response, has been isolated and characterized. Expression in U5A cells of the polypeptide with the long cytoplasmic domain reconstitutes a functional receptor that restores normal interferon binding, activation of the JAK/STAT signal transduction pathway, interferon-inducible gene expression and antiviral response. The IFNAR2 gene maps at 0.5 kb from the CRFB4 gene, establishing that together IFNAR2, CRFB4, IFNAR1 and AF1 form a cluster of class II cytokine receptor genes on human chromosome 21.

  2. In silico study of curcumol, curcumenol, isocurcumenol, and β-sitosterol as potential inhibitors of estrogen receptor alpha of breast cancer

    Directory of Open Access Journals (Sweden)

    Resmi Mustarichiei

    2014-03-01

    Full Text Available Background: Based on data from the Hospital Information System (HIS in 2007, breast cancer is the top ranked diagnosed cancer in Indonesia. Estrogen receptor alpha (ERα is associated with breast cancer because it is found in high levels in cancer tissues. Curcumol, curcumenol, isocurcumenol of white tumeric rhizomes (Curcuma zedoaria (Christm. Roscoe, and β-sitosterol from seeds of pumpkin (Cucurbita pepo L. have been reported to have inhibitory activity against cancer cells. This study presents the in silico study of these compounds as inhibitors of ERα.Methods: Docking simulations are carried out in this paper to visualize molecular-level interactions between the four compounds with ERα. Docking simulations between estradiol and tamoxifen on ERα are carried out as well.Results: Docking results indicated that curcumol, curcumenol, isocurcumenol, and β-sitosterol showed inhibitory activity againts estrogen receptor alpha (ERα.  The order of potency is shown consecutively by isocurcumenol, curcumol, curcumenol, and β-sitosterol with values 0.584 M, 1.36 M, 1.61 M, and 7.35 M respectively. Curcumenol and estradiol interacts with ERα through hydrogen bonds and hydrophobic interactions, whereas curcumol, isocurcumenol, β-sitosterol and tamoxifen through hydrophobic interactions in succession. Conclusion: Natural products containing all four compounds have the potential to be used as drugs or adjuvant drugs in breast cancer therapy.Keywords: β-sitosterol, breast cancer, curcumol, curcumenol, estradiol, ERα, isocurcumenol

  3. Membrane progestin receptor alpha mediates progestin-induced sperm hypermotility and increased fertilization success in southern flounder (Paralichthys lethostigma).

    Science.gov (United States)

    Tan, Wenxian; Aizen, Joseph; Thomas, Peter

    2014-05-01

    Progestin hormones stimulate sperm motility in teleosts but their mechanisms of action remain unclear. Preliminary results suggest that progestin upregulation of sperm motility in southern flounder and several other marine species is mediated through a sperm membrane progestin receptor with the characteristics of membrane progestin receptor alpha (mPRα, also known as Paqr7b). The hypothesis that mPRα has an important role in progestin regulation of southern flounder sperm motility and fertility was tested in the present study. The specific mPRα agonist, 10-ethenyl-19-norprogesterone (Org OD 02-0, 100nM), mimicked the stimulatory actions of the endogenous progestin, 17,20β, 21-trihydroxy-4-pregnen-3-one (20β-S, 100nM) on flounder sperm motility. The concentration of the mPRα protein on sperm plasma membranes was positively correlated to sperm motility as well as the responsiveness of sperm to progestin stimulation. Acute in vitro progestin treatment of sperm with high mPRα protein levels increased both sperm motility and fertilization success in strip spawning experiments. However, in vitro progestin treatments were ineffective on sperm with low receptor abundance. A single injection of the superactive gonadotropin-releasing hormone analog (LHRHa, 100μg/kg) increased sperm motility and fertilization success in strip spawning experiments 72h post-injection which was accompanied by an increase in mPRα protein concentrations on sperm plasma membranes. These results provide clear evidence that southern flounder sperm hypermotility is mediated through mPRα. Stimulatory G proteins, but not inhibitory G proteins, were identified in flounder sperm plasma membrane fractions. The finding that treatment of flounder sperm plasma membrane fractions with either 20β-S or Org OD 02-0 increases cAMP levels suggests progestins stimulate flounder sperm motility by activating an mPRα/stimulatory G protein/membrane adenylyl cyclase pathway. A similar mechanism has been

  4. Association of estrogen receptor alpha gene polymorphisms with bone mineral density: a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    WANG Ke-jie; SHI Dong-quan; SUN Li-sheng; JIANG Xu; L(U) Yan-yun; DAI Jin; CHEN Dong-yang; XU Zhi-hong; JIANG Qing

    2012-01-01

    Background A number of studies have examined the association between estrogen receptor alpha (ESR-α) gene polymorphisms and bone mineral density (BMD),but previous studies of ESR-α gene Xbal (rs9340799) and Pvull (rs2234693) polymorphisms have been hampered by small sample size,regional restrictions and inconclusive results.Thus a meta-analysis is needed to assess their pooled effects.üMethods This study reviewed all published articles indexed in Pubmed using the keywords in the title or abstract.All data were extracted independently by two reviewers using a standard form,the studies were mete-analyzed and minor discrepancies were resolved by authors' discussion.Results Twenty seven eligible studies involving 8467 women and 2032 men were identified.The Xbal and Pvull polymorphisms were significantly associated with BMD of the lumbar spine.XX and PP homozygotes had a protective effect in comparison with carriers of the x and p alleles,the effects were more significant in premenopausal women or Western women.At the femoral neck,the results were different.XX served as a protective factor in postmenopausal women,Western women,Western postmenopausal women,and men,while PP was likely to serve as a risk factor in Eastern women,Eastern postmenopausal women,and men.Conclusions The Xbal polymorphism is correlated to BMD at diverse skeletal sites.PP had a protective role for the lumbar spine but might be a risk factor for the femoral neck.

  5. Demethylation of Circulating Estrogen Receptor Alpha Gene in Cerebral Ischemic Stroke.

    Directory of Open Access Journals (Sweden)

    Hsiu-Fen Lin

    Full Text Available Estrogen is involved in neuron plasticity and can promote neuronal survival in stroke. Its actions are mostly exerted via estrogen receptor alpha (ERα. Previous animal studies have shown that ERα is upregulated by DNA demethylation following ischemic injury. This study investigated the methylation levels in the ERα promoter in the peripheral blood of ischemic stroke patients.The study included 201 ischemic stroke patients, and 217 age- and sex-comparable healthy controls. The quantitative methylation level in the 14 CpG sites of the ERα promoter was measured by pyrosequencing in each participant. Multivariate regression model was used to adjust for stroke traditional risk factors. Stroke subtypes and sex-specific analysis were also conducted.The results demonstrated that the stroke cases had a lower ERα methylation level than controls in all 14 CpG sites, and site 13 and site 14 had significant adjusted p-values of 0.035 and 0.026, respectively. Stroke subtypes analysis showed that large-artery atherosclerosis and cardio-embolic subtypes had significantly lower methylation levels than the healthy controls at CpG site 5, site 9, site 12, site 13 and site 14 with adjusted p = 0.039, 0.009, 0.025, 0.046 and 0.027 respectively. However, the methylation level for the patients with small vessel subtype was not significant. We combined the methylation data from the above five sites for further sex-specific analysis. The results showed that the significant association only existed in women (adjusted p = 0.011, but not in men (adjusted p = 0.300.Female stroke cases have lower ERα methylation levels than those in the controls, especially in large-artery and cardio-embolic stroke subtypes. The study implies that women suffering from ischemic stroke of specific subtype may undergo different protective mechanisms to reduce the brain injury.

  6. Choline Kinase Alpha as an Androgen Receptor Chaperone and Prostate Cancer Therapeutic Target

    Science.gov (United States)

    Asim, Mohammad; Massie, Charles E.; Orafidiya, Folake; Pértega-Gomes, Nelma; Warren, Anne Y.; Esmaeili, Mohsen; Selth, Luke A.; Zecchini, Heather I.; Luko, Katarina; Qureshi, Arham; Baridi, Ajoeb; Menon, Suraj; Madhu, Basetti; Escriu, Carlos; Lyons, Scott; Vowler, Sarah L.; Zecchini, Vincent R.; Shaw, Greg; Hessenkemper, Wiebke; Russell, Roslin; Mohammed, Hisham; Stefanos, Niki; Lynch, Andy G.; Grigorenko, Elena; D’Santos, Clive; Taylor, Chris; Lamb, Alastair; Sriranjan, Rouchelle; Yang, Jiali; Stark, Rory; Dehm, Scott M.; Rennie, Paul S.; Carroll, Jason S.; Griffiths, John R.; Tavaré, Simon; Mills, Ian G.; McEwan, Iain J.; Baniahmad, Aria; Tilley, Wayne D.; Neal, David E.

    2016-01-01

    Background: The androgen receptor (AR) is a major drug target in prostate cancer (PCa). We profiled the AR-regulated kinome to identify clinically relevant and druggable effectors of AR signaling. Methods: Using genome-wide approaches, we interrogated all AR regulated kinases. Among these, choline kinase alpha (CHKA) expression was evaluated in benign (n = 195), prostatic intraepithelial neoplasia (PIN) (n = 153) and prostate cancer (PCa) lesions (n = 359). We interrogated how CHKA regulates AR signaling using biochemical assays and investigated androgen regulation of CHKA expression in men with PCa, both untreated (n = 20) and treated with an androgen biosynthesis inhibitor degarelix (n = 27). We studied the effect of CHKA inhibition on the PCa transcriptome using RNA sequencing and tested the effect of CHKA inhibition on cell growth, clonogenic survival and invasion. Tumor xenografts (n = 6 per group) were generated in mice using genetically engineered prostate cancer cells with inducible CHKA knockdown. Data were analyzed with χ2 tests, Cox regression analysis, and Kaplan-Meier methods. All statistical tests were two-sided. Results: CHKA expression was shown to be androgen regulated in cell lines, xenografts, and human tissue (log fold change from 6.75 to 6.59, P = .002) and was positively associated with tumor stage. CHKA binds directly to the ligand-binding domain (LBD) of AR, enhancing its stability. As such, CHKA is the first kinase identified as an AR chaperone. Inhibition of CHKA repressed the AR transcriptional program including pathways enriched for regulation of protein folding, decreased AR protein levels, and inhibited the growth of PCa cell lines, human PCa explants, and tumor xenografts. Conclusions: CHKA can act as an AR chaperone, providing, to our knowledge, the first evidence for kinases as molecular chaperones, making CHKA both a marker of tumor progression and a potential therapeutic target for PCa. PMID:26657335

  7. Essential role of IL-7 receptor alpha in the formation of Peyer's patch anlage.

    Science.gov (United States)

    Adachi, S; Yoshida, H; Honda, K; Maki, K; Saijo, K; Ikuta, K; Saito, T; Nishikawa, S I

    1998-01-01

    We investigated the role of IL-7 receptor alpha (IL-7Ralpha) signal in the formation of Peyer's patch (PP) anlage. Although pan-lymphopenia is a common phenotype of rag2-/- and il7ralpha-/- mice, a close inspection revealed nodules corresponding to PP in the adult rag2-/- but not in the il7ralpha-/- mouse. In our previous study, three histologically distinct steps in the formation of PP were identified. The first is the appearance of VCAM-1 + spots in the intestine, which probably represents an initial stage of the formation of the PP anlage. Accumulation of cells bearing IL-7Ralpha, CD4 or Ia in this region then follows and eventually entry of mature lymphocytes expressing CD3 or B220 occurs just before birth. Based on this criterion, we next investigated which of these events is defective in mice with severe combined immunodeficiency. Formation of VCAM-1 + spots and cluster formation of IL-7Ralpha+ cells proceed normally in the rag2-/- mouse which completely lacks mature lymphocytes. In contrast, no VCAM-1+ spots were detected in the embryonic nor neonatal il7ralpha-/- mice, suggesting that IL-7Ralpha signal is involved in the early phase of PP anlage formation. The same defect was found in the jak3-/- mouse. In addition to the appearance of VCAM1+ spots, the clustering of IL-7Ralpha+ cells was absent in the jak3-/- mouse, though IL-7Ralpha+ cells are found to scatter over the intestine. These results indicate that IL-7Ralpha is an essential signal for an early step of PP anlage formation, without which the subsequent processes cannot be initiated.

  8. Assessment of alpha activity of building materials commonly used in West Bengal, India

    International Nuclear Information System (INIS)

    This paper, reports for the first time, an extensive study of alpha activity of all widely used building materials (plaster of Paris, stone chips, marble, white cement, mosaic stone, limestone, sand, granite, cement brick, asbestos, red brick, cement tile, ceramic tile and ceramics) in West Bengal, India. The alpha activities have been measured using Solid State Nuclear Track Detector (SSNTD), a very sensitive detector for alpha particles. The samples were collected from local markets of Kolkata. The measured average alpha activities ranged from 22.7 ± 2.5 to 590.6 ± 16.8 Bq kg-1. The alpha activity of ceramic tiles was highest and provides additional data to estimate the effect of environmental radiation exposure on human health

  9. RXR alpha, a promiscuous partner of retinoic acid and thyroid hormone receptors.

    OpenAIRE

    Bugge, T H; Pohl, J.; Lonnoy, O; Stunnenberg, H G

    1992-01-01

    Retinoic acid receptor (RAR), thyroid hormone receptor (T3R) and vitamin D3 receptor (VD3R) differ from steroid hormone receptors in that they bind and transactivate through responsive elements organized as direct rather than inverted repeats. We now show that recombinant RAR and T3R are monomers in solution and cannot form stable homodimeric complexes on their responsive elements. Stable binding of the receptors to their responsive elements requires heterodimerization with a nuclear factor. ...

  10. Activation of two new alpha(1,3)fucosyltransferase activities in Chinese hamster ovary cells by 5-azacytidine.

    Science.gov (United States)

    Potvin, B; Stanley, P

    1991-01-01

    Several mammalian alpha(1,3)fucosyltransferases (alpha[1,3]Fuc-T) that synthesize carbohydrates containing alpha(1,3)fucosylated lactosamine units have been identified. Although Chinese hamster ovary (CHO) cells do not express alpha(1,3)Fuc-T activity, the rare mutants LEC11 and LEC12, isolated after mutagenesis or DNA transfection, each express an alpha(1,3)Fuc-T that may be distinguished by several criteria. Two new CHO mutants possessing alpha(1,3)Fuc-T activity (LEC29 and LEC30) have now been isolated after treatment of a CHO cell population with 5-azacytidine (5-AzaC), ethylnitrosourea (ENU), or 5-AzaC followed by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Like LEC12, both mutants possess an N-ethylmaleimide-resistant alpha(1,3)Fuc-T activity that can utilize a variety of acceptors and both express the Lewis X (Lex) determinant (Gal beta[1,4](Fuc alpha[1,3])GlcNAc beta 1)) but not the sialyl alpha(2,3)Lex determinant on cell-surface carbohydrates. However, LEC29 and LEC30 may be distinguished from LEC11 and LEC12, as well as from each other, on the basis of their unique patterns of lectin resistance and their abilities to bind the VIM-2 monoclonal antibody that recognizes carbohydrates terminating in NeuNAc alpha(2,3)Gal beta(1,4)GlcNAc beta(1,3)Gal beta(1,4)(Fuc alpha[1,3])GlcNAc beta and also by the different in vitro substrate specificities and kinetic properties of their respective alpha(1,3)Fuc-T activities. The combined data provide good evidence that the LEC29 and LEC30 alpha(1,3)Fuc-Ts are novel transferases encoded by distinct gene products. PMID:1724918

  11. Rhodocytin (aggretin) activates platelets lacking alpha(2)beta(1) integrin, glycoprotein VI, and the ligand-binding domain of glycoprotein Ibalpha

    DEFF Research Database (Denmark)

    Bergmeier, W; Bouvard, D; Eble, J A;

    2001-01-01

    Although alpha(2)beta(1) integrin (glycoprotein Ia/IIa) has been established as a platelet collagen receptor, its role in collagen-induced platelet activation has been controversial. Recently, it has been demonstrated that rhodocytin (also termed aggretin), a snake venom toxin purified from...... that collagen may activate platelets by a similar mechanism. In contrast to these findings, we provided evidence that rhodocytin does not bind to alpha(2)beta(1) integrin. Here we show that the Cre/loxP-mediated loss of beta(1) integrin on mouse platelets has no effect on rhodocytin-induced platelet activation......, excluding an essential role of alpha(2)beta(1) integrin in this process. Furthermore, proteolytic cleavage of the 45-kDa N-terminal domain of glycoprotein (GP) Ibalpha either on normal or on beta(1)-null platelets had no significant effect on rhodocytin-induced platelet activation. Moreover, mouse platelets...

  12. Repeated administration of alpha7 nicotinic acetylcholine receptor (nAChR) agonists, but not positive allosteric modulators, increases alpha7 nAChR levels in the brain

    DEFF Research Database (Denmark)

    Christensen, Ditte Z; Mikkelsen, Jens D; Hansen, Henrik H;

    2010-01-01

    -induced phosphorylation of Erk2 in the prefrontal cortex occurs following acute, but not repeated administration. Our results demonstrate that repeated agonist administration increases the number of alpha7 nAChRs in the brain, and leads to coupling versus uncoupling of specific intracellular signaling....... Here we investigate the effects of repeated agonism on alpha7 nAChR receptor levels and responsiveness in vivo in rats. Using [(125)I]-alpha-bungarotoxin (BTX) autoradiography we show that acute or repeated administration with the selective alpha7 nAChR agonist A-582941 increases the number of alpha7 n......-120596 and NS1738 do not increase [(125)I]-BTX binding. Furthermore, A-582941-induced increase in Arc and c-fos mRNA expression in the prefrontal cortex is enhanced and unaltered, respectively, after repeated administration, demonstrating that the alpha7 nAChRs remain responsive. Contrarily, A-582941...

  13. The aryl hydrocarbon receptor and estrogen receptor alpha differentially modulate nuclear factor erythroid-2-related factor 2 transactivation in MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Raymond; Matthews, Jason, E-mail: jason.matthews@utoronto.ca

    2013-07-15

    Nuclear factor erythroid-2-related factor 2 (NRF2; NFE2L2) plays an important role in mediating cellular protection against reactive oxygen species. NRF2 signaling is positively modulated by the aryl hydrocarbon receptor (AHR) but inhibited by estrogen receptor alpha (ERα). In this study we investigated the crosstalk among NRF2, AHR and ERα in MCF-7 breast cancer cells treated with the NRF2 activator sulforaphane (SFN), a dual AHR and ERα activator, 3,3′-diindolylmethane (DIM), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 17β-estradiol (E2). SFN-dependent increases in NADPH-dependent oxidoreductase 1 (NQO1) and heme oxygenase I (HMOX1) mRNA levels were significantly reduced after co-treatment with E2. E2-dependent repression of NQO1 and HMOX1 was associated with increased ERα but reduced p300 recruitment and reduced histone H3 acetylation at both genes. In contrast, DIM + SFN or TCDD + SFN induced NQO1 and HMOX1 mRNA expression to levels higher than SFN alone, which was prevented by RNAi-mediated knockdown of AHR. DIM + SFN but not TCDD + SFN also induced recruitment of ERα to NQO1 and HMOX1. However, the presence of AHR at NQO1 and HMOX1 restored p300 recruitment and histone H3 acetylation, thereby reversing the ERα-dependent repression of NRF2. Taken together, our study provides further evidence of functional interplay among NRF2, AHR and ERα signaling pathways through altered p300 recruitment to NRF2-regulated target genes. - Highlights: • We examined crosstalk among ERα, AHR, and NRF2 in MCF-7 breast cancer cells. • AHR enhanced the mRNA expression levels of two NRF2 target genes – HMOX1 and NQO1. • ERα repressed HMOX1 and NQO1 expression via decreased histone acetylation. • AHR prevented ERα-dependent repression of HMOX1 and NQO1.

  14. Molecular characterization of a novel human hybrid-type receptor that binds the alpha2-macroglobulin receptor-associated protein

    DEFF Research Database (Denmark)

    Jacobsen, Linda; Madsen, P; Moestrup, S K;

    1996-01-01

    but not in several major organs. Both RAP and an antibody against a synthetic peptide derived from a sequence determined in the mature protein detected sorLA-1 in crude human brain extracts. The domain structure suggests that sorLA-1 is an endocytic receptor possibly implicated in the uptake of lipoproteins...... density lipoprotein receptor gene family receptors, and 3) six tandemly arranged fibronectin type III repeats also found in certain neural adhesion proteins. sorLA-1 may therefore be classified as a hybrid receptor. Northern blotting revealed specific mRNA transcripts in brain, spinal cord, and testis...

  15. Tumor cell alpha-N-acetylgalactosaminidase activity and its involvement in GcMAF-related macrophage activation.

    Science.gov (United States)

    Mohamad, Saharuddin B; Nagasawa, Hideko; Uto, Yoshihiro; Hori, Hitoshi

    2002-05-01

    Alpha-N-acetyl galactosaminidase (alpha-NaGalase) has been reported to accumulate in serum of cancer patients and be responsible for deglycosylation of Gc protein, which is a precursor of GcMAF-mediated macrophage activation cascade, finally leading to immunosuppression in advanced cancer patients. We studied the biochemical characterization of alpha-NaGalase from several human tumor cell lines. We also examined its effect on the potency of GcMAF to activate mouse peritoneal macrophage to produce superoxide in GcMAF-mediated macrophage activation cascade. The specific activity of alpha-NaGalases from human colon tumor cell line HCT116, human hepatoma cell line HepG2, and normal human liver cells (Chang liver cell line) were evaluated using two types of substrates; GalNAc-alpha-PNP (exo-type substrate) and Gal-beta-GalNAc-alpha-PNP (endo-type substrate). Tumor-derived alpha-NaGalase having higher activity than normal alpha-NaGalase, had higher substrate specificity to the exo-type substrate than to the endo-type substrate, and still maintained its activity at pH 7. GcMAF enhance superoxide production in mouse macrophage, and pre-treatment of GcMAF with tumor cell lysate reduce the activity. We conclude that tumor-derived alpha-NaGalase is different in biochemical characterization compared to normal alpha-NaGalase from normal Chang liver cells. In addition, tumor cell-derived alpha-NaGalase decreases the potency of GcMAF on macrophage activation. PMID:12062184

  16. Exposure to Folate Receptor Alpha Antibodies during Gestation and Weaning Leads to Severe Behavioral Deficits in Rats: A Pilot Study.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Sequeira

    Full Text Available The central nervous system continues to develop during gestation and after birth, and folate is an essential nutrient in this process. Folate deficiency and folate receptor alpha autoantibodies (FRα-AuAb have been associated with pregnancy-related complications and neurodevelopmental disorders. In this pilot study, we investigated the effect of exposure to FRα antibodies (Ab during gestation (GST, the pre-weaning (PRW, and the post weaning (POW periods on learning and behavior in adulthood in a rat model. In the open field test and novel object recognition task, which examine locomotor activity and anxiety-like behavior, deficits in rats exposed to Ab during gestation and pre-weaning (GST+PRW included more time spent in the periphery or corner areas, less time in the central area, frequent self-grooming akin to stereotypy, and longer time to explore a novel object compared to a control group; these are all indicative of increased levels of anxiety. In the place avoidance tasks that assess learning and spatial memory formation, only 30% of GST+PRW rats were able to learn the passive place avoidance task. None of these rats learned the active place avoidance task indicating severe learning deficits and cognitive impairment. Similar but less severe deficits were observed in rats exposed to Ab during GST alone or only during the PRW period, suggesting the extreme sensitivity of the fetal as well as the neonatal rat brain to the deleterious effects of exposure to Ab during this period. Behavioral deficits were not seen in rats exposed to antibody post weaning. These observations have implications in the pathology of FRα-AuAb associated with neural tube defect pregnancy, preterm birth and neurodevelopmental disorders including autism.

  17. Platelet-derived growth factor-receptor alpha strongly inhibits melanoma growth in vitro and in vivo.

    Science.gov (United States)

    Faraone, Debora; Aguzzi, Maria Simona; Toietta, Gabriele; Facchiano, Angelo M; Facchiano, Francesco; Magenta, Alessandra; Martelli, Fabio; Truffa, Silvia; Cesareo, Eleonora; Ribatti, Domenico; Capogrossi, Maurizio C; Facchiano, Antonio

    2009-08-01

    Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs) is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Ralpha may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Ralpha respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Ralpha. Proliferation was rescued by PDGF-Ralpha inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Ralpha mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Ralpha was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Ralpha show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Balpha and a marked increase of p38gamma, mitogen-activated protein kinase kinase 3, and signal regulatory protein alpha1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Ralpha reached a significant 70% inhibition of primary melanoma growth (P < .001) and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Ralpha strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control. PMID:19649203

  18. Differential involvement of 5-HT(1A) and 5-HT(1B/1D) receptors in human interferon-alpha-induced immobility in the mouse forced swimming test.

    Science.gov (United States)

    Zhang, Hongmei; Wang, Wei; Jiang, Zhenzhou; Shang, Jing; Zhang, Luyong

    2010-01-01

    Although Interferon-alpha (IFN-alpha, CAS 9008-11-1) is a powerful drug in treating several viral infections and certain tumors, a considerable amount of neuropsychiatric side-effects such as depression and anxiety are an unavoidable consequence. Combination with the selective serotonin (5-HT) reuptake inhibitor (SSRI) fluoxetine (CAS 56296-78-7) significantly improved the situation. However, the potential 5-HT(1A) receptor- and 5-HT(1B) receptor-signals involved in the antidepressant effects are still unclear. The effects of 5-HT(1A) receptor- and 5-HT(1B) receptor signals were analyzed by using the mouse forced swimming test (FST), a predictive test of antidepressant-like action. The present results indicated that (1) fluoxetine (administrated intragastrically, 30 mg/kg; not subactive dose: 15 mg/kg) significantly reduced IFN-alpha-induced increase of the immobility time in the forced swimming test; (2) 5-HT(1A) receptor- and 5-HT(1B) receptor ligands alone or in combination had no effects on IFN-alpha-induced increase of the immobility time in the FST; (3) surprisingly, WAY 100635 (5-HT(1A) receptor antagonist, 634908-75-1) and 8-OH-DPAT(5-HT(1A) receptor agonist, CAS 78950-78-4) markedly enhanced the antidepressant effect of fluoxetine at the subactive dose (15 mg/kg, i. g.) on the IFN-alpha-treated mice in the FST. Further investigations showed that fluoxetine combined with WAY 100635 and 8-OH-DPAT failed to produce antidepressant effects in the FST. (4) Co-application of CGS 12066A (5-HT(1B) receptor agonist, CAS 109028-09-3) or GR 127935 (5-HT(1B/1D) receptor antagonist, CAS 148642-42-6) with fluoxetine had no synergistic effects on the IFN-alpha-induced increase of immobility time in FST. (5) Interestingly, co-administration of GR 127935, WAY 100635 and fluoxetine significantly reduced the IFN-alpha-induced increase in immobility time of FST, being more effective than co-administration of WAY 100635 and fluoxetine. All results suggest that (1) compared to

  19. PPAR{alpha} deficiency augments a ketogenic diet-induced circadian PAI-1 expression possibly through PPAR{gamma} activation in the liver

    Energy Technology Data Exchange (ETDEWEB)

    Oishi, Katsutaka, E-mail: k-ooishi@aist.go.jp [Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Uchida, Daisuke [Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki (Japan); Ohkura, Naoki [Department of Clinical Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, Sagamihara, Kanagawa (Japan); Horie, Shuichi [Department of Clinical Biochemistry, Kagawa Nutrition University, Sakado, Saitama (Japan)

    2010-10-15

    Research highlights: {yields} PPAR{alpha} deficiency augments a ketogenic diet-induced circadian PAI-1 expression. {yields} Hepatic expressions of PPAR{gamma} and PCG-1{alpha} are induced by a ketogenic diet. {yields} PPAR{gamma} antagonist attenuates a ketogenic diet-induced PAI-1 expression. {yields} Ketogenic diet advances the phase of circadian clock in a PPAR{alpha}-independent manner. -- Abstract: An increased level of plasminogen activator inhibitor-1 (PAI-1) is considered a risk factor for cardiovascular diseases, and PAI-1 gene expression is under the control of molecular circadian clocks in mammals. We recently showed that PAI-1 expression is augmented in a phase-advanced circadian manner in mice fed with a ketogenic diet (KD). To determine whether peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}) is involved in hypofibrinolytic status induced by a KD, we examined the expression profiles of PAI-1 and circadian clock genes in PPAR{alpha}-null KD mice. Chronic administration of bezafibrate induced the PAI-1 gene expression in a PPAR{alpha}-dependent manner. Feeding with a KD augmented the circadian expression of PAI-1 mRNA in the hearts and livers of wild-type (WT) mice as previously described. The KD-induced mRNA expression of typical PPAR{alpha} target genes such as Cyp4A10 and FGF21 was damped in PPAR{alpha}-null mice. However, plasma PAI-1 concentrations were significantly more elevated in PPAR{alpha}-null KD mice in accordance with hepatic mRNA levels. These observations suggest that PPAR{alpha} activation is dispensable for KD-induced PAI-1 expression. We also found that hyperlipidemia, fatty liver, and the hepatic expressions of PPAR{gamma} and its coactivator PCG-1{alpha} were more effectively induced in PPAR{alpha}-null, than in WT mice on a KD. Furthermore, KD-induced hepatic PAI-1 expression was significantly suppressed by supplementation with bisphenol A diglycidyl ether, a PPAR{gamma} antagonist, in both WT and PPAR{alpha

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-13

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

  1. Estrogen impairs glucocorticoid dependent negative feedback on the hypothalamic-pituitary-adrenal axis via estrogen receptor alpha within the hypothalamus.

    Science.gov (United States)

    Weiser, M J; Handa, R J

    2009-03-17

    Numerous studies have established a link between individuals with affective disorders and a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, most notably characterized by a reduced sensitivity to glucocorticoid negative (-) feedback. Furthermore there is a sex difference in the etiology of mood disorders with incidence in females being two to three times that of males, an association that may be a result of the influence of estradiol (E2) on HPA axis function. In these studies, we have examined the effect of E2 on glucocorticoid-mediated HPA axis (-) feedback during both the diurnal peak and the stress-induced rise in corticosterone (CORT). Young adult female Sprague-Dawley (SD) rats were ovariectomized (OVX) and 1 week later treated subcutaneous (s.c.) with oil or estradiol benzoate (EB) for 4 days. On the 4th day of treatment, animals were injected with a single dose of dexamethasone (DEX), or vehicle. EB treatment significantly increased the evening elevation in CORT and the stress-induced rise in CORT. In contrast, DEX treatment reduced the diurnal and stress induced rise in CORT and adrenocorticotropic hormone (ACTH), and this reduction was not apparent following co-treatment with EB. To determine a potential site of E2's action, female SD rats were OVX and 1 week later, wax pellets containing E2, the estrogen receptor beta (ERbeta) agonist diarylpropionitrile (DPN), or the estrogen receptor alpha (ERalpha) agonist propylpyrazoletriol (PPT), was implanted bilaterally and dorsal to the paraventricular nucleus of the hypothalamus (PVN). Seven days later, animals were injected s.c. with a single dose of DEX, or vehicle to test for glucocorticoid-dependent (-) feedback. Results show that E2 and PPT increased, while DPN decreased the diurnal peak and stress-induced CORT and ACTH levels as compared to controls. Furthermore, E2 and PPT impaired the ability of DEX to inhibit both the diurnal and the stress-induced rise in CORT and ACTH, whereas DPN had

  2. Influence of estrogen receptor alpha and progesterone receptor polymorphisms on the effects of hormone therapy on mammographic density.

    NARCIS (Netherlands)

    Duijnhoven, F.J.B. van; Peeters, P.H.; Warren, R.M.; Bingham, S.; Uitterlinden, A.G.; Noord, P.A.H. van; Monninkhof, E.M.; Grobbee, D.E.; Gils, C.H. van

    2006-01-01

    Postmenopausal hormone therapy increases mammographic density, a strong breast cancer risk factor, but effects vary across women. We investigated whether the effect of hormone therapy use is modified by polymorphisms in the estrogen receptor (ESR1) and progesterone receptor (PGR) genes in the Dutch

  3. Tumor necrosis factor (TNF)-alpha, soluble TNF receptors and endometrial cancer risk : the EPIC study

    NARCIS (Netherlands)

    Dossus, Laure; Becker, Susen; Rinaldi, Sabina; Lukanova, Annekatrin; Tjonneland, Anne; Olsen, Anja; Overvad, Kim; Chabbert-Buffet, Nathalie; Boutron-Ruault, Marie-Christine; Clavel-Chapelon, Francoise; Teucher, Birgit; Chang-Claude, Jenny; Pischon, Tobias; Boeing, Heiner; Trichopoulou, Antonia; Benetou, Vasiliki; Valanou, Elisavet; Palli, Domenico; Sieri, Sabina; Tumino, Rosario; Sacerdote, Carlotta; Galasso, Rocco; Redondo, Maria-Luisa; Bonet Bonet, Catalina; Molina-Montes, Esther; Altzibar, Jone M.; Chirlaque, Maria-Dolores; Ardanaz, Eva; Bueno-de-Mesquita, H. Bas; van Duijnhoven, Franzel J. B.; Peeters, Petra H. M.; Onland-Moret, N. Charlotte; Lundin, Eva; Idahl, Annika; Khaw, Kay-Tee; Wareham, Nicholas; Allen, Naomi; Romieu, Isabelle; Fedirko, Veronika; Hainaut, Pierre; Romaguera, Dora; Norat, Teresa; Riboli, Elio; Kaaks, Rudolf

    2011-01-01

    Chronic inflammation has been hypothesized to play a role in endometrial cancer development. Tumor necrosis factor-alpha (TNF-alpha), one of the major pro-inflammatory cytokines, has also been implicated in endometrial physiology. We conducted a case-control study nested within the European prospect

  4. Adenosine inhibits neutrophil vascular endothelial growth factor release and transendothelial migration via A2B receptor activation.

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

    The effects of adenosine on neutrophil (polymorphonuclear neutrophils; PMN)-directed changes in vascular permeability are poorly characterized. This study investigated whether adenosine modulates activated PMN vascular endothelial growth factor (vascular permeability factor; VEGF) release and transendothelial migration. PMN activated with tumour necrosis factor-alpha (TNF-alpha, 10 ng\\/mL) were incubated with adenosine and its receptor-specific analogues. Culture supernatants were assayed for VEGF. PMN transendothelial migration across human umbilical vein endothelial cell (HUVEC) monolayers was assessed in vitro. Adhesion molecule receptor expression was assessed flow cytometrically. Adenosine and some of its receptor-specific analogues dose-dependently inhibited activated PMN VEGF release. The rank order of potency was consistent with the affinity profile of human A2B receptors. The inhibitory effect of adenosine was reversed by 3,7-dimethyl-1-propargylxanthine, an A2 receptor antagonist. Adenosine (100 microM) or the A2B receptor agonist 5\\'-N-ethylcarboxamidoadenosine (NECA, 100 microM) significantly reduced PMN transendothelial migration. However, expression of activated PMN beta2 integrins and HUVEC ICAM-1 were not significantly altered by adenosine or NECA. Adenosine attenuates human PMN VEGF release and transendothelial migration via the A2B receptor. This provides a novel target for the modulation of PMN-directed vascular hyperpermeability in conditions such as the capillary leak syndrome.

  5. Specific in vitro toxicity of crude and refined petroleum products: II. Estrogen (alpha and beta) and androgen receptor-mediated responses in yeast assays.

    NARCIS (Netherlands)

    Vrabie, C.M.; Candido, A.; van Duursen, M.B.M.; Jonker, M.T.O.

    2010-01-01

    The present study is the second in a series aiming at a systematic inventory of specific toxic effects of oils. By employing a recombinant yeast stably transfected with human estrogen receptor-alpha (ERalpha) or -beta (ERbeta) or androgen receptor (AR) and expressing yeast enhanced green fluorescent

  6. Cell surface estrogen receptor alpha is upregulated during subchronic metabolic stress and inhibits neuronal cell degeneration.

    Directory of Open Access Journals (Sweden)

    Cristiana Barbati

    Full Text Available In addition to the classical nuclear estrogen receptor, the expression of non-nuclear estrogen receptors localized to the cell surface membrane (mER has recently been demonstrated. Estrogen and its receptors have been implicated in the development or progression of numerous neurodegenerative disorders. Furthermore, the pathogenesis of these diseases has been associated with disturbances of two key cellular programs: apoptosis and autophagy. An excess of apoptosis or a defect in autophagy has been implicated in neurodegeneration. The aim of this study was to clarify the role of ER in determining neuronal cell fate and the possible implication of these receptors in regulating either apoptosis or autophagy. The human neuronal cell line SH-SY5Y and mouse neuronal cells in primary culture were thus exposed to chronic minimal peroxide treatment (CMP, a form of subcytotoxic minimal chronic stress previously that mimics multiple aspects of long-term cell stress and represents a limited molecular proxy for neurodegenerative processes. We actually found that either E2 or E2-bovine serum albumin construct (E2BSA, i.e. a non-permeant form of E2 was capable of modulating intracellular cell signals and regulating cell survival and death. In particular, under CMP, the up-regulation of mERα, but not mERβ, was associated with functional signals (ERK phosphorylation and p38 dephosphorylation compatible with autophagic cytoprotection triggering and leading to cell survival. The mERα trafficking appeared to be independent of the microfilament system cytoskeletal network but was seemingly associated with microtubular apparatus network, i.e., to MAP2 molecular chaperone. Importantly, antioxidant treatments, administration of siRNA to ERα, or the presence of antagonist of ERα hindered these events. These results support that the surface expression of mERα plays a pivotal role in determining cell fate, and that ligand-induced activation of mER signalling exerts a

  7. Activated AMPK inhibits PPAR-{alpha} and PPAR-{gamma} transcriptional activity in hepatoma cells.

    Science.gov (United States)

    Sozio, Margaret S; Lu, Changyue; Zeng, Yan; Liangpunsakul, Suthat; Crabb, David W

    2011-10-01

    AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-α (PPAR-α) are critical regulators of short-term and long-term fatty acid oxidation, respectively. We examined whether the activities of these molecules were coordinately regulated. H4IIEC3 cells were transfected with PPAR-α and PPAR-γ expression plasmids and a peroxisome-proliferator-response element (PPRE) luciferase reporter plasmid. The cells were treated with PPAR agonists (WY-14,643 and rosiglitazone), AMPK activators 5-aminoimidazole-4-carboxamide riboside (AICAR) and metformin, and the AMPK inhibitor compound C. Both AICAR and metformin decreased basal and WY-14,643-stimulated PPAR-α activity; compound C increased agonist-stimulated reporter activity and partially reversed the effect of the AMPK activators. Similar effects on PPAR-γ were seen, with both AICAR and metformin inhibiting PPRE reporter activity. Compound C increased basal PPAR-γ activity and rosiglitazone-stimulated activity. In contrast, retinoic acid receptor-α (RAR-α), another nuclear receptor that dimerizes with retinoid X receptor (RXR), was largely unaffected by the AMPK activators. Compound C modestly increased AM580 (an RAR agonist)-stimulated activity. The AMPK activators did not affect PPAR-α binding to DNA, and there was no consistent correlation between effects of the AMPK activators and inhibitor on PPAR and the nuclear localization of AMPK-α subunits. Expression of either a constitutively active or dominant negative AMPK-α inhibited basal and WY-14,643-stimulated PPAR-α activity and basal and rosiglitazone-stimulated PPAR-γ activity. We concluded that the AMPK activators AICAR and metformin inhibited transcriptional activities of PPAR-α and PPAR-γ, whereas inhibition of AMPK with compound C activated both PPARs. The effects of AMPK do not appear to be mediated through effects on RXR or on PPAR/RXR binding to DNA. These effects are independent of kinase activity and instead appear to

  8. The human IgA-Fc alpha receptor interaction and its blockade by streptococcal IgA-binding proteins.

    Science.gov (United States)

    Woof, J M

    2002-08-01

    IgA plays a key role in immune defence of the mucosal surfaces. IgA can trigger elimination mechanisms against pathogens through the interaction of its Fc region with Fc alpha Rs (receptors specific for the Fc region of IgA) present on neutrophils, macrophages, monocytes and eosinophils. The human Fc alpha R (CD89) shares homology with receptors specific for the Fc region of IgG (Fc gamma Rs) and IgE (Fc epsilon RIs), but is a more distantly related member of the receptor family. CD89 interacts with residues lying at the interface of the two domains of IgA Fc, a site quite distinct from the homologous regions at the top of IgG and IgE Fc recognized by Fc gamma R and Fc epsilon RI respectively. Certain pathogenic bacteria express surface proteins that bind to human IgA Fc. Experiments with domain-swap antibodies and mutant IgAs indicate that binding of three such proteins (Sir22 and Arp4 of Streptococcus pyogenes and beta protein of group B streptococci) depend on sites in the Fc interdomain region of IgA, the binding region also used by CD89. Further, we have found that the streptococcal proteins can inhibit interaction of IgA with CD89, and have thereby identified a mechanism by which a bacterial IgA-binding protein may modulate IgA effector function. PMID:12196121

  9. Effects of estradiol, sex, and season on estrogen receptor alpha mRNA expression and forebrain morphology in adult green anole lizards.

    Science.gov (United States)

    Beck, L A; Wade, J

    2009-05-19

    Steroid hormones, especially estradiol, facilitate reproductive behaviors in male and female rodents and birds. In green anole lizards estradiol facilitates receptivity in females but, unlike in some other species, is not the activating hormone for courtship and copulatory behavior in males. Instead, testicular androgens directly facilitate male courtship and copulation. Yet, activity of the estradiol synthesizing enzyme aromatase is higher in the brain of male than female green anoles, and it is increased during the breeding compared to the non-breeding season. The functional relevance of these differences in local estradiol production is unknown. They might prime the male forebrain to facilitate production of appropriate sexual behaviors, perhaps by modifying morphology of relevant brain regions. In addition, we recently reported increased expression of estrogen receptor alpha (ERalpha) in selected brain regions in females compared to males [Beck LA, Wade J (2009b) Sexually dimorphic estrogen receptor alpha mRNA expression in the preoptic area and ventromedial hypothalamus of green anole lizards. 55:398-403]. Thus, it is possible that the hormone serves to downregulate its receptor in males to inhibit the expression of estradiol-dependent receptive behaviors. To begin to address these ideas, the present study examines the effects of estradiol treatment, sex, and season on forebrain morphology and ERalpha mRNA abundance in three regions important for anole reproductive behavior-the preoptic area, ventromedial amygdala, and ventromedial hypothalamus. While a number of effects of sex and season on forebrain morphology were detected, direct effects of estradiol treatment on these measures were minimal. ERalpha expression was greatest in the ventromedial hypothalamus, and a large female-biased sex difference was detected in this area alone; it resulted from estradiol-treated animals. These results indicate a sex- and region-specific mechanism by which estradiol can

  10. Study of alpha activity in the region of rare earths

    International Nuclear Information System (INIS)

    The alpha decay half-lives of the Nd144, Cd152 and Er162 isotopes were redetermined using Ilford L4 nuclear emulsions charged with rare earth complexes of natural isotopic composition. The results were compared to results obtained by other authors, and with results calculated by potential barrier penetration theory. (M.C.K.)

  11. Immunohistochemical detection of estrogen receptor alpha in pituitary adenomas and its correlation with cellular replication.

    Science.gov (United States)

    Pereira-Lima, Julia F S; Marroni, Caroline P; Pizarro, Cristina B; Barbosa-Coutinho, Ligia M; Ferreira, Nelson P; Oliveira, Miriam C

    2004-03-01

    With the aim of evaluating the relationship between pituitary tumorigenesis and the presence of estrogen receptor-alpha (ERalpha) by immunohistochemistry (IH) and their relevance to patients' clinical presentation, hormonal phenotypes of adenomas, preoperative neuroimaging findings, and the index of cellular replication MIB-1, a study was conducted with material from 91 women and 67 men with pituitary adenomas. The patients had acromegaly (29.7%), Cushing's disease (14.6%), hyperprolactinemic syndrome (20.9%), and clinically nonfunctioning tumors (34.8%). Of the patients, 14.6% had microadenomas, 52.5% had macroadenomas with or without suprasellar growth, 28.5% had invasive macroadenomas and in 4.4% the adenoma was not visualized. IH showed that 43 were positive for growth hormone (GH), 16 for corticotropin (ACTH), 18 for prolactin (PRL), 18 for PRL+GH, 6 for luteinizing hormone (LH) and follicle-stimulating hormone (FSH), 15 had a plurihormonal reaction, and 42 had nonfunctioning adenomas. The presence of ERalpha was positive in 9/158 adenomas with a median value for the percentage of labeled cells of 42.89%, and in 6/16 controls (autopsy samples) with a median value for the percentage of labeled cells of 0.024%. ERalpha was significantly more prevalent in controls than in patients with adenomas (37.5 versus 5.7%; p = 0.001); however, the mean ERalpha concentration in adenomas was significantly greater than in controls (42.89 versus 0.024%; p < 0.001). No significant difference in the concentration of ERalpha was found across the clinical presentations, hormonal phenotypes or findings of preoperative CT. Among the ERalpha-positive adenomas, ERalpha values were significantly greater in invasive macroadenomas (80%) than in microadenomas (3.33%). MIB-1 values did not differ significantly between ERalpha-positive and -negative adenomas, nor did the correlation between ERalpha values and the MIB-1 index attain significance in the total sample, even when only ERalpha

  12. The localization of estrogen receptor alpha and its function in the ovaries of postmenopausal women.

    Directory of Open Access Journals (Sweden)

    Jacek Brodowski

    2008-01-01

    Full Text Available The localization of estrogen receptor alpha (ERalpha in the ovaries of postmenopausal women is a very up-to-date topic in the aspect of using estrogens therapy in the clinical situations of different type. In ovaries of reproductive age women ERalpha is present in ovary stroma, theca and granulosa cells, ovary surface epithelium (OSE and in corpus luteum. The ovaries of postmenopausal women are smaller than those of women at the reproductive age, the division into cortex and medulla gets blurred, the ovaries have no follicles any longer, and the stroma is mainly composed of fibrous connective tissue, corpora albicantia, nerves, and blood and lymphatic vessels. The aim of our study was to investigate the immunolocalization and immunoexpression of ERalpha in the ovaries of postmenopausal women. The study involved 50 postmenopausal women who had their ovaries removed by laparotomy due to non-neoplastic diseases of the uterus. The women were divided into 3 groups (A, B, and C depending on the time that had passed since the last menstruation. Group A consisted of women who had their last menstruation no more than 5 years earlier, in group B menopause occurred 5 to 10 years earlier, group C was composed of patients who had the last menstruation over 10 years earlier. In all the patients concentrations of follicle stimulating hormone (FSH, luteinizing stimulating hormone (LH, estradiol (E2, testosterone (T, androstendione (A and dehydroepiandrosterone sulphate (DHEAS in blood plasma were measured. Ovarian tissue was obtained during surgery. For morphological studies, ovaries were fixed in Bouin;s solution and 4% formalin and embedded in paraffin. Morphological analysis was carried out after hematoxylin-eosin (HE staining. Comparing to groups A and B, the ovaries in group C contained a small number of corpora albicantia located in the medullary part as well as thinned blood vessels and few lymphatic vessels and nerves. For immunoohistochemical

  13. Rationale for the development of IMC-3G3, a fully human immunoglobulin G subclass 1 monoclonal antibody targeting the platelet-derived growth factor receptor alpha.

    Science.gov (United States)

    Shah, Gaurav D; Loizos, Nick; Youssoufian, Hagop; Schwartz, Jonathan D; Rowinsky, Eric K

    2010-02-15

    A large body of evidence suggests that the platelet-derived growth factor (PDGF) family and associated receptors are potential targets in oncology therapeutic development because of their critical roles in the proliferation and survival of various cancers and in the regulation and growth of the tumor stroma and blood vessels. Several small molecules that nonspecifically target the PDGF signaling axis are in current use or development as anticancer therapies. However, for the majority of these agents, PDGF and its receptors are neither the primary targets nor the principal mediators of anticancer activity. IMC-3G3, a fully human monoclonal antibody of the immunoglobulin G subclass 1, specifically binds to the human PDGF receptor alpha (PDGFRalpha) with high affinity and blocks PDGF ligand binding and PDGFRalpha activation. The results of preclinical studies and the frequent expression of PDGFRalpha in many types of cancer and in cancer-associated stroma support a rationale for the clinical development of IMC-3G3. Currently, IMC-3G3 is being evaluated in early clinical development for patients with several types of solid malignancies.

  14. Mapping of the {alpha}{sub 4} subunit gene (GABRA4) to human chromosome 4 defines an {alpha}{sub 2}-{alpha}{sub 4}-{beta}{sub 1}-{gamma}{sub 1} gene cluster: Further evidence that modern GABA{sub a} receptor gene clusters are derived from an ancestral cluster

    Energy Technology Data Exchange (ETDEWEB)

    McLean, P.J.; Farb, D.H.; Russek, S.J. [Boston Univ. School of Medicine, MA (United States)] [and others

    1995-04-10

    We demonstrated previously that an {alpha}{sub 1}-{beta}{sub 2}-{gamma}{sub 2} gene cluster of the {gamma}-aminobutyric acid (GABA{sub A}) receptor is located on human chromosome 5q34-q35 and that an ancestral {alpha}-{beta}-{gamma} gene cluster probably spawned clusters on chromosomes 4, 5, and 15. Here, we report that the {alpha}{sub 4} gene (GABRA4) maps to human chromosome 4p14-q12, defining a cluster comprising the {alpha}{sub 2}, {alpha}{sub 4}, {beta}{sub 1}, and {gamma}{sub 1} genes. The existence of an {alpha}{sub 2}-{alpha}{sub 4}-{beta}{sub 1}-{gamma}{sub 2} cluster on chromosome 4 and an {alpha}{sub 1}-{alpha}{sub 6}-{beta}{sub 2}-{gamma}{sub 2} cluster on chromosome 5 provides further evidence that the number of ancestral GABA{sub A} receptor subunit genes has been expanded by duplication within an ancestral gene cluster. Moreover, if duplication of the {alpha} gene occurred before duplication of the ancestral gene cluster, then a heretofore undiscovered subtype of a subunit should be located on human chromosome 15q11-q13 within an {alpha}{sub 5}-{alpha}{sub x}-{beta}{sub 3}-{gamma}{sub 3} gene cluster at the locus for Angelman and Prader-Willi syndromes. 34 refs., 6 figs., 1 tab.

  15. 64Cu-labeled alpha-melanocyte-stimulating hormone analog for microPET imaging of melanocortin 1 receptor expression.

    Science.gov (United States)

    Cheng, Zhen; Xiong, Zhengming; Subbarayan, Murugesan; Chen, Xiaoyuan; Gambhir, Sanjiv Sam

    2007-01-01

    The alpha-melanocyte-stimulating hormone (alpha-MSH) receptor (melanocortin type 1 receptor, or MC1R) plays an important role in the development and growth of melanoma cells. It was found that MC1R was overexpressed on most murine and human melanoma, making it a promising molecular target for melanoma imaging and therapy. Radiolabeled alpha-MSH peptide and its analogs that can specifically bind with MC1R have been extensively explored for developing novel agents for melanoma detection and radionuclide therapy. The goal of this study was to evaluate a 64Cu-labeled alpha-MSH analog, Ac-Nle-Asp-His-D-Phe-Arg-Trp-Gly-Lys(DOTA)-NH2 (DOTA-NAPamide), as a potential molecular probe for microPET imaging of melanoma and MC1R expression in melanoma xenografted mouse models. 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) conjugated NAPamide was synthesized and radiolabeled with 64Cu (t1/2=12 h) in NH4OAc (0.1 M; pH 5.5) buffered solution for 60 min at 50 degrees C. Cell culture studies reveal rapid and high uptake and internalization of 64Cu-DOTA-NAPamide in B16F10 cells. Over 90% of receptor-bound tracer is internalized at 3 h incubation. A cellular retention study demonstrates that the receptor-bound 64Cu-DOTA-NAPamide is slowly released from the B16F10 cells into the medium; 66% of the radioactivity is still associated with the cells even after 3 h incubation. The biodistribution of 64Cu-DOTA-NAPamide was then investigated in C57BL/6 mice bearing subcutaneous murine B16F10 melanoma tumors with high capacity of MC1R and Fox Chase Scid mice bearing human A375M melanoma with a relatively low number of MC1R receptors. Tumor uptake values of 64Cu-DOTA-NAPamide are found to be 4.63 +/- 0.45% and 2.49 +/- 0.31% ID/g in B16F10 and A375M xenografted melanoma at 2 h postinjection (pi), respectively. The B16F10 tumor uptake at 2 h pi is further inhibited to 2.29 +/- 0.24% ID/g, while A375M tumor uptake at 2 h pi remains 2.20 +/- 0.41% ID/g with a coinjection of excess

  16. Recruitment of activation receptors at inhibitory NK cell immune synapses.

    Directory of Open Access Journals (Sweden)

    Nicolas Schleinitz

    Full Text Available Natural killer (NK cell activation receptors accumulate by an actin-dependent process at cytotoxic immune synapses where they provide synergistic signals that trigger NK cell effector functions. In contrast, NK cell inhibitory receptors, including members of the MHC class I-specific killer cell Ig-like receptor (KIR family, accumulate at inhibitory immune synapses, block actin dynamics, and prevent actin-dependent phosphorylation of activation receptors. Therefore, one would predict inhibition of actin-dependent accumulation of activation receptors when inhibitory receptors are engaged. By confocal imaging of primary human NK cells in contact with target cells expressing physiological ligands of NK cell receptors, we show here that this prediction is incorrect. Target cells included a human cell line and transfected Drosophila insect cells that expressed ligands of NK cell activation receptors in combination with an MHC class I ligand of inhibitory KIR. The two NK cell activation receptors CD2 and 2B4 accumulated and co-localized with KIR at inhibitory immune synapses. In fact, KIR promoted CD2 and 2B4 clustering, as CD2 and 2B4 accumulated more efficiently at inhibitory synapses. In contrast, accumulation of KIR and of activation receptors at inhibitory synapses correlated with reduced density of the integrin LFA-1. These results imply that inhibitory KIR does not prevent CD2 and 2B4 signaling by blocking their accumulation at NK cell immune synapses, but by blocking their ability to signal within inhibitory synapses.

  17. Positive allosteric modulators of alpha 7 nicotinic acetylcholine receptors reverse ketamine-induced schizophrenia-like deficits in rats.

    Science.gov (United States)

    Nikiforuk, Agnieszka; Kos, Tomasz; Hołuj, Małgorzata; Potasiewicz, Agnieszka; Popik, Piotr

    2016-02-01

    Alpha 7 nicotinic acetylcholine receptors (α7-nAChRs) have generated great interest as targets of new pharmacological treatments for cognitive dysfunction in schizophrenia. One promising recent approach is based on the use of positive allosteric modulators (PAMs) of α7-nAChRs, which demonstrate several advantages over direct agonists. Nevertheless, the efficacy of these newly introduced α7-nAChR agents has not been extensively characterised in animal models of schizophrenia. The aim of the present study was to evaluate the efficacy of type I and II PAMs, N-(5-chloro-2,4-dimethoxyphenyl)-N'-(5-methyl-3-isoxazolyl)urea (PNU-120596) and N-(4-chlorophenyl)-[[(4-chlorophenyl)amino]methylene]-3-methyl-5-isoxazoleacet-amide (CCMI), respectively, and galantamine, an acetylcholinesterase inhibitor (AChE) that also allosterically modulates nAChRs, against ketamine-induced cognitive deficits and social withdrawal in rats. The orthosteric α7-nAChR agonist octahydro-2-methyl-5-(6-phenyl-3-pyridazinyl)-pyrrolo[3,4-c]pyrrole (A-582941) was used as a positive control. Additionally, the antipsychotic activities of the tested compounds were assessed using the conditioned avoidance response (CAR) test. PNU-120596, CCMI, galantamine and A-582941 reversed ketamine-induced cognitive inflexibility, as assessed in the attentional set-shifting task (ASST). The tested compounds were also effective against ketamine-induced impairment in the novel object recognition task (NORT). PNU-120596, CCMI, and A-582941 ameliorated ketamine-induced social interaction deficits, whereas galantamine was ineffective. Moreover, all tested compounds selectively suppressed the CAR. The positive allosteric modulation of α7-nAChRs demonstrates preclinical efficacy not only against schizophrenia-like cognition impairments but also positive and negative symptoms. Therefore, the use of α7-nAChR PAMs as a potential treatment strategy in schizophrenia is supported.

  18. Expression of IFN-γ and its receptor alpha in the peripheral blood of patients with chronic hepatitis C

    Institute of Scientific and Technical Information of China (English)

    张萍; 陈智; 陈峰; 李敏伟; 范骏; 周慧明; 刘继洪; 黄珠

    2004-01-01

    Background It has been known that intra-cellualr immunity is important for defense against viral infections and this function lies with interferon gamma (INF-γ). Here we evaluated the role of IFN-γ system in the pathogenesis of chronic hepatitis C (CHC).Methods The levels of interferon gamma receptor alpha (IFNGRα) on the peripheral lymphocyte membrane were assayed with flow cytometry. The plasma concentrations of the cytokines IFN-γ and IL-10 in CHC patients and normal controls were assayed by enzume-linked-immunosorbent assay (ELISA). The samples were collected randomly from Xinjiang Autonomous Region, Zhejiang and the northern regions of Jiangsu Province in China.Results The levels of IFNGRα in CHC patients were significantly lower than that of normal controls (NC), especially among patients during the stable stage (P<0.001), whereas there were no significant differences between CHC in active and stable stages. Among the patients of the three regions, there were no significant differences between patients from Xinjiang and Zhejiang provinces, but both had statistically significant difference compared with the patients from Jiangsu Province (P<0.001). Plasma IFN-γ and IL-10 concentrations in CHC patients decreased significantly, IFN-γ in particular, but there were no significant differences in these levels between various stages of the disease. The IFN-γ/IL-10 (Th1/Th2 ) ratio in patients was reversed. Conclusion There may be defects in the IFN-γ system in chronic HCV infected subjects and a low immune response, which may play an important role in the persistence of HCV infection.

  19. The androgen 5alpha-dihydrotestosterone and its metabolite 5alpha-androstan-3beta, 17beta-diol inhibit the hypothalamo-pituitary-adrenal response to stress by acting through estrogen receptor beta-expressing neurons in the hypothalamus.

    Science.gov (United States)

    Lund, Trent D; Hinds, Laura R; Handa, Robert J

    2006-02-01

    Estrogen receptor beta (ERbeta) and androgen receptor (AR) are found in high levels within populations of neurons in the hypothalamus. To determine whether AR or ERbeta plays a role in regulating hypothalamo-pituitary-adrenal (HPA) axis function by direct action on these neurons, we examined the effects of central implants of 17beta-estradiol (E2), 5alpha-dihydrotestosterone (DHT), the DHT metabolite 5alpha-androstan-3beta, 17beta-diol (3beta-diol), and several ER subtype-selective agonists on the corticosterone and adrenocorticotropin (ACTH) response to immobilization stress. In addition, activation of neurons in the paraventricular nucleus (PVN) was monitored by examining c-fos mRNA expression. Pellets containing these compounds were stereotaxically implanted near the PVN of gonadectomized male rats. Seven days later, animals were killed directly from their home cage (nonstressed) or were restrained for 30 min (stressed) before they were killed. Compared with controls, E2 and the ERalpha-selective agonists moxestrol and propyl-pyrazole-triol significantly increased the stress induced release of corticosterone and ACTH. In contrast, central administration of DHT, 3beta-diol, and the ERbeta-selective compound diarylpropionitrile significantly decreased the corticosterone and ACTH response to immobilization. Cotreatment with the ER antagonist tamoxifen completely blocked the effects of 3beta-diol and partially blocked the effect of DHT, whereas the AR antagonist flutamide had no effect. Moreover, DHT, 3beta-diol, and diarylpropionitrile treatment significantly decreased restraint-induced c-fos mRNA expression in the PVN. Together, these studies indicate that the inhibitory effects of DHT on HPA axis activity may be in part mediated via its conversion to 3beta-diol and subsequent binding to ERbeta. PMID:16452668

  20. Differential actions of antiparkinson agents at multiple classes of monoaminergic receptor. II. Agonist and antagonist properties at subtypes of dopamine D(2)-like receptor and alpha(1)/alpha(2)-adrenoceptor.

    Science.gov (United States)

    Newman-Tancredi, Adrian; Cussac, Didier; Audinot, Valérie; Nicolas, Jean-Paul; De Ceuninck, Frédéric; Boutin, Jean-A; Millan, Mark J

    2002-11-01

    properties at multiple subtypes of D(2)-like receptor and alpha(1)/alpha(2)-AR, actions, which likely contribute to their contrasting functional profiles. PMID:12388667

  1. Prostaglandin F2-alpha receptor (FPr expression on porcine corpus luteum microvascular endothelial cells (pCL-MVECs

    Directory of Open Access Journals (Sweden)

    Forni Monica

    2007-07-01

    Full Text Available Abstract Background The corpus luteum (CL is a transient endocrine gland and prostaglandin F2-alpha is considered to be the principal luteolysin in pigs. In this species, the in vivo administration of prostaglandin F2-alpha induces apoptosis in large vessels as early as 6 hours after administration. The presence of the prostaglandin F2-alpha receptor (FPr on the microvascular endothelial cells (pCL-MVECs of the porcine corpus luteum has not yet been defined. The aim of the study was to assess FPr expression in pCL-MVECs in the early and mid-luteal phases (EL-p, ML-p, and during pregnancy (P-p. Moreover, the effectiveness of prostaglandin F2-alpha treatment in inducing pCL-MVEC apoptosis was tested. Methods Porcine CLs were collected in the EL and ML phases and during P-p. All CLs from each animal were minced together and the homogenates underwent enzymatic digestion. The pCL-MVECs were then positively selected by an immunomagnetic separation protocol using Dynabeads coated with anti-CD31 monoclonal antibody and seeded in flasks in the presence of EGM 2-MV (Microvascular Endothelial Cell Medium-2. After 4 days of culture, the cells underwent additional immunomagnetic selection and were seeded in flasks until the confluent stage. PCR Real time, western blot and immunodetection assays were utilized to assess the presence of FPr on pCL-MVEC primary cultures. Furthermore, the influence of culture time (freshly isolated, cultured overnight and at confluence and hormonal treatment (P4 and E2 on FPr expression in pCL-MVECs was also investigated. Apoptosis was detected by TUNEL assay of pCL-MVECs exposed to prostaglandin F2-alpha. Results We obtained primary cultures of pCL-MVECs from all animals. FPr mRNA and protein levels showed the highest value (ANOVA in CL-MVECs derived from the early-luteal phase. Moreover, freshly isolated MVECs showed a higher FPr mRNA value than those cultured overnight and confluent cells (ANOVA. prostaglandin F2-alpha

  2. Polymorphism analysis in estrogen receptors alpha and beta genes and their association with infertile population in Pakistan

    OpenAIRE

    Liaqat, Sinha; Hasnain, Shahida; Muzammil, Saima; Hayat, Sumreen

    2015-01-01

    Studies on polymorphism of estrogen receptor (ESR) alpha and beta genes have been mostly implicated in infertility, but the results have been controversial due to lack of comprehensive data. The present study focused on association of ESR genes with both male and female infertility. In ESRα, PvuII (rs2234693) and XbaI (rs9340799) were studied while in ESRβ gene, risk of infertility was determined for silent G/A RsaI (rs1256049) polymorphism. Total 124 subjects (74 cases and 50 controls) were ...

  3. The insulin receptor C-terminus is involved in regulation of the receptor kinase activity.

    Science.gov (United States)

    Kaliman, P; Baron, V; Alengrin, F; Takata, Y; Webster, N J; Olefsky, J M; Van Obberghen, E

    1993-09-21

    During the insulin receptor activation process, ligand binding and autophosphorylation induce two distinct conformational changes in the C-terminal domain of the receptor beta-subunit. To analyze the role of this domain and the involvement of the C-terminal autophosphorylation sites (Tyr1316 and Tyr1322) in receptor activation, we used (i) antipeptide antibodies against three different C-terminal sequences (1270-1281, 1294-1317, and 1309-1326) and (ii) an insulin receptor mutant (Y/F2) where Tyr1316 and Tyr1322 have been replaced by Phe. We show that the autophosphorylation-induced C-terminal conformational change is preserved in the Y/F2 receptor, indicating that this change is not induced by phosphorylation of the C-terminal sites but most likely by phosphorylation of the major sites in the kinase domain (Tyr1146, Tyr1150, and Tyr1151). Binding of antipeptide antibodies to the C-terminal domain modulated (activated or inhibited) both mutant and wild-type receptor-mediated phosphorylation of poly(Glu/Tyr). In contrast to the wild-type receptor, Y/F2 exhibited the same C-terminal configuration before and after insulin binding, evidencing that mutation of Tyr1316 and Tyr1322 introduced conformational changes in the C-terminus. Finally, the mutant receptor was 2-fold more active than the wild-type receptor for poly(Glu/Tyr) phosphorylation. In conclusion, the whole C-terminal region of the insulin receptor beta-subunit is likely to exert a regulatory influence on the receptor kinase activity. Perturbations of the C-terminal region, such as binding of antipeptides or mutation of Tyr1316 and Tyr1322, provoke alterations at the receptor kinase level, leading to activation or inhibition of the enzymic activity. PMID:7690586

  4. Alexa Fluor 546-ArIB[V11L;V16A] is a potent ligand for selectively labeling alpha 7 nicotinic acetylcholine receptors.

    Science.gov (United States)

    Hone, Arik J; Whiteaker, Paul; Mohn, Jesse L; Jacob, Michele H; McIntosh, J Michael

    2010-08-01

    The alpha7* (*denotes the possible presence of additional subunits) nicotinic acetylcholine receptor (nAChR) subtype is widely expressed in the vertebrate nervous system and implicated in neuropsychiatric disorders that compromise thought and cognition. In this report, we demonstrate that the recently developed fluorescent ligand Cy3-ArIB[V11L;V16A] labels alpha7 nAChRs in cultured hippocampal neurons. However, photobleaching of this ligand during long image acquisition times prompted us to develop a new derivative. In photostability studies, this new ligand, Alexa Fluor 546-ArIB[V11L;V16A], was significantly more resistant to bleaching than the Cy3 derivative. The classic alpha7 ligand alpha-bungarotoxin binds to alpha1* and alpha9* nAChRs. In contrast, Alexa Fluor 546-ArIB[V11L;V16A] potently (IC(50) 1.8 nM) and selectively blocked alpha7 nAChRs but not alpha1* or alpha9* nAChRs expressed in Xenopus oocytes. Selectivity was further confirmed by competition binding studies of native nAChRs in rat brain membranes. The fluorescence properties of Alexa Fluor 546-ArIB[V11L;V16A] were assessed using human embryonic kidney-293 cells stably transfected with nAChRs; labeling was observed on cells expressing alpha7 but not cells expressing alpha3beta2, alpha3beta4, or alpha4beta2 nAChRs. Further imaging studies demonstrate that Alexa Fluor 546-ArIB[V11L;V16A] labels hippocampal neurons from wild-type mice but not from nAChR alpha7 subunit-null mice. Thus, Alexa Fluor 546-ArIB[V11L;V16A] represents a potent and selective ligand for imaging alpha7 nAChRs.

  5. The WSXWS motif in cytokine receptors is a molecular switch involved in receptor activation

    DEFF Research Database (Denmark)

    Dagil, Robert; Knudsen, Maiken J.; Olsen, Johan Gotthardt;

    2012-01-01

    The prolactin receptor (PRLR) is activated by binding of prolactin in a 2:1 complex, but the activation mechanism is poorly understood. PRLR has a conserved WSXWS motif generic to cytokine class I receptors. We have determined the nuclear magnetic resonance solution structure of the membrane...

  6. alpha-Glycosidase inhibitory activity of hexagalloylglucose from the galls of Quercus infectoria.

    Science.gov (United States)

    Hwang, J K; Kong, T W; Baek, N I; Pyun, Y R

    2000-04-01

    Hexagalloylglucose (3-O-digalloyl-1,2,4,6-tetra-O-galloyl-beta-D- glucose), which was isolated from the methanol extract of the galls of Quercus infectoria, significantly inhibited alpha-glycosidases such as sucrase, maltase and isomaltase. Its inhibitory activity was comparable to acarbose being used as a hypoglycemic agent, while the inhibitory activity on alpha-amylase was approximately 10 times lower than that of acarbose. The results indicate that, when compared to acarbose, hexagalloylglucose might reduce the side effects by reducing inhibition of alpha-amylase. PMID:10821056

  7. Molecular Characterization and Sex-Specific Tissue Expression of Estrogen Receptor Alpha (esr1), Estrogen Receptor Beta-a (esr2a) and Ovarian Aromatase (cyp19a1a) in Yellow Perch (Perca flavescens)

    Science.gov (United States)

    Yellow perch (Perca flavescens) exhibit an estrogen-stimulated sexual size dimorphism (SSD) wherein females grow faster and larger than males. To aid in the examination of this phenomenon, the cDNA sequences encoding estrogen receptor-alpha (esr1), estrogen receptor-beta-a (esr2a) and ovarian aroma...

  8. A possible role of vitamin D receptors in regulating vitamin D activation in the kidney.

    OpenAIRE

    Iida, K; Shinki, T; Yamaguchi, A; DeLuca, H F; Kurokawa, K; Suda, T.

    1995-01-01

    The vitamin D endocrine system is regulated reciprocally by renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylases. Previously, we reported that renal proximal convoluted tubules, the major site of 1 alpha, 25-dihydroxyvitamin D3 production, have vitamin D receptors. In the presence of vitamin D receptors, renal proximal convoluted tubules cannot maintain the state of enhanced production of 1 alpha, 25-dihydroxyvitamin D3. To clarify this discrepancy, we proposed a working hypothesis for the...

  9. Gross alpha and gross beta activity in the products and by-product of amang tin tailings process

    International Nuclear Information System (INIS)

    Gross alpha and gross beta activities were determined for mineral samples collected from five amang tailing factories. The measured activity of alpha ranged from 31 to 220,000 Bq kg-1 with an average 9,154 Bq kg-1, whereas for beta activity ranged from 9 to 552,000 Bq kg-1 with an average 19,811 Bq kg-1. The higher gross alpha and gross beta observed of monazite while the lowest recorded of waste (sand) and pyrite for gross alpha and gross beta activity respectively. The minimum detectable activities were 180 and 40 Bq kg-1 for gross alpha and gross beta respectively. (author)

  10. Activation of multiple mitogen-activated protein kinases by recombinant calcitonin gene-related peptide receptor.

    Science.gov (United States)

    Parameswaran, N; Disa, J; Spielman, W S; Brooks, D P; Nambi, P; Aiyar, N

    2000-02-18

    Calcitonin gene-related peptide is a 37-amino-acid neuropeptide and a potent vasodilator. Although calcitonin gene-related peptide has been shown to have a number of effects in a variety of systems, the mechanisms of action and the intracellular signaling pathways, especially the regulation of mitogen-activated protien kinase (MAPK) pathway, is not known. In the present study we investigated the role of calcitonin gene-related peptide in the regulation of MAPKs in human embryonic kidney (HEK) 293 cells stably transfected with a recombinant porcine calcitonin gene-related peptide-1 receptor. Calcitonin gene-related peptide caused a significant dose-dependent increase in cAMP response and the effect was inhibited by calcitonin gene-related peptide(8-37), the calcitonin gene-related peptide-receptor antagonist. Calcitonin gene-related peptide also caused a time- and concentration-dependent increase in extracellular signal-regulated kinase (ERK) and P38 mitogen-activated protein kinase (P38 MAPK) activities, with apparently no significant change in cjun-N-terminal kinase (JNK) activity. Forskolin, a direct activator of adenylyl cyclase also stimulated ERK and P38 activities in these cells suggesting the invovement of cAMP in this process. Calcitonin gene-related peptide-stimulated ERK and P38 MAPK activities were inhibited significantly by calcitonin gene-related peptide receptor antagonist, calcitonin gene-related peptide-(8-37) suggesting the involvement of calcitonin gene-related peptide-1 receptor. Preincubation of the cells with the cAMP-dependent protein kinase inhibitor, H89 [¿N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide, hydrochloride¿] inhibited calcitonin gene-related peptide-mediated activation of ERK and p38 kinases. On the other hand, preincubation of the cells with wortmannin ¿[1S-(1alpha,6balpha,9abeta,11alpha, 11bbeta)]-11-(acetyloxy)-1,6b,7,8,9a,10,11, 11b-octahydro-1-(methoxymethyl)-9a,11b-dimethyl-3H-furo[4,3, 2-de]indeno[4,5-h]-2

  11. Structure of the T-cell receptor in a Ti alpha beta, Ti gamma delta double positive T-cell line

    DEFF Research Database (Denmark)

    Kuhlmann, J; Geisler, C

    1993-01-01

    is still not known. It has been suggested that each T-cell receptor contains two Ti dimers. To gain insight into the structure of the T-cell receptor we constructed a Ti alpha beta, Ti gamma delta double positive T-cell line which contained four functional Ti chains (Ti alpha, beta, gamma, and delta......The multichain T-cell receptor is composed of at least six different polypeptide chains. The clonotypic Ti heterodimer (Ti alpha beta or Ti gamma delta) is non-covalently associated with the CD3 chains (CD3 gamma delta epsilon zeta). The exact number of subunits constituting the T-cell receptor......). The data demonstrated an absence of Ti dimers containing mixtures of chains other than the typical Ti alpha beta and Ti gamma delta combinations. Furthermore, by co-modulation experiments we demonstrated that the Ti alpha beta and the Ti gamma delta dimers were not expressed in the same T-cell receptor...

  12. Inhibition of activated protein C by recombinant alpha 1-antitrypsin variants with substitution of arginine or leucine for methionine358

    NARCIS (Netherlands)

    Heeb, M.J.; Bischoff, Rainer; Courtney, M.; Griffin, J.H.

    1990-01-01

    alpha 1-Antitrypsin (alpha 1-AT) was recently identified as a major physiologic plasma inhibitor of activated protein C. The reaction with activated protein C of recombinant alpha 1-AT containing amino acid substitutions at the reactive center was studied. The substitution of Arg358 for Met, as obse

  13. Cell death sensitization of leukemia cells by opioid receptor activation

    Science.gov (United States)

    Friesen, Claudia; Roscher, Mareike; Hormann, Inis; Fichtner, Iduna; Alt, Andreas; Hilger, Ralf A.; Debatin, Klaus-Michael; Miltner, Erich

    2013-01-01

    Cyclic AMP (cAMP) regulates a number of cellular processes and modulates cell death induction. cAMP levels are altered upon stimulation of specific G-protein-coupled receptors inhibiting or activating adenylyl cyclases. Opioid receptor stimulation can activate inhibitory Gi-proteins which in turn block adenylyl cyclase activity reducing cAMP. Opioids such as D,L-methadone induce cell death in leukemia cells. However, the mechanism how opioids trigger apoptosis and activate caspases in leukemia cells is not understood. In this study, we demonstrate that downregulation of cAMP induced by opioid receptor activation using the opioid D,L-methadone kills and sensitizes leukemia cells for doxorubicin treatment. Enhancing cAMP levels by blocking opioid-receptor signaling strongly reduced D,L-methadone-induced apoptosis, caspase activation and doxorubicin-sensitivity. Induction of cell death in leukemia cells by activation of opioid receptors using the opioid D,L-methadone depends on critical levels of opioid receptor expression on the cell surface. Doxorubicin increased opioid receptor expression in leukemia cells. In addition, the opioid D,L-methadone increased doxorubicin uptake and decreased doxorubicin efflux in leukemia cells, suggesting that the opioid D,L-methadone as well as doxorubicin mutually increase their cytotoxic potential. Furthermore, we found that opioid receptor activation using D,L-methadone alone or in addition to doxorubicin inhibits tumor growth significantly in vivo. These results demonstrate that opioid receptor activation via triggering the downregulation of cAMP induces apoptosis, activates caspases and sensitizes leukemia cells for doxorubicin treatment. Hence, opioid receptor activation seems to be a promising strategy to improve anticancer therapies. PMID:23633472

  14. beta-Naphthoflavone protects from peritonitis by reducing TNF-alpha-induced endothelial cell activation.

    Science.gov (United States)

    Hsu, Sheng-Yao; Liou, Je-Wen; Cheng, Tsung-Lin; Peng, Shih-Yi; Lin, Chi-Chen; Chu, Yuan-Yuan; Luo, Wei-Cheng; Huang, Zheng-Kai; Jiang, Shinn-Jong

    2015-12-01

    β-Naphthoflavone (β-NF), a ligand of the aryl hydrocarbon receptor, has been shown to possess anti-oxidative properties. We investigated the anti-oxidative and anti-inflammatory potential of β-NF in human microvascular endothelial cells treated with tumor necrosis factor-alpha (TNF-α). Pretreatment with β-NF significantly inhibited TNF-α-induced intracellular reactive oxygen species, translocation of p67(phox), and TNF-α-induced monocyte binding and transmigration. In addition, β-NF significantly inhibited TNF-α-induced ICAM-1 and VCAM-1 expression. The mRNA expression levels of the inflammatory cytokines TNF-α and IL-6 were reduced by β-NF, as was the infiltration of white blood cells, in a peritonitis model. The inhibition of adhesion molecules was associated with suppressed nuclear translocation of NF-κB p65 and Akt, and suppressed phosphorylation of ERK1/2 and p38. The translocation of Egr-1, a downstream transcription factor involved in the MEK-ERK signaling pathway, was suppressed by β-NF treatment. Our findings show that β-NF inhibits TNF-α-induced NF-kB and ERK1/2 activation and ROS generation, thereby suppressing the expression of adhesion molecules. This results in reduced adhesion and transmigration of leukocytes in vitro and prevents the infiltration of leukocytes in a peritonitis model. Our findings also suggest that β-NF might prevent TNF-α-induced inflammation.

  15. Relation between increased anxiety and reduced expression of alpha1 and alpha2 subunits of GABA(A) receptors in Wfs1-deficient mice.

    Science.gov (United States)

    Raud, Sirli; Sütt, Silva; Luuk, Hendrik; Plaas, Mario; Innos, Jürgen; Kõks, Sulev; Vasar, Eero

    2009-08-28

    Mutations in the coding region of the WFS1 gene cause Wolfram syndrome, a rare multisystem neurodegenerative disorder of autosomal recessive inheritance. In clinical studies a relation between mutations in the Wfs1 gene and increased susceptibility for mood disorders has been established. According to our previous studies, mice lacking Wfs1 gene displayed increased anxiety in stressful environment. As the GABA-ergic system plays a significant role in the regulation of anxiety, we analyzed the expression of GABA-related genes in the forebrain structures of wild-type and Wfs1-deficient mice. Experimentally naïve Wfs1-deficient animals displayed a significant down-regulation of alpha1 (Gabra1) and alpha2 (Gabra2) subunits of GABA(A) receptors in the temporal lobe and frontal cortex. Exposure of wild-type mice to the elevated plus-maze decreased levels of Gabra1 and Gabra2 genes in the temporal lobe. A similar tendency was also established in the frontal cortex of wild-type animals exposed to behavioral test. In Wfs1-deficient mice the elevated plus-maze exposure did not induce further changes in the expression of Gabra1 and Gabra2 genes. By contrast, the expression of Gad1 and Gad2 genes, enzymes responsible for the synthesis of GABA, was not significantly affected by the exposure of mice to the elevated plus-maze or by the invalidation of Wfs1 gene. Altogether, the present study demonstrates that increased anxiety of Wfs1-deficient mice is probably linked to reduced expression of Gabra1 and Gabra2 genes in the frontal cortex and temporal lobe. PMID:19477223

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

    Science.gov (United States)

    Brooks, Andrew J; Waters, Michael J

    2010-09-01

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

  17. Measurement of natural radioactivity in chemical fertilizer and agricultural soil: evidence of high alpha activity.

    Science.gov (United States)

    Ghosh, Dipak; Deb, Argha; Bera, Sukumar; Sengupta, Rosalima; Patra, Kanchan Kumar

    2008-02-01

    People are exposed to ionizing radiation from the radionuclides that are present in different types of natural sources, of which phosphate fertilizer is one of the most important sources. Radionuclides in phosphate fertilizer belonging to 232Th and 238U series as well as radioisotope of potassium (40K) are the major contributors of outdoor terrestrial natural radiation. The study of alpha activity in fertilizers, which is the first ever in West Bengal, has been performed in order to determine the effect of the use of phosphate fertilizers on human health. The data have been compared with the alpha activity of different types of chemical fertilizers. The measurement of alpha activity in surface soil samples collected from the cultivated land was also performed. The sampling sites were randomly selected in the cultivated land in the Midnapore district, which is the largest district in West Bengal. The phosphate fertilizer is widely used for large agricultural production, mainly potatoes. The alpha activities have been measured using solid-state nuclear track detectors (SSNTD), a very sensitive detector for alpha particles. The results show that alpha activity of those fertilizer and soil samples varies from 141 Bq/kg to 2,589 Bq/kg and from 109 Bq/kg to 660 Bq/kg, respectively. These results were used to estimate environmental radiation exposure on human health contributed by the direct application of fertilizers.

  18. Embryonic expression of zebrafish AMPA receptor genes: zygotic gria2alpha expression initiates at the midblastula transition.

    Science.gov (United States)

    Lin, Wei-Hsiang; Wu, Chan-Hwa; Chen, Yu-Chia; Chow, Wei-Yuan

    2006-09-19

    The AMPA-preferring receptors (AMPARs) mediate rapid excitatory synaptic transmission in the central nervous system of vertebrates. Expression profiles of 8 AMPAR genes were studied by RT-PCR analyses to elucidate the properties of AMPARs during early zebrafish development. Transcripts of all AMPAR genes are detected at the time of fertilization, suggesting maternal transcriptions of zebrafish AMPAR genes. The amounts of gria1 and gria2 transcripts are several-fold higher than that of gria3 and gria4 between 10 and 72 hpf (hour postfertilization). The edited gria2alpha transcript decreases during gastrulation period, suggesting that zygotic expression of gria2alpha begins around the time of midblastula transition. Relative to the amount of beta-actin, the amounts of AMPAR transcripts increase significantly after the completion of neurulation. The amounts of gria2 transcripts exceed the total amounts of the remaining AMPAR transcripts after 36 hpf, suggesting increases in the representation of low Ca2+ permeable AMPARs during neuronal maturation. Many but not all of the known mammalian protein-protein interaction motifs are preserved in the C-terminal domains (CTD) of zebrafish AMPARs. Before 16 hpf, the embryos express predominantly the alternative splice forms encoding longer CTD. Representations of the short CTD splice forms of gria2 and gria4alpha increase after 24 hpf, when neurulation is nearly completed.

  19. Saccharomyces cerevisiae nuclear fusion requires prior activation by alpha factor.

    OpenAIRE

    Rose, M D; Price, B R; Fink, G. R.

    1986-01-01

    We have developed a protocol for efficient fusion of spheroplasts of the same mating type. Nuclear fusion in this whole-cell system is also efficient and closely parallels nuclear fusion in heterosexual mating of intact cells. In the spheroplast fusion system, nuclear fusion is dependent on both the KAR1 gene and prior exposure to alpha factor. The major products of nuclear fusion in the spheroplast fusion assay were true diploids that were homozygous at the mating-type locus. An additional 1...

  20. Comparison of the activation kinetics of the M3 acetylcholine receptor and a constitutively active mutant receptor in living cells.

    Science.gov (United States)

    Hoffmann, Carsten; Nuber, Susanne; Zabel, Ulrike; Ziegler, Nicole; Winkler, Christiane; Hein, Peter; Berlot, Catherine H; Bünemann, Moritz; Lohse, Martin J

    2012-08-01

    Activation of G-protein-coupled receptors is the first step of the signaling cascade triggered by binding of an agonist. Here we compare the activation kinetics of the G(q)-coupled M(3) acetylcholine receptor (M(3)-AChR) with that of a constitutively active mutant receptor (M(3)-AChR-N514Y) using M(3)-AChR constructs that report receptor activation by changes in the fluorescence resonance energy transfer (FRET) signal. We observed a leftward shift in the concentration-dependent FRET response for acetylcholine and carbachol with M(3)-AChR-N514Y. Consistent with this result, at submaximal agonist concentrations, the activation kinetics of M(3)-AChR-N514Y were significantly faster, whereas at maximal agonist concentrations the kinetics of receptor activation were identical. Receptor deactivation was significantly faster with carbachol than with acetylcholine and was significantly delayed by the N514Y mutation. Receptor-G-protein interaction was measured by FRET between M(3)-AChR-yellow fluorescent protein (YFP) and cyan fluorescent protein (CFP)-Gγ(2). Agonist-induced receptor-G-protein coupling was of a time scale similar to that of receptor activation. As observed for receptor deactivation, receptor-G-protein dissociation was slower for acetylcholine than that for carbachol. Acetylcholine-stimulated increases in receptor-G-protein coupling of M(3)-AChR-N514Y reached only 12% of that of M(3)-AChR and thus cannot be kinetically analyzed. G-protein activation was measured using YFP-tagged Gα(q) and CFP-tagged Gγ(2). Activation of G(q) was significantly slower than receptor activation and indistinguishable for the two agonists. However, G(q) deactivation was significantly prolonged for acetylcholine compared with that for carbachol. Consistent with decreased agonist-stimulated coupling to G(q), agonist-stimulated G(q) activation by M(3)-AChR-N514Y was not detected. Taken together, these results indicate that the N514Y mutation produces constitutive activation of M(3

  1. Family C 7TM receptor dimerization and activation

    DEFF Research Database (Denmark)

    Bonde, Marie Mi; Sheikh, Søren P; Hansen, Jakob Lerche

    2006-01-01

    The family C seven transmembrane (7TM) receptors constitutes a small and especially well characterized subfamily of the large 7TM receptor superfamily. Approximately 50% of current prescription drugs target 7TM receptors, this biologically important family represents the largest class of drug......-targets today. It is well established that family C 7TM receptors form homo- or hetero-dimers on the cell surface of living cells. The large extra-cellular domains (ECD) have been crystallized as a dimer in the presence and absence of agonist. Upon agonist binding, the dimeric ECD undergoes large conformational...... to be fully defined. This review presents the biochemical support for family C 7TM receptor dimerization and discusses its importance for receptor biosynthesis, surface expression, ligand binding and activation, since lessons learnt here may well be applicable to the whole superfamily of 7TM receptors....

  2. The Orphan Nuclear Receptor TR4 Is a Vitamin A-activated Nuclear Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X. Edward; Suino-Powell, Kelly M.; Xu, Yong; Chan, Cee-Wah; Tanabe, Osamu; Kruse, Schoen W.; Reynolds, Ross; Engel, James Douglas; Xu, H. Eric (Michigan-Med); (Van Andel)

    2015-11-30

    Testicular receptors 2 and 4 (TR2/4) constitute a subgroup of orphan nuclear receptors that play important roles in spermatogenesis, lipid and lipoprotein regulation, and the development of the central nervous system. Currently, little is known about the structural features and the ligand regulation of these receptors. Here we report the crystal structure of the ligand-free TR4 ligand binding domain, which reveals an autorepressed conformation. The ligand binding pocket of TR4 is filled by the C-terminal half of helix 10, and the cofactor binding site is occupied by the AF-2 helix, thus preventing ligand-independent activation of the receptor. However, TR4 exhibits constitutive transcriptional activity on multiple promoters, which can be further potentiated by nuclear receptor coactivators. Mutations designed to disrupt cofactor binding, dimerization, or ligand binding substantially reduce the transcriptional activity of this receptor. Importantly, both retinol and retinoic acid are able to promote TR4 to recruit coactivators and to activate a TR4-regulated reporter. These findings demonstrate that TR4 is a ligand-regulated nuclear receptor and suggest that retinoids might have a much wider regulatory role via activation of orphan receptors such as TR4.

  3. Limited species differences in estrogen receptor alpha-medicated reporter gene transactivation by xenoestrogens.

    Science.gov (United States)

    Sumida, Kayo; Ooe, Norihisa; Saito, Koichi; Kaneko, Hideo

    2003-01-01

    Estrogen receptors (ERs) play an important role in estrogen function. However, it is well known that there are species differences in amino acid sequences of the ligand binding domains. Here, we report on the analysis of species differences in ER-dependent transactivation with some chemicals using reporter gene assays. Full-length ER cDNAs from human, rat, chicken, alligator (Caiman), whiptail lizard, African clawed frog and rainbow trout were prepared from hepatic mRNA by the RT-PCR method and inserted into expression plasmids. Both expression and reporter plasmids were transiently transfected into HeLa cells, and then the estrogenic effects of chemicals were analyzed in terms of induction of luciferase activity. No species differences in transactivation were found among human, rat, chicken, alligator, whiptail lizard and African clawed frog ERs. However, thermo-dependent alteration in susceptibility to 17-beta-estradiol was observed with the rainbow trout ER because of thermo-dependence of estrogen binding. PMID:12648522

  4. Nonclinical safety of mavrilimumab, an anti-GMCSF receptor alpha monoclonal antibody, in cynomolgus monkeys: Relevance for human safety

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Patricia C., E-mail: ryanp@medimmune.com [MedImmune, LLC, Gaithersburg, MD (United States); Sleeman, Matthew A. [MedImmune, LLC, Cambridge (United Kingdom); Rebelatto, Marlon [MedImmune, LLC, Gaithersburg, MD (United States); Wang, Bing; Lu, Hong [MedImmune, LLC, Moutain View, CA (United States); Chen, Xiaomin [Novartis, East Hanover, NJ (United States); Wu, Chi-Yuan [MedImmune, LLC, Moutain View, CA (United States); Hinrichs, Mary Jane; Roskos, Lorin [MedImmune, LLC, Gaithersburg, MD (United States); Towers, Heidi [MedImmune, LLC, Cambridge (United Kingdom); McKeever, Kathleen; Dixit, Rakesh [MedImmune, LLC, Gaithersburg, MD (United States)

    2014-09-01

    Mavrilimumab (CAM-3001) is an investigational human IgG4 monoclonal antibody (MAb) targeting GM-CSF receptor alpha which is currently being developed for the treatment of RA. GM-CSF plays a central role in the pathogenesis of rheumatoid arthritis (RA) through the activation, differentiation, and survival of macrophages and neutrophils. To support clinical development, the nonclinical safety of mavrilimumab was evaluated in several studies with cynomolgus monkeys as the pharmacologically relevant species. Comprehensive toxicity parameters were assessed in each study, and treatment duration ranged from 4 to 26 weeks. Mavrilimumab has an acceptable safety profile in monkeys with no changes in any parameters other than microscopic findings in lung. In several studies, minimal accumulation of foamy alveolar macrophages was observed. This finding was only seen in studies of at least 11 weeks duration, was reversible following a dose-free recovery period and was considered non-adverse. At higher dose levels (≥ 30 mg/kg/week), in a 26-week repeat-IV dose study, the presence of lung foreign material, cholesterol clefts, and granulomatous inflammation was also observed in a few animals and was considered adverse. The dose- and time-related accumulation of foamy macrophages in lung following exposure to mavrilimumab observed in several NHP studies was expected based upon the known role of GM-CSFRα signaling in the function of alveolar macrophages. Overall, a clean no-observed-adverse-effect-level (NOAEL) without any effects in lung was established and provided adequate clinical safety margins. In clinical studies in RA patients, mavrilimumab has demonstrated good clinical activity with adequate safety to support further clinical development. A Phase 2b study of mavrilimumab in subjects with RA is in progress. - Highlights: • Mavrilimumab is a MAB targeting GM-CSFRα being developed for RA therapy. • Mavrilimumab has an acceptable safety profile in cynomolgus monkeys.

  5. Nonclinical safety of mavrilimumab, an anti-GMCSF receptor alpha monoclonal antibody, in cynomolgus monkeys: Relevance for human safety

    International Nuclear Information System (INIS)

    Mavrilimumab (CAM-3001) is an investigational human IgG4 monoclonal antibody (MAb) targeting GM-CSF receptor alpha which is currently being developed for the treatment of RA. GM-CSF plays a central role in the pathogenesis of rheumatoid arthritis (RA) through the activation, differentiation, and survival of macrophages and neutrophils. To support clinical development, the nonclinical safety of mavrilimumab was evaluated in several studies with cynomolgus monkeys as the pharmacologically relevant species. Comprehensive toxicity parameters were assessed in each study, and treatment duration ranged from 4 to 26 weeks. Mavrilimumab has an acceptable safety profile in monkeys with no changes in any parameters other than microscopic findings in lung. In several studies, minimal accumulation of foamy alveolar macrophages was observed. This finding was only seen in studies of at least 11 weeks duration, was reversible following a dose-free recovery period and was considered non-adverse. At higher dose levels (≥ 30 mg/kg/week), in a 26-week repeat-IV dose study, the presence of lung foreign material, cholesterol clefts, and granulomatous inflammation was also observed in a few animals and was considered adverse. The dose- and time-related accumulation of foamy macrophages in lung following exposure to mavrilimumab observed in several NHP studies was expected based upon the known role of GM-CSFRα signaling in the function of alveolar macrophages. Overall, a clean no-observed-adverse-effect-level (NOAEL) without any effects in lung was established and provided adequate clinical safety margins. In clinical studies in RA patients, mavrilimumab has demonstrated good clinical activity with adequate safety to support further clinical development. A Phase 2b study of mavrilimumab in subjects with RA is in progress. - Highlights: • Mavrilimumab is a MAB targeting GM-CSFRα being developed for RA therapy. • Mavrilimumab has an acceptable safety profile in cynomolgus monkeys.

  6. Absolute measurements of the alpha-gamma emitters activities by a sum-coincidence method

    International Nuclear Information System (INIS)

    The absolute activity of U-235 contained in a UO2 sample, using a sum-coincidence circuit which selected only the alpha particles which were simultaneous with the well known 184 Kev gamma radiation from Th-231. The alpha particles were detected by ZnS(Ag) scintillator specially designed to show its maximun efficiency for U-235 alpha particles, whereas the gamma radiation was detected by NaI(Tl) scintillation detector. The values obtained for the half-life of U-235 was compared with data from various observers using different experimental techniques. (Author)

  7. Radiosynthesis and in vitro validation of 3H-NS14492 as a novel high affinity alpha7 nicotinic receptor radioligand

    DEFF Research Database (Denmark)

    Magnussen, Janus H.; Ettrup, Anders; Donat, Cornelius K.;

    2015-01-01

    The neuronal alpha 7 nicotinic acetylcholine receptor is a homo-pentameric ligand-gated ion channel that is a promising drug target for cognitive deficits in Alzheimer's disease and schizophrenia. We have previously described 11C-NS14492 as a suitable agonist radioligand for in vivo positron...... emission tomography (PET) occupancy studies of the alpha 7 nicotinic receptor in the pig brain. In order to investigate the utility of the same compound for in vitro studies, 3H-NS14492 was synthesized and its binding properties were characterized using in vitro autoradiography and homogenate binding...... assays in pig frontal cortex. 3H-NS14492 showed specific binding to alpha 7 nicotinic receptors in autoradiography, revealing a dissociation constant (Kd) of 2.1 ± 0.7 nM and a maximum number of binding sites (Bmax) of 15.7±2.0 fmol/mg tissue equivalent. Binding distribution was similar...

  8. Synthesis and biological evaluation of phenolic 4,5-dihydroisoxazoles and 3-hydroxy ketones as estrogen receptor alpha and beta agonists.

    Science.gov (United States)

    Poutiainen, Pekka K; Venäläinen, Tuomas A; Peräkylä, Mikael; Matilainen, Juha M; Väisänen, Sami; Honkakoski, Paavo; Laatikainen, Reino; Pulkkinen, Juha T

    2010-05-15

    In this work, 52 diphenyl-4,5-dihydroisoxazoles and -3-hydroxy ketones were prepared and their estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta) activities were explored in order to systematize and maximize their biological activity. The biological activity was firstly screened by using ERE reporter assay to find out how aromatic hydroxylation and methylation of the chiral centers of the compounds affect the ability of ER to mediate biological responses. For selected 19 compounds, the relative binding affinities (RBA, relative to 3,17beta-estradiol) and ability to induce transcription of primary E2 target gene pS2 in human MCF-7 breast cancer cells were determined. In the reporter assay, many compounds showed even stronger activity than E2 and some of them showed RBA larger than 1%. The highest RBAs were determined for the enantiomers of 1-hydroxy-6-(4-hydroxy-phenyl)-1-phenyl-hexan-3-one (50a and 50b). Isomer 50a showed high binding affinity both to ERalpha (with RBA approximately 200%) and ERbeta (with RBA approximately 60%), while the RBAs of 50b were ca. 40% of those. Some of the other compounds (with RBA approximately 1-16%) showed also notable ERalpha binding selectivity. When four most promising ligands (50a, 50b, 45a, and 45b) were studied with respect to their ability to induce the transcription of primary E2 target gene pS2, the compounds acted as agonists or partial agonists. Computer modeling was used to predict receptor binding conformations and to rationalize the RBA differences of the compounds. PMID:20430632

  9. 运动性过氧化物酶体增殖物受体γ共激活因子1α的变化机制%Peroxisome proliferator-activated receptor-gamma coactivator-1 alpha and exercise-induced skeletal muscle adaptations

    Institute of Scientific and Technical Information of China (English)

    周建新; 马继政

    2013-01-01

    BACKGROUND:Peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α) may play an important role in the exercise-induced skeletal muscle adaptation, which is involved in the regulation of a variety of exercise-induced biological reactions. OBJECTIVE:To review the PGC-1αand endurance training induced skeletal muscle adaptations. METHODS:The relevant articles about relationship between PGC-1αand endurance training-induced skeletal muscle adaptations were searched from PubMed database (1995-01/2010-10) by using the keywords of“PGC-1α, skeletal muscle, exercise, mitochondrial biogenesis, adaptations”, and the language was limited to English. Repetitive contents were deleted. The 59 col ected articles were searched. According to the criterion, 37 were classified and sorted. RESULTS AND CONCLUSION:Endurance training can typical y increase the expression/activity of membrane transporters and mitochondrial metabolic enzymes as wel as increase capil arisation in the skeletal muscle, together enhancing the oxidative capacity of the muscle and the ability to oxidize both carbohydrates and fatty acids. Studies in PGC-1αknockout and overexpression mice have clearly demonstrated that PGC-1αplays an important role in maintaining the expression of mitochondrial metabolic and anti-oxidant enzymes in the skeletal muscle and does influence exercise-induced adaptations of mitochondrial proteins. However, PGC-1αis not exclusively required, and additional factors must be involved in the regulation of both basal expression and exercise-induced adaptations. Exercise-induced PGC-1αexpression and potential y increased PGC-1αactivity are likely the mechanisms contributing to skeletal muscle mitochondrial adaptations and concomitant health beneficial effects of regular physical activity.%背景:研究发现,过氧化物酶体增殖物受体γ共激活因子1α可能在运动诱导骨骼肌的适应机制起着重要的作用,参与调节运动诱导多

  10. The topography of alpha-band activity tracks the content of spatial working memory.

    Science.gov (United States)

    Foster, Joshua J; Sutterer, David W; Serences, John T; Vogel, Edward K; Awh, Edward

    2016-01-01

    Working memory (WM) is a system for the online storage of information. An emerging view is that neuronal oscillations coordinate the cellular assemblies that code the content of WM. In line with this view, previous work has demonstrated that oscillatory activity in the alpha band (8-12 Hz) plays a role in WM maintenance, but the exact contributions of this activity have remained unclear. Here, we used an inverted spatial encoding model in combination with electroencephalography (EEG) to test whether the topographic distribution of alpha-band activity tracks spatial representations held in WM. Participants in three experiments performed spatial WM tasks that required them to remember the precise angular location of a sample stimulus for 1,000-1,750 ms. Across all three experiments, we found that the topographic distribution of alpha-band activity tracked the specific location that was held in WM. Evoked (i.e., activity phase-locked to stimulus onset) and total (i.e., activity regardless of phase) power across a range of low-frequency bands transiently tracked the location of the sample stimulus following stimulus onset. However, only total power in the alpha band tracked the content of spatial WM throughout the memory delay period, which enabled reconstruction of location-selective channel tuning functions (CTFs). These findings demonstrate that alpha-band activity is directly related to the coding of spatial representations held in WM and provide a promising method for tracking the content of this online memory system.

  11. Biological activity of 1. cap alpha. -hydroxyvitamin D/sub 2/ in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Reeve, L.E.; Schnoes, H.K.; DeLuca, H.F.

    1978-01-01

    The biological activity of 1..cap alpha..-hydroxyvitamin D/sub 2/ has been determined in vitamin D-deficient rats. In the calcification of the rachitic epiphyseal plate, 1..cap alpha..-hydroxyvitamin D/sub 2/ is more active than 25-hydroxyvitamin D/sub 3/, while it is equally active in stimulating intestinal calcium absorption. On the other hand, it is much less active (one-third to one-fifth) than 25-hydroxyvitamin D/sub 3/ in the mobilization of calcium from bone. In both the intestinal and bone responses, 1..cap alpha..-hydroxyvitamin D/sub 2/ (312 pmol) is active in nephrectomized rats while 15-hydroxyvitamin D/sub 3/ is not.

  12. INDUCTION OF MAMMARY GLAND DEVELOPMENT IN ESTROGEN RECEPTOR-ALPHA KNOCKOUT MICE

    Science.gov (United States)

    Mammary glands from the estrogen receptor knockout ( ERKO) mouse do not undergo ductal morphogenesis or alveolar development. Disrupted Er signaling may result in reduced estrogen-responsive gene products in the mammary gland or reduced mammotropic hormones that contribute t...

  13. Modulation of the chaperone-like activity of bovine alpha-crystallin.

    Science.gov (United States)

    Clark, J I; Huang, Q L

    1996-12-24

    The effects of pantethine, glutathione, and selected chemical reagents on the anti-aggregation activity of alpha-crystallin was evaluated. Protein aggregation was monitored by light scattering of solutions of denatured beta L-crystallin or alcohol dehydrogenase (ADH). The ratios of beta L-crystallin/alpha-crystallin and ADH/alpha-crystallin were adjusted so that partial inhibition of protein aggregation at 60 degrees C or 37 degrees C, respectively, was observed and modulation of the chaperone action of alpha-crystallin could be evaluated easily with selected endogenous metabolites. Enhancement of the anti-aggregation activity in the beta L-crystallin assay was strongest with pantethine, which appeared to interact with alpha-crystallin. Enhancement of the anti-aggregation activity in the ADH assay was strongest with glutathione which appeared to interact with ADH. The results indicated that the products of common metabolic pathways can modulate the chaperone-like effects of alpha-crystallin on protein aggregation. PMID:8986785

  14. Dextromethorphan and its metabolite dextrorphan block alpha3beta4 neuronal nicotinic receptors.

    Science.gov (United States)

    Hernandez, S C; Bertolino, M; Xiao, Y; Pringle, K E; Caruso, F S; Kellar, K J

    2000-06-01

    Dextromethorphan (DM), a structural analog of morphine and codeine, has been widely used as a cough suppressant for more than 40 years. DM is not itself a potent analgesic, but it has been reported to enhance analgesia produced by morphine and nonsteroidal anti-inflammatory drugs. Although DM is considered to be nonaddictive, it has been reported to reduce morphine tolerance in rats and to be useful in helping addicted subjects to withdraw from heroin. Here we studied the effects of DM on neuronal nicotinic receptors stably expressed in human embryonic kidney cells. Studies were carried out to examine the effects of DM on nicotine-stimulated whole cell currents and nicotine-stimulated (86)Rb(+) efflux. We found that both DM and its metabolite dextrorphan block nicotinic receptor function in a noncompetitive but reversible manner, suggesting that both drugs block the receptor channel. Consistent with blockade of the receptor channel, neither drug competed for the nicotinic agonist binding sites labeled by [(3)H]epibatidine. Although DM is approximately 9-fold less potent than the widely used noncompetitive nicotinic antagonist mecamylamine in blocking nicotinic receptor function, the block by DM appears to reverse more slowly than that by mecamylamine. These data indicate that DM is a useful antagonist for studying nicotinic receptor function and suggest that it might prove to be a clinically useful neuronal nicotinic receptor antagonist, possibly helpful as an aid for helping people addicted to nicotine to refrain from smoking, as well as in other conditions where blockade of neuronal nicotinic receptors would be helpful. PMID:10869398

  15. Circulating sex hormones and gene expression of subcutaneous adipose tissue oestrogen and alpha-adrenergic receptors in HIV-lipodystrophy: implications for fat distribution

    DEFF Research Database (Denmark)

    Andersen, Ove; Pedersen, Steen B; Svenstrup, Birgit;

    2007-01-01

    determined in 31 nondiabetic HIV-infected male patients receiving HAART (16 with lipodystrophy), in whom measures of fat distribution (CT and DEXA-scans) and insulin sensitivity (hyperinsulinaemic euglycaemic clamp) were available. RESULTS: Total and free oestradiol and testosterone were decreased...... of alpha2A-adrenergic-receptor correlated positively with expression of oestrogen-receptor-alpha. CONCLUSIONS: The results fit the hypothesis that sex hormones play a role in altered fat distribution and insulin sensitivity of male patients with HIV-lipodystrophy. The effect of oestradiol...

  16. Progesterone-induced blocking factor activates STAT6 via binding to a novel IL-4 receptor.

    Science.gov (United States)

    Kozma, Noemi; Halasz, Melinda; Polgar, Beata; Poehlmann, Tobias G; Markert, Udo R; Palkovics, Tamas; Keszei, Marton; Par, Gabriella; Kiss, Katalin; Szeberenyi, Jozsef; Grama, Laszlo; Szekeres-Bartho, Julia

    2006-01-15

    Progesterone-induced blocking factor (PIBF) induces Th2-dominant cytokine production. Western blotting and EMSA revealed phosphorylation as well as nuclear translocation of STAT6 and inhibition of STAT4 phosphorylation in PIBF-treated cells. The silencing of STAT6 by small interfering RNA reduced the cytokine effects. Because the activation of the STAT6 pathway depends on the ligation of IL-4R, we tested the involvement of IL-4R in PIBF-induced STAT6 activation. Although PIBF does not bind to IL-4R, the blocking of the latter with an Ab abolished PIBF-induced STAT6 activation, whereas the blocking of the IL-13R had no effect. PIBF activated suppressor of cytokine signaling-3 and inhibited IL-12-induced suppressor of cytokine signaling-1 activation. The blocking of IL-4R counteracted all the described effects, suggesting that the PIBF receptor interacts with IL-4R alpha-chain, allowing PIBF to activate the STAT6 pathway. PIBF did not phosphorylate Jak3, suggesting that the gamma-chain is not needed for PIBF signaling. Confocal microscopic analysis revealed a colocalization and at 37 degrees C a cocapping of the FITC PIBF-activated PIBF receptor and PE anti-IL-4R-labeled IL-4R. After the digestion of the cells with phosphatidylinositol-specific phospholipase C, the STAT6-activating effect of PIBF was lost, whereas that of IL-4 remained unaltered. These data suggest the existence of a novel type of IL-4R composed of the IL-4R alpha-chain and the GPI-anchored PIBF receptor. PMID:16393965

  17. Transcriptomic signatures of peroxisome proliferator-activated receptor a (PPARa) in different mouse liver models identify novel aspects of its biology

    NARCIS (Netherlands)

    Szalowska, E.; Tesfay, H.A.; Hijum, van S.A.F.T.; Kersten, A.H.

    2014-01-01

    Background The peroxisome proliferator-activated receptor alpha (PPARa) is a ligand-activated transcription factor that regulates lipid catabolism and inflammation and is hepatocarcinogenic in rodents. It is presumed that the functions of PPARa in liver depend on cross-talk between parenchymal (hepa

  18. BDNF selectively regulates GABAA receptor transcription by activation of the JAK/STAT pathway.

    Science.gov (United States)

    Lund, Ingrid V; Hu, Yinghui; Raol, YogendraSinh H; Benham, Rebecca S; Faris, Ramona; Russek, Shelley J; Brooks-Kayal, Amy R

    2008-01-01

    The gamma-aminobutyric acid (GABA) type A receptor (GABA(A)R) is the major inhibitory neurotransmitter receptor in the brain. Its multiple subunits show regional, developmental, and disease-related plasticity of expression; however, the regulatory networks controlling GABA(A)R subunit expression remain poorly understood. We report that the seizure-induced decrease in GABA(A)R alpha1 subunit expression associated with epilepsy is mediated by the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway regulated by brain-derived neurotrophic factor (BDNF). BDNF- and seizure-dependent phosphorylation of STAT3 cause the adenosine 3',5'-monophosphate (cAMP) response element-binding protein (CREB) family member ICER (inducible cAMP early repressor) to bind with phosphorylated CREB at the Gabra1:CRE site. JAK/STAT pathway inhibition prevents the seizure-induced decrease in GABA(A)R alpha1 abundance in vivo and, given that BDNF is known to increase the abundance of GABA(A)R alpha4 in a JAK/STAT-independent manne