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Sample records for brain beta tubulin

  1. A gene encoding the major beta tubulin of the mitotic spindle in Physarum polycephalum plasmodia

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    Burland, T.G.; Paul, E.C.A.; Oetliker, M.; Dove, W.F.

    1988-03-01

    The multinucleate plasmodium of Physarum polycephalum is unusual among eucaryotic cells in that it uses tubulins only in mitotic-spindle microtubules; cytoskeletal, flagellar, and centriolar microtubules are absent in this cell type. The authors identified a ..beta..-tubulin cDNA clone, ..beta..105, which is shown to correspond to the transcript of the betC ..beta..-tubulin locus and to encode ..beta..2 tubulin, the ..beta.. tubulin expressed specifically in the plasmodium and used exclusively in the mitotic spindle. Physarum amoebae utilize tubulins in the cytoskeleton, centrioles, and flagella, in addition to the mitotic spindle. Sequence analysis shows that ..beta..2 tubulin is only 83% identical to the two ..beta.. tubulins expressed in amoebae. This compares with 70 to 83% identity between Physarum ..beta..2 tubulin and the ..beta.. tubulins of yeasts, fungi, alga, trypanosome, fruit fly, chicken, and mouse. On the other hand, Physarum ..beta..2 tubulin is no more similar to, for example, Aspergillus ..beta.. tubulins than it is to those of Drosophila melanogaster or mammals. Several eucaryotes express at least one widely diverged ..beta.. tubulin as well as one or more ..beta.. tubulins that conform more closely to a consensus ..beta..-tubulin sequence. The authors suggest that ..beta..-tubulins diverge more when their expression pattern is restricted, especially when this restriction results in their use in fewer functions. This divergence among ..beta.. tubulins could have resulted through neutral drift. For example, exclusive use of Physarum ..beta..2 tubulin in the spindle may have allowed more amino acid substitutions than would be functionally tolerable in the ..beta.. tubulins that are utilized in multiple microtubular organelles. Alternatively, restricted use of ..beta.. tubulins may allow positive selection to operate more freely to refine ..beta..-tubulin function.

  2. Biochemical studies of mouse brain tubulin: colchicine binding (DEAE-cellulose filter) assay and subunits ( α and β) biosynthesis and degradation (in newborn brain)

    Energy Technology Data Exchange (ETDEWEB)

    Tse, Cek-Fyne [Univ. of Rochester, NY (United States)

    1978-01-01

    A DEAE-cellulose filter assay, measuring (3H)colchicine bound to colchicine binding protein (CBP) absorbed on filter discs, has been modified to include lM sucrose in the incubation medium for complexing colchicine to CBP in samples before applying the samples to filter discs (single point assay). Due to the much greater stability of colchicine binding capacity in the presence of lM sucrose, multiple time-point assays and least squares linear regression analysis were not necessary for accurate determination of CBP in hybrid mouse brain at different stages of development. The highest concentrations of CBP were observed in the 160,000g supernatant and pellet of newborn brain homogenate. Further studies of the modified filter assay documented that the assay has an overall counting efficiency of 27.3%, that DEAE-cellulose filters bind and retain all tubulin in the assay samples, and that one molecule of colchicine binds approximately one molecule of tubulin dimer. Therefore, millimoles of colchicine bound per milligram total protein can be used to calculate tubulin content. With this technique tubulin content of brain supernatant was found to be 11.9% for newborn, and 7.15% for 11 month old mice. Quantitative densitometry was also used to measure mouse brain supernatant actin content for these two stages. In vivo synthesis and degradation rates of tubulin ..cap alpha.. and ..beta.. subunits of two day mouse brain 100,000g supernatant were studied after intracerebral injection of (3H)leucine. Quantitative changes of the ratio of tritium specific activities of tubulin ..cap alpha.. and ..beta.. subunits with time were determined. The pattern of change was biphasic. During the first phase the ratio decreased; during the second phase the ratio increased continuously. An interpretation consistent with all the data in this study is that the ..cap alpha.. subunit is synthesized at a more rapid rate than the ..beta.. subunit. (ERB)

  3. TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

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    Chung, Eun Jee [Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do (Korea, Republic of); Chun, Ji Na; Jung, Sun-Ah [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of); Cho, Jin Won [Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lee, Joon H., E-mail: joonhlee@konyang.ac.kr [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of)

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful information

  4. Molecular characterization of four beta-tubulin genes from dinitroaniline susceptible and resistant biotypes of Eleusine indica.

    Science.gov (United States)

    Yamamoto, E; Baird, W V

    1999-01-01

    Dinitroaniline herbicides are antimicrotubule drugs that bind to tubulins and inhibit polymerization. As a result of repeated application of dinitroaniline herbicides, resistant biotypes of goosegrass (Eleusine indica) developed in previously susceptible wild-type populations. We have previously reported that alpha-tubulin missense mutations correlate with dinitroaniline response phenotypes (Drp) (Plant Cell 10: 297-308, 1998). In order to ascertain associations of other tubulins with dinitroaniline resistance, four beta-tubulin cDNA classes (designated TUB1, TUB2, TUB3, and TUB4) were isolated from dinitroaniline-susceptible and -resistant biotypes. Sequence analysis of the four beta-tubulin cDNA classes identified no missense mutations. Identified nucleotide substitutions did not result in amino acid replacements. These results suggest that the molecular basis of dinitroaniline resistance in goosegrass differs from those of colchicine/dinitroaniline cross-resistant Chlamydomonas reinhardtii and benzimidazole-resistant fungi and yeast. Expression of the four beta-tubulins was highest in inflorescences. This is in contrast to alpha-tubulin TUA1 that is expressed predominantly in roots. Collectively, these results imply that beta-tubulin genes are not associated with dinitroaniline resistance in goosegrass. Phylogenetic analysis of the four beta-tubulins, together with three alpha-tubulins, suggests that the resistant biotype developed independently in multiple locations rather than spreading from one location.

  5. Differential expression of gamma-tubulin and class III beta-tubulin in medulloblastomas and human medulloblastoma cell lines

    Czech Academy of Sciences Publication Activity Database

    Caracciolo, V.; D´Agostino, L.; Dráberová, Eduarda; Sládková, Vladimíra; Crozier-Fitzgerald, C.; Agamanolis, D.P.; De Chadarévian, J.P.; Legido, A.; Giordano, A.; Dráber, Pavel; Katsetos, C.D.

    2010-01-01

    Roč. 223, č. 2 (2010), s. 519-529 ISSN 0021-9541 R&D Projects: GA AV ČR KAN200520701 Institutional research plan: CEZ:AV0Z50520514 Keywords : gamma-tubulin * beta III-tubulin * meduloblastoma Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.986, year: 2010

  6. Tubulin targets in the pathobiology and therapy of glioblastoma multiforme. I. class III beta-tubulin

    Czech Academy of Sciences Publication Activity Database

    Katsetos, C.D.; Dráberová, Eduarda; Legido, A.; Dumontet, C.; Dráber, Pavel

    2009-01-01

    Roč. 221, č. 3 (2009), s. 505-513 ISSN 0021-9541 R&D Projects: GA AV ČR KAN200520701 Institutional research plan: CEZ:AV0Z50520514 Keywords : Beta-II-tubulin * glioblastoma Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.586, year: 2009

  7. [Molecular and structural-biological analysis of Nicotiana plumbaginifolia mutants for identification of the site of beta-tubulins interaction with dinitroanilines and phosphorotioamidates].

    Science.gov (United States)

    Emets, A I; Baiard, U V; Nyporko, A Iu; Swire-Clark, G A; Blium, Ia B

    2009-01-01

    The identification of point mutation locations on beta-tubulin molecules of amiprophosmethyl- and trifluralin-resistant Nicotiana plumbaginifolia lines have described in the work. It was shown that in the first case this mutation is connected with the substitution ofserine residue on proline in position 248; in the second case--with the substitution of phenilalanine on serine in position 317 of beta-tubulin amino acid sequence. Three-dimensional models of beta-tubulin molecule from Chlamydomonas with well-known location of mutations conferring dinitroaniline- and phosphorotioamidate resistance (substitution of lysine residue to methionine on position 350), and beta-tubulin from Nicotiana plumbaginifolia have been reconstructed. On the basis of analysis of site of interaction with dinitroanilines and phosphorotioamides on Chlamydomonas beta-tubulin molecule it was concluded that the revealed mutations on Nicotiana plumbaginifolia beta-tubulin affect amino acid residues participating in formation of this site.

  8. Expression of class III beta tubulin in cervical cancer patients administered preoperative radiochemotherapy: correlation with response to treatment and clinical outcome.

    Science.gov (United States)

    Ferrandina, Gabriella; Martinelli, Enrica; Zannoni, Gian Franco; Distefano, Mariagrazia; Paglia, Amelia; Ferlini, Cristiano; Scambia, Giovanni

    2007-02-01

    Alterations of the beta subunit of tubulin have been reported to be predictive of resistance to radiation and antitubulin agents in several solid tumors. The aim of the study was to investigate the clinical role of beta III tubulin expression as prognostic factor for survival and as a predictive parameter of response to preoperative radiochemotherapy in a single institutional series of locally advanced cervical cancer (LACC) patients. The study included 98 LACC patients admitted to the Gynecologic Oncology Unit, Catholic University of Rome and Campobasso between January 1998 and January 2005. Immunohistochemistry was performed by using the polyclonal rabbit anti-beta III tubulin antibody (Covance, Princeton, NJ, USA). The value of 10% immunostained tumor cells was arbitrarily chosen as cut-off value to distinguish cases with high versus low beta III tubulin content. In the whole series, beta III tubulin immunoreaction was detectable in 66/98 cases (67.3%), and the percentage of positively stained cells ranged from 0 to 100% (median=10%). The percentages of cases with high beta III tubulin expression were shown not to be differently distributed according to clinico-pathological characteristics. There was no statistically significant difference in the distribution of cases with high beta III tubulin expression according to clinical and pathological response to treatment. During the follow-up period, recurrence and death of disease occurred in 15 and 13 cases, respectively. There was no difference in disease-free and overall survival in cases with high versus low beta III tubulin expression. The assessment of class III beta tubulin status seems of little usefulness in order to identify LACC patients with poor chance of response to concomitant radiochemotherapy and unfavorable prognosis.

  9. Antiprotozoal activities of benzimidazoles and correlations with beta-tubulin sequence.

    Science.gov (United States)

    Katiyar, S K; Gordon, V R; McLaughlin, G L; Edlind, T D

    1994-01-01

    Benzimidazoles have been widely used since the 1960s as anthelmintic agents in veterinary and human medicine and as antifungal agents in agriculture. More recently, selected benzimidazole derivatives were shown to be active in vitro against two protozoan parasites, Trichomonas vaginalis and Giardia lamblia, and clinical studies with AIDS patients have suggested that microsporidia are susceptible as well. Here, we first present in vitro susceptibility data for T. vaginalis and G. lamblia using an expanded set of benzimidazole derivatives. Both parasites were highly susceptible to four derivatives, including mebendazole, flubendazole, and fenbendazole (50% inhibitory concentrations of 0.005 to 0.16 microgram/ml). These derivatives also had lethal activity that was time dependent: 90% of T. vaginalis cells failed to recover following a 20-h exposure to mebendazole at 0.17 microgram/ml. G. lamblia, but not T. vaginalis, was highly susceptible to five additional derivatives. Next, we examined in vitro activity of benzimidazoles against additional protozoan parasites: little or no activity was observed against Entamoeba histolytica, Leishmania major, and Acanthamoeba polyphaga. Since the microtubule protein beta-tubulin has been identified as the benzimidazole target in helminths and fungi, potential correlations between benzimidazole activity and beta-tubulin sequence were examined. This analysis included partial sequences (residues 108 to 259) from the organisms mentioned above, as well as the microsporidia Encephalitozoon hellem and Encephalitozoon cuniculi and the sporozoan Cryptosporidium parvum. beta-tubulin residues Glu-198 and, in particular, Phe-200 are strong predictors of benzimidazole susceptibility; both are present in Encephalitozoon spp. but absent in C. parvum. PMID:7811023

  10. Detection of beta-tubulin in the cytoplasm of the interphasic Entamoeba histolytica trophozoites.

    Science.gov (United States)

    Gómez-Conde, Eduardo; Vargas-Mejía, Miguel Ángel; Díaz-Orea, María Alicia; Hernández-Rivas, Rosaura; Cárdenas-Perea, María Elena; Guerrero-González, Tayde; González-Barrios, Juan Antonio; Montiel-Jarquín, Álvaro José

    2016-08-01

    It is known that the microtubules (MT) of Entamoeba histolytica trophozoites form an intranuclear mitotic spindle. However, electron microscopy studies and the employment of anti-beta-tubulin (β-tubulin) antibodies have not exhibited these cytoskeletal structures in the cytoplasm of these parasites. The purpose of this work was to detect β-tubulin in the cytoplasm of interphasic E. histolytica trophozoites. Activated or non-activated HMI-IMSS-strain E. histolytica trophozoites were used and cultured for 72 h at 37 °C in TYI-S-33 medium, and then these were incubated with the anti-β-tubulin antibody of E. histolytica. The anti-β-tubulin antibody reacted with the intranuclear mitotic spindle of E. histolytica-activated trophozoites as control. In contrast, in non-activated interphasic parasites, anti-β-tubulin antibody reacted with diverse puntiform structures in the cytoplasm and with ring-shaped structures localized in the cytoplasm, cellular membrane and endocytic stomas. In this work, for the first time, the presence of β-tubulin is shown in the cytoplasm of E. histolytica trophozoites. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Mass spectrometry identifies multiple organophosphorylated sites on tubulin

    International Nuclear Information System (INIS)

    Grigoryan, Hasmik; Schopfer, Lawrence M.; Peeples, Eric S.; Duysen, Ellen G.; Grigoryan, Marine; Thompson, Charles M.; Lockridge, Oksana

    2009-01-01

    Acute toxicity of organophosphorus poisons (OP) is explained by inhibition of acetylcholinesterase in nerve synapses. Low-dose effects are hypothesized to result from modification of other proteins, whose identity is not yet established. The goal of the present work was to obtain information that would make it possible to identify tubulin as a target of OP exposure. Tubulin was selected for study because live mice injected with a nontoxic dose of a biotinylated organophosphorus agent appeared to have OP-labeled tubulin in brain as determined by binding to avidin beads and mass spectrometry. The experiments with live mice were not conclusive because binding to avidin beads could be nonspecific. To be convincing, it is necessary to find and characterize the OP-labeled tubulin peptide. The search for OP-labeled tubulin peptides was begun by identifying residues capable of making a covalent bond with OP. Pure bovine tubulin (0.012 mM) was treated with 0.01-0.5 mM chlorpyrifos oxon for 24 h at 37 o C in pH 8.3 buffer. The identity of labeled amino acids and percent labeling was determined by mass spectrometry. Chlorpyrifos oxon bound covalently to tyrosines 83, 103, 108, 161, 224, 262, 272, 357, and 399 in bovine alpha tubulin, and to tyrosines 50, 51, 59, 106, 159, 281, 310, and 340 in bovine beta tubulin. The most reactive were tyrosine 83 in alpha and tyrosine 281 in beta tubulin. In the presence of 1 mM GTP, percent labeling increased 2-fold. Based on the crystal structure of the tubulin heterodimer (PDB 1jff) tyrosines 83 and 281 are well exposed to solvent. In conclusion seventeen tyrosines in tubulin have the potential to covalently bind chlorpyrifos oxon. These results will be useful when searching for OP-labeled tubulin in live animals.

  12. Microtubule disruption induced in vivo by alkylation of beta-tubulin by 1-aryl-3-(2-chloroethyl)ureas, a novel class of soft alkylating agents.

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    Legault, J; Gaulin, J F; Mounetou, E; Bolduc, S; Lacroix, J; Poyet, P; Gaudreault, R C

    2000-02-15

    We have previously reported that 4-tert-butyl-[3-(2-chloroethyl)ureido] benzene (4-tBCEU), a potent cytotoxic agent, modulates the synthesis of tubulins, suggesting that its cytotoxicity may be mediated through an antimicrotubule mechanism. Indeed, 4-tBCEU and its 4-iso-propyl (4-isopropyl [3-(2-chloroethyl)ureido] benzene) and 4-sec-butyl (4-sec-butyl [3-(2-chloroethyl)ureido] benzene) homologues induced disruption of the cytoskeleton and arrest of the cell cycle in G2 transition and mitosis. To better understand the mechanisms responsible for microtubule disruption by 1-aryl-3-(2-chloroethyl)ureas (CEU), we first examined their cytotoxicity on Chinese hamster ovary cells resistant to vinblastine and colchicine due to the expression of mutated tubulins (CHO-VV 3-2). These cells showed resistance to CEU, e.g., 4-tBCEU having an IC50 of 21.3+/-1.1 microM as compared with an IC50 of 11.6+/-0.7 microM for wild-type cells, suggesting a direct effect of the drugs on tubulins. Western blot analysis confirmed the disruption of microtubules and evidenced the formation of an additional immunoreactive beta-tubulin with an apparent lower molecular weight on SDS polyacrylamide gel. Incubation of MDA-MB-231 cells with [urea-14C]-4-tBCEU revealed the presence of a radioactive protein that coincided with the additional beta-tubulin band, indicating that CEU could covalently bind to the beta-tubulin. The 4-tBCEU-binding site on beta-tubulin was identified by competition of the CEU with colchicine, vinblastine, and iodoacetamide, a specific alkylating agent of sulfhydryl groups of cysteine residues. Colchicine, but not vinblastine, prevented the formation of the additional beta-tubulin band, suggesting that 4-tBCEU alkylates either Cys239 or Cys354 residues near the colchicine-binding site. To determine the cysteine residue alkylated by 4-tBCEU, we incubated the radiolabeled drug with human neuroblastoma cells (SK-N-SH) that overexpress the betaIII-tubulin, an isoform where Cys239

  13. Homologous expression of a mutated beta-tubulin gene does not confer benomyl resistance on Trichoderma virens.

    Science.gov (United States)

    Mukherjee, M; Hadar, R; Mukherjee, P K; Horwitz, B A

    2003-01-01

    To clone the beta-tubulins and to induce resistance to benzimidazoles in the biocontrol fungus Trichoderma virens through site-directed mutagenesis. Two beta-tubulin genes have been cloned using PCR amplification followed by the screening of a T. virens cDNA library. The full-length cDNA clones, coding for 445 and 446 amino acids, have been designated as T. virens tub1 and T. virens tub2. A sequence alignment of these two tubulins with tubulins from other filamentous fungi has shown the presence of some unique amino acid sequences not found in those positions in other beta-tubulins. Constitutive expression of the tub2 gene with a histidine to tyrosine substitution at position 6 (known to impart benomyl/methyl benzimadazol-2-yl carbamate resistance in other fungi), under the Pgpd promoter of Aspergillus nidulans, did not impart resistance to benomyl. The homologous expression of tub2 gene with a histidine to tyrosine mutation at position +6, which is known to impart benomyl tolerance in other fungi, does not impart resistance in T. virens. Unlike other Trichoderma spp., T. virens, has been difficult to mutate for benomyl tolerance. The present study, through site-directed mutagenesis, shows that a mutation known to impart benomyl tolerance in T. viride and other fungi does not impart resistance in this fungus. Understanding the mechanisms of this phenomenon will have a profound impact in plant-disease management, as many plant pathogenic fungi develop resistance to this group of fungicides forcing its withdrawal after a short period of use.

  14. Identification of morphological and molecular Aspergillus species isolated from patients based on beta-tubulin gene sequencing

    Directory of Open Access Journals (Sweden)

    Mahnaz Kheirkhah

    2017-06-01

    Full Text Available Background: Aspergillus species are opportunistic pathogens among immunocompromised patients. In terms of pathogenesis and mycotoxin production, they are in great value. The aim of the this study was to evaluate of beta-tubulin gene for identification of clinical Aspergillus species by PCR-sequencing method compared to morphological features of clinical isolates (such as conidial shape in direct microscopic examination, colony shape in culture, and physiological tests. Materials and Methods: In this study, 465 patients referred to the Shefa laboratory of Isfahan were evaluated. Morphological and molecular identification of clinical samples were performed using culture on sabouraud agar, malt extract agar, czapekdox agar, direct microscopy, and PCR-sequencing of beta tubulin gene, respectively. Sequences were analyzed in comparison with gene bank data. Results: Thirty nine out of 465 suspected cases (8.4% had aspergillosis. The most prevalent species were Aspergillus flavus (56.4%, A. oryzae (20.5%, and A. fumigatus (10.2%, respectively. Fifty nine percent of patients were females and 49% were males. Conclusion: In comparison with phenotypic tests, sequencing of beta-tubulin gene for identification of Aspergillus species is at great value. Replacement of molecular techniques with conventional tests is recommended for precise identification of microorganism for better management of infection.

  15. Maternal vitamin C deficiency does not reduce hippocampal volume and beta-tubulin III intensity in prenatal Guinea pigs

    DEFF Research Database (Denmark)

    Hansen, Stine Normann; Schjoldager, Janne Gram; Paidi, Maya Devi

    2016-01-01

    Marginal vitamin C (vitC) deficiency affects 5% to 10% of adults including subpopulations such as pregnant women and newborns. Animal studies link vitC deficiency to deleterious effects on the developing brain, but exactly how the brain adapts to vitC deficiency and the mechanisms behind...... the observed deficits remain largely unknown. We hypothesized that vitC deficiency in utero may lead to a decreased neuronal maturation and increased cellular death giving rise to alterations of the hippocampal morphology in a guinea pig model. Brains from prenatal guinea pig pups (n = 9-10 in each group......) subjected to either a sufficient (918 mg vitC/kg feed) or deficient (100 mg vitC/kg feed) maternal dietary regimen were assessed with regards to hippocampal volume and beta-tubulin isotype III staining intensity at 2 gestational time points (45 and 56). We found a distinct differential regional growth...

  16. Biochemical studies of mouse brain tubulin: colchicine binding (DEAE-cellulose filter) assay and subunits (α and β) biosynthesis and degradation (in newborn brain)

    International Nuclear Information System (INIS)

    Tse, C.F.

    1978-01-01

    A DEAE-cellulose filter assay, measuring [ 3 H]colchicine bound to colchicine binding protein (CBP) absorbed on filter discs, has been modified to include lM sucrose in the incubation medium for complexing colchicine to CBP in samples before applying the samples to filter discs (single point assay). Due to the much greater stability of colchicine binding capacity in the presence of lM sucrose, multiple time-point assays and least squares linear regression analysis were not necessary for accurate determination of CBP in hybrid mouse brain at different stages of development. The highest concentrations of CBP were observed in the 160,000g supernatant and pellet of newborn brain homogenate. Further studies of the modified filter assay documented that the assay has an overall counting efficiency of 27.3%, that DEAE-cellulose filters bind and retain all tubulin in the assay samples, and that one molecule of colchicine binds approximately one molecule of tubulin dimer. Therefore, millimoles of colchicine bound per milligram total protein can be used to calculate tubulin content. With this technique tubulin content of brain supernatant was found to be 11.9% for newborn, and 7.15% for 11 month old mice. Quantitative densitometry was also used to measure mouse brain supernatant actin content for these two stages. In vivo synthesis and degradation rates of tubulin α and β subunits of two day mouse brain 100,000g supernatant were studied after intracerebral injection of [ 3 H]leucine. Quantitative changes of the ratio of tritium specific activities of tubulin α and β subunits with time were determined. The pattern of change was biphasic. During the first phase the ratio decreased; during the second phase the ratio increased continuously. An interpretation consistent with all the data in this study is that the α subunit is synthesized at a more rapid rate than the β subunit

  17. Structural and Functional Consequences of Increased Tubulin Glycosylation in Diabetes Mellitus

    Science.gov (United States)

    Williams, Stuart K.; Howarth, Nancy L.; Devenny, James J.; Bitensky, Mark W.

    1982-11-01

    The extent of in vitro nonenzymatic glycosylation of purified rat brain tubulin was dependent on time and glucose concentration. Tubulin glycosylation profoundly inhibited GTP-dependent tubulin polymerization. Electron microscopy and NaDodSO4/polyacrylamide gel electrophoresis showed that glycosylated tubulin forms high molecular weight amorphous aggregates that are not disrupted by detergents or reducing agents. The amount of covalently bound NaB3H4-reducible sugars in tubulin recovered from brain of streptozotocin-induced diabetic rats was dramatically increased as compared with tubulin recovered from normal rat brain. Moreover, tubulin recovered from diabetic rat brain exhibited less GTP-induced polymerization than tubulin from nondiabetic controls. The possible implications of these data for diabetic neuropathy are discussed.

  18. Tubulin evolution in insects: gene duplication and subfunctionalization provide specialized isoforms in a functionally constrained gene family

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    Gadagkar Sudhindra R

    2010-04-01

    Full Text Available Abstract Background The completion of 19 insect genome sequencing projects spanning six insect orders provides the opportunity to investigate the evolution of important gene families, here tubulins. Tubulins are a family of eukaryotic structural genes that form microtubules, fundamental components of the cytoskeleton that mediate cell division, shape, motility, and intracellular trafficking. Previous in vivo studies in Drosophila find a stringent relationship between tubulin structure and function; small, biochemically similar changes in the major alpha 1 or testis-specific beta 2 tubulin protein render each unable to generate a motile spermtail axoneme. This has evolutionary implications, not a single non-synonymous substitution is found in beta 2 among 17 species of Drosophila and Hirtodrosophila flies spanning 60 Myr of evolution. This raises an important question, How do tubulins evolve while maintaining their function? To answer, we use molecular evolutionary analyses to characterize the evolution of insect tubulins. Results Sixty-six alpha tubulins and eighty-six beta tubulin gene copies were retrieved and subjected to molecular evolutionary analyses. Four ancient clades of alpha and beta tubulins are found in insects, a major isoform clade (alpha 1, beta 1 and three minor, tissue-specific clades (alpha 2-4, beta 2-4. Based on a Homarus americanus (lobster outgroup, these were generated through gene duplication events on major beta and alpha tubulin ancestors, followed by subfunctionalization in expression domain. Strong purifying selection acts on all tubulins, yet maximum pairwise amino acid distances between tubulin paralogs are large (0.464 substitutions/site beta tubulins, 0.707 alpha tubulins. Conversely orthologs, with the exception of reproductive tissue isoforms, show little sequence variation except in the last 15 carboxy terminus tail (CTT residues, which serve as sites for post-translational modifications (PTMs and interactions

  19. Nanoimages show disruption of tubulin polymerization by chlorpyrifos oxon: Implications for neurotoxicity

    International Nuclear Information System (INIS)

    Grigoryan, Hasmik; Lockridge, Oksana

    2009-01-01

    Organophosphorus agents cause cognitive deficits and depression in some people. We hypothesize that the mechanism by which organophosphorus agents cause these disorders is by modification of proteins in the brain. One such protein could be tubulin. Tubulin polymerizes to make the microtubules that transport cell components to nerve axons. The goal of the present work was to measure the effect of the organophosphorus agent chlorpyrifos oxon on tubulin polymerization. An additional goal was to identify the amino acids covalently modified by chlorpyrifos oxon in microtubule polymers and to compare them to the amino acids modified in unpolymerized tubulin dimers. Purified bovine tubulin (0.1 mM) was treated with 0.005-0.1 mM chlorpyrifos oxon for 30 min at room temperature and then polymerized by addition of 1 mM GTP to generate microtubules. Microtubules were visualized by atomic force microscopy. Chlorpyrifos oxon-modified residues were identified by tandem ion trap electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry of tryptic peptides. Nanoimaging showed that low concentrations (0.005 and 0.01 mM) of chlorpyrifos oxon yielded short, thin microtubules. A concentration of 0.025 mM stimulated polymerization, while high concentrations (0.05 and 0.1 mM) caused aggregation. Of the 17 tyrosines covalently modified by chlorpyrifos oxon in unpolymerized tubulin dimers, only 2 tyrosines were labeled in polymerized microtubules. The two labeled tyrosines in polymerized tubulin were Tyr 103 in EDAANNY*R of alpha tubulin, and Tyr 281 in GSQQY*R of beta tubulin. In conclusion, chlorpyrifos oxon binding to tubulin disrupts tubulin polymerization. These results may lead to an understanding of the neurotoxicity of organophosphorus agents.

  20. Distinct localization of a beta-tubulin epitope in the Tetrahymena thermophila and Paramecium caudatum cortex

    Czech Academy of Sciences Publication Activity Database

    Libusová, Lenka; Sulimenko, Tetyana; Sulimenko, Vadym; Janisch, R.; Hozák, Pavel; Dráber, Pavel

    2005-01-01

    Roč. 225, 3-4 (2005), s. 157-167 ISSN 0033-183X R&D Projects: GA MŠk(CZ) LN00A026; GA AV ČR(CZ) IBS5052301; GA ČR(CZ) GA304/04/1386; GA AV ČR(CZ) KSK5020115 Institutional research plan: CEZ:AV0Z50520514 Keywords : antibody * beta-tubulin * cortex Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.573, year: 2005

  1. Tubulin Beta-3 Chain as a New Candidate Protein Biomarker of Human Skin Aging: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Sylvia G. Lehmann

    2017-01-01

    Full Text Available Skin aging is a complex process, and a lot of efforts have been made to identify new and specific targets that could help to diagnose, prevent, and treat skin aging. Several studies concerning skin aging have analyzed the changes in gene expression, and very few investigations have been performed at the protein level. Moreover, none of these proteomic studies has used a global quantitative labeled proteomic offgel approach that allows a more accurate description of aging phenotype. We applied such an approach on human primary keratinocytes obtained from sun-nonexposed skin biopsies of young and elderly women. A total of 517 unique proteins were identified, and 58 proteins were significantly differentially expressed with 40 that were downregulated and 18 upregulated with aging. Gene ontology and pathway analysis performed on these 58 putative biomarkers of skin aging evidenced that these dysregulated proteins were mostly involved in metabolism and cellular processes such as cell cycle and signaling pathways. Change of expression of tubulin beta-3 chain was confirmed by western blot on samples originated from several donors. Thus, this study suggested the tubulin beta-3 chain has a promising biomarker in skin aging.

  2. Evolutionary relationships in Aspergillus section Fumigati inferred from partial beta-tubulin and hydrophobin sequences

    DEFF Research Database (Denmark)

    Geiser, D.M.; Frisvad, Jens Christian; Taylor, J.W.

    1998-01-01

    are heterothallic. Phylogenetic relationships were inferred among members of Aspergillus section Fumigati based on partial DNA sequences from the benA beta-tubulin and rodA hydrophobin genes. Aspergillus clavatus was chosen as an outgroup. The two gene regions provided nearly equal numbers of phylogenetically...... informative nucleotide characters. The rodA region possessed a considerably higher level of inferred amino acid variation than did the benA region. The results of a partition homogeneity test showed that the benA and rodA data sets were not in significant conflict, and the topologies of the most parsimonious...

  3. Inhibition of cytosolic Phospholipase A2 prevents prion peptide-induced neuronal damage and co-localisation with Beta III Tubulin

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    Last Victoria

    2012-08-01

    Full Text Available Abstract Background Activation of phospholipase A2 (PLA2 and the subsequent metabolism of arachidonic acid (AA to prostaglandins have been shown to play an important role in neuronal death in neurodegenerative disease. Here we report the effects of the prion peptide fragment HuPrP106-126 on the PLA2 cascade in primary cortical neurons and translocation of cPLA2 to neurites. Results Exposure of primary cortical neurons to HuPrP106-126 increased the levels of phosphorylated cPLA2 and caused phosphorylated cPLA2 to relocate from the cell body to the cellular neurite in a PrP-dependent manner, a previously unreported observation. HuPrP106-126 also induced significant AA release, an indicator of cPLA2 activation; this preceded synapse damage and subsequent cellular death. The novel translocation of p-cPLA2 postulated the potential for exposure to HuPrP106-126 to result in a re-arrangement of the cellular cytoskeleton. However p-cPLA2 did not colocalise significantly with F-actin, intermediate filaments, or microtubule-associated proteins. Conversely, p-cPLA2 did significantly colocalise with the cytoskeletal protein beta III tubulin. Pre-treatment with the PLA2 inhibitor, palmitoyl trifluoromethyl ketone (PACOCF3 reduced cPLA2 activation, AA release and damage to the neuronal synapse. Furthermore, PACOCF3 reduced expression of p-cPLA2 in neurites and inhibited colocalisation with beta III tubulin, resulting in protection against PrP-induced cell death. Conclusions Collectively, these findings suggest that cPLA2 plays a vital role in the action of HuPrP106-126 and that the colocalisation of p-cPLA2 with beta III tubulin could be central to the progress of neurodegeneration caused by prion peptides. Further work is needed to define exactly how PLA2 inhibitors protect neurons from peptide-induced toxicity and how this relates to intracellular structural changes occurring in neurodegeneration.

  4. Preventing an identity crisis: unexpected co-expression of class III beta-tubulin and glial fibrillary acidic protein in human fetal astrocytes in culture

    Czech Academy of Sciences Publication Activity Database

    Katsetos, C.D.; Dráberová, Eduarda; Del Valle, L.; Bertrand, L.; Agamanolis, D.P.; de Chadarévian, J.-P.; Legido, A.; Dráber, Pavel

    2007-01-01

    Roč. 26, č. 11 (2007), s. 107-107 ISSN 0364-5134 R&D Projects: GA MŠk LC545; GA ČR GA204/05/2375 Institutional research plan: CEZ:AV0Z50520514 Keywords : class III beta-tubulin * fetal glia Subject RIV: EB - Genetics ; Molecular Biology

  5. Class III beta-tubulin is constitutively coexpressed with glial fibrillary acidic protein and nestin in midgestational human fetal astrocytes: implications for phenotypic identity

    Czech Academy of Sciences Publication Activity Database

    Dráberová, Eduarda; Del Valle, L.; Gordon, J.; Marková, Vladimíra; Šmejkalová, Barbora; Bertrand, L.; de Chadarévian, J.-P.; Agamanolis, D.P.; Legido, A.; Khalili, K.; Dráber, Pavel; Katsetos, C.D.

    2008-01-01

    Roč. 67, č. 4 (2008), s. 341-354 ISSN 0022-3069 R&D Projects: GA MŠk LC545; GA ČR GA204/05/2375 Institutional research plan: CEZ:AV0Z50520514 Keywords : astrocytes * class III beta-tubulin * fetal glia Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.140, year: 2008

  6. Activity of benzimidazoles against Dientamoeba fragilis (Trichomonadida, Monocercomonadidae) in vitro and correlation of beta-tubulin sequences as an indicator of resistance.

    Science.gov (United States)

    Stark, Damien; Barratt, Joel L N; Roberts, Tamalee; Marriott, Deborah; Harkness, John T; Ellis, John

    2014-01-01

    Recently, Dientamoeba fragilis has emerged as a significant and common enteropathogen. The majority of patients with dientamoebiasis present with gastrointestinal complaints and chronic symptoms are common. Numerous studies have successfully demonstrated parasite clearance, coupled with complete resolution of clinical symptoms following treatment with various antiparasitic compounds. Despite this, there is very little in vitro susceptibility data available for the organism. Benzimidazoles are a class of antiparasitic drugs that are commonly used for the treatment of protozoan and helminthic infections. Susceptibility testing was undertaken on four D. fragilis clinical isolates against the following benzimidazoles: albendazole, flubendazole, mebendazole, nocodazole, triclabendazole and thiabendazole. The activities of the antiprotozoal compounds at concentrations ranging from 2 μg/mL to 500 μg/mL were determined via cell counts of D. fragilis grown in xenic culture. All tested drugs showed no efficacy. The beta-tubulin transcript was sequenced from two of the D. fragilis isolates and amino acid sequences predicted a susceptibility to benzimidazoles. This is the first study to report susceptibility profiles for benzimidazoles against D. fragilis, all of which were not active against the organism. This study also found that beta-tubulin sequences cannot be used as a reliable marker for resistance of benzimidazoles in D. fragilis. D. Stark et al., published by EDP Sciences, 2014

  7. Activity of benzimidazoles against Dientamoeba fragilis (Trichomonadida, Monocercomonadidae in vitro and correlation of beta-tubulin sequences as an indicator of resistance

    Directory of Open Access Journals (Sweden)

    Stark Damien

    2014-01-01

    Full Text Available Recently, Dientamoeba fragilis has emerged as a significant and common enteropathogen. The majority of patients with dientamoebiasis present with gastrointestinal complaints and chronic symptoms are common. Numerous studies have successfully demonstrated parasite clearance, coupled with complete resolution of clinical symptoms following treatment with various antiparasitic compounds. Despite this, there is very little in vitro susceptibility data available for the organism. Benzimidazoles are a class of antiparasitic drugs that are commonly used for the treatment of protozoan and helminthic infections. Susceptibility testing was undertaken on four D. fragilis clinical isolates against the following benzimidazoles: albendazole, flubendazole, mebendazole, nocodazole, triclabendazole and thiabendazole. The activities of the antiprotozoal compounds at concentrations ranging from 2 μg/mL to 500 μg/mL were determined via cell counts of D. fragilis grown in xenic culture. All tested drugs showed no efficacy. The beta-tubulin transcript was sequenced from two of the D. fragilis isolates and amino acid sequences predicted a susceptibility to benzimidazoles. This is the first study to report susceptibility profiles for benzimidazoles against D. fragilis, all of which were not active against the organism. This study also found that beta-tubulin sequences cannot be used as a reliable marker for resistance of benzimidazoles in D. fragilis.

  8. Analysis of the Beta-Tubulin Gene and morphological changes of the Microsporidium Anncaliia algerae both Suggest Albendazole Sensitivity*

    Science.gov (United States)

    Santiana, Marianita; Pau, Cyrilla; Takvorian, Peter M.; Cali, Ann

    2014-01-01

    The Microsporidium, Anncaliia algerae, an obligate intracellular parasite, has been identified as an opportunistic human pathogen but treatment has not been evaluated for infections with this organism. Albendazole, an anti-tubulin polymerization drug used against parasitic worm infections, has been the medication of choice used to treat some microsporidial infections affecting humans, with varying results ranging from clearing infection (Encephalitozoon) to resistance (Enterocytozoon). This study illustrates the effect of albendazole treatment on A. algerae infection in Rabbit Kidney (RK13) cells and Human Fetal Lung (HFL-1) fibroblasts. Albendazole appears to have an attenuating effect on A. algerae infection and albendazole’s IC50 in RK13 cells is 0.1μg/ml. Long-term treatment inhibits up to 98% of spore production, but interrupting treatment re-establishes the infection without new exposure to the parasite as supported by microscopic observations. The parasite’s Beta-Tubulin gene was purified, cloned, and sequenced. Five of the six specific amino acids, associated with benzimidazole sensitivity, are conserved in A. algerae. These findings suggest that A. algerae is sensitive to albendazole; however, the organism is not completely cleared from cultures. PMID:25105446

  9. Synthesis of [sup 14]C labelled electrophilic ligands of the colchicine binding site of tubulin: chloroacetates of demethylthiocolchicines and of N-acetylcolchinol; isothiocyanate of 9-deoxy-N-acetylcolchinol

    Energy Technology Data Exchange (ETDEWEB)

    Boye, O.; Brossi, A. (NIDDK (United States). Lab. of Structural Biology); Getahun, Z.; Grover, S.; Hamel, E. (National Inst. of Health, Bethesda, MD (United States))

    1993-01-01

    [sup 14]C-Chloroacetates of 2-demethylthiocolchicine 7 and of 3-demethylthiocolchicine 8 were synthesized and found to covalently bind with high specificity to the [beta]-subunit of tubulin. The [sup 14]C-chloroacetate of N-acetylcolchinol and the [sup 14]C-isothiocyanate were also prepared and found to react covalently with tubulin but in a nonspecific manner. With the radiolabelled chloroacetates 7 and 8 two compounds are now available to further characterize the colchicine binding site on the [beta] subunit of tubulin. (author).

  10. Effects Of Amitryptilin Administration on Rat Sera and Brain Beta-endorphins

    Directory of Open Access Journals (Sweden)

    Radivoj Jadrić

    2006-11-01

    Full Text Available The aim of our study was to establish the influence of antidepressive drugs on serum and brain beta-endorphins in experimental animals. Experiment was performed on albino Wistar rats. Antidepressant amitryptiline was used, and for quantification of sera and brain beta-endorphins RIA technique. Our results showed difference between sera and brain beta-endorphins concentration in amitryptiline pretreated animals, vs. those in serum and brain of control group treated with 0.95% NaCl. This study shows that use of psychoactive drugs have influence on sera and brain beta-endorphins concentration. Beta-endorphins could be of great importance, used as markers for evaluation of antidepressant drug effects.

  11. PCR based diagnostic assay targeting the beta tubulin gene for the detection of Trichomonas vaginalis infection in vaginal swab samples of symptomatic and asymptomatic women in India

    Directory of Open Access Journals (Sweden)

    Surya Prakash Dwivedi

    2012-10-01

    Full Text Available Objective: To develop an in-house PCR based diagnostic assay for identification of strains isolated from symptomatic and asymptomatic subjects of India, targeting the 毬 -tubulin gene using specific primers. Methods: In the present study a primer set is designed to target a well-conserved region in the beta-tubulin gene of Trichomonas vaginalis (T. vaginalis. All strains of T. vaginalis were tested and successfully detected by PCR yielding a single predicted product of 198 bp in gel electrophoresis, while there was negative response with DNA from Giardia lamblia, Toxoplasma gondii, Leishmania donovani and Entamoeba histolytica. The sensitivity and specificity for a single T. vaginalis cell per PCR was achieved. Axenic Culture, performed with long term axenized T. vaginalis culture system, was routinely examined to identify T. vaginalis. Results: The PCR based investigations with 498 vaginal swab samples from women attending OPD clinics of Halberg Hospital Moradabad and Queen Mary ’s Hospital, Lucknow, India and 17 long term axenic cultures maintained at PGIMER, Chandigarh, India using primer set BTUB 1 & BTUB 2 showed sensitivity and specificity response of 98% and 100%, respectively, while wet preparation in clinically isolated samples responded up to 62.5%. The PCR product sequencing result of symptomatic strains (SS1 of T. vaginalis (744 bp long was submitted to NCBI (Accession No: JF513200. It shows maximum identity 98 % with XM_001284521 Trichomonas vaginalis G-3 beta-tubulin (btub putative partial mRNA. Conclusions: The data gathered in the present study entail that the diagnosis of T. vaginalis infection by PCR may be established as a sensitive and specific protocol, to be incorporated into a joint strategy for the screening of multiple STDs by employing molecular amplification technique. The merits and precautions of the protocol have been discussed.

  12. Evolutionary characterization and transcript profiling of β-tubulin genes in flax (Linum usitatissimum L.) during plant development.

    Science.gov (United States)

    Gavazzi, Floriana; Pigna, Gaia; Braglia, Luca; Gianì, Silvia; Breviario, Diego; Morello, Laura

    2017-12-08

    Microtubules, polymerized from alpha and beta-tubulin monomers, play a fundamental role in plant morphogenesis, determining the cell division plane, the direction of cell expansion and the deposition of cell wall material. During polarized pollen tube elongation, microtubules serve as tracks for vesicular transport and deposition of proteins/lipids at the tip membrane. Such functions are controlled by cortical microtubule arrays. Aim of this study was to first characterize the flax β-tubulin family by sequence and phylogenetic analysis and to investigate differential expression of β-tubulin genes possibly related to fibre elongation and to flower development. We report the cloning and characterization of the complete flax β-tubulin gene family: exon-intron organization, duplicated gene comparison, phylogenetic analysis and expression pattern during stem and hypocotyl elongation and during flower development. Sequence analysis of the fourteen expressed β-tubulin genes revealed that the recent whole genome duplication of the flax genome was followed by massive retention of duplicated tubulin genes. Expression analysis showed that β-tubulin mRNA profiles gradually changed along with phloem fibre development in both the stem and hypocotyl. In flowers, changes in relative tubulin transcript levels took place at anthesis in anthers, but not in carpels. Phylogenetic analysis supports the origin of extant plant β-tubulin genes from four ancestral genes pre-dating angiosperm separation. Expression analysis suggests that particular tubulin subpopulations are more suitable to sustain different microtubule functions such as cell elongation, cell wall thickening or pollen tube growth. Tubulin genes possibly related to different microtubule functions were identified as candidate for more detailed studies.

  13. Ionizing radiation alters beta-endorphin-like immunoreactivity in brain but not blood

    International Nuclear Information System (INIS)

    Mickley, G.A.; Stevens, K.E.; Moore, G.H.; Deere, W.; White, G.A.; Gibbs, G.L.; Mueller, G.P.

    1983-01-01

    Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of beta-END-LI in the brain than in the periphery. Other endogenous opiate systems may also contribute to this behavioral change in the C57BL/6J mouse

  14. Ionizing radiation alters beta-endorphin-like immunoreactivity in brain but not blood

    Energy Technology Data Exchange (ETDEWEB)

    Mickley, G.A.; Stevens, K.E.; Moore, G.H.; Deere, W.; White, G.A.; Gibbs, G.L.; Mueller, G.P.

    1983-12-01

    Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of beta-END-LI in the brain than in the periphery. Other endogenous opiate systems may also contribute to this behavioral change in the C57BL/6J mouse.

  15. Rationalization of paclitaxel insensitivity of yeast β-tubulin and human βIII-tubulin isotype using principal component analysis

    Directory of Open Access Journals (Sweden)

    Das Lalita

    2012-08-01

    Full Text Available Abstract Background The chemotherapeutic agent paclitaxel arrests cell division by binding to the hetero-dimeric protein tubulin. Subtle differences in tubulin sequences, across eukaryotes and among β-tubulin isotypes, can have profound impact on paclitaxel-tubulin binding. To capture the experimentally observed paclitaxel-resistance of human βIII tubulin isotype and yeast β-tubulin, within a common theoretical framework, we have performed structural principal component analyses of β-tubulin sequences across eukaryotes. Results The paclitaxel-resistance of human βIII tubulin isotype and yeast β-tubulin uniquely mapped on to the lowest two principal components, defining the paclitaxel-binding site residues of β-tubulin. The molecular mechanisms behind paclitaxel-resistance, mediated through key residues, were identified from structural consequences of characteristic mutations that confer paclitaxel-resistance. Specifically, Ala277 in βIII isotype was shown to be crucial for paclitaxel-resistance. Conclusions The present analysis captures the origin of two apparently unrelated events, paclitaxel-insensitivity of yeast tubulin and human βIII tubulin isotype, through two common collective sequence vectors.

  16. A tubulin alpha 8 mouse knockout model indicates a likely role in spermatogenesis but not in brain development.

    Directory of Open Access Journals (Sweden)

    Christine P Diggle

    Full Text Available Tubulin alpha 8 (Tuba8 is the most divergent member of the highly conserved alpha tubulin family, and uniquely lacks two key post-translational modification sites. It is abundantly expressed in testis and muscle, with lower levels in the brain. We previously identified homozygous hypomorphic TUBA8 mutations in human subjects with a polymicrogyria (PMG syndrome, suggesting its involvement in development of the cerebral cortex. We have now generated and characterized a Tuba8 knockout mouse model. Homozygous mice were confirmed to lack Tuba8 protein in the testis, but did not display PMG and appeared to be neurologically normal. In response to this finding, we re-analyzed the human PMG subjects using whole exome sequencing. This resulted in identification of an additional homozygous loss-of-function mutation in SNAP29, suggesting that SNAP29 deficiency, rather than TUBA8 deficiency, may underlie most or all of the neurodevelopmental anomalies in these subjects. Nonetheless, in the mouse brain, Tuba8 specifically localised to the cerebellar Purkinje cells, suggesting that the human mutations may affect or modify motor control. In the testis, Tuba8 localisation was cell-type specific. It was restricted to spermiogenesis with a strong acrosomal localization that was gradually replaced by cytoplasmic distribution and was absent from spermatozoa. Although the knockout mice were fertile, the localisation pattern indicated that Tuba8 may have a role in spermatid development during spermatogenesis, rather than as a component of the mature microtubule-rich flagellum itself.

  17. Affinity Purification and Characterization of Functional Tubulin from Cell Suspension Cultures of Arabidopsis and Tobacco1

    Science.gov (United States)

    Fujita, Satoshi; Uchimura, Seiichi; Noguchi, Masahiro; Demura, Taku

    2016-01-01

    Microtubules assemble into several distinct arrays that play important roles in cell division and cell morphogenesis. To decipher the mechanisms that regulate the dynamics and organization of this versatile cytoskeletal component, it is essential to establish in vitro assays that use functional tubulin. Although plant tubulin has been purified previously from protoplasts by reversible taxol-induced polymerization, a simple and efficient purification method has yet to be developed. Here, we used a Tumor Overexpressed Gene (TOG) column, in which the tubulin-binding domains of a yeast (Saccharomyces cerevisiae) TOG homolog are immobilized on resin, to isolate functional plant tubulin. We found that several hundred micrograms of pure tubulin can readily be purified from cell suspension cultures of tobacco (Nicotiana tabacum) and Arabidopsis (Arabidopsis thaliana). The tubulin purified by the TOG column showed high assembly competence, partly because of low levels of polymerization-inhibitory phosphorylation of α-tubulin. Compared with porcine brain tubulin, Arabidopsis tubulin is highly dynamic in vitro at both the plus and minus ends, exhibiting faster shrinkage rates and more frequent catastrophe events, and exhibits frequent spontaneous nucleation. Furthermore, our study shows that an internal histidine tag in α-tubulin can be used to prepare particular isotypes and specifically engineered versions of α-tubulin. In contrast to previous studies of plant tubulin, our mass spectrometry and immunoblot analyses failed to detect posttranslational modification of the isolated Arabidopsis tubulin or detected only low levels of posttranslational modification. This novel technology can be used to prepare assembly-competent, highly dynamic pure tubulin from plant cell cultures. PMID:26747285

  18. Archaeal origin of tubulin

    Directory of Open Access Journals (Sweden)

    Yutin Natalya

    2012-03-01

    Full Text Available Abstract Tubulins are a family of GTPases that are key components of the cytoskeleton in all eukaryotes and are distantly related to the FtsZ GTPase that is involved in cell division in most bacteria and many archaea. Among prokaryotes, bona fide tubulins have been identified only in bacteria of the genus Prosthecobacter. These bacterial tubulin genes appear to have been horizontally transferred from eukaryotes. Here we describe tubulins encoded in the genomes of thaumarchaeota of the genus Nitrosoarchaeum that we denote artubulins Phylogenetic analysis results are compatible with the origin of eukaryotic tubulins from artubulins. These findings expand the emerging picture of the origin of key components of eukaryotic functional systems from ancestral forms that are scattered among the extant archaea. Reviewers This article was reviewed by Gáspár Jékely and J. Peter Gogarten.

  19. Effect of radio frequency waves of electromagnetic field on the tubulin.

    Science.gov (United States)

    Taghi, Mousavi; Gholamhosein, Riazi; Saeed, Rezayi-Zarchi

    2013-09-01

    Microtubules (MTs) are macromolecular structures consisting of tubulin heterodimers and present in almost every eukaryotic cell. MTs fulfill all conditions for generation of electromagnetic field and are electrically polar due to the electrical polarity of a tubulin heterodimer. The calculated static electric dipole moment of about 1000 Debye makes them capable of being aligned parallel to the applied electromagnetic field direction. In the present study, the tubulin heterodimers were extracted and purified from the rat brains. MTs were obtained by polymerization in vitro. Samples of microtubules were adsorbed in the absence and in the presence of electromagnetic fields with radio frequency of 900 Hz. Our results demonstrate the effect of electromagnetic field with 900 Hz frequency to change the structure of MTs. In this paper, a related patent was used that will help to better understand the studied subject.

  20. The NMDAR subunit NR3A interacts with microtubule-associated protein 1S in the brain

    DEFF Research Database (Denmark)

    Eriksson, Maria; Samuelsson, Helena; Samuelsson, Eva-Britt

    2007-01-01

    -proximal part of the NR3A C-terminus. MAP1S belongs to the same family as MAP1A and MAP1B, and was found to be abundant in both postnatal and adult rat brain. In hippocampal neurons the distribution-pattern of MAP1S resembled that of beta-tubulin III, but a fraction of the protein colocalized with synaptic...

  1. Double mutation in eleusine indica alpha-tubulin increases the resistance of transgenic maize calli to dinitroaniline and phosphorothioamidate herbicides

    Science.gov (United States)

    Anthony; Hussey

    1999-06-01

    The repeated use of dinitroaniline herbicides on the cotton and soybean fields of the southern United States has resulted in the appearance of resistant biotypes of one of the world's worst weeds, Eleusine indica. Two biotypes have been characterized, a highly resistant (R) biotype and an intermediate resistant (I) biotype. In both cases the resistance has been attributed to a mutation in alpha-tubulin, a component of the alpha/beta tubulin dimer that is the major constituent of microtubules. We show here that the I-biotype mutation, like the R-biotype mutation shown in earlier work, can confer dinitroaniline resistance on transgenic maize calli. The level of resistance obtained is the same as that for E. indica I- or R-biotype seedlings. The combined I- and R-biotype mutations increase the herbicide tolerance of transgenic maize calli by a value close to the summation of the maximum herbicide tolerances of calli harbouring the single mutations. These data, taken together with the position of the two different mutations within the atomic structure of the alpha/beta tubulin dimer, imply that each mutation is likely to exert its effect by a different mechanism. These mechanisms may involve increasing the stability of microtubules against the depolymerizing effects of the herbicide or changing the conformation of the alpha/beta dimer so that herbicide binding is less effective, or a combination of both possibilities.

  2. Could the beta rebound in the EEG be suitable to realize a "brain switch"?

    Science.gov (United States)

    Pfurtscheller, G; Solis-Escalante, T

    2009-01-01

    Performing foot motor imagery is accompanied by a peri-imagery ERD and a post-imagery beta ERS (beta rebound). Our aim was to study whether the post-imagery beta rebound is a suitable feature for a simple "brain switch". Such a brain switch is a specifically designed brain-computer interface (BCI) with the aim to detect only one predefined brain state (e.g. EEG pattern) in ongoing brain activity. One EEG (Laplacian) recorded at the vertex during cue-based brisk foot motor imagery was analysed in 5 healthy subjects. The peri-imagery ERD and the post-imagery beta rebound (ERS) were analysed in detail between 6 and 40Hz and classified with two support vector machines. The ERD was detected in ongoing EEG (simulation of asynchronous BCI) with a true positive rate (TPR) of 28.4%+/-13.5 and the beta rebound with a TPR of 59.2%+/-20.3. In single runs with 30 cues each, the TPR for beta rebound detection was 78.6%+/-12.8. The false positive rate was always kept below 10%. The findings suggest that the beta rebound at Cz during foot motor imagery is a relatively stable and reproducible phenomenon detectable in single EEG trials. Our results indicate that the beta rebound is a suitable feature to realize a "brain switch" with one single EEG (Laplacian) channel only.

  3. GDP-tubulin incorporation into growing microtubules modulates polymer stability.

    Science.gov (United States)

    Valiron, Odile; Arnal, Isabelle; Caudron, Nicolas; Job, Didier

    2010-06-04

    Microtubule growth proceeds through the endwise addition of nucleotide-bound tubulin dimers. The microtubule wall is composed of GDP-tubulin subunits, which are thought to come exclusively from the incorporation of GTP-tubulin complexes at microtubule ends followed by GTP hydrolysis within the polymer. The possibility of a direct GDP-tubulin incorporation into growing polymers is regarded as hardly compatible with recent structural data. Here, we have examined GTP-tubulin and GDP-tubulin incorporation into polymerizing microtubules using a minimal assembly system comprised of nucleotide-bound tubulin dimers, in the absence of free nucleotide. We find that GDP-tubulin complexes can efficiently co-polymerize with GTP-tubulin complexes during microtubule assembly. GDP-tubulin incorporation into microtubules occurs with similar efficiency during bulk microtubule assembly as during microtubule growth from seeds or centrosomes. Microtubules formed from GTP-tubulin/GDP-tubulin mixtures display altered microtubule dynamics, in particular a decreased shrinkage rate, apparently due to intrinsic modifications of the polymer disassembly properties. Thus, although microtubules polymerized from GTP-tubulin/GDP-tubulin mixtures or from homogeneous GTP-tubulin solutions are both composed of GDP-tubulin subunits, they have different dynamic properties, and this may reveal a novel form of microtubule "structural plasticity."

  4. Qualitative determination of tubulin by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Joniau, M [Louvain Univ. (Belgium). Interdisciplinary Research Centre; Brabander, M de [Janssen Pharmaceutica, Beerse (Belgium). Lab. of Oncology; Mey, J de [Brussels Univ. (Belgium). Medische Stichting Koningin Elisabeth; Hoebeke, J [Brussels Univ. (Belgium). Lab. of Biochemical Pathology

    1977-06-15

    The use of an antiserum specific for tubulin in cytochemical studies was described previously. Here a report is presented on its application in a radioimmunoassay for tubulin useful in the concentration range of 0.5 to 20 ..mu..g tubulin/ml. The advantages of this technique over the classical colchicine binding assay are discussed in terms of sensitivity and nonsusceptibility to the degree of polymerization and thermal denaturation of tubulin allowing its application to cell culture homogenates.

  5. Antileishmanial activity and tubulin polymerization inhibition of podophyllotoxin derivatives on Leishmania infantum

    Directory of Open Access Journals (Sweden)

    José Miguel Escudero-Martínez

    2017-12-01

    Full Text Available Leishmania microtubules play an important role not only in cell division, but also in keeping the shape of the parasite and motility of its free-living stages. Microtubules result from the self-assembly of alpha and beta tubulins, two phylogenetically conserved and very abundant eukaryotic proteins in kinetoplastids. The colchicine binding domain has inspired the discovery and development of several drugs currently in clinical use against parasites. However, this domain is less conserved in kinetoplastids and may be selectively targeted by new compounds. This report shows the antileishmanial effect of several series of compounds (53, derived from podophyllotoxin (a natural cyclolignan isolated from rhizomes of Podophyllum spp. and podophyllic aldehyde, on a transgenic, fluorescence-emitting strain of Leishmania infantum. These compounds were tested on both promastigotes and amastigote-infected mouse splenocytes, and in mammalian – mouse non-infected splenocytes and liver HepG2 cells – in order to determine selective indexes of the drugs. Results obtained with podophyllotoxin derivatives showed that the hydroxyl group at position C-7α was a structural requisite to kill the parasites. On regards podophyllic aldehyde, derivatives with C9-aldehyde group integrated into a bicyclic heterostructure displayed more potent antileishmanial effects and were relatively safe for host cells. Docking studies of podophyllotoxin and podophyllic aldehyde derivatives showed that these compounds share a similar pattern of interaction at the colchicine site of Leishmania tubulin, thus pointing to a common mechanism of action. However, the results obtained suggested that despite tubulin is a remarkable target against leishmaniasis, there is a poor correlation between inhibition of tubulin polymerization and antileishmanial effect of many of the compounds tested, fact that points to alternative pathways to kill the parasites. Keywords: Leishmania, Tubulin, DNA

  6. [{sup 125}I]{beta}-CIT-FE and [{sup 125}I]{beta}-CIT-FP are superior to [{sup 125}I]{beta}-CIT for dopamine transporter visualization: Autoradiographic evaluation in the human brain

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Ilonka; Hall, Haakan; Halldin, Christer; Swahn, Carl-Gunnar; Farde, Lars; Sedvall, Goeran

    1997-10-01

    The binding of the three dopamine transporter radioligands ([{sup 125}I]{beta}-CIT, [{sup 125}I]{beta}-CIT-FE, and [{sup 125}I]{beta}-CIT-FP) was studied using whole-hemisphere autoradiography on postmortem human brains. The autoradiograms revealed an intense and homogeneous labeling of the nucleus caudatus and putamen but also to varying extent to serotonergic and noradrenergic transporters of neocortex and thalamus. The order of specificity estimated (striatum over neocortex ratios) was {beta}-CIT-FP > {beta}-CIT-FE >> {beta}-CIT, suggesting that {beta}-CIT-FE and {beta}-CIT-FP should be preferred for in vivo studies of the dopamine transporter in the human brain.

  7. The modulatory effect of adaptive deep brain stimulation on beta bursts in Parkinson's disease.

    Science.gov (United States)

    Tinkhauser, Gerd; Pogosyan, Alek; Little, Simon; Beudel, Martijn; Herz, Damian M; Tan, Huiling; Brown, Peter

    2017-04-01

    Adaptive deep brain stimulation uses feedback about the state of neural circuits to control stimulation rather than delivering fixed stimulation all the time, as currently performed. In patients with Parkinson's disease, elevations in beta activity (13-35 Hz) in the subthalamic nucleus have been demonstrated to correlate with clinical impairment and have provided the basis for feedback control in trials of adaptive deep brain stimulation. These pilot studies have suggested that adaptive deep brain stimulation may potentially be more effective, efficient and selective than conventional deep brain stimulation, implying mechanistic differences between the two approaches. Here we test the hypothesis that such differences arise through differential effects on the temporal dynamics of beta activity. The latter is not constantly increased in Parkinson's disease, but comes in bursts of different durations and amplitudes. We demonstrate that the amplitude of beta activity in the subthalamic nucleus increases in proportion to burst duration, consistent with progressively increasing synchronization. Effective adaptive deep brain stimulation truncated long beta bursts shifting the distribution of burst duration away from long duration with large amplitude towards short duration, lower amplitude bursts. Critically, bursts with shorter duration are negatively and bursts with longer duration positively correlated with the motor impairment off stimulation. Conventional deep brain stimulation did not change the distribution of burst durations. Although both adaptive and conventional deep brain stimulation suppressed mean beta activity amplitude compared to the unstimulated state, this was achieved by a selective effect on burst duration during adaptive deep brain stimulation, whereas conventional deep brain stimulation globally suppressed beta activity. We posit that the relatively selective effect of adaptive deep brain stimulation provides a rationale for why this approach could

  8. [H-3]dihydroalprenolol binding to beta adrenergic receptors in multiple sclerosis brain

    NARCIS (Netherlands)

    Zeinstra, E; Wilczak, N; De Keyser, J

    2000-01-01

    By using immunocytochemistry we previously reported the absence of beta(2) adrenergic receptors on astrocytes in multiple sclerosis (MS) white matter. Here, we measured beta(1) and beta(2) adrenergic receptor concentrations in postmortem brain sections of six MS patients and six controls by using

  9. Tubulin polymerization-stimulating activity of Ganoderma triterpenoids.

    Science.gov (United States)

    Kohno, Toshitaka; Hai-Bang, Tran; Zhu, Qinchang; Amen, Yhiya; Sakamoto, Seiichi; Tanaka, Hiroyuki; Morimoto, Satoshi; Shimizu, Kuniyoshi

    2017-04-01

    Tubulin polymerization is an important target for anticancer therapies. Even though the potential of Ganoderma triterpenoids against various cancer targets had been well documented, studies on their tubulin polymerization-stimulating activity are scarce. This study was conducted to evaluate the effect of Ganoderma triterpenoids on tubulin polymerization. A total of twenty-four compounds were investigated using an in vitro tubulin polymerization assay. Results showed that most of the studied triterpenoids exhibited microtuble-stabilizing activity to different degrees. Among the investigated compounds, ganoderic acid T-Q, ganoderiol F, ganoderic acid S, ganodermanontriol and ganoderic acid TR were found to have the highest activities. A structure-activity relationship (SAR) analysis was performed. Extensive investigation of the SAR suggests the favorable structural features for the tubulin polymerization-stimulating activity of lanostane triterpenes. These findings would be helpful for further studies on the potential mechanisms of the anticancer activity of Ganoderma triterpenoids and give some indications on the design of tubulin-targeting anticancer agents.

  10. Molecular insight into γ-γ tubulin lateral interactions within the γ-tubulin ring complex (γ-TuRC)

    Science.gov (United States)

    Suri, Charu; Hendrickson, Triscia W.; Joshi, Harish C.; Naik, Pradeep Kumar

    2014-09-01

    γ-tubulin is essential for the nucleation and organization of mitotic microtubules in dividing cells. It is localized at the microtubule organizing centers and mitotic spindle fibres. The most well accepted hypothesis for the initiation of microtubule polymerization is that α/β-tubulin dimers add onto a γ-tubulin ring complex (γTuRC), in which adjacent γ-tubulin subunits bind to the underlying non-tubulin components of the γTuRC. This template thus determines the resulting microtubule lattice. In this study we use molecular modelling and molecular dynamics simulations, combined with computational MM-PBSA/MM-GBSA methods, to determine the extent of the lateral atomic interaction between two adjacent γ-tubulins within the γTuRC. To do this we simulated a γ-γ homodimer for 10 ns and calculated the ensemble average of binding free energies of -107.76 kcal/mol by the MM-PBSA method and of -87.12 kcal/mol by the MM-GBSA method. These highly favourable binding free energy values imply robust lateral interactions between adjacent γ-tubulin subunits in addition to their end-interactions longitudinally with other proteins of γTuRC. Although the functional reconstitution of γ-TuRC subunits and their stepwise in vitro assembly from purified components is not yet feasible, we nevertheless wanted to recognize hotspot amino acids responsible for key γ-γ interactions. Our free energy decomposition data from converting a compendium of amino acid residues identified an array of hotspot amino acids. A subset of such mutants can be expressed in vivo in living yeast. Because γTuRC is important for the growth of yeast, we could test whether this subset of the hotspot mutations support growth of yeast. Consistent with our model, γ-tubulin mutants that fall into our identified hotspot do not support yeast growth.

  11. The 'tubulin-like' S1 protein of Spirochaeta is a member of the hsp65 stress protein family

    Science.gov (United States)

    Munson, D.; Obar, R.; Tzertzinis, G.; Margulis, L.

    1993-01-01

    A 65-kDa protein (called S1) from Spirochaeta bajacaliforniensis was identified as 'tubulin-like' because it cross-reacted with at least four different antisera raised against tubulin and was isolated, with a co-polymerizing 45-kDa protein, by warm-cold cycling procedures used to purify tubulin from mammalian brain. Furthermore, at least three genera of non-cultivable symbiotic spirochetes (Pillotina, Diplocalyx, and Hollandina) that contain conspicuous 24-nm cytoplasmic tubules displayed a strong fluorescence in situ when treated with polyclonal antisera raised against tubulin. Here we summarize results that lead to the conclusion that this 65-kDa protein has no homology to tubulin. S1 is an hsp65 stress protein homologue. Hsp65 is a highly immunogenic family of hsp60 proteins which includes the 65-kDa antigens of Mycobacterium tuberculosis (an active component of Freund's complete adjuvant), Borrelia, Treponema, Chlamydia, Legionella, and Salmonella. The hsp60s, also known as chaperonins, include E. coli GroEL, mitochondrial and chloroplast chaperonins, the pea aphid 'symbionin' and many other proteins involved in protein folding and the stress response.

  12. Induced tubulin synthesis is caused by induced gene transcription in Tetrahymena

    International Nuclear Information System (INIS)

    Seyfert, H.M.; Kohle, D.; Jenovai, S.

    1987-01-01

    Tubulin synthesis and tubulin mRNA concentrations increase to variable extents during ciliary regeneration in the ciliate Tetrahymena. Experiments described here were carried out to determine whether the increased tubulin mRNa concentrations are due to induced transcription of tubulin genes or to stabilization of tubulin mRNA. In vivo labeling experiments with [ 3 H]uridine and in vitro transcription assays suggest that under conditions of increased protein and tubulin synthesis the rate of transcription is enhanced. Hybridization assays of in vitro transcribed RNA also demonstrate qualitatively that the tubulin genes are transcribed at higher rates when tubulin synthesis is stimulated during ciliary regeneration. This observation is supported by measurements of the half-life of tubulin mRNA molecules in nondeciliated cells: This is approximately 2 h. Since the concentration of tubulin mRNA in cells engaged in cilia regeneration increases from 5 to 19-fold during the first hour of the regeneration period, even a complete stabilization of the tubulin mRNA molecules could not account for an increase in tubulin mRNA concentration of this magnitude

  13. {beta}-adrenergic receptor density and adenylate cyclase activity in lead-exposed rat brain after cessation of lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Huoy-Rou [I-Shou University, Department of Biomedical Engineering, Dashu Shiang, Kaohsiung County (Taiwan); Tsao, Der-An [Fooyin University of Technology, Department of Medical Technology (Taiwan); Yu, Hsin-Su [Taiwan University, Department of Dermatology, College of Medicine (Taiwan); Ho, Chi-Kung [Kaohsiung Medical University, Occupational Medicine (Taiwan); Kaohsiung Medical University, Graduate Institute of Medicine, Research Center for Occupational Disease (Taiwan)

    2005-01-01

    To understanding the reversible or irreversible harm to the {beta}-adrenergic system in the brain of lead-exposed rats, this study sets up an animal model to estimate the change in the sympathetic nervous system of brain after lead exposure was withdrawn. We address the following topics in this study: (a) the relationship between withdrawal time of lead exposure and brain {beta}-adrenergic receptor, blood lead level, and brain lead level in lead-exposed rats after lead exposure was stopped; and (b) the relationship between lead level and {beta}-adrenergic receptor and cyclic AMP (c-AMP) in brain. Wistar rats were chronically fed with 2% lead acetate and water for 2 months. Radioligand binding was assayed by a method that fulfilled strict criteria of {beta}-adrenergic receptor using the ligand [{sup 125}I]iodocyanopindolol. The levels of lead were determined by electrothermal atomic absorption spectrometry. The c-AMP level was determined by radioimmunoassay. The results showed a close relationship between decreasing lead levels and increasing numbers of brain {beta}-adrenergic receptors and brain adenylate cyclase activity after lead exposure was withdrawn. The effect of lead exposure on the {beta}-adrenergic system of the brain is a partly reversible condition. (orig.)

  14. Comparison of iodine-123 labelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane and 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)-N-(3-fluoropropyl)nortropane for imaging of the dopamine transporter in the living human brain

    Energy Technology Data Exchange (ETDEWEB)

    Kuikka, J.T. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Bergstroem, K.A. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Ahonen, A. [Dept. of Clinical Chemistry, Oulu Univ. Central Hospital (Finland); Hiltunen, J. [MAP Medical Technologies Oy, Tikkakoski (Finland); Haukka, J. [MAP Medical Technologies Oy, Tikkakoski (Finland); Laensimies, E. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Wang Shaoyin [Research Biochemicals International (RBI), Natick, MA (United States); Neumeyer, J.L. [Research Biochemicals International (RBI), Natick, MA (United States)

    1995-04-01

    Several cocaine congeners are of potential for imaging the dopamine transporter (DAT). Previous studies have shown that iodine-123 labelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ([{sup 123}I]{beta}-CIT) is a promising radiotracer for imaging the serotonin (5-HT) and dopamine (DA) transporters in the living human brain with single-photon emission tomography (SPET). [{sup 123}I]{beta}-CIT was found to be not very practical for 1-day DAT imaging protocols since peak DAT uptake occurs later than 8 h. Here we report a pilot comparison of [{sup 123}I]{beta}-CIT and 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)-N-(3-fluoropropyl)nortropane ([{sup 123}I]{beta}-CIT-FP), using SPET imaging in four healthy male subjects. Peak uptake of [{sup 123}I]{beta}-CIT-FP into the basal ganglia occurred earlier (3-4 h after injection of tracer) than that of [{sup 123}I]{beta}-CIT (>8 h). However, the specific DAT binding of [{sup 123}I]{beta}-CIT-FP in the basal ganglia was somewhat less (0.813{+-}0.047) than that of [{sup 123}I]{beta}-CIT (0.922{+-}0.004). Imaging quality is excellent with both tracers and they are potentially of value for brain imaging in various neuropsychiatric disorders. (orig.)

  15. Brain-predicted age in Down syndrome is associated with beta amyloid deposition and cognitive decline.

    Science.gov (United States)

    Cole, James H; Annus, Tiina; Wilson, Liam R; Remtulla, Ridhaa; Hong, Young T; Fryer, Tim D; Acosta-Cabronero, Julio; Cardenas-Blanco, Arturo; Smith, Robert; Menon, David K; Zaman, Shahid H; Nestor, Peter J; Holland, Anthony J

    2017-08-01

    Individuals with Down syndrome (DS) are more likely to experience earlier onset of multiple facets of physiological aging. This includes brain atrophy, beta amyloid deposition, cognitive decline, and Alzheimer's disease-factors indicative of brain aging. Here, we employed a machine learning approach, using structural neuroimaging data to predict age (i.e., brain-predicted age) in people with DS (N = 46) and typically developing controls (N = 30). Chronological age was then subtracted from brain-predicted age to generate a brain-predicted age difference (brain-PAD) score. DS participants also underwent [ 11 C]-PiB positron emission tomography (PET) scans to index the levels of cerebral beta amyloid deposition, and cognitive assessment. Mean brain-PAD in DS participants' was +2.49 years, significantly greater than controls (p brain-PAD was associated with the presence and the magnitude of PiB-binding and levels of cognitive performance. Our study indicates that DS is associated with premature structural brain aging, and that age-related alterations in brain structure are associated with individual differences in the rate of beta amyloid deposition and cognitive impairment. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Timing of neurodegeneration and beta-amyloid (Abeta) peptide deposition in the brain of aging kokanee salmon.

    Science.gov (United States)

    Maldonado, Tammy A; Jones, Richard E; Norris, David O

    2002-10-01

    Brains of kokanee salmon (Oncorhynchus nerka kennerlyi) in one of four reproductive stages (sexually immature, maturing, sexually mature, and spawning) were stained with cresyl violet and silver stain to visualize neurodegeneration. These reproductive stages correlate with increasing somatic aging of kokanee salmon, which die after spawning. Twenty-four regions of each brain were examined. Brains of sexually immature fish exhibited low levels of neurodegeneration, whereas neurodegeneration was more marked in maturing fish and greatest in spawning fish. Neurodegeneration was present in specific regions of the telencephalon, diencephalon, mesencephalon, and rhombencephalon. Pyknotic neurons were observed in all regions previously reported to be immunopositive for A beta. Regions that did not exhibit neurodegeneration during aging included the magnocellular vestibular nucleus, the nucleus lateralis tuberis of the hypothalamus, and Purkinje cells of the cerebellum, all of which also lack A beta; perhaps these regions are neuroprotected. In 14 of 16 brain areas for which data were available on both the increase in A beta deposition and pyknosis, neurodegeneration preceded or appeared more or less simultaneously with A beta production, whereas in only two regions did A beta deposition precede neurodegeneration. This information supports the hypothesis that A beta deposition is a downstream product of neurodegeneration in most brain regions. Other conclusions are that the degree of neurodegeneration varies among brain regions, neurodegeneration begins in maturing fish and peaks in spawning fish, the timing of neurodegeneration varies among brain regions, and some regions do not exhibit accelerated neurodegeneration during aging. Copyright 2002 Wiley Periodicals, Inc.

  17. PCR-RFLP on β-tubulin gene for rapid identification of the most clinically important species of Aspergillus.

    Science.gov (United States)

    Nasri, Tuba; Hedayati, Mohammad Taghi; Abastabar, Mahdi; Pasqualotto, Alessandro C; Armaki, Mojtaba Taghizadeh; Hoseinnejad, Akbar; Nabili, Mojtaba

    2015-10-01

    Aspergillus species are important agents of life-threatening infections in immunosuppressed patients. Proper speciation in the Aspergilli has been justified based on varied fungal virulence, clinical presentations, and antifungal resistance. Accurate identification of Aspergillus species usually relies on fungal DNA sequencing but this requires expensive equipment that is not available in most clinical laboratories. We developed and validated a discriminative low-cost PCR-based test to discriminate Aspergillus isolates at the species level. The Beta tubulin gene of various reference strains of Aspergillus species was amplified using the universal fungal primers Bt2a and Bt2b. The PCR products were subjected to digestion with a single restriction enzyme AlwI. All Aspergillus isolates were subjected to DNA sequencing for final species characterization. The PCR-RFLP test generated unique patterns for six clinically important Aspergillus species, including Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus terreus, Aspergillus clavatus and Aspergillus nidulans. The one-enzyme PCR-RFLP on Beta tubulin gene designed in this study is a low-cost tool for the reliable and rapid differentiation of the clinically important Aspergillus species. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Prion protein inhibits microtubule assembly by inducing tubulin oligomerization

    International Nuclear Information System (INIS)

    Nieznanski, Krzysztof; Podlubnaya, Zoya A.; Nieznanska, Hanna

    2006-01-01

    A growing body of evidence points to an association of prion protein (PrP) with microtubular cytoskeleton. Recently, direct binding of PrP to tubulin has also been found. In this work, using standard light scattering measurements, sedimentation experiments, and electron microscopy, we show for First time the effect of a direct interaction between these proteins on tubulin polymerization. We demonstrate that full-length recombinant PrP induces a rapid increase in the turbidity of tubulin diluted below the critical concentration for microtubule assembly. This effect requires magnesium ions and is weakened by NaCl. Moreover, the PrP-induced light scattering structures of tubulin are cold-stable. In preparations of diluted tubulin incubated with PrP, electron microscopy revealed the presence of ∼50 nm disc-shaped structures not reported so far. These unique tubulin oligomers may form large aggregates. The effect of PrP is more pronounced under the conditions promoting microtubule formation. In these tubulin samples, PrP induces formation of the above oligomers associated with short protofilaments and sheets of protofilaments into aggregates. Noticeably, this is accompanied by a significant reduction of the number and length of microtubules. Hence, we postulate that prion protein may act as an inhibitor of microtubule assembly by inducing formation of stable tubulin oligomers

  19. GSK-3beta is required for memory reconsolidation in adult brain.

    Directory of Open Access Journals (Sweden)

    Tetsuya Kimura

    Full Text Available Activation of GSK-3beta is presumed to be involved in various neurodegenerative diseases, including Alzheimer's disease (AD, which is characterized by memory disturbances during early stages of the disease. The normal function of GSK-3beta in adult brain is not well understood. Here, we analyzed the ability of heterozygote GSK-3beta knockout (GSK+/- mice to form memories. In the Morris water maze (MWM, learning and memory performance of GSK+/- mice was no different from that of wild-type (WT mice for the first 3 days of training. With continued learning on subsequent days, however, retrograde amnesia was induced in GSK+/- mice, suggesting that GSK+/- mice might be impaired in their ability to form long-term memories. In contextual fear conditioning (CFC, context memory was normally consolidated in GSK+/- mice, but once the original memory was reactivated, they showed reduced freezing, suggesting that GSK+/- mice had impaired memory reconsolidation. Biochemical analysis showed that GSK-3beta was activated after memory reactivation in WT mice. Intraperitoneal injection of a GSK-3 inhibitor before memory reactivation impaired memory reconsolidation in WT mice. These results suggest that memory reconsolidation requires activation of GSK-3beta in the adult brain.

  20. [3H]-beta-endorphin binding in rat brain

    International Nuclear Information System (INIS)

    Houghten, R.A.; Johnson, N.; Pasternak, G.W.

    1984-01-01

    The binding of [ 3 H]-beta-endorphin to rat brain homogenates is complex. Although Scatchard analysis of saturation studies yields a straight line, detailed competition studies are multiphasic, suggesting that even at low concentrations of the compound, the 3 H-ligand is binding to more than one class of site. A portion of [ 3 H]-beta-endorphin binding is sensitive to low concentrations of morphine or D-Ala2-Leu5-enkephalin (less than 5 nM). The inhibition observed with each compound alone (5 nM) is the same as that seen with both together (each at 5 nM). Thus, the binding remaining in the presence of both morphine and the enkephalin does not correspond to either mu or delta sites. The portion of [ 3 H]-beta-endorphin binding that is inhibited under these conditions appears to be equally sensitive to both morphine and the enkephalin and may correspond to mu1 sites. Treating membrane homogenates with naloxonazine, a mu1 selective antagonist, lowers [ 3 H]-beta-endorphin binding to the same degree as morphine and D-Ala2-Leu5-enkephalin alone or together. This possible binding of [ 3 H]-beta-endorphin to mu1 sites is consistent with the role of mu1 sites in beta-endorphin analgesia and catalepsy in vivo

  1. Tubulin-isotype analysis of two grass species-resistant to dinitroaniline herbicides.

    Science.gov (United States)

    Waldin, T R; Ellis, J R; Hussey, P J

    1992-09-01

    Trifluralin-resistant biotypes of Eleusine indica (L.) Gaertn. (goosegrass) and Setaria viridis (L.) Beauv. (green foxtail) exhibit cross-resistance to other dinitroaniline herbicides. Since microtubules are considered the primary target site for dinitroaniline herbicides we investigated whether the differential sensitivity of resistant and susceptible biotypes of these species results from modified tubulin polypeptides. One-dimensional and two-dimensional polyacrylamide gel electrophoresis combined with immunoblotting using well-characterised anti-tubulin monoclonal antibodies were used to display the family of tubulin isotypes in each species. Seedlings of E. indica exhibited four β-tubulin isotypes and one α-tubulin isotype, whereas those of S. viridis exhibited two β-tubulin and two α-tubulin isotypes. Comparison of the susceptible and resistant biotypes within each species revealed no differences in electrophoretic properties of the multiple tubulin isotypes. These results provide no evidence that resistance to dinitroaniline herbicides is associated with a modified tubulin polypeptide in these biotypes of E. indica or S. viridis.

  2. Beta-endorphin chimeric peptides: Transport through the blood-brain barrier in vivo and cleavage of disulfide linkage by brain

    International Nuclear Information System (INIS)

    Pardridge, W.M.; Triguero, D.; Buciak, J.L.

    1990-01-01

    Water soluble peptides are normally not transported through the blood-brain barrier (BBB). Chimeric peptides may be transportable through the BBB and are formed by the covalent coupling of a nontransportable peptide to a transportable peptide vector, e.g. cationized albumin, using disulfide-based coupling reagents such as N-succinimidyl 3-[2-pyridyldithio(propionate)] (SPDP). The transcytosis of peptide into brain parenchyma, as opposed to vascular sequestration of blood-borne peptide, was quantified using an internal carotid artery perfusion/capillary depletion method. It is shown that [125I]beta-endorphin is not transported through the BBB, but is rapidly cleaved to free [125I] tyrosine via capillary peptidase. Therefore, chimeric peptide was prepared using [125I] [D-Ala2]beta-endorphin (DABE), owing to the resistance of this analogue to peptidase degradation. The [125I] DABE-cationized albumin chimeric peptide is shown to enter brain parenchyma at a rate comparable to that reported previously for unconjugated cationized albumin. When the [125I] DABE-cationized albumin chimeric peptide was incubated with rat brain homogenate at 37 C, the free [125I] DABE was liberated from the cationized albumin conjugate prior to its subsequent degradation into free [125I] tyrosine. Approximately 50% of the chimeric peptide was cleaved within 60 sec of incubation at 37 C. These studies demonstrate that (1) [125I]beta-endorphin is not transported through the BBB in its unconjugated form, (2) a [125I] DABE-cationized albumin chimeric peptide is transported through the BBB into brain parenchyma at a rate comparable to the unconjugated cationized albumin, and (3) brain contains the necessary disulfide reductases for rapid cleavage of the chimeric peptide into free beta-endorphin and this cleavage occurs before degradation of the [125I] DABE into [125I] tyrosine

  3. Beta-endorphin chimeric peptides: Transport through the blood-brain barrier in vivo and cleavage of disulfide linkage by brain

    Energy Technology Data Exchange (ETDEWEB)

    Pardridge, W.M.; Triguero, D.; Buciak, J.L. (UCLA School of Medicine (USA))

    1990-02-01

    Water soluble peptides are normally not transported through the blood-brain barrier (BBB). Chimeric peptides may be transportable through the BBB and are formed by the covalent coupling of a nontransportable peptide to a transportable peptide vector, e.g. cationized albumin, using disulfide-based coupling reagents such as N-succinimidyl 3-(2-pyridyldithio(propionate)) (SPDP). The transcytosis of peptide into brain parenchyma, as opposed to vascular sequestration of blood-borne peptide, was quantified using an internal carotid artery perfusion/capillary depletion method. It is shown that (125I)beta-endorphin is not transported through the BBB, but is rapidly cleaved to free (125I) tyrosine via capillary peptidase. Therefore, chimeric peptide was prepared using (125I) (D-Ala2)beta-endorphin (DABE), owing to the resistance of this analogue to peptidase degradation. The (125I) DABE-cationized albumin chimeric peptide is shown to enter brain parenchyma at a rate comparable to that reported previously for unconjugated cationized albumin. When the (125I) DABE-cationized albumin chimeric peptide was incubated with rat brain homogenate at 37 C, the free (125I) DABE was liberated from the cationized albumin conjugate prior to its subsequent degradation into free (125I) tyrosine. Approximately 50% of the chimeric peptide was cleaved within 60 sec of incubation at 37 C. These studies demonstrate that (1) (125I)beta-endorphin is not transported through the BBB in its unconjugated form, (2) a (125I) DABE-cationized albumin chimeric peptide is transported through the BBB into brain parenchyma at a rate comparable to the unconjugated cationized albumin, and (3) brain contains the necessary disulfide reductases for rapid cleavage of the chimeric peptide into free beta-endorphin and this cleavage occurs before degradation of the (125I) DABE into (125I) tyrosine.

  4. Diurnal variation of. beta. -endorphin like immunoreactivity in rat brain, pituitary gland, and plasma

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, I.A.; Perry, M.L.S.; Carrasco, M.A.; Dias, R.D. (Rio Grande do Sul Univ., Porto Alegre (Brazil). Inst. de Biociencias); Orsingher, O.A. (Universidad Nacional de Cordoba (Argentina))

    1984-09-01

    ..beta..-endorphin like immunoreactivity was measured in the brain, pituitary gland and plasma of rats at 2 A.M, 8 A.M, 2 P.M and 8 P.M. Values were higher in the brain and pituitary gland at 8 P.M and in the plasma at 8 A.M and 2 P.M. The findings suggest a circadian rhythm in the production and release of ..beta..-endorphin immunoreactive material.

  5. Photoaffinity studies of the tubulin-colchicine binding site

    International Nuclear Information System (INIS)

    Hahn, K.M.

    1987-01-01

    A variety of colchicine derivatives were synthesized and coupled with 3,3,3-trifluoro-2-diazapropionyl chloride (TFDP-Cl) to produce colchicine photoaffinity analogs for use in tubulin labelling studies. Photoaffinity analogs of allocolchicine and podophylotoxin were also made using the same photoreactive moiety. Several labels were found to be effective inhibitors of tubulin polymerization. The approximate tubulin binding constants of the labels, calculated from polymerization inhibition data, varied between 2.2 x 10 5 to 2.5 x 10 3 M -1 . The labels chosen for use in tubulin labelling experiments were (N-TFDP) deacetyl-thiocolchicine 1, (O-TFDP)thiocolchifoline 2, and (O-TFDP)-2-demethylthiocolchicine 3. Compound 1 was found to bind tubulin reversibly and to competitively inhibit colchicine binding. Methods for the incorporation of tritium and 14 C in these labels were developed. Conditions were found which caused labels to insert into solvent without photorearrangement of the colchicine skeleton. Catalytic base caused the α-diazo amide of 1 to rearrange to a triazole

  6. Tubulin in vitro, in vivo and in silico

    Science.gov (United States)

    Mershin, Andreas

    Tubulin, microtubules and associated proteins were studied theoretically, computationally and experimentally in vitro and in vivo in order to elucidate the possible role these play in cellular information processing and storage. Use of the electric dipole moment of tubulin as the basis for binary switches (biobits) in nanofabricated circuits was explored with surface plasmon resonance, refractometry and dielectric spectroscopy. The effects of burdening the microtubular cytoskeleton of olfactory associative memory neurons with excess microtubule associated protein TAU in Drosophila fruitflies were determined. To investigate whether tubulin may be used as the substrate for quantum computation as a bioqubit, suggestions for experimental detection of quantum coherence and entanglement among tubulin electric dipole moment states were developed.

  7. -NH-dansyl isocolchicine exhibits a significantly improved tubulin-binding affinity and microtubule inhibition in comparison to isocolchicine by binding tubulin through its A and B rings.

    Science.gov (United States)

    Das, Lalita; Datta, Ajit B; Gupta, Suvroma; Poddar, Asim; Sengupta, Suparna; Janik, Mark E; Bhattacharyya, Bhabatarak

    2005-03-08

    Structure-activity relationship studies have established that the A and C rings of colchicine comprise the minimum structural feature necessary for high affinity drug-tubulin binding. Thus, colchicine acts as a bifunctional ligand by making two points of attachment to the protein. Furthermore, analogues belonging to the iso series of colchicine are virtually inactive in binding to tubulin and inhibiting microtubule assembly. In the present study, we found that the substitution of a hydrophobic dansyl group on the B-ring side chain (C7 position) of isocolchicine reverses the structural alterations at the C ring and the newly synthesized -NH-dansyl isocolchicine restores the lost biological activity of the compound. It inhibits microtubule assembly efficiently with an IC(50) value of 10 microM and competes with [(3)H]colchicine for binding to tubulin. Moreover, although -NH-dansyl colchicine binding to tubulin involves two steps, the -NH-dansyl isocolchicine-tubulin interaction has been found to occur via a one-step process. Also, the affinity constant of the -NH-dansyl isocolchicine-tubulin interaction is roughly only 3 times lower than that of the -NH-dansyl colchicine-tubulin interaction. These results suggest that the enhanced microtubule inhibitory ability of -NH-dansyl isocolchicine is therefore related to the affinity of the drug-tubulin interaction and not to any conformational changes upon binding tubulin. We also observed that the competition of -NH-dansyl isocolchicine with [(3)H]colchicine for binding to tubulin was dependent on the tubulin concentration. In conclusion, this paper for the first time indicates that a biologically active bifuntional colchicine analogue can be designed where the drug binds tubulin through its A and B rings, while the C ring remains inactive.

  8. β class II tubulin predominates in normal and tumor breast tissues

    International Nuclear Information System (INIS)

    Dozier, James H; Hiser, Laree; Davis, Jennifer A; Thomas, Nancy Stubbs; Tucci, Michelle A; Benghuzzi, Hamed A; Frankfurter, Anthony; Correia, John J; Lobert, Sharon

    2003-01-01

    Antimitotic chemotherapeutic agents target tubulin, the major protein in mitotic spindles. Tubulin isotype composition is thought to be both diagnostic of tumor progression and a determinant of the cellular response to chemotherapy. This implies that there is a difference in isotype composition between normal and tumor tissues. To determine whether such a difference occurs in breast tissues, total tubulin was fractionated from lysates of paired normal and tumor breast tissues, and the amounts of β-tubulin classes I + IV, II, and III were measured by competitive enzyme-linked immunosorbent assay (ELISA). Only primary tumor tissues, before chemotherapy, were examined. Her2/neu protein amplification occurs in about 30% of breast tumors and is considered a marker for poor prognosis. To gain insight into whether tubulin isotype levels might be correlated with prognosis, ELISAs were used to quantify Her2/neu protein levels in these tissues. β-Tubulin isotype distributions in normal and tumor breast tissues were similar. The most abundant β-tubulin isotypes in these tissues were β-tubulin classes II and I + IV. Her2/neu levels in tumor tissues were 5–30-fold those in normal tissues, although there was no correlation between the Her2/neu biomarker and tubulin isotype levels. These results suggest that tubulin isotype levels, alone or in combination with Her2/neu protein levels, might not be diagnostic of tumorigenesis in breast cancer. However, the presence of a broad distribution of these tubulin isotypes (for example, 40–75% β-tubulin class II) in breast tissue, in conjunction with other factors, might still be relevant to disease progression and cellular response to antimitotic drugs

  9. Centrobin–tubulin interaction is required for centriole elongation and stability

    Science.gov (United States)

    Gudi, Radhika; Zou, Chaozhong; Li, Jun

    2011-01-01

    Centrobin is a daughter centriole protein that is essential for centrosome duplication. However, the molecular mechanism by which centrobin functions during centriole duplication remains undefined. In this study, we show that centrobin interacts with tubulin directly, and centrobin–tubulin interaction is pivotal for the function of centrobin during centriole duplication. We found that centrobin is recruited to the centriole biogenesis site via its interaction with tubulins during the early stage of centriole biogenesis, and its recruitment is dependent on hSAS-6 but not centrosomal P4.1–associated protein (CPAP) and CP110. The function of centrobin is also required for the elongation of centrioles, which is likely mediated by its interaction with tubulin. Furthermore, disruption of centrobin–tubulin interaction led to destabilization of existing centrioles and the preformed procentriole-like structures induced by CPAP expression, indicating that centrobin–tubulin interaction is critical for the stability of centrioles. Together, our study demonstrates that centrobin facilitates the elongation and stability of centrioles via its interaction with tubulins. PMID:21576394

  10. C239S mutation in the β-tubulin of Phytophthora sojae confers resistance to zoxamide

    Directory of Open Access Journals (Sweden)

    Meng eCai

    2016-05-01

    Full Text Available Zoxamide is the sole β-tubulin inhibitor registered for the control of oomycete pathogens. The current study investigated the activity of zoxamide against Phytophthora sojae and a baseline sensitivity was established with a mean EC50 of 0.048 μg/ml. Three stable resistant mutants with a high resistance level were obtained by selection on zoxamide amended media. Although the development of resistance occurred at a low frequency, there were no apparent fitness penalty in the acquired mutants in terms of growth rate, sporulation, germination and pathogenicity. Based on the biological profiles and mutagenesis rate, the resistance risk of P. sojae to zoxamide can be estimated as low to medium. Further investigation revealed all the zoxamide-resistant mutants had a point mutation of C239S in their β-tubulin. Zoxamide also exhibited high activity against most species from the genus Pythium in which only Py. aphanidermatum was found resistant to zoxamide and harboring the natural point mutation S239 in the beta-tubulin. Back-transformation in P. sojae with the mutated allele (S239 confirmed the C239S mutation induced resistance to zoxamide, and the resistance level was positively related to the expression level of the mutated gene. In contrast, the overexpression of the wild type gene was unable to cause zoxamide resistance. It is the first report on the resistance molecular mechanism of zoxamide in oomycetes. Based on our study, C239 is supposed to be a key target site of zoxamide, which distinguishes zoxamide from benzimidazoles and accounts for its low resistance risk. The result can provide advice on the design of new β-tubulin inhibitors in future.

  11. Cationization increases brain distribution of an amyloid-beta protofibril selective F(ab')2 fragment

    OpenAIRE

    Syvänen, Stina; Edén, Desireé; Sehlin, Dag

    2017-01-01

    Antibodies and fragments thereof are, because of high selectivity for their targets, considered as potential therapeutics and biomarkers for several neurological disorders. However, due to their large molecular size, antibodies/fragments do not easily penetrate into the brain. The aim of the present study was to improve the brain distribution via adsorptive-mediated transcytosis of an amyloid-beta (A beta) protofibril selective F(ab')2 fragment (F(ab')2-h158). F(ab')2-h158 was cationized to d...

  12. (/sup 3/H)-beta-endorphin binding in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Houghten, R.A.; Johnson, N.; Pasternak, G.W.

    1984-10-01

    The binding of (/sup 3/H)-beta-endorphin to rat brain homogenates is complex. Although Scatchard analysis of saturation studies yields a straight line, detailed competition studies are multiphasic, suggesting that even at low concentrations of the compound, the /sup 3/H-ligand is binding to more than one class of site. A portion of (/sup 3/H)-beta-endorphin binding is sensitive to low concentrations of morphine or D-Ala2-Leu5-enkephalin (less than 5 nM). The inhibition observed with each compound alone (5 nM) is the same as that seen with both together (each at 5 nM). Thus, the binding remaining in the presence of both morphine and the enkephalin does not correspond to either mu or delta sites. The portion of (/sup 3/H)-beta-endorphin binding that is inhibited under these conditions appears to be equally sensitive to both morphine and the enkephalin and may correspond to mu1 sites. Treating membrane homogenates with naloxonazine, a mu1 selective antagonist, lowers (/sup 3/H)-beta-endorphin binding to the same degree as morphine and D-Ala2-Leu5-enkephalin alone or together. This possible binding of (/sup 3/H)-beta-endorphin to mu1 sites is consistent with the role of mu1 sites in beta-endorphin analgesia and catalepsy in vivo.

  13. A direct interaction between leucine-rich repeat kinase 2 and specific β-tubulin isoforms regulates tubulin acetylation.

    Science.gov (United States)

    Law, Bernard M H; Spain, Victoria A; Leinster, Veronica H L; Chia, Ruth; Beilina, Alexandra; Cho, Hyun J; Taymans, Jean-Marc; Urban, Mary K; Sancho, Rosa M; Blanca Ramírez, Marian; Biskup, Saskia; Baekelandt, Veerle; Cai, Huaibin; Cookson, Mark R; Berwick, Daniel C; Harvey, Kirsten

    2014-01-10

    Mutations in LRRK2, encoding the multifunctional protein leucine-rich repeat kinase 2 (LRRK2), are a common cause of Parkinson disease. LRRK2 has been suggested to influence the cytoskeleton as LRRK2 mutants reduce neurite outgrowth and cause an accumulation of hyperphosphorylated Tau. This might cause alterations in the dynamic instability of microtubules suggested to contribute to the pathogenesis of Parkinson disease. Here, we describe a direct interaction between LRRK2 and β-tubulin. This interaction is conferred by the LRRK2 Roc domain and is disrupted by the familial R1441G mutation and artificial Roc domain mutations that mimic autophosphorylation. LRRK2 selectively interacts with three β-tubulin isoforms: TUBB, TUBB4, and TUBB6, one of which (TUBB4) is mutated in the movement disorder dystonia type 4 (DYT4). Binding specificity is determined by lysine 362 and alanine 364 of β-tubulin. Molecular modeling was used to map the interaction surface to the luminal face of microtubule protofibrils in close proximity to the lysine 40 acetylation site in α-tubulin. This location is predicted to be poorly accessible within mature stabilized microtubules, but exposed in dynamic microtubule populations. Consistent with this finding, endogenous LRRK2 displays a preferential localization to dynamic microtubules within growth cones, rather than adjacent axonal microtubule bundles. This interaction is functionally relevant to microtubule dynamics, as mouse embryonic fibroblasts derived from LRRK2 knock-out mice display increased microtubule acetylation. Taken together, our data shed light on the nature of the LRRK2-tubulin interaction, and indicate that alterations in microtubule stability caused by changes in LRRK2 might contribute to the pathogenesis of Parkinson disease.

  14. Distribution of tubulin, kinesin, and dynein in light- and dark-adapted octopus retinas.

    Science.gov (United States)

    Martinez, J M; Elfarissi, H; De Velasco, B; Ochoa, G H; Miller, A M; Clark, Y M; Matsumoto, B; Robles, L J

    2000-01-01

    Cephalopod retinas exhibit several responses to light and dark adaptation, including rhabdom size changes, photopigment movements, and pigment granule migration. Light- and dark-directed rearrangements of microfilament and microtubule cytoskeletal transport pathways could drive these changes. Recently, we localized actin-binding proteins in light-/dark-adapted octopus rhabdoms and suggested that actin cytoskeletal rearrangements bring about the formation and degradation of rhabdomere microvilli subsets. To determine if the microtubule cytoskeleton and associated motor proteins control the other light/dark changes, we used immunoblotting and immunocytochemical procedures to map the distribution of tubulin, kinesin, and dynein in dorsal and ventral halves of light- and dark-adapted octopus retinas. Immunoblots detected alpha- and beta-tubulin, dynein intermediate chain, and kinesin heavy chain in extracts of whole retinas. Epifluorescence and confocal microscopy showed that the tubulin proteins were distributed throughout the retina with more immunoreactivity in retinas exposed to light. Kinesin localization was heavy in the pigment layer of light- and dark-adapted ventral retinas but was less prominent in the dorsal region. Dynein distribution also varied in dorsal and ventral retinas with more immunoreactivity in light- and dark-adapted ventral retinas and confocal microscopy emphasized the granular nature of this labeling. We suggest that light may regulate the distribution of microtubule cytoskeletal proteins in the octopus retina and that position, dorsal versus ventral, also influences the distribution of motor proteins. The microtubule cytoskeleton is most likely involved in pigment granule migration in the light and dark and with the movement of transport vesicles from the photoreceptor inner segments to the rhabdoms.

  15. The kinesin–tubulin complex: considerations in structural and functional complexity

    Directory of Open Access Journals (Sweden)

    Olmsted ZT

    2015-02-01

    Full Text Available Zachary T Olmsted, Andrew G Colliver, Janet L Paluh State University of New York Polytechnic Institute, Colleges of Nanoscale Science and Engineering, College of Nanoscale Science, Nanobioscience Constellation, Albany, NY, USA Abstract: The ability of cells to respond to external cues by appropriately manipulating their internal environment requires a dynamic microtubule cytoskeleton that is facilitated by associated kinesin motor interactions. The evolutionary adaptations of kinesins and tubulins when merged generate a highly adaptable communication and infrastructure cellular network that is important to understanding specialized cell functions, human disease, and disease therapies. Here, we review the state of the field in the complex relationship of kinesin–tubulin interactions. We propose 12 mechanistic specializations of kinesins. In one category, referred to as sortability, we describe how kinesin interactions with tubulin isoforms, isotypes, or posttranslationally modified tubulins contribute to diverse cellular roles. Fourteen kinesin families have previously been described. Here, we illustrate the great depth of functional complexity that is possible in members within a single kinesin family by mechanistic specialization through discussion of the well-studied Kinesin-14 family. This includes new roles of Kinesin-14 in regulating supramolecular structures such as the microtubule-organizing center γ-tubulin ring complex of centrosomes. We next explore the value of an improved mechanistic understanding of kinesin–tubulin interactions in regard to human development, disease mechanisms, and improving treatments that target kinesin–tubulin complexes. The ability to combine the current kinesin nomenclature along with a more precisely defined kinesin and tubulin molecular toolbox is needed to support more detailed exploration of kinesin–tubulin interaction mechanisms including functional uniqueness, redundancy, or adaptations to new

  16. NCBI nr-aa BLAST: CBRC-MMUR-01-0199 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-MMUR-01-0199 emb|CAX76110.1| putative tubulin, beta, 2 [Schistosoma japonicum]... emb|CAX76111.1| putative tubulin, beta, 2 [Schistosoma japonicum] emb|CAX76112.1| putative tubulin, beta, 2 [Schistosoma jap...onicum] emb|CAX76113.1| putative tubulin, beta, 2 [Schistosoma japonicum] emb|CAX76114.1| p...utative tubulin, beta, 2 [Schistosoma japonicum] emb|CAX76115.1| putative tubulin..., beta, 2 [Schistosoma japonicum] emb|CAX76116.1| putative tubulin, beta, 2 [Schistosoma japonicum] CAX76110.1 2e-31 82% ...

  17. Water deficit modulates gene expression in growing zones of soybean seedlings. Analysis of differentially expressed cDNAs, a new beta-tubulin gene, and expression of genes encoding cell wall proteins.

    Science.gov (United States)

    Creelman, R A; Mullet, J E

    1991-10-01

    Transfer of soybean seedlings to low-water-potential vermiculite (psi w = -0.3 MPa) results in a reversible decrease in hypocotyl growth and modulation of several polysomal mRNAs (Plant Physiol 92: 205-214). We report here the isolation of two cDNA clones (pGE16 and pGE95) which correspond to genes whose mRNA levels are increased, and one cDNA clone (pGE23) which corresponds to a gene whose mRNA level is decreased in the hypocotyl zone of cell elongation by water deficit. In well-watered seedlings mRNAs hybridizing to pGE16 and pGE95 are most abundant in mature regions of the seedling, but in water-deficient seedlings mRNA levels are reduced in mature regions and enhanced in elongating regions. RNA corresponding to soybean proline-rich protein 1 (sbPRP1) shows a similar tissue distribution and response to water deficit. In contrast, in well-watered seedlings, the gene corresponding to pGE23 was highly expressed in the hypocotyl and root growing zones. Transfer of seedlings to low-water-potential vermiculite caused a rapid decrease in mRNA hybridizing to pGE23. Sequence analysis revealed that pGE23 has high homology with beta-tubulin. Water deficit also reduced the level of mRNA hybridizing to JCW1, an auxin-modulated gene, although with different kinetics. Furthermore, mRNA encoding actin, glycine-rich proteins (GRPs), and hydroxyproline-rich glycoproteins (HRGPs) were down-regulated in the hypocotyl zone of elongation of seedlings exposed to water deficit. No effect of water deficit was observed on the expression of chalcone synthase. Decreased expression of beta-tubulin, actin, JCW1, HRGP and GRP and increased expression of sbPRP1, pGE95 and pGE16 in the hypocotyl zone of cell elongation could participate in the reversible growth inhibition observed in water-deficient soybean seedlings.

  18. Tubulin posttranslational modifications induced by cadmium in the sponge Clathrina clathrus

    Energy Technology Data Exchange (ETDEWEB)

    Ledda, F.D., E-mail: f.ledda@hotmail.it [Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università di Genova, Corso Europa 26, I-16132 Genova (Italy); Dipartimento di Scienze della Natura e del Territorio (DIPNET), Università di Sassari, Via Muroni 25, I-07100 Sassari (Italy); Ramoino, P. [Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università di Genova, Corso Europa 26, I-16132 Genova (Italy); Ravera, S. [Dipartimento di Farmacia (DIFAR), Viale Cembrano 4, I-16147 Genova (Italy); Perino, E. [Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università di Genova, Corso Europa 26, I-16132 Genova (Italy); Bianchini, P. [Istituto Italiano di Tecnologia (IIT), Dipartimento di Nanofisica, Via Morego 30, I-16163 Genova (Italy); Diaspro, A. [Istituto Italiano di Tecnologia (IIT), Dipartimento di Nanofisica, Via Morego 30, I-16163 Genova (Italy); Dipartimento di Fisica (DIFI), Università di Genova, Via Dodecaneso 33, I-16146 Genova (Italy); Gallus, L.; Pronzato, R. [Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università di Genova, Corso Europa 26, I-16132 Genova (Italy); Manconi, R. [Dipartimento di Scienze della Natura e del Territorio (DIPNET), Università di Sassari, Via Muroni 25, I-07100 Sassari (Italy)

    2013-09-15

    Highlights: •The effect of Cd{sup 2+} on Clathrina clathrus microtubule network was studied. •Cd{sup 2+} exposure increases acetylated and detyrosinated α-tubulin levels. •Microtubules enriched in acetylated/detyrosinated α-tubulin were resistant to cold. •Clathrina clathrus exposed to Cd{sup 2+} showed cytoplasmic microtubules with an enhanced stability. -- Abstract: As sessile filter feeders, sponges are exposed to environmental stress due to pollutants of both anthropogenic and natural origins and are able to accumulate harmful substances. Thus, sponges are considered a good tool for the biomonitoring of coastal areas. In this study, we used biochemical and immunocytochemical analyses to provide new data on the cadmium-related changes in sponge cells. In particular, we analyzed the effects of different concentrations of cadmium on the microtubule network in the calcisponge Clathrina clathrus. Quantitative densitometry of the immunoblots showed that, while the levels of α- and β-tubulin remained relatively constant in C. clathrus when exposed to 1 and 5 μM CdCl{sub 2}, there were progressive shifts in the levels of some tubulin isoforms. Exposure for 24 h to sublethal concentrations of cadmium reduced the level of tyrosinated α-tubulin and enhanced the levels of acetylated and detyrosinated α-tubulin relative to the levels in controls. Confocal microscopy analysis of immunolabeled tissue sections showed that the inhibitory effect of cadmium was associated with a decrease in the labeling of the cells with a monoclonal antibody that recognizes tyrosinated α-tubulin. By contrast, the reactivity with a monoclonal antibody that recognizes acetylated α-tubulin and with a polyclonal antibody specific for detyrosinated α-tubulin was enhanced at the same time points. Because the acetylation and detyrosination of α-tubulin occur on stable microtubules, the marked enhancement of α-tubulin acetylation and detyrosination in Cd{sup 2+}-treated cells

  19. alpha-Tubulin of Histriculus cavicola (Ciliophora; Hypotrichea).

    Science.gov (United States)

    Pérez-Romero, P; Villalobo, E; Díaz-Ramos, C; Calvo, P; Santos-Rosa, F; Torres, A

    1997-03-01

    An alpha-tubulin gene fragment amplified by PCR from the hypotrichous ciliate Histriculus cavicola has been sequenced. This fragment, 1,182 bp long, contains an in-frame "stop" codon (UAA), which in other hypotrichous species codes for a glutamine residue. The comparison of the alpha-tubulin genes from several ciliates classes have revealed amino acid positions which could serve to distinguish these taxonomic groups.

  20. Beta oscillations in freely moving Parkinson's subjects are attenuated during deep brain stimulation.

    Science.gov (United States)

    Quinn, Emma J; Blumenfeld, Zack; Velisar, Anca; Koop, Mandy Miller; Shreve, Lauren A; Trager, Megan H; Hill, Bruce C; Kilbane, Camilla; Henderson, Jaimie M; Brontë-Stewart, Helen

    2015-11-01

    Investigations into the effect of deep brain stimulation (DBS) on subthalamic (STN) beta (13-30 Hz) oscillations have been performed in the perioperative period with the subject tethered to equipment. Using an embedded sensing neurostimulator, this study investigated whether beta power was similar in different resting postures and during forward walking in freely moving subjects with Parkinson's disease (PD) and whether STN DBS attenuated beta power in a voltage-dependent manner. Subthalamic local field potentials were recorded from the DBS lead, using a sensing neurostimulator (Activa(®) PC+S, Medtronic, Inc., Food and Drug Administration- Investigational Device Exemption (IDE)-, institutional review board-approved) from 15 PD subjects (30 STNs) off medication during lying, sitting, and standing, during forward walking, and during randomized periods of 140 Hz DBS at 0 V, 1 V, and 2.5/3 V. Continuous video, limb angular velocity, and forearm electromyography recordings were synchronized with neural recordings. Data were parsed to avoid any movement or electrical artifact during resting states. Beta power was similar during lying, sitting, and standing (P = 0.077, n = 28) and during forward walking compared with the averaged resting state (P = 0.466, n = 24), although akinetic rigid PD subjects tended to exhibit decreased beta power when walking. Deep brain stimulation at 3 V and at 1 V attenuated beta power compared with 0 V (P closed-loop DBS. © 2015 International Parkinson and Movement Disorder Society.

  1. Tubulin post-translational modifications in the primitive protist Trichomonas vaginalis.

    Science.gov (United States)

    Delgado-Viscogliosi, P; Brugerolle, G; Viscogliosi, E

    1996-01-01

    Using several specific monoclonal antibodies, we investigated the occurrence and distribution of different post-translationally modified tubulin during interphase and division of the primitive flagellated protist Trichomonas vaginalis. Immunoblotting and immunofluorescence experiments revealed that interphasic microtubular structures of T. vaginalis contained acetylated and glutamylated but non-tyrosinated and non-glycylated [Brugerolle and Adoutte, 1988: Bio Systems 21: 255-268] tubulin. Immunofluorescence studies performed on dividing cells showed that the extranuclear mitotic spindle (or paradesmosis) was acetylated and glutamylated, which contrast with the ephemeral nature of this structure. Newly formed short axostyles also contained acetylated and glutamylated tubulin suggesting that both post-translational modifications might take place very early after assembly of microtubular structures. Our results indicate that acetylation and glutamylation of tubulin appeared early in the history of eukaryotes and could reflect the occurrence of post-translational modifications of tubulin in the primitive eukaryotic cells. These cells probably had a highly ordered cross-linked microtubular cytoskeleton in which microtubules showed a low level of subunit exchange dynamics.

  2. Signaling pathways of interleukin-1 actions in the brain: anatomical distribution of phospho-ERK1/2 in the brain of rat treated systemically with interleukin-1beta.

    Science.gov (United States)

    Nadjar, A; Combe, C; Busquet, P; Dantzer, R; Parnet, P

    2005-01-01

    Interleukin-1beta is released at the periphery during infection and acts on the nervous system to induce fever, neuroendocrine activation, and behavioral changes. These effects are mediated by brain type I IL-1 receptors. In vitro studies have shown the ability of interleukin-1beta to activate mitogen-activated protein kinase signaling pathways including p38, c-Jun N-terminal kinase and extracellular signal-regulated protein kinase 1 and 2 (ERK1/2). In contrast to other mitogen-activated protein kinases, little is known about ERK1/2 activation in the rat brain in response to interleukin-1beta. The aim of the present study was therefore to investigate spatial and temporal activation of ERK1/2 in the rat brain after peripheral administration of interleukin-1beta using immunohistochemistry to detect the phosphorylated form of the kinase. In non-stimulated conditions, phosphorylated ERK1/2 immunoreactivity was observed in neurons throughout the brain. Administration of interleukin-1beta (60 microg/kg, i.p.) induced the phosphorylation of ERK1/2 in areas at the interface between brain and blood or cerebrospinal fluid: meninges, circumventricular organs, endothelial like cells of the blood vessels, and in brain nuclei involved in behavioral depression, fever and neuroendocrine activation: paraventricular nucleus of the hypothalamus, supraoptic nucleus, central amygdala and arcuate nucleus. Double labeling of phosphorylated ERK1/2 and cell markers revealed the expression of phosphorylated ERK1/2 in neurons, astrocytes and microglia. Since phosphorylated ERK1/2 was found in structures in which type I IL-1 receptor has already been identified as well as in structures lacking this receptor, activation of ERK1/2 is likely to occur in response to both direct and indirect action of interleukin-1beta on its target cells.

  3. Tubulin Inhibitor-Based Antibody-Drug Conjugates for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Hao Chen

    2017-08-01

    Full Text Available Antibody-drug conjugates (ADCs are a class of highly potent biopharmaceutical drugs generated by conjugating cytotoxic drugs with specific monoclonal antibodies through appropriate linkers. Specific antibodies used to guide potent warheads to tumor tissues can effectively reduce undesired side effects of the cytotoxic drugs. An in-depth understanding of antibodies, linkers, conjugation strategies, cytotoxic drugs, and their molecular targets has led to the successful development of several approved ADCs. These ADCs are powerful therapeutics for cancer treatment, enabling wider therapeutic windows, improved pharmacokinetic/pharmacodynamic properties, and enhanced efficacy. Since tubulin inhibitors are one of the most successful cytotoxic drugs in the ADC armamentarium, this review focuses on the progress in tubulin inhibitor-based ADCs, as well as lessons learned from the unsuccessful ADCs containing tubulin inhibitors. This review should be helpful to facilitate future development of new generations of tubulin inhibitor-based ADCs for cancer therapy.

  4. Identification of a 48 kDa tubulin or tubulin-like C6/36 mosquito cells protein that binds dengue virus 2 using mass spectrometry

    International Nuclear Information System (INIS)

    Chee, H.-Y.; AbuBakar, Sazaly

    2004-01-01

    Binding of dengue virus 2 (DENV-2) to C6/36 mosquito cells protein was investigated. A 48 kDa DENV-2-binding C6/36 cells protein (D2BP) was detected in a virus overlay protein-binding assay. The binding occurred only to the C6/36 cells cytosolic protein fraction and it was inhibited by free D2BP. D2BP was shown to bind to DENV-2 E in the far-Western-binding studies and using mass spectrometry (MS) and MS/MS, peptide masses of the D2BP that matched to β-tubulin and α-tubulin chains were identified. These findings suggest that DENV-2 through DENV-2 E binds directly to a 48 kDa tubulin or tubulin-like protein of C6/36 mosquito cells

  5. Initial experience with single-photon emission tomography using iodine-123-labelled 2[beta]-carbomethoxy-3[beta](4-iodophnyl)tropane in human brain

    Energy Technology Data Exchange (ETDEWEB)

    Kuikka, J T [Kuopio Univ. Hospital (Finland). Dept. of Clinical Physiology; Bergstroem, K A [Kuopio Univ. Hospital (Finland). Dept. of Clinical Physiology; Vanninen, E [Kuopio Univ. Hospital (Finland). Dept. of Clinical Physiology; Laulumaa, V [Kuopio Univ. Hospital (Finland). Dept. of Neurology; Hartikainen, P [Kuopio Univ. Hospital (Finland). Dept. of Neurology; Laensimies, E [Kuopio Univ. Hospital (Finland). Dept. of Clinical Physiology

    1993-09-01

    The iodinated cocaine analogue 2[beta]-carbomethoxy-3[beta]-(4-iodophenyl)tropane ([sup 123]I[beta]-CIT), a new dopamine transporter, was preliminarily tested in human brain. Two normal volunteers and two patients with Parkinson's disease were imaged with a high-resolution single-photon emission tomography scanner. The specific binding of [sup 123]I[beta]-CIT in the basal ganglia and thalamus was high in normal volunteers. In addition, there was relatively intense uptake in the medial prefrontal area. Patients with Parkinson's disease who were older than controls showed significantly lower specific binding in the basal ganglia and thalamus and no uptake in the medial prefrontal cortex. This decrease in the dopamine transporter may be age related. (orig.)

  6. The Caenorhabditis elegans Elongator complex regulates neuronal alpha-tubulin acetylation.

    Directory of Open Access Journals (Sweden)

    Jachen A Solinger

    2010-01-01

    Full Text Available Although acetylated alpha-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate alpha-tubulin acetylation are, to date, largely unknown. Therefore, a genetic screen was employed in the nematode Caenorhabditis elegans that identified the Elongator complex as a possible regulator of alpha-tubulin acetylation. Detailed characterization of mutant animals revealed that the acetyltransferase activity of the Elongator is indeed required for correct acetylation of microtubules and for neuronal development. Moreover, the velocity of vesicles on microtubules was affected by mutations in Elongator. Elongator mutants also displayed defects in neurotransmitter levels. Furthermore, acetylation of alpha-tubulin was shown to act as a novel signal for the fine-tuning of microtubules dynamics by modulating alpha-tubulin turnover, which in turn affected neuronal shape. Given that mutations in the acetyltransferase subunit of the Elongator (Elp3 and in a scaffold subunit (Elp1 have previously been linked to human neurodegenerative diseases, namely Amyotrophic Lateral Sclerosis and Familial Dysautonomia respectively highlights the importance of this work and offers new insights to understand their etiology.

  7. In vitro and in vivo characterisation of nor-{beta}-CIT: a potential radioligand for visualisation of the serotonin transporter in the brain

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, K.A. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden)]|[Kuopio University Hospital, Clinical Physiology, FIN-70210 Kuopio (Finland); Halldin, C. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Hall, H. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Lundkvist, C. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Ginovart, N. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Swahn, C.G. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden); Farde, L. [Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm (Sweden)

    1997-06-10

    Radiolabelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ({beta}-CIT) has been used in clinical studies for the imaging of dopamine and serotonin transporters with single-photon emission tomography (SPET). 2{beta}-Carbomethoxy-3{beta}-(4-iodophenyl)nortropane (nor-{beta}-CIT) is a des-methyl analogue of {beta}-CIT, which in vitro has tenfold higher affinity (IC{sub 50}=0.36 nM) to the serotonin transporter than {beta}-CIT (IC{sub 50}=4.2 nM). Nor-{beta}-CIT may thus be a useful radioligand for imaging of the serotonin transporter. In the present study iodine-125 and carbon-11 labelled nor-{beta}-CIT were prepared for in vitro autoradiographic studies on post-mortem human brain cryosections and for in vivo positron emission tomography (PET) studies in Cynomolgus monkeys. Whole hemisphere autoradiography with [{sup 125}I]nor-{beta}-CIT demonstrated high binding in the striatum, the thalamus and cortical regions of the human brain. Addition of a high concentration (1 {mu}M) of citalopram inhibited binding in the thalamus and the neocortex, but not in the striatum. In PET studies with [{sup 11}C]nor-{beta}-CIT there was rapid uptake of radioactivity in the monkey brain (6% of injected dose at 15 min) and high accumulation of radioactivity in the striatum, thalamus and neocortex. Thalamus to cerebellum and cortex to cerebellum ratios were 2.5 and 1.8 at 60 min, respectively. The ratios obtained with [{sup 11}C]nor-{beta}-CIT were 20%-40% higher than those previously obtained with [{sup 11}C]{beta}-CIT. Radioactivity in the thalamus and the neocortex but not in the striatum was displaceable with citalopram (5 mg/kg). In conclusion, nor-{beta}-CIT binds to the serotonin transporter in the primate brain in vitro and in vivo and has potential for PET and SPET imaging of the serotonin transporter in human brain. (orig.). With 4 figs.

  8. [Analysis of structural characteristics of alpha-tubulins in plants with enhanced cold tolerance].

    Science.gov (United States)

    Nyporko, A Iu; Demchuk, O N; Blium, Ia B

    2003-01-01

    The uniqueness of the point substitutions in the sequences of two alpha-tubulin isotypes from psychrophilic alga Chloromonas that can determine the increased cold tolerance of this alga was analyzed. The comparison of all known amino acid sequences of plant alpha-tubulins enabled to ascertain that only M268-->V replacement is unique and may have a significant influence on spatial structure of plant alpha-tubulins. Modeling of molecular surfaces of alpha-tubulins from Chloromonas, Chalmydomonas reinhardtii and goose grass Eleusine indica showed that insertion of the amino acid replacement M268-->V into the sequence of goose grace tubulin led to the likening of this protein surface to the surface of native alpha-tubulin from Chloromonas. Alteration of local hydrophobic properties of alpha-tubulin molecular surface in interdimeric contact zone as a result of the mentioned replacement was shown that may play important role in increasing the level of cold resistance of microtubules. The crucial role of amino acid residue in 268 position for forming the interdimeric contact surface of alpha-tubulin molecule was revealed. The assumption is made about the importance of replacements at this position for plant tolerance to abiotic factors of different nature (cold, herbicides).

  9. Nuclear γ-tubulin associates with nucleoli and interacts with tumor suppressor protein C53.

    Science.gov (United States)

    Hořejší, Barbora; Vinopal, Stanislav; Sládková, Vladimíra; Dráberová, Eduarda; Sulimenko, Vadym; Sulimenko, Tetyana; Vosecká, Věra; Philimonenko, Anatoly; Hozák, Pavel; Katsetos, Christos D; Dráber, Pavel

    2012-01-01

    γ-Tubulin is assumed to be a typical cytosolic protein necessary for nucleation of microtubules from microtubule organizing centers. Using immunolocalization and cell fractionation techniques in combination with siRNAi and expression of FLAG-tagged constructs, we have obtained evidence that γ-tubulin is also present in nucleoli of mammalian interphase cells of diverse cellular origins. Immunoelectron microscopy has revealed γ-tubulin localization outside fibrillar centers where transcription of ribosomal DNA takes place. γ-Tubulin was associated with nucleolar remnants after nuclear envelope breakdown and could be translocated to nucleoli during mitosis. Pretreatment of cells with leptomycin B did not affect the distribution of nuclear γ-tubulin, making it unlikely that rapid active transport via nuclear pores participates in the transport of γ-tubulin into the nucleus. This finding was confirmed by heterokaryon assay and time-lapse imaging of photoconvertible protein Dendra2 tagged to γ-tubulin. Immunoprecipitation from nuclear extracts combined with mass spectrometry revealed an association of γ-tubulin with tumor suppressor protein C53 located at multiple subcellular compartments including nucleoli. The notion of an interaction between γ-tubulin and C53 was corroborated by pull-down and co-immunoprecipitation experiments. Overexpression of γ-tubulin antagonized the inhibitory effect of C53 on DNA damage G(2) /M checkpoint activation. The combined results indicate that aside from its known role in microtubule nucleation, γ-tubulin may also have nuclear-specific function(s). Copyright © 2011 Wiley Periodicals, Inc.

  10. Inhibition of. beta. -bungarotoxin binding to brain membranes by mast cell degranulating peptide, toxin I, and ethylene glycol bis(. beta. -aminoethyl ether)-N,N,N',N'-tetraacetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.R.; Betz, H.; Rehm, H.

    1988-02-09

    The presynaptically active snake venom neurotoxin ..beta..-bungarotoxin (..beta..-Butx) is known to affect neurotransmitter release by binding to a subtype of voltage-activated K/sup +/ channels. Here the authors show that mast cell degranulating (MCD) peptide from bee venom inhibits the binding of /sup 125/I-labeled ..beta..-Butx to chick and rat brain membranes with apparent K/sub i/ values of 180 nM and 1100 nM, respectively. The mechanisms of inhibition of MCD peptide is noncompetitive, as is inhibition of /sup 125/I-..beta..-Butx binding by the protease inhibitor homologue from mamba venom, toxin I. ..beta..-Butx and its binding antagonists thus bind to different sites of the same membrane protein. Removal of Ca/sup 2 +/ by ethylene glycol bis(..beta..-aminoethyl ether)-N,N,N',N'-tetraacetic acid inhibits the binding of /sup 125/I-..beta..-Butx by lowering its affinity to brain membranes.

  11. Loss of γ-tubulin, GCP-WD/NEDD1 and CDK5RAP2 from the Centrosome of Neurons in Developing Mouse Cerebral and Cerebellar Cortex

    International Nuclear Information System (INIS)

    Yonezawa, Satoshi; Shigematsu, Momoko; Hirata, Kazuto; Hayashi, Kensuke

    2015-01-01

    It has been recently reported that the centrosome of neurons does not have microtubule nucleating activity. Microtubule nucleation requires γ-tubulin as well as its recruiting proteins, GCP-WD/NEDD1 and CDK5RAP2 that anchor γ-tubulin to the centrosome. Change in the localization of these proteins during in vivo development of brain, however, has not been well examined. In this study we investigate the localization of γ-tubulin, GCP-WD and CDK5RAP2 in developing cerebral and cerebellar cortex with immunofluorescence. We found that γ-tubulin and its recruiting proteins were localized at centrosomes of immature neurons, while they were lost at centrosomes in mature neurons. This indicated that the loss of microtubule nucleating activity at the centrosome of neurons is due to the loss of γ-tubulin-recruiting proteins from the centrosome. RT-PCR analysis revealed that these proteins are still expressed after birth, suggesting that they have a role in microtubule generation in cell body and dendrites of mature neurons. Microtubule regrowth experiments on cultured mature neurons showed that microtubules are nucleated not at the centrosome but within dendrites. These data indicated the translocation of microtubule-organizing activity from the centrosome to dendrites during maturation of neurons, which would explain the mixed polarity of microtubules in dendrites

  12. Absorptive-mediated endocytosis of cationized albumin and a beta-endorphin-cationized albumin chimeric peptide by isolated brain capillaries. Model system of blood-brain barrier transport

    International Nuclear Information System (INIS)

    Kumagai, A.K.; Eisenberg, J.B.; Pardridge, W.M.

    1987-01-01

    Cationized albumin (pI greater than 8), unlike native albumin (pI approximately 4), enters cerebrospinal fluid (CSF) rapidly from blood. This suggests that a specific uptake mechanism for cationized albumin may exist at the brain capillary wall, i.e. the blood-brain barrier. Isolated bovine brain capillaries rapidly bound cationized [ 3 H]albumin and approximately 70% of the bound radioactivity was resistant to mild acid wash, which is assumed to represent internalized peptide. Binding was saturable and a Scatchard plot gave a maximal binding capacity (Ro) = 5.5 +/- 0.7 micrograms/mgp (79 +/- 10 pmol/mgp), and a half-saturation constant (KD) = 55 +/- 8 micrograms/ml (0.8 +/- 0.1 microM). The binding of cationized [ 3 H]albumin (pI = 8.5-9) was inhibited by protamine, protamine sulfate, and polylysine (molecular weight = 70,000) with a Ki of approximately 3 micrograms/ml for all three proteins. The use of cationized albumin in directed delivery of peptides through the blood-brain barrier was examined by coupling [ 3 H]beta-endorphin to unlabeled cationized albumin (pI = 8.5-9) using the bifunctional reagent, N-succinimidyl 3-(2-pyridyldithio)proprionate. The [ 3 H]beta-endorphin-cationized albumin chimeric peptide was rapidly bound and endocytosed by isolated bovine brain capillaries, and this was inhibited by unlabeled cationized albumin but not by unconjugated beta-endorphin or native bovine albumin. Cationized albumin provides a new tool for studying absorptive-mediated endocytosis at the brain capillary and may also provide a vehicle for directed drug delivery through the blood-brain barrier

  13. Absorptive-mediated endocytosis of cationized albumin and a beta-endorphin-cationized albumin chimeric peptide by isolated brain capillaries. Model system of blood-brain barrier transport

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, A.K.; Eisenberg, J.B.; Pardridge, W.M.

    1987-11-05

    Cationized albumin (pI greater than 8), unlike native albumin (pI approximately 4), enters cerebrospinal fluid (CSF) rapidly from blood. This suggests that a specific uptake mechanism for cationized albumin may exist at the brain capillary wall, i.e. the blood-brain barrier. Isolated bovine brain capillaries rapidly bound cationized (/sup 3/H)albumin and approximately 70% of the bound radioactivity was resistant to mild acid wash, which is assumed to represent internalized peptide. Binding was saturable and a Scatchard plot gave a maximal binding capacity (Ro) = 5.5 +/- 0.7 micrograms/mgp (79 +/- 10 pmol/mgp), and a half-saturation constant (KD) = 55 +/- 8 micrograms/ml (0.8 +/- 0.1 microM). The binding of cationized (/sup 3/H)albumin (pI = 8.5-9) was inhibited by protamine, protamine sulfate, and polylysine (molecular weight = 70,000) with a Ki of approximately 3 micrograms/ml for all three proteins. The use of cationized albumin in directed delivery of peptides through the blood-brain barrier was examined by coupling (/sup 3/H)beta-endorphin to unlabeled cationized albumin (pI = 8.5-9) using the bifunctional reagent, N-succinimidyl 3-(2-pyridyldithio)proprionate. The (/sup 3/H)beta-endorphin-cationized albumin chimeric peptide was rapidly bound and endocytosed by isolated bovine brain capillaries, and this was inhibited by unlabeled cationized albumin but not by unconjugated beta-endorphin or native bovine albumin. Cationized albumin provides a new tool for studying absorptive-mediated endocytosis at the brain capillary and may also provide a vehicle for directed drug delivery through the blood-brain barrier.

  14. Correlation between cortical beta power and gait speed is suppressed in a parkinsonian model, but restored by therapeutic deep brain stimulation.

    Science.gov (United States)

    Polar, Christian A; Gupta, Rahul; Lehmkuhle, Mark J; Dorval, Alan D

    2018-05-30

    The motor cortex and subthalamic nucleus (STN) of patients with Parkinson's disease (PD) exhibit abnormally high levels of electrophysiological oscillations in the ~12-35 Hz beta-frequency range. Recent studies have shown that beta is partly carried forward to regulate future motor states in the healthy condition, suggesting that steady state beta power is lower when a sequence of movements occurs in a short period of time, such as during fast gait. However, whether this relationship between beta power and motor states persists upon parkinsonian onset or in response to effective therapy is unclear. Using a 6-hydroxy dopamine (6-OHDA) rat model of PD and a custom-built behavioral and neurophysiological recording system, we aimed to elucidate a better understanding of the mechanisms underlying cortical beta power and PD symptoms. In addition to elevated levels of beta oscillations, we show that parkinsonian onset was accompanied by a decoupling of movement intensity - quantified as gait speed - from cortical beta power. Although subthalamic deep brain stimulation (DBS) reduced general levels of beta oscillations in the cortex of all PD animals, the brain's capacity to regulate steady state levels of beta power as a function of movement intensity was only restored in animals with therapeutic DBS. We propose that, in addition to lowering general levels of cortical beta power, restoring the brain's ability to maintain this inverse relationship is critical for effective symptom suppression. Copyright © 2017. Published by Elsevier Inc.

  15. Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test.

    Science.gov (United States)

    Strekalova, Tatyana; Markova, Nataliia; Shevtsova, Elena; Zubareva, Olga; Bakhmet, Anastassia; Steinbusch, Harry M; Bachurin, Sergey; Lesch, Klaus-Peter

    2016-01-01

    While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.

  16. Arylthioindole inhibitors of tubulin polymerization. 3. Biological evaluation, structure-activity relationships and molecular modeling studies.

    Science.gov (United States)

    La Regina, Giuseppe; Edler, Michael C; Brancale, Andrea; Kandil, Sahar; Coluccia, Antonio; Piscitelli, Francesco; Hamel, Ernest; De Martino, Gabriella; Matesanz, Ruth; Díaz, José Fernando; Scovassi, Anna Ivana; Prosperi, Ennio; Lavecchia, Antonio; Novellino, Ettore; Artico, Marino; Silvestri, Romano

    2007-06-14

    The new arylthioindole (ATI) derivatives 10, 14-18, and 21-24, which bear a halogen atom or a small size ether group at position 5 of the indole moiety, were compared with the reference compounds colchicine and combretastatin A-4 for biological activity. Derivatives 10, 11, 16, and 21-24 inhibited MCF-7 cell growth with IC50 values <50 nM. A halogen atom (14-17) at position 5 caused a significant reduction in the free energy of binding of compound to tubulin, with a concomitant reduction in cytotoxicity. In contrast, methyl (21) and methoxy (22) substituents at position 5 caused an increase in cytotoxicity. Compound 16, the most potent antitubulin agent, led to a large increase (56%) in HeLa cells in the G2/M phase at 24 h, and at 48 h, 26% of the cells were hyperploid. Molecular modeling studies showed that, despite the absence of the ester moiety present in the previously examined analogues, most of the compounds bind in the colchicine site in the same orientation as the previously studied ATIs. Binding to beta-tubulin involved formation of a hydrogen bond between the indole and Thr179 and positioning of the trimethoxy phenyl group in a hydrophobic pocket near Cys241.

  17. Feeding cells induced by phytoparasitic nematodes require γ-tubulin ring complex for microtubule reorganization.

    Directory of Open Access Journals (Sweden)

    Mohamed Youssef Banora

    2011-12-01

    Full Text Available Reorganization of the microtubule network is important for the fast isodiametric expansion of giant-feeding cells induced by root-knot nematodes. The efficiency of microtubule reorganization depends on the nucleation of new microtubules, their elongation rate and activity of microtubule severing factors. New microtubules in plants are nucleated by cytoplasmic or microtubule-bound γ-tubulin ring complexes. Here we investigate the requirement of γ-tubulin complexes for giant feeding cells development using the interaction between Arabidopsis and Meloidogyne spp. as a model system. Immunocytochemical analyses demonstrate that γ-tubulin localizes to both cortical cytoplasm and mitotic microtubule arrays of the giant cells where it can associate with microtubules. The transcripts of two Arabidopsis γ-tubulin (TUBG1 and TUBG2 and two γ-tubulin complex proteins genes (GCP3 and GCP4 are upregulated in galls. Electron microscopy demonstrates association of GCP3 and γ-tubulin as part of a complex in the cytoplasm of giant cells. Knockout of either or both γ-tubulin genes results in the gene dose-dependent alteration of the morphology of feeding site and failure of nematode life cycle completion. We conclude that the γ-tubulin complex is essential for the control of microtubular network remodelling in the course of initiation and development of giant-feeding cells, and for the successful reproduction of nematodes in their plant hosts.

  18. Imidazoles and benzimidazoles as tubulin-modulators for anti-cancer therapy.

    Science.gov (United States)

    Torres, Fernando C; García-Rubiño, M Eugenia; Lozano-López, César; Kawano, Daniel F; Eifler-Lima, Vera L; von Poser, Gilsane L; Campos, Joaquín M

    2015-01-01

    Imidazoles and benzimidazoles are privileged heterocyclic bioactive compounds used with success in the clinical practice of innumerous diseases. Although there are many advancements in cancer therapy, microtubules remain as one of the few macromolecular targets validated for planning active anti-cancer compounds, and the design of drugs that modulate microtubule dynamics in unknown sites of tubulin is one of the goals of the medicinal chemistry. The discussion of the role of new and commercially available imidazole and benzimidazole derivatives as tubulin modulators is scattered throughout scientific literature, and indicates that these compounds have a tubulin modulation mechanism different from that of tubulin modulators clinically available, such as paclitaxel, docetaxel, vincristine and vinblastine. In fact, recent literature indicates that these derivatives inhibit microtubule formation binding to the colchicine site, present good pharmacokinetic properties and are capable of overcoming multidrug resistance in many cell lines. The understanding of the mechanisms involved in the imidazoles/benzimidazoles modulation of microtubule dynamics is very important to develop new strategies to overcome the resistance to anti-cancer drugs and to discover new biomarkers and targets for cancer chemotherapy.

  19. Significance of β-tubulin Expression in Breast Premalignant Lesions and Carcinomas

    Institute of Scientific and Technical Information of China (English)

    Yuxia Gao; Yun Niu; Xiumin Ding; Yong Yu

    2008-01-01

    OBJECTIVE To explore the expression of β-tubulin in premalignant lesions and carcinomas of the breast, and to observe the relationship of its expression with breast cancer pathological features.METHODS The expression of β-tubulin was detected immunohistochemically in 50 specimens of premalignant lesions of the breast (ADH and Peri-PM with ADH), 50 specimens of breast in situ ductal carcinomas (DCIS), and 50 specimens of invasive ductal carcinomas (IDC). Thirty specimens of normal breast tissues served as a control group.RESULTS Immunohistochemical analysis showed that: the differences among the 4 groups (normal breast tissues, breast premalignant lesions, DCIS and IDC, P < 0.05) were significant,and there were also statistically significant differences between any 2 groups (P < 0.05) except for the β-tubulin positive expression comparing DCIS versus IDC (P > 0.05). In addition, β-tubulin was expressed at a higher level in Peri-PM with ADH compared to ADH (P < 0.05). Following the degree of breast epithelial hyperplasia involved, and its development into carcinoma, the β-tubulin positive expression displayed an elevating tendency.We also found a significant positive relationship of β-tubulin expression with lymph node metastasis (P < 0.05), but no significant correlation with histological grading and nuclear grade.CONCLUSION Centrosome defects may be an early event in the development of breast cancer and they can also promote tumor progression. Studies of aberrations of centrosomal proteins provide a new way to explore the mechanism of breast tumorigenesis.

  20. Post-translational glutamylation and tyrosination in tubulin of tritrichomonads and the diplomonad Giardia intestinalis.

    Science.gov (United States)

    Boggild, A K; Sundermann, C A; Estridge, B H

    2002-01-01

    Glutamylated and tyrosinated tubulin were localized in Giardia intestinalis and selected trichomonads of the Tritrichomonadinae subfamily, using specific monoclonal antibodies directed at each of the post-translational modifications. Analysis was carried out using indirect immunofluorescence microscopy. Although trichomonad tubulins remained unlabeled by anti-tyrosine tubulin (TUB-1A2), the presence of the glutamylation motif (GT 335) was confirmed and found to differ in distribution among tritrichomonads. Tritrichomonas muris was most heavily labeled with GT 335, while T. foetus was the least so. Like trichomonads, Giardia was unreactive to anti-tyrosine tubulin; however, the GT 335 antibody produced marked fluorescence in Giardia trophozoites. This study is the first to report immunofluorescent localization of tubulin glutamylation in Giardia and confirms previously reported mass spectrometry data.

  1. YB-1 promotes microtubule assembly in vitro through interaction with tubulin and microtubules

    Directory of Open Access Journals (Sweden)

    Baconnais Sonia

    2008-09-01

    Full Text Available Abstract Background YB-1 is a major regulator of gene expression in eukaryotic cells. In addition to its role in transcription, YB-1 plays a key role in translation and stabilization of mRNAs. Results We show here that YB-1 interacts with tubulin and microtubules and stimulates microtubule assembly in vitro. High resolution imaging via electron and atomic force microscopy revealed that microtubules assembled in the presence of YB-1 exhibited a normal single wall ultrastructure and indicated that YB-1 most probably coats the outer microtubule wall. Furthermore, we found that YB-1 also promotes the assembly of MAPs-tubulin and subtilisin-treated tubulin. Finally, we demonstrated that tubulin interferes with RNA:YB-1 complexes. Conclusion These results suggest that YB-1 may regulate microtubule assembly in vivo and that its interaction with tubulin may contribute to the control of mRNA translation.

  2. Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test

    Directory of Open Access Journals (Sweden)

    Tatyana Strekalova

    2016-01-01

    Full Text Available While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.

  3. Comparison of (/sup 125/I)beta-endorphin binding to rat brain and NG108-15 cells using a monoclonal antibody directed against the opioid receptor

    Energy Technology Data Exchange (ETDEWEB)

    Bidlack, J.M.; O' Malley, W.E.; Schulz, R.

    1988-02-01

    The properties of (/sup 125/I)beta h-endorphin-binding sites from rat brain membranes and membranes from the NG108-15 cell line were compared using a monoclonal antibody directed against the opioid receptor and opioid peptides as probes. The binding of (/sup 125/I)beta h-endorphin to both rat brain and NG108-15 membranes yielded linear Scatchard plots with Kd values of 1.2 nM and 1.5 nM, respectively, and Bmax values of 865 fmol/mg rat brain membrane protein and 1077 fmol/mg NG108-15 membrane protein. A monoclonal antibody, OR-689.2.4, capable of inhibiting mu and delta binding but not kappa binding to rat brain membranes, noncompetitively inhibited the binding of 1 nM (/sup 125/I)beta h-endorphin to rat brain and NG108-15 membranes with an IC50 value of 405 nM for rat brain membranes and 543 nM for NG108-15 membranes. The monoclonal antibody also inhibited the binding of 3 nM (/sup 3/H) (D-penicillamine2, D-penicillamine5) enkephalin to NG108-15 membranes with an IC50 value of 370 nM. In addition to blocking the binding of (/sup 125/I)beta h-endorphin to brain membranes, the antibody also displaced (/sup 125/I)beta h-endorphin from membranes. Site-specific opioid peptides had large variations in their IC50 values depending on whether they were inhibiting (/sup 125/I)beta h-endorphin binding to rat brain or the NG108-15 membranes. When the peptides were tested with the monoclonal antibody for their combined ability to inhibit (/sup 125/I)beta h-endorphin binding to both membrane preparations, the peptides and antibody blocked binding as though they were acting at allosterically coupled sites, not two totally independent sites. These studies suggest that mu-, delta-, and beta-endorphin-binding sites share some sequence homology with the 35,000-dalton protein that the antibody is directed against.

  4. Brain Metastases from Lung Cancer Show Increased Expression of DVL1, DVL3 and Beta-Catenin and Down-Regulation of E-Cadherin

    Directory of Open Access Journals (Sweden)

    Anja Kafka

    2014-06-01

    Full Text Available The susceptibility of brain to secondary formation from lung cancer primaries is a well-known phenomenon. In contrast, the molecular basis for invasion and metastasis to the brain is largely unknown. In the present study, 31 brain metastases that originated from primary lung carcinomas were analyzed regarding over expression of Dishevelled-1 (DVL1, Dishevelled-3 (DVL3, E-cadherin (CDH1 and beta-catenin (CTNNB1. Protein expressions and localizations were analyzed by immunohistochemistry. Genetic alterations of E-cadherin were tested by polymerase chain reaction (PCR/loss of heterozygosity (LOH. Heteroduplex was used to investigate mutations in beta-catenin. DVL1 and DVL3 showed over expression in brain metastasis in 87.1% and 90.3% of samples respectively. Nuclear staining was observed in 54.8% of cases for DVL1 and 53.3% for DVL3. The main effector of the Wnt signaling, beta-catenin, was up-regulated in 56%, and transferred to the nucleus in 36% of metastases. When DVL1 and DVL3 were up-regulated the number of cases with nuclear beta-catenin significantly increased (p = 0.0001. Down-regulation of E-cadherin was observed in 80% of samples. Genetic analysis showed 36% of samples with LOH of the CDH1. In comparison to other lung cancer pathologies, the diagnoses adenocarcinoma and small cell lung cancer (SCLC were significantly associated to CDH1 LOH (p = 0.001. Microsatellite instability was detected in one metastasis from adenocarcinoma. Exon 3 of beta-catenin was not targeted. Altered expression of Dishevelled-1, Dishevelled-3, E-cadherin and beta-catenin were present in brain metastases which indicates that Wnt signaling is important and may contribute to better understanding of genetic profile conditioning lung cancer metastasis to the brain.

  5. Biallelic Mutations in TBCD, Encoding the Tubulin Folding Cofactor D, Perturb Microtubule Dynamics and Cause Early-Onset Encephalopathy.

    Science.gov (United States)

    Flex, Elisabetta; Niceta, Marcello; Cecchetti, Serena; Thiffault, Isabelle; Au, Margaret G; Capuano, Alessandro; Piermarini, Emanuela; Ivanova, Anna A; Francis, Joshua W; Chillemi, Giovanni; Chandramouli, Balasubramanian; Carpentieri, Giovanna; Haaxma, Charlotte A; Ciolfi, Andrea; Pizzi, Simone; Douglas, Ganka V; Levine, Kara; Sferra, Antonella; Dentici, Maria Lisa; Pfundt, Rolph R; Le Pichon, Jean-Baptiste; Farrow, Emily; Baas, Frank; Piemonte, Fiorella; Dallapiccola, Bruno; Graham, John M; Saunders, Carol J; Bertini, Enrico; Kahn, Richard A; Koolen, David A; Tartaglia, Marco

    2016-10-06

    Microtubules are dynamic cytoskeletal elements coordinating and supporting a variety of neuronal processes, including cell division, migration, polarity, intracellular trafficking, and signal transduction. Mutations in genes encoding tubulins and microtubule-associated proteins are known to cause neurodevelopmental and neurodegenerative disorders. Growing evidence suggests that altered microtubule dynamics may also underlie or contribute to neurodevelopmental disorders and neurodegeneration. We report that biallelic mutations in TBCD, encoding one of the five co-chaperones required for assembly and disassembly of the αβ-tubulin heterodimer, the structural unit of microtubules, cause a disease with neurodevelopmental and neurodegenerative features characterized by early-onset cortical atrophy, secondary hypomyelination, microcephaly, thin corpus callosum, developmental delay, intellectual disability, seizures, optic atrophy, and spastic quadriplegia. Molecular dynamics simulations predicted long-range and/or local structural perturbations associated with the disease-causing mutations. Biochemical analyses documented variably reduced levels of TBCD, indicating relative instability of mutant proteins, and defective β-tubulin binding in a subset of the tested mutants. Reduced or defective TBCD function resulted in decreased soluble α/β-tubulin levels and accelerated microtubule polymerization in fibroblasts from affected subjects, demonstrating an overall shift toward a more rapidly growing and stable microtubule population. These cells displayed an aberrant mitotic spindle with disorganized, tangle-shaped microtubules and reduced aster formation, which however did not alter appreciably the rate of cell proliferation. Our findings establish that defective TBCD function underlies a recognizable encephalopathy and drives accelerated microtubule polymerization and enhanced microtubule stability, underscoring an additional cause of altered microtubule dynamics with

  6. Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, S.V.; Changeux, J.P.; Granon, S. [Unite de Neurobiologie Integrative du Systeme Cholinergique, URA CNRS 2182, Institut Pasteur, Departement de Neuroscience, 25 rue du Dr Roux, 75015 Paris (France); Amadon, A.; Giacomini, E.; Le Bihan, D. [Service Hospitalier Frederic Joliot, 4 place du general Leclerc, 91400 Orsay (France); Wiklund, A. [Section of Anaesthesiology and Intensive Care Medicine, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm (Sweden)

    2009-07-01

    Rationale: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity {beta}2-containing nicotinic receptors ({beta}2*nAChRs) are located. Objectives We intend to see which brain circuits are activated when nicotine is given in animals naive for nicotine and whether the {beta}2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. Materials and methods: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and {beta}2 knockout (KO) mice. Results: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, {beta}2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via {alpha}7 nicotinic receptors. Conclusions: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on {beta}2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice. (authors)

  7. Role of delta-tubulin and the C-tubule in assembly of Paramecium basal bodies

    Directory of Open Access Journals (Sweden)

    Beisson Janine

    2001-03-01

    Full Text Available Abstract Background A breakthrough in the understanding of centriole assembly was provided by the characterization of the UNI3 gene in Chlamydomonas. Deletion of this gene, found to encode a novel member of the tubulin superfamily, delta-tubulin, results in the loss of the C-tubule, in the nine microtubule triplets which are the hallmark of centrioles and basal bodies. Delta-tubulin homologs have been identified in the genomes of mammals and protozoa, but their phylogenetic relationships are unclear and their function is not yet known. Results Using the method of gene-specific silencing, we have inactivated the Paramecium delta-tubulin gene, which was recently identified. This inactivation leads to loss of the C-tubule in all basal bodies, without any effect on ciliogenesis. This deficiency does not directly affect basal body duplication, but perturbs the cortical cytoskeleton, progressively leading to mislocalization and loss of basal bodies and to altered cell size and shape. Furthermore, additional loss of B- and even A-tubules at one or more triplet sites are observed: around these incomplete cylinders, the remaining doublets are nevertheless positioned according to the native ninefold symmetry. Conclusions The fact that in two distinct phyla, delta-tubulin plays a similar role provides a new basis for interpreting phylogenetic relationships among delta-tubulins. The role of delta-tubulin in C-tubule assembly reveals that tubulins contribute subtle specificities at microtubule nucleation sites. Our observations also demonstrate the existence of a prepattern for the ninefold symmetry of the organelle which is maintained even if less than 9 triplets develop.

  8. Six subgroups and extensive recent duplications characterize the evolution of the eukaryotic tubulin protein family.

    Science.gov (United States)

    Findeisen, Peggy; Mühlhausen, Stefanie; Dempewolf, Silke; Hertzog, Jonny; Zietlow, Alexander; Carlomagno, Teresa; Kollmar, Martin

    2014-08-27

    Tubulins belong to the most abundant proteins in eukaryotes providing the backbone for many cellular substructures like the mitotic and meiotic spindles, the intracellular cytoskeletal network, and the axonemes of cilia and flagella. Homologs have even been reported for archaea and bacteria. However, a taxonomically broad and whole-genome-based analysis of the tubulin protein family has never been performed, and thus, the number of subfamilies, their taxonomic distribution, and the exact grouping of the supposed archaeal and bacterial homologs are unknown. Here, we present the analysis of 3,524 tubulins from 504 species. The tubulins formed six major subfamilies, α to ζ. Species of all major kingdoms of the eukaryotes encode members of these subfamilies implying that they must have already been present in the last common eukaryotic ancestor. The proposed archaeal homologs grouped together with the bacterial TubZ proteins as sister clade to the FtsZ proteins indicating that tubulins are unique to eukaryotes. Most species contained α- and/or β-tubulin gene duplicates resulting from recent branch- and species-specific duplication events. This shows that tubulins cannot be used for constructing species phylogenies without resolving their ortholog-paralog relationships. The many gene duplicates and also the independent loss of the δ-, ε-, or ζ-tubulins, which have been shown to be part of the triplet microtubules in basal bodies, suggest that tubulins can functionally substitute each other. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  9. Dictyoceratidan poisons: Defined mark on microtubule-tubulin dynamics.

    Science.gov (United States)

    Gnanambal K, Mary Elizabeth; Lakshmipathy, Shailaja Vommi

    2016-03-01

    Tubulin/microtubule assembly and disassembly is characterized as one of the chief processes during cell growth and division. Hence drugs those perturb these process are considered to be effective in killing fast multiplying cancer cells. There is a collection of natural compounds which disturb microtubule/tubulin dis/assemblage and there have been a lot of efforts concerted in the marine realm too, to surveying such killer molecules. Close to half the natural compounds shooting out from marine invertebrates are generally with no traceable definite mechanisms of action though may be tough anti-cancerous hits at nanogram levels, hence fatefully those discoveries conclude therein without a capacity of translation from laboratory to pharmacy. Astoundingly at least 50% of natural compounds which have definite mechanisms of action causing disorders in tubulin/microtubule kinetics have an isolation history from sponges belonging to the Phylum: Porifera. Poriferans have always been a wonder worker to treat cancers with a choice of, yet precise targets on cancerous tissues. There is a specific order: Dictyoceratida within this Phylum which has contributed to yielding at least 50% of effective compounds possessing this unique mechanism of action mentioned above. However, not much notice is driven to Dictyoceratidans alongside the order: Demospongiae thus dictating the need to know its select microtubule/tubulin irritants since the unearthing of avarol in the year 1974 till date. Hence this review selectively pinpoints all the compounds, noteworthy derivatives and analogs stemming from order: Dictyoceratida focusing on the past, present and future. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Interhemispheric EEG differences in olfactory bulbectomized rats with different cognitive abilities and brain beta-amyloid levels.

    Science.gov (United States)

    Bobkova, Natalia; Vorobyov, Vasily; Medvinskaya, Natalia; Aleksandrova, Irina; Nesterova, Inna

    2008-09-26

    Alterations in electroencephalogram (EEG) asymmetry and deficits in interhemispheric integration of information have been shown in patients with Alzheimer's disease (AD). However, no direct evidence of an association between EEG asymmetry, morphological markers in the brain, and cognition was found either in AD patients or in AD models. In this study we used rats with bilateral olfactory bulbectomy (OBX) as one of the AD models and measured their learning/memory abilities, brain beta-amyloid levels and EEG spectra in symmetrical frontal and occipital cortices. One year after OBX or sham-surgery, the rats were tested with the Morris water paradigm and assigned to three groups: sham-operated rats, SO, and OBX rats with virtually normal, OBX(+), or abnormal, OBX(-), learning (memory) abilities. In OBX vs. SO, the theta EEG activity was enhanced to a higher extent in the right frontal cortex and in the left occipital cortex. This produced significant interhemispheric differences in the frontal cortex of the OBX(-) rats and in the occipital cortex of both OBX groups. The beta1 EEG asymmetry in SO was attenuated in OBX(+) and completely eliminated in OBX(-). OBX produced highly significant beta2 EEG decline in the right frontal cortex, with OBX(-)>OBX(+) rank order of strength. The beta-amyloid level, examined by post-mortem immunological DOT-analysis in the cortex-hippocampus samples, was about six-fold higher in OBX(-) than in SO, but significantly less (enhanced by 82% vs. SO) in OBX(+) than in OBX(-). The involvement of the brain mediatory systems in the observed EEG asymmetry differences is discussed.

  11. Rapid and sensitive determination of beta-phenylethylamine in animal brains by high performance liquid chromatography with fluorometric detection.

    Science.gov (United States)

    Taga, C; Tsuji, M; Nakajima, T

    1989-05-01

    A reversed phase HPLC method with fluorometric detection for the analysis of beta-phenylethylamine has been developed using p-methoxyphenylethylamine as an internal standard. Two columns, containing 200 microL of Dowex 50-X8 and Amberlite CG-50 respectively, were used to prepare a fraction containing beta-phenylethylamine. The recoveries of beta-phenylethylamine and p-methoxyphenylethylamine were 53.9 +/- 9.4% and 68.1 +/- 12.4%, respectively, and elution profile of p-methoxyphenylethylamine was sufficiently well correlated with that of beta-phenylethylamine. Regional distributions of beta-phenylethylamine in rat and mouse brains were determined. The highest concentrations were found in hypothalamus and hippocampus in both animals.

  12. Aluminum complexing enhances amyloid beta protein penetration of blood-brain barrier.

    Science.gov (United States)

    Banks, William A; Niehoff, Michael L; Drago, Denise; Zatta, Paolo

    2006-10-20

    A significant co-morbidity of Alzheimer's disease and cerebrovascular impairment suggests that cerebrovascular dysregulation is an important feature of dementia. Amyloid beta protein (Abeta), a relevant risk factor in Alzheimer's disease, has neurotoxic properties and is thought to play a critical role in the cognitive impairments. Previously, we demonstrated that the 42mer of Abeta (Abeta42) complexed with aluminum (Al-Abeta42) is much more cytotoxic than non-complexed Abeta42. The level of Abeta in the brain is a balance between synthesis, degradation, and fluxes across the blood-brain barrier (BBB). In the present paper, we determined whether complexing with aluminum affected the ability of radioactively iodinated Abeta to cross the in vivo BBB. We found that the rates of uptake of Al-Abeta42 and Abeta42 were similar, but that Al-Abeta42 was sequestered by brain endothelial cells much less than Abeta42 and so more readily entered the parenchymal space of the brain. Al-Abeta42 also had a longer half-life in blood and had increased permeation at the striatum and thalamus. Brain-to-blood transport was similar for Al-Abeta42 and Abeta42. In conclusion, complexing with aluminum affects some aspects of blood-to-brain permeability so that Al-Abeta42 would have more ready access to brain cells than Abeta42.

  13. Acetylated tubulin is essential for touch sensation in mice.

    Science.gov (United States)

    Morley, Shane J; Qi, Yanmei; Iovino, Loredana; Andolfi, Laura; Guo, Da; Kalebic, Nereo; Castaldi, Laura; Tischer, Christian; Portulano, Carla; Bolasco, Giulia; Shirlekar, Kalyanee; Fusco, Claudia M; Asaro, Antonino; Fermani, Federica; Sundukova, Mayya; Matti, Ulf; Reymond, Luc; De Ninno, Adele; Businaro, Luca; Johnsson, Kai; Lazzarino, Marco; Ries, Jonas; Schwab, Yannick; Hu, Jing; Heppenstall, Paul A

    2016-12-13

    At its most fundamental level, touch sensation requires the translation of mechanical energy into mechanosensitive ion channel opening, thereby generating electro-chemical signals. Our understanding of this process, especially how the cytoskeleton influences it, remains unknown. Here we demonstrate that mice lacking the α-tubulin acetyltransferase Atat1 in sensory neurons display profound deficits in their ability to detect mechanical stimuli. We show that all cutaneous afferent subtypes, including nociceptors have strongly reduced mechanosensitivity upon Atat1 deletion, and that consequently, mice are largely insensitive to mechanical touch and pain. We establish that this broad loss of mechanosensitivity is dependent upon the acetyltransferase activity of Atat1, which when absent leads to a decrease in cellular elasticity. By mimicking α-tubulin acetylation genetically, we show both cellular rigidity and mechanosensitivity can be restored in Atat1 deficient sensory neurons. Hence, our results indicate that by influencing cellular stiffness, α-tubulin acetylation sets the force required for touch.

  14. The modulatory effect of adaptive deep brain stimulation on beta bursts in Parkinson's disease

    NARCIS (Netherlands)

    Tinkhauser, Gerd; Pogosyan, Alek; Little, Simon; Beudel, Martijn; Herz, Damian M.; Tan, Huiling; Brown, Peter

    Adaptive deep brain stimulation uses feedback about the state of neural circuits to control stimulation rather than delivering fixed stimulation all the time, as currently performed. In patients with Parkinson's disease, elevations in beta activity (13-35 Hz) in the subthalamic nucleus have been

  15. Molecular recognition of epothilones by microtubules and tubulin dimers revealed by biochemical and NMR approaches.

    Science.gov (United States)

    Canales, Angeles; Nieto, Lidia; Rodríguez-Salarichs, Javier; Sánchez-Murcia, Pedro A; Coderch, Claire; Cortés-Cabrera, Alvaro; Paterson, Ian; Carlomagno, Teresa; Gago, Federico; Andreu, José M; Altmann, Karl-Heinz; Jiménez-Barbero, Jesús; Díaz, J Fernando

    2014-04-18

    The binding of epothilones to dimeric tubulin and to microtubules has been studied by means of biochemical and NMR techniques. We have determined the binding constants of epothilone A (EpoA) and B (EpoB) to dimeric tubulin, which are 4 orders of magnitude lower than those for microtubules, and we have elucidated the conformation and binding epitopes of EpoA and EpoB when bound to tubulin dimers and microtubules in solution. The determined conformation of epothilones when bound to dimeric tubulin is similar to that found by X-ray crystallographic techniques for the binding of EpoA to the Tubulin/RB3/TTL complex; it is markedly different from that reported for EpoA bound to zinc-induced sheets obtained by electron crystallography. Likewise, only the X-ray structure of EpoA bound to the Tubulin/RB3/TTL complex at the luminal site, but not the electron crystallography structure, is compatible with the results obtained by STD on the binding epitope of EpoA bound to dimeric tubulin, thus confirming that the allosteric change (structuring of the M-loop) is the biochemical mechanism of induction of tubulin assembly by epothilones. TR-NOESY signals of EpoA bound to microtubules have been obtained, supporting the interaction with a transient binding site with a fast exchange rate (pore site), consistent with the notion that epothilones access the luminal site through the pore site, as has also been observed for taxanes. Finally, the differences in the tubulin binding affinities of a series of epothilone analogues has been quantitatively explained using the newly determined binding pose and the COMBINE methodology.

  16. Polyamine sharing between tubulin dimers favours microtubule nucleation and elongation via facilitated diffusion.

    Directory of Open Access Journals (Sweden)

    Alain Mechulam

    2009-01-01

    Full Text Available We suggest for the first time that the action of multivalent cations on microtubule dynamics can result from facilitated diffusion of GTP-tubulin to the microtubule ends. Facilitated diffusion can promote microtubule assembly, because, upon encountering a growing nucleus or the microtubule wall, random GTP-tubulin sliding on their surfaces will increase the probability of association to the target sites (nucleation sites or MT ends. This is an original explanation for understanding the apparent discrepancy between the high rate of microtubule elongation and the low rate of tubulin association at the microtubule ends in the viscous cytoplasm. The mechanism of facilitated diffusion requires an attraction force between two tubulins, which can result from the sharing of multivalent counterions. Natural polyamines (putrescine, spermidine, and spermine are present in all living cells and are potent agents to trigger tubulin self-attraction. By using an analytical model, we analyze the implication of facilitated diffusion mediated by polyamines on nucleation and elongation of microtubules. In vitro experiments using pure tubulin indicate that the promotion of microtubule assembly by polyamines is typical of facilitated diffusion. The results presented here show that polyamines can be of particular importance for the regulation of the microtubule network in vivo and provide the basis for further investigations into the effects of facilitated diffusion on cytoskeleton dynamics.

  17. A wireless beta-microprobe based on pixelated silicon for in vivo brain studies in freely moving rats

    Science.gov (United States)

    Märk, J.; Benoit, D.; Balasse, L.; Benoit, M.; Clémens, J. C.; Fieux, S.; Fougeron, D.; Graber-Bolis, J.; Janvier, B.; Jevaud, M.; Genoux, A.; Gisquet-Verrier, P.; Menouni, M.; Pain, F.; Pinot, L.; Tourvielle, C.; Zimmer, L.; Morel, C.; Laniece, P.

    2013-07-01

    The investigation of neurophysiological mechanisms underlying the functional specificity of brain regions requires the development of technologies that are well adjusted to in vivo studies in small animals. An exciting challenge remains the combination of brain imaging and behavioural studies, which associates molecular processes of neuronal communications to their related actions. A pixelated intracerebral probe (PIXSIC) presents a novel strategy using a submillimetric probe for beta+ radiotracer detection based on a pixelated silicon diode that can be stereotaxically implanted in the brain region of interest. This fully autonomous detection system permits time-resolved high sensitivity measurements of radiotracers with additional imaging features in freely moving rats. An application-specific integrated circuit (ASIC) allows for parallel signal processing of each pixel and enables the wireless operation. All components of the detector were tested and characterized. The beta+ sensitivity of the system was determined with the probe dipped into radiotracer solutions. Monte Carlo simulations served to validate the experimental values and assess the contribution of gamma noise. Preliminary implantation tests on anaesthetized rats proved PIXSIC's functionality in brain tissue. High spatial resolution allows for the visualization of radiotracer concentration in different brain regions with high temporal resolution.

  18. Microtubule protein ADP-ribosylation in vitro leads to assembly inhibition and rapid depolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Scaife, R.M. (Fred Hutchinson Cancer Research Center, Seattle, WA (United States)); Wilson, L. (Univ. of California, Santa Barbara (United States)); Purich, D.L. (Univ. of Florida, Gainesville (United States))

    1992-01-14

    Bovine brain microtubule protein, containing both tubulin and microtubule-associated proteins, undergoes ADP-ribosylation in the presence of ({sup 14}C)NAD{sup +} and a turkey erythrocyte mono-ADP-ribosyltransferase in vitro. The modification reaction could be demonstrated in crude brain tissue extracts where selective ADP-ribosylation of both the {alpha} and {beta} chains of tubulin and of the high molecular weight microtubule-associated protein MAP-2 occurred. In experiments with purified microtubule protein, tubulin dimer, the high molecular weight microtubule-associated protein MAP-2, and another high molecular weight microtubule-associated protein which may be a MAP-1 species were heavily labeled. Tubulin and MAP-2 incorporated ({sup 14}C)ADP-ribose to an average extent of approximately 2.4 and 30 mol of ADP-ribose/mol of protein, respectively. Assembly of microtubule protein into microtubules in vitro was inhibited by ADP-ribosylation, and incubation of assembled steady-state microtubules with ADP-ribosyltransferase and NAD{sup +} resulted in rapid depolymerization of the microtubules. Thus, the eukaryotic enzyme can ADP-ribosylate tubulin and microtubule-associated proteins to much greater extents than previously observed with cholera and pertussis toxins, and the modification can significantly modulate microtubule assembly and disassembly.

  19. Indicine N-oxide binds to tubulin at a distinct site and inhibits the assembly of microtubules: a mechanism for its cytotoxic activity.

    Science.gov (United States)

    Appadurai, Prakash; Rathinasamy, Krishnan

    2014-02-10

    Indicine N-oxide, a pyrrolizidine alkaloid present in the plant Heliotropium indicum had shown promising cytotoxic activity in various tumor models. The compound exhibited severe toxicity to hepatocytes and bone marrow cells. The present work was aimed to evaluate the molecular mechanism of the toxicity of indicine N-oxide. We found that indicine N-oxide inhibited the proliferation of various cancer cell lines in a concentration dependent manner with IC50 ranging from 46 to 100 μM. At the half maximal inhibitory concentration it blocked the cell cycle progression at mitosis without significantly altering the organization of the spindle and interphase microtubules. The toxicities of the compound at higher concentrations are attributed to its severe depolymerizing effect on both the interphase and spindle microtubules. Binding studies using purified goat brain tubulin indicated that indicine N-oxide binds to tubulin at a distinct site not shared by colchicine or taxol. It decreased the polymer mass of both purified tubulin and MAP-rich tubulin. It was found to induce cleavage of DNA using pUC18 plasmid. The interactions of indicine N-oxide on DNA were also confirmed by computational analysis; which predicted its binding site at the minor groove of DNA. These studies bring to light that the toxicities of indicine N-oxide were due to its DNA damaging effects and depolymerization of microtubules. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. Measurement of antibodies to tubulin by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Mead, G M; Cowin, P; Whitehouse, J M.A. [CRC Medical Oncology Unit, Southampton General Hospital, Southampton, U.K.

    1979-07-24

    A solid-phase double antibody radioimmunoassay capable of measuring antibody to tubulin, the principal component of microtubules, is described. This assay is simple, combining sensitivity with specificity and also allowing determination of antibody subclasses.

  1. SKLB060 Reversibly Binds to Colchicine Site of Tubulin and Possesses Efficacy in Multidrug-Resistant Cell Lines.

    Science.gov (United States)

    Yan, Wei; Yang, Tao; Yang, Jianhong; Wang, Taijin; Yu, Yamei; Wang, Yuxi; Chen, Qiang; Bai, Peng; Li, Dan; Ye, Haoyu; Qiu, Qiang; Zhou, Yongzhao; Hu, Yiguo; Yang, Shengyong; Wei, Yuquan; Li, Weimin; Chen, Lijuan

    2018-05-22

    Many tubulin inhibitors are in clinical use as anti-cancer drugs. In our previous study, a novel series of 4-substituted coumarins derivatives were identified as novel tubulin inhibitors. Here, we report the anti-cancer activity and underlying mechanism of one of the 4-substituted coumarins derivatives (SKLB060). The anti-cancer activity of SKLB060 was tested on 13 different cancer cell lines and four xenograft cancer models. Immunofluorescence staining, cell cycle analysis, and tubulin polymerization assay were employed to study the inhibition of tubulin. N, N '-Ethylenebis(iodoacetamide) assay was used to measure binding to the colchicine site. Wound-healing migration and tube formation assays were performed on human umbilical vascular endothelial cells to study anti-vascular activity (the ability to inhibit blood vessel growth). Mitotic block reversibility and structural biology assays were used to investigate the SKLB060-tubulin bound model. SKLB060 inhibited tubulin polymerization and subsequently induced G2/M cell cycle arrest and apoptosis in cancer cells. SKLB060 bound to the colchicine site of β-tubulin and showed antivascular activity in vitro. Moreover, SKLB060 induced reversible cell cycle arrest and reversible inhibition of tubulin polymerization. A mitotic block reversibility assay showed that the effects of SKLB060 have greater reversibility than those of colcemid (a reversible tubulin inhibitor), indicating that SKLB060 binds to tubulin in a totally reversible manner. The crystal structures of SKLB060-tubulin complexes confirmed that SKLB060 binds to the colchicine site, and the natural coumarin ring in SKLB060 enables reversible binding. These results reveal that SKLB060 is a powerful and reversible microtubule inhibitor that binds to the colchicine site and is effective in multidrug-resistant cell lines. © 2018 The Author(s). Published by S. Karger AG, Basel.

  2. The tubulins of animals, plants, fungi and protists implications for metazoan evolution

    Science.gov (United States)

    Little, Melvyn; Ludueña, Richard F.; Morejohn, Louis C.; Asnes, Clara; Hoffman, Eugene

    1984-03-01

    α-Tubulin subunits from trout (S. gairdneri) sperm tails, sea urchin (S. purpuratus) cilia, protistan alga (C. elongatum) flagella and rose (Paul's Scarlet) cytoplasm have been characterized by limited proteolytic cleavage with the enzymeStaphylococcus aureus protease and electrophoresis of the digestion products on SDS-PAGE. The resulting patterns corresponded to either of two major types representative of animal and non-animal α-tubulins, respectively. A total of 28 α-tubulins have now been characterized by this method. They are classified in this paper according to the type of cleavage pattern generated by the enzymeS. aureus protease. The implications of these results for metazoan evolution are discussed.

  3. NCBI nr-aa BLAST: CBRC-MMUR-01-0199 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-MMUR-01-0199 emb|CAX75788.1| Tubulin beta-2C chain [Schistosoma japonicum] emb...|CAX75790.1| Tubulin beta-2C chain [Schistosoma japonicum] emb|CAX75791.1| Tubulin beta-2C chain [Schistosoma japonicum] CAX75788.1 2e-31 82% ...

  4. Down-regulated βIII-tubulin Expression Can Reverse Paclitaxel Resistance in A549/Taxol Cells Lines

    Directory of Open Access Journals (Sweden)

    Yinling ZHUO

    2014-08-01

    Full Text Available Background and objective Chemotherapy drug resistance is the primary causes of death in patients with pulmonary carcinoma which make tumor recurrence or metastasis. β-tubulin is the main cell targets of anti-microtubule drug. Increased expression of βIII-tubulin has been implicated in non-small cell lung cancer (NSCLC cell lines. To explore the relationship among the expression level of βIII-tubulin and the sensitivity of A549/Taxolcell lines to Taxol and cell cycles and cell apoptosis by RNA interference-mediated inhibition of βIII-tubulin in A549/Taxol cells. Methods Three pairs of siRNA targetd βIII-tubulin were designed and prepared, which were transfected into A549/Taxol cells using LipofectamineTM 2000. We detected the expression of βIII-tubulin mRNA using Real-time fluorescence qRT-PCR. Tedhen we selected the most efficient siRNA by the expression of βIII-tubulin mRNA in transfected group. βIII-tubulin protein level were mesured by Western blot. The taxol sensitivity in transfected group were evaluated by MTT assay. And the cell apoptosis and cell cycles were determined by flow cytometry. Results βIII-tubulin mRNA levels in A549/Taxol cells were significantly decreased in transfected grop by Real-time qRT-PCR than control groups. And βIII-tubulin siRNA-1 sequence showed the highest transfection efficiency, which was (87.73±4.87% (P<0.01; Western blot results showed that the expressional level of BIII tublin protein was significantly down-reulated in the transfectant cells than thant in the control cells. By MTT assay, we showed that the inhibition ratio of Taxol to A549/Taxol cells transfeced was higher than that of control group (51.77±4.60% (P<0.01. The early apoptosis rate of A549/Taxol cells in transfected group were significantly higher than that of control group (P<0.01; G2-M content in taxol group obviously increased than untreated samples by the cell cycle (P<0.05. Conclusion βIII-tubulin down-regulated significantly

  5. Genetic Analysis of Resistance to Benzimidazoles in Physarum: Differential Expression of β-Tubulin Genes

    Science.gov (United States)

    Burland, Timothy G.; Schedl, Tim; Gull, Keith; Dove, William F.

    1984-01-01

    Physarum displays two vegetative cell types, uninucleate myxamoebae and multinucleate plasmodia. Mutant myxamoebae of Physarum resistant to the antitubulin drug methylbenzimidazole-2-yl-carbamate (MBC) were isolated. All mutants tested were cross-resistant to other benzimidazoles but not to cycloheximide or emetine. Genetic analysis showed that mutation to MBC resistance can occur at any one of four unlinked loci, benA, benB, benC or benD. MBC resistance of benB and benD mutants was expressed in plasmodia, but benA and benC mutant plasmodia were MBC sensitive, suggesting that benA and benC encode myxamoeba-specific products. Myxamoebae carrying the recessive benD210 mutation express a β-tubulin with noval electrophoretic mobility, in addition to a β-tubulin with wild-type mobility. This and other evidence indicates that benD is a structural gene for β-tubulin, and that at least two β-tubulin genes are expressed in myxamoebae. Comparisons of the β-tubulins of wildtype and benD210 strains by gel electrophoresis revealed that, of the three (or more) β-tubulin genes expressed in Physarum, one, benD, is expressed in both myxamoebae and plasmodia, one is expressed specifically in myxamoebae and one is expressed specifically in plasmodia. However, mutation in only one gene, benD, is sufficient to confer MBC resistance on both myxamoebae and plasmodia. PMID:6479584

  6. Blood supply to the brain and. beta. -endorphin and acth levels under the influence of thyrotrophin releasing hormone

    Energy Technology Data Exchange (ETDEWEB)

    Mirzoyan, R.S.; Ganshina, T.S.; Mirzoyan, R.A.; Ragimov, K.S.

    1985-08-01

    The authors studied beta-endorphin because of its possible mediator role in terms of the cerebrovascular effects of thyrotrophin releasing hormone (TRH), and also because of data in the literature on antagonistic relations between TRH and the endogenous opioid system of the brain. Beta-endorphin was determined by radioimmunoassay; its level was determined after its separation from the beta-lipotrophin fraction. The investigation showed that TRH has a marked depressant effect on cerebrovascular vasoconstrictor refleces. Elevation of the blood ACTH level causes an increase in BP and in the tone of the cerebral vessels. An absence of correlation between the beta-endorphin and ACTH levels in the blood and CSF under the influence of TRH is shown.

  7. Exploring the binding sites and binding mechanism for hydrotrope encapsulated griseofulvin drug on γ-tubulin protein.

    Directory of Open Access Journals (Sweden)

    Shubhadip Das

    Full Text Available The protein γ-tubulin plays an important role in centrosomal clustering and this makes it an attractive therapeutic target for treating cancers. Griseofulvin, an antifungal drug, has recently been used to inhibit proliferation of various types of cancer cells. It can also affect the microtubule dynamics by targeting the γ-tubulin protein. So far, the binding pockets of γ-tubulin protein are not properly identified and the exact mechanism by which the drug binds to it is an area of intense speculation and research. The aim of the present study is to investigate the binding mechanism and binding affinity of griseofulvin on γ-tubulin protein using classical molecular dynamics simulations. Since the drug griseofulvin is sparingly soluble in water, here we also present a promising approach for formulating and achieving delivery of hydrophobic griseofulvin drug via hydrotrope sodium cumene sulfonate (SCS cluster. We observe that the binding pockets of γ-tubulin protein are mainly formed by the H8, H9 helices and S7, S8, S14 strands and the hydrophobic interactions between the drug and γ-tubulin protein drive the binding process. The release of the drug griseofulvin from the SCS cluster is confirmed by the coordination number analysis. We also find hydrotrope-induced alteration of the binding sites of γ-tubulin protein and the weakening of the drug-protein interactions.

  8. γ-Tubulin complex in Trypanosoma brucei: molecular composition, subunit interdependence and requirement for axonemal central pair protein assembly.

    Science.gov (United States)

    Zhou, Qing; Li, Ziyin

    2015-11-01

    γ-Tubulin complex constitutes a key component of the microtubule-organizing center and nucleates microtubule assembly. This complex differs in complexity in different organisms: the budding yeast contains the γ-tubulin small complex (γTuSC) composed of γ-tubulin, gamma-tubulin complex protein (GCP)2 and GCP3, whereas animals contain the γ-tubulin ring complex (γTuRC) composed of γTuSC and three additional proteins, GCP4, GCP5 and GCP6. In Trypanosoma brucei, the composition of the γ-tubulin complex remains elusive, and it is not known whether it also regulates assembly of the subpellicular microtubules and the spindle microtubules. Here we report that the γ-tubulin complex in T. brucei is composed of γ-tubulin and three GCP proteins, GCP2-GCP4, and is primarily localized in the basal body throughout the cell cycle. Depletion of GCP2 and GCP3, but not GCP4, disrupted the axonemal central pair microtubules, but not the subpellicular microtubules and the spindle microtubules. Furthermore, we showed that the γTuSC is required for assembly of two central pair proteins and that γTuSC subunits are mutually required for stability. Together, these results identified an unusual γ-tubulin complex in T. brucei, uncovered an essential role of γTuSC in central pair protein assembly, and demonstrated the interdependence of individual γTuSC components for maintaining a stable complex. © 2015 John Wiley & Sons Ltd.

  9. Genome-wide identification, phylogenetic classification, and exon-intron structure characterisation of the tubulin and actin genes in flax (Linum usitatissimum).

    Science.gov (United States)

    Pydiura, Nikolay; Pirko, Yaroslav; Galinousky, Dmitry; Postovoitova, Anastasiia; Yemets, Alla; Kilchevsky, Aleksandr; Blume, Yaroslav

    2018-06-08

    Flax (Linum usitatissimum L.) is a valuable food and fiber crop cultivated for its quality fiber and seed oil. α-, β-, γ-tubulins and actins are the main structural proteins of the cytoskeleton. α- and γ-tubulin and actin genes have not been characterized yet in the flax genome. In this study, we have identified 6 α-tubulin genes, 13 β-tubulin genes, 2 γ-tubulin genes, and 15 actin genes in the flax genome and analysed the phylogenetic relationships between flax and A. thaliana tubulin and actin genes. Six α-tubulin genes are represented by 3 paralogous pairs, among 13 β-tubulin genes 7 different isotypes can be distinguished, 6 of which are encoded by two paralogous genes each. γ-tubulin is represented by a paralogous pair of genes one of which may be not functional. Fifteen actin genes represent 7 paralogous pairs - 7 actin isotypes and a sequentially duplicated copy of one of the genes of one of the isotypes. Exon-intron structure analysis has shown intron length polymorphism within the β-tubulin genes and intron number variation among the α-tubulin gene: 3 or 4 introns are found in two or four genes, respectively. Intron positioning occurs at conservative sites, as observed in numerous other plant species. Flax actin genes show both intron length polymorphisms and variation in the number of intron that may be 2 or 3. These data will be useful to support further studies on the specificity, functioning, regulation and evolution of the flax cytoskeleton proteins. This article is protected by copyright. All rights reserved.

  10. SPECT imaging of dopamine and serotonin transporters with [[sup 123]I][beta]-CIT. Binding kinetics in the human brain

    Energy Technology Data Exchange (ETDEWEB)

    Bruecke, T; Asenbaum, S; Frassine, H; Podreka, I [Vienna Univ. (Austria). Neurologische Klinik; Kornhuber, J [Wuerzburg Univ. (Germany); Angelberger, P [Oesterreichisches Forschungszentrum Seibersdorf GmbH (Austria)

    1993-01-01

    Single photon emission computerized tomography (SPECT) studies in non-human primates have previously shown that the cocaine derivative [[sup 123]I]-2-[beta]-carbomethoxy-3-[beta]-(4-iodophenyl)-tropane ([[sup 123]I][beta]-CIT) labels dopamine transporters in the striatum and serotonin transporters in the hypothalamus-midbrain area. Here, we report on the regional kinetic uptake of [[sup 123]I][beta]-CIT in the brain of 4 normal volunteers and 2 patients with Parkinson's disease. In healthy subjects striatal activity increased slowly to reach peak values at about 20 hours post injection. In the hypothalamus-midbrain area peak activities were observed at about 4 hours with a slow decrease thereafter. Low activity was observed in cortical and cerebellar areas. The striatal to cerebellar ratio was about 4 after 5 hours and 9 after 20 hours. In 2 patients with idiopathic Parkinson's disease striatal activity was markedly decreased while the activity in hypothalamus-midbrain areas was only diminished. Uptake into cortical and cerebellar areas appeared to be unchanged in Parkinson's disease. Consequently, in Parkinson's disease the striatal to cerebellar ratio was decreased to values around 2.5 after 20 hours. These preliminary methodological studies suggest that [[sup 123]I][beta]-CIT is a useful SPECT ligand for studying dopamine and possibly also serotonin transporters in the living human brain.

  11. {beta} - amyloid imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

  12. Complexes of γ-tubulin with nonreceptor protein tyrosine kinases Src and Fyn in differentiating P19 embryonal carcinoma cells

    International Nuclear Information System (INIS)

    Kukharskyy, Vitaliy; Sulimenko, Vadym; Macurek, Libor; Sulimenko, Tetyana; Draberova, Eduarda; Draber, Pavel

    2004-01-01

    Nonreceptor protein tyrosine kinases of the Src family have been shown to play an important role in signal transduction as well as in regulation of microtubule protein interactions. Here we show that γ-tubulin (γ-Tb) in P19 embryonal carcinoma cells undergoing neuronal differentiation is phosphorylated and forms complexes with protein tyrosine kinases of the Src family, Src and Fyn. Elevated expression of both kinases during differentiation corresponded with increased level of proteins phosphorylated on tyrosine. Immunoprecipitation experiments with antibodies against Src, Fyn, γ-tubulin, and with anti-phosphotyrosine antibody revealed that γ-tubulin appeared in complexes with these kinases. In vitro kinase assays showed tyrosine phosphorylation of proteins in γ-tubulin complexes isolated from differentiated cells. Pretreatment of cells with Src family selective tyrosine kinase inhibitor PP2 reduced the amount of phosphorylated γ-tubulin in the complexes. Binding experiments with recombinant SH2 and SH3 domains of Src and Fyn kinases revealed that protein complexes containing γ-tubulin bound to SH2 domains and that these interactions were of SH2-phosphotyrosine type. The combined data suggest that Src family kinases might have an important role in the regulation of γ-tubulin interaction with tubulin dimers or other proteins during neurogenesis

  13. GEC1, a protein related to GABARAP, interacts with tubulin and GABAA receptor

    International Nuclear Information System (INIS)

    Mansuy, Virginie; Boireau, Wilfrid; Fraichard, Annick; Schlick, Jean-Luc; Jouvenot, Michele; Delage-Mourroux, Regis

    2004-01-01

    We have previously identified in uterine cells a novel estrogen-regulated gene called gec1. GEC1 presents 87% identity with GABARAP which, so far, was the only protein found to associate with tubulin and GABA A receptor. We demonstrated then that GEC1 interacts in vitro with tubulin and GABA A receptor, and promotes tubulin assembly and microtubule bundling. Since all polyclonal antibodies failed in discrimination of both proteins GEC1 and GABARAP, a GEC1-GFP fusion protein was used to specifically localize GEC1. GEC1-GFP was distributed over the cytoplasm in perinuclear vesicles with a scattered pattern. Overall, our data show that GEC1 could be a new member of the GABARAP family involved in the transport of GABA A receptor

  14. XMAP215 is a microtubule nucleation factor that functions synergistically with the γ-tubulin ring complex.

    Science.gov (United States)

    Thawani, Akanksha; Kadzik, Rachel S; Petry, Sabine

    2018-05-01

    How microtubules (MTs) are generated in the cell is a major question in understanding how the cytoskeleton is assembled. For several decades, γ-tubulin has been accepted as the universal MT nucleator of the cell. Although there is evidence that γ-tubulin complexes are not the sole MT nucleators, identification of other nucleation factors has proven difficult. Here, we report that the well-characterized MT polymerase XMAP215 (chTOG/Msps/Stu2p/Alp14/Dis1 homologue) is essential for MT nucleation in Xenopus egg extracts. The concentration of XMAP215 determines the extent of MT nucleation. Even though XMAP215 and the γ-tubulin ring complex (γ-TuRC) possess minimal nucleation activity individually, together, these factors synergistically stimulate MT nucleation in vitro. The amino-terminal TOG domains 1-5 of XMAP215 bind to αβ-tubulin and promote MT polymerization, whereas the conserved carboxy terminus is required for efficient MT nucleation and directly binds to γ-tubulin. In summary, XMAP215 and γ-TuRC together function as the principal nucleation module that generates MTs in cells.

  15. GIT1/beta PIX signaling proteins and PAK1 kinase regulate microtubule nucleation

    Czech Academy of Sciences Publication Activity Database

    Černohorská, Markéta; Sulimenko, Vadym; Hájková, Zuzana; Sulimenko, Tetyana; Sládková, Vladimíra; Vinopal, Stanislav; Dráberová, Eduarda; Dráber, Pavel

    2016-01-01

    Roč. 1863, č. 6 (2016), s. 1282-1297 ISSN 0167-4889 R&D Projects: GA ČR GAP302/12/1673; GA ČR GA15-22194S; GA MŠk LH12050; GA MZd NT14467; GA ČR GA16-23702S Institutional support: RVO:68378050 Keywords : Centrosome * Microtubule nucleation * gamma-tubulin * GIT1/beta PIX signaling proteins * PAK1 kinase Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.521, year: 2016

  16. A carrier for non-covalent delivery of functional beta-galactosidase and antibodies against amyloid plaques and IgM to the brain.

    Directory of Open Access Journals (Sweden)

    Gobinda Sarkar

    Full Text Available BACKGROUND: Therapeutic intervention of numerous brain-associated disorders currently remains unrealized due to serious limitations imposed by the blood-brain-barrier (BBB. The BBB generally allows transport of small molecules, typically <600 daltons with high octanol/water partition coefficients, but denies passage to most larger molecules. However, some receptors present on the BBB allow passage of cognate proteins to the brain. Utilizing such receptor-ligand systems, several investigators have developed methods for delivering proteins to the brain, a critical requirement of which involves covalent linking of the target protein to a carrier entity. Such covalent modifications involve extensive preparative and post-preparative chemistry that poses daunting limitations in the context of delivery to any organ. Here, we report creation of a 36-amino acid peptide transporter, which can transport a protein to the brain after routine intravenous injection of the transporter-protein mixture. No covalent linkage of the protein with the transporter is necessary. APPROACH: A peptide transporter comprising sixteen lysine residues and 20 amino acids corresponding to the LDLR-binding domain of apolipoprotein E (ApoE was synthesized. Transport of beta-galactosidase, IgG, IgM, and antibodies against amyloid plques to the brain upon iv injection of the protein-transporter mixture was evaluated through staining for enzyme activity or micro single photon emission tomography (micro-SPECT or immunostaining. Effect of the transporter on the integrity of the BBB was also investigated. PRINCIPAL FINDINGS: The transporter enabled delivery to the mouse brain of functional beta-galactosidase, human IgG and IgM, and two antibodies that labeled brain-associated amyloid beta plaques in a mouse model of Alzheimer's disease. SIGNIFICANCE: The results suggest the transporter is able to transport most or all proteins to the brain without the need for chemically linking the

  17. On the nature and shape of tubulin trails: implications on microtubule self-organization.

    Science.gov (United States)

    Glade, Nicolas

    2012-06-01

    Microtubules, major elements of the cell skeleton are, most of the time, well organized in vivo, but they can also show self-organizing behaviors in time and/or space in purified solutions in vitro. Theoretical studies and models based on the concepts of collective dynamics in complex systems, reaction-diffusion processes and emergent phenomena were proposed to explain some of these behaviors. In the particular case of microtubule spatial self-organization, it has been advanced that microtubules could behave like ants, self-organizing by 'talking to each other' by way of hypothetic (because never observed) concentrated chemical trails of tubulin that are expected to be released by their disassembling ends. Deterministic models based on this idea yielded indeed like-looking spatio-temporal self-organizing behaviors. Nevertheless the question remains of whether microscopic tubulin trails produced by individual or bundles of several microtubules are intense enough to allow microtubule self-organization at a macroscopic level. In the present work, by simulating the diffusion of tubulin in microtubule solutions at the microscopic scale, we measure the shape and intensity of tubulin trails and discuss about the assumption of microtubule self-organization due to the production of chemical trails by disassembling microtubules. We show that the tubulin trails produced by individual microtubules or small microtubule arrays are very weak and not elongated even at very high reactive rates. Although the variations of concentration due to such trails are not significant compared to natural fluctuations of the concentration of tubuline in the chemical environment, the study shows that heterogeneities of biochemical composition can form due to microtubule disassembly. They could become significant when produced by numerous microtubule ends located in the same place. Their possible formation could play a role in certain conditions of reaction. In particular, it gives a mesoscopic

  18. The free energy profile of tubulin straight-bent conformational changes, with implications for microtubule assembly and drug discovery.

    Directory of Open Access Journals (Sweden)

    Lili X Peng

    2014-02-01

    Full Text Available αβ-tubulin dimers need to convert between a 'bent' conformation observed for free dimers in solution and a 'straight' conformation required for incorporation into the microtubule lattice. Here, we investigate the free energy landscape of αβ-tubulin using molecular dynamics simulations, emphasizing implications for models of assembly, and modulation of the conformational landscape by colchicine, a tubulin-binding drug that inhibits microtubule polymerization. Specifically, we performed molecular dynamics, potential-of-mean force simulations to obtain the free energy profile for unpolymerized GDP-bound tubulin as a function of the ∼12° intradimer rotation differentiating the straight and bent conformers. Our results predict that the unassembled GDP-tubulin heterodimer exists in a continuum of conformations ranging between straight and bent, but, in agreement with existing structural data, suggests that an intermediate bent state has a lower free energy (by ∼1 kcal/mol and thus dominates in solution. In agreement with predictions of the lattice model of microtubule assembly, lateral binding of two αβ-tubulins strongly shifts the conformational equilibrium towards the straight state, which is then ∼1 kcal/mol lower in free energy than the bent state. Finally, calculations of colchicine binding to a single αβ-tubulin dimer strongly shifts the equilibrium toward the bent states, and disfavors the straight state to the extent that it is no longer thermodynamically populated.

  19. The effect of altered 5-hydroxytryptamine levels on beta-endorphin

    Science.gov (United States)

    Soliman, Karam F. A.; Mash, Deborah C.; Walker, Charles A.

    1986-01-01

    The purpose of the present study was to examine the effect of altering the concentration of 5-hydroxytryptamine (5-HT) on beta-endorphin (beta-Ep) content in the hypothalamus, thalamus, and periaqueductal gray (PAG)-rostral pons regions of the rat brain. The selective 5-HT reuptake inhibitor, fluoxetine (10 mg/kg), significantly lowered beta-Ep content in the hypothalamus and the PAG. Parachlorophenylalanine, which inhibits 5-HT synthesis, significantly elevated beta-Ep in all brain parts studied. Intracisternal injections of the neurotoxin 5-prime, 7-prime-dihydroxytryptamine with desmethylimipramine pretreatment significantly increased beta-Ep content in the hypothalamus and the PAG. In adrenalectomized rats, fluoxetine significantly decreased beta-Ep levels in the hypothalamus and increased the levels in the PAG. The results indicate that 5-HT may modulate the levels of brain beta-Ep.

  20. Alpha-tubulin missense mutations correlate with antimicrotubule drug resistance in Eleusine indica.

    Science.gov (United States)

    Yamamoto, E; Zeng, L; Baird, W V

    1998-02-01

    Dinitroaniline herbicides are antimicrotubule drugs that bind to tubulins and inhibit polymerization. As a result of repeated application of dinitroaniline herbicides, highly resistant and intermediately resistant biotypes of goosegrass (Eleusine indica) developed in previously wild-type populations. Three alpha-tubulin cDNA classes (designated TUA1, TUA2, and TUA3) were isolated from each biotype. Nucleotide differences between the susceptible and the resistant (R) alpha-tubulins were identified in TUA1 and TUA2. The most significant differences were missense mutations that occurred in TUA1 of the R and intermediately resistant (I) biotypes. Such mutations convert Thr-239 to Ile in the R biotype and Met-268 to Thr in the I biotype. These amino acid substitutions alter hydrophobicity; therefore, they may alter the dinitroaniline binding property of the protein. These mutations were correlated with the dinitroaniline response phenotypes (Drp). Plants homozygous for susceptibility possessed the wild-type TUA1 allele; plants homozygous for resistance possessed the mutant tua1 allele; and plants heterozygous for susceptibility possessed both wild-type and mutant alleles. Thus, we conclude that TUA1 is at the Drp locus. Using polymerase chain reaction primer-introduced restriction analysis, we demonstrated that goosegrass genomic DNA can be diagnosed for Drp alleles. Although not direct proof, these results suggest that a mutation in an alpha-tubulin gene confers resistance to dinitroanilines in goosegrass.

  1. Crystallization and preliminary X-ray analysis of tubulin-folding cofactor A from Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Lu, Lu; Nan, Jie; Mi, Wei; Wei, Chun-Hong; Li, Lan-Fen; Li, Yi

    2010-01-01

    Tubulin-folding cofactor A from A. thaliana has been crystallized and preliminarily analyzed using X-ray diffraction. Tubulin-folding cofactor A (TFC A) is a molecular post-chaperonin that is involved in the β-tubulin-folding pathway. It has been identified in many organisms including yeasts, humans and plants. In this work, Arabidopsis thaliana TFC A was expressed in Escherichia coli and purified to homogeneity. After thrombin cleavage, a well diffracting crystal was obtained by the sitting-drop vapour-diffusion method at 289 K. The crystal diffracted to 1.6 Å resolution using synchrotron radiation and belonged to space group I4 1 , with unit-cell parameters a = 55.0, b = 55.0, c = 67.4 Å

  2. Hexavalent chromium-induced differential disruption of cortical microtubules in some Fabaceae species is correlated with acetylation of α-tubulin.

    Science.gov (United States)

    Eleftheriou, Eleftherios P; Adamakis, Ioannis-Dimosthenis S; Michalopoulou, Vasiliki A

    2016-03-01

    The effects of hexavalent chromium [Cr(VI)] on the cortical microtubules (MTs) of five species of the Fabaceae family (Vicia faba, Pisum sativum, Vigna sinensis, Vigna angularis, and Medicago sativa) were investigated by confocal laser scanning microscopy after immunolocalization of total tubulin with conventional immunofluorescence techniques and of acetylated α-tubulin with the specific 6-11B-1 monoclonal antibody. Moreover, total α-tubulin and acetylated α-tubulin were quantified by Western immunoblotting and scanning densitometry. Results showed the universality of Cr(VI) detrimental effects to cortical MTs, which proved to be a sensitive and reliable subcellular marker for monitoring Cr(VI) toxicity in plant cells. However, a species-specific response was recorded, and a correlation of MT disturbance with the acetylation status of α-tubulin was demonstrated. In V. faba, MTs were depolymerized at the gain of cytoplasmic tubulin background and displayed low α-tubulin acetylation, while in P. sativum, V. sinensis, V. angularis, and M. sativa, MTs became bundled and changed orientation from perpendicular to oblique or longitudinal. Bundled MTs were highly acetylated as determined by both immunofluorescence and Western immunoblotting. Tubulin acetylation in P. sativum and M. sativa preceded MT bundling; in V. sinensis it followed MT derangement, while in V. angularis the two phenomena coincided. Total α-tubulin remained constant in all treatments. Should acetylation be an indicator of MT stabilization, it is deduced that bundled MTs became stabilized, lost their dynamic properties, and were rendered inactive. Results of this report allow the conclusion that Cr(VI) toxicity disrupts MTs and deranges the MT-mediated functions either by depolymerizing or stabilizing them.

  3. The γ-tubulin complex in Trypanosoma brucei: molecular composition, subunit interdependence and requirement for axonemal central pair protein assembly

    Science.gov (United States)

    Zhou, Qing; Li, Ziyin

    2015-01-01

    The γ-tubulin complex constitutes a key component of the microtubule-organizing center and nucleates microtubule assembly. This complex differs in complexity in different organisms: the budding yeast contains the γ-tubulin small complex (γTuSC) composed of γ-tubulin, GCP2 and GCP3, whereas animals contain the γ-tubulin ring complex (γTuRC) composed of γTuSC and three additional proteins, GCP4, GCP5 and GCP6. In Trypanosoma brucei, the composition of the γ-tubulin complex remains elusive, and it is not known whether it also regulates assembly of the subpellicular microtubules and the spindle microtubules. Here we report that the γ-tubulin complex in T. brucei is composed of γ-tubulin and three GCP proteins, GCP2-GCP4, and is primarily localized in the basal body throughout the cell cycle. Depletion of GCP2 and GCP3, but not GCP4, disrupted the axonemal central pair microtubules, but not the subpellicular microtubules and the spindle microtubules. Furthermore, we showed that the γTuSC is required for assembly of two central pair proteins and that γTuSC subunits are mutually required for stability. Together, these results identified an unusual γ-tubulin complex in T. brucei, uncovered an essential role of γTuSC in central pair protein assembly, and demonstrated the interdependence of individual γTuSC components for maintaining a stable complex. PMID:26224545

  4. Versatile and Efficient Site-Specific Protein Functionalization by Tubulin Tyrosine Ligase.

    Science.gov (United States)

    Schumacher, Dominik; Helma, Jonas; Mann, Florian A; Pichler, Garwin; Natale, Francesco; Krause, Eberhard; Cardoso, M Cristina; Hackenberger, Christian P R; Leonhardt, Heinrich

    2015-11-09

    A novel chemoenzymatic approach for simple and fast site-specific protein labeling is reported. Recombinant tubulin tyrosine ligase (TTL) was repurposed to attach various unnatural tyrosine derivatives as small bioorthogonal handles to proteins containing a short tubulin-derived recognition sequence (Tub-tag). This novel strategy enables a broad range of high-yielding and fast chemoselective C-terminal protein modifications on isolated proteins or in cell lysates for applications in biochemistry, cell biology, and beyond, as demonstrated by the site-specific labeling of nanobodies, GFP, and ubiquitin. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. A tripartite mode of action approach for investigating the impact of aneugens on tubulin polymerization.

    Science.gov (United States)

    Stock, Valerie; Sutter, Andreas; Raschke, Marian; Queisser, Nina

    2018-04-01

    Chemical-induced disruption of the cellular microtubule network is one key mechanism of aneugenicity. Since recent data indicate that genotoxic effects of aneugens show nonlinear dose-response relationships, margins of safety can be derived with the ultimate goal to perform a risk assessment for the support of drug development. Furthermore, microtubule-interacting compounds are widely used for cancer treatment. While there is a need to support the risk assessment of tubulin-interacting chemicals using reliable mechanistic assays, no standard assays exist to date in regulatory genotoxicity testing for the distinction of aneugenic mechanisms. Recently reported methods exclusively rely on either biochemical, morphological, or cytometric endpoints. Since data requirements for the diverse fields of application of those assays differ strongly, the use of multiple assays for a correct classification of aneugens is ideal. We here report a tripartite mode of action approach comprising a cell-free biochemical polymerization assay and the cell-based methods cellular imaging and flow cytometry. The biochemical assay measures tubulin polymerization over time whereas the two cell-based assays quantify tubulin polymer mass. We herein show that the flow cytometric method yielded IC 50 values for tubulin destabilizers and EC 50 values for tubulin stabilizers as well as cell cycle information. In contrast, cellular imaging complemented these findings with characteristic morphological patterns. Biochemical analysis yielded kinetic information on tubulin polymerization. This multiplex approach is able to create holistic effect profiles which can be individually customized to the research question with regard to quality, quantity, usability, and economy. Environ. Mol. Mutagen. 59:188-201, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. Synthesis, anticancer activity, and inhibition of tubulin polymerization by conformationally restricted analogues of lavendustin A.

    Science.gov (United States)

    Mu, Fanrong; Hamel, Ernest; Lee, Debbie J; Pryor, Donald E; Cushman, Mark

    2003-04-24

    Compounds in the lavendustin A series have been shown to inhibit both protein-tyrosine kinases (PTKs) and tubulin polymerization. Since certain lavendustin A derivatives can exist in conformations that resemble both the trans-stilbene structure of the PTK inhibitor piceatannol and the cis-stilbene structure of the tubulin polymerization inhibitor combretastatin A-4, the possibility exists that the ratio of the two types of activities of the lavendustins could be influenced through the synthesis of conformationally restricted analogues. Accordingly, the benzylaniline structure of a series of pharmacologically active lavendustin A fragments was replaced by either their cis- or their trans-stilbene relatives, and effects on both inhibition of tubulin polymerization and cytotoxicity in cancer cell cultures were monitored. Both dihydrostilbene and 1,2-diphenylalkyne congeners were also prepared and evaluated biologically. Surprisingly, conformational restriction of the bridge between the two aromatic rings of the lavendustins had no significant effect on biological activity. On the other hand, conversion of the three phenolic hydroxyl groups of the lavendustin A derivatives to their corresponding methyl ethers consistently abolished their ability to inhibit tubulin polymerization and usually decreased cytotoxicity in cancer cell cultures as well, indicating the importance of at least one of the phenolic hydroxyl groups. Further investigation suggested that the phenolic hydroxyl group in the salicylamide ring was required for activity, while the two phenol moieties in the hydroquinone ring could be methylated with retention of activity. Two of the lavendustin A derivatives displayed IC(50) values of 1.4 microM for inhibition of tubulin polymerization, which ranks them among the most potent of the known tubulin polymerization inhibitors.

  7. Vitamin K3 disrupts the microtubule networks by binding to tubulin: a novel mechanism of its antiproliferative activity.

    Science.gov (United States)

    Acharya, Bipul R; Choudhury, Diptiman; Das, Amlan; Chakrabarti, Gopal

    2009-07-28

    Vitamin K3 (2-methyl-1,4-naphthoquinone), also known as menadione, is the synthetic precursor of all the naturally occurring vitamin K in the body. Vitamin K is necessary for the production of prothrombin and five other blood-clotting factors in humans. We have examined the effects of menadione on cellular microtubules ex vivo as well as its binding with purified tubulin and microtubules in vitro. Cell viability experiments using human cervical epithelial cancer cells (HeLa) and human oral epithelial cancer cells (KB) indicated that the IC(50) values for menadione are 25.6 +/- 0.6 and 64.3 +/- 0.36 microM, respectively, in those cells. Mendione arrests HeLa cells in mitosis. Immunofluorescence studies using an anti-alpha-tubulin antibody showed a significant irreversible depolymeriztion of the interphase microtubule network and spindle microtubule in a dose-dependent manner. In vitro polymerization of purified tubulin into microtubules is inhibited by menadione with an IC(50) value of 47 +/- 0.65 microM. The binding of menadione with tubulin was studied using menadione fluorescence and intrinsic tryptophan fluorescence of tubulin. Binding of menadione to tubulin is slow, taking 35 min for equilibration at 25 degrees C. The association reaction kinetics is biphasic in nature, and the association rate constants for fast and slow phases are 189.12 +/- 17 and 32.44 +/- 21 M(-1) s(-1) at 25 degrees C, respectively. The stoichiometry of menadione binding to tubulin is 1:1 (molar ratio) with a dissociation constant from 2.44 +/- 0.34 to 3.65 +/- 0.25 microM at 25 degrees C. Menadione competes for the colchicine binding site with a K(i) of 2.5 muM as determined from a modified Dixon plot. The obtained data suggested that menadione binds at the colchicine binding site to tubulin. Thus, we can conclude one novel mechanism of inhibition of cancer cell proliferation by menadione is through tubulin binding.

  8. Mutations in Human Tubulin Proximal to the Kinesin-Binding Site Alter Dynamic Instability at Microtubule Plus- and Minus-Ends

    Energy Technology Data Exchange (ETDEWEB)

    Ti, Shih-Chieh; Pamula, Melissa C.; Howes, Stuart C.; Duellberg, Christian; Cade, Nicholas I.; Kleiner, Ralph E.; Forth, Scott; Surrey, Thomas; Nogales, Eva; Kapoor, Tarun M.

    2016-04-01

    The assembly of microtubule-based cellular structures depends on regulated tubulin polymerization and directional transport. In this research, we have purified and characterized tubulin heterodimers that have human β-tubulin isotype III (TUBB3), as well as heterodimers with one of two β-tubulin mutations (D417H or R262H). Both point mutations are proximal to the kinesin-binding site and have been linked to an ocular motility disorder in humans. Compared to wild-type, microtubules with these mutations have decreased catastrophe frequencies and increased average lifetimes of plus- and minus-end-stabilizing caps. Importantly, the D417H mutation does not alter microtubule lattice structure or Mal3 binding to growing filaments. Instead, this mutation reduces the affinity of tubulin for TOG domains and colchicine, suggesting that the distribution of tubulin heterodimer conformations is changed. Together, our findings reveal how residues on the surface of microtubules, distal from the GTP-hydrolysis site and inter-subunit contacts, can alter polymerization dynamics at the plus- and minus-ends of microtubules.

  9. Tubulin binding cofactor C (TBCC) suppresses tumor growth and enhances chemosensitivity in human breast cancer cells

    International Nuclear Information System (INIS)

    Hage-Sleiman, Rouba; Herveau, Stéphanie; Matera, Eva-Laure; Laurier, Jean-Fabien; Dumontet, Charles

    2010-01-01

    Microtubules are considered major therapeutic targets in patients with breast cancer. In spite of their essential role in biological functions including cell motility, cell division and intracellular transport, microtubules have not yet been considered as critical actors influencing tumor cell aggressivity. To evaluate the impact of microtubule mass and dynamics on the phenotype and sensitivity of breast cancer cells, we have targeted tubulin binding cofactor C (TBCC), a crucial protein for the proper folding of α and β tubulins into polymerization-competent tubulin heterodimers. We developed variants of human breast cancer cells with increased content of TBCC. Analysis of proliferation, cell cycle distribution and mitotic durations were assayed to investigate the influence of TBCC on the cell phenotype. In vivo growth of tumors was monitored in mice xenografted with breast cancer cells. The microtubule dynamics and the different fractions of tubulins were studied by time-lapse microscopy and lysate fractionation, respectively. In vitro sensitivity to antimicrotubule agents was studied by flow cytometry. In vivo chemosensitivity was assayed by treatment of mice implanted with tumor cells. TBCC overexpression influenced tubulin fraction distribution, with higher content of nonpolymerizable tubulins and lower content of polymerizable dimers and microtubules. Microtubule dynamicity was reduced in cells overexpressing TBCC. Cell cycle distribution was altered in cells containing larger amounts of TBCC with higher percentage of cells in G2-M phase and lower percentage in S-phase, along with slower passage into mitosis. While increased content of TBCC had little effect on cell proliferation in vitro, we observed a significant delay in tumor growth with respect to controls when TBCC overexpressing cells were implanted as xenografts in vivo. TBCC overexpressing variants displayed enhanced sensitivity to antimicrotubule agents both in vitro and in xenografts. These

  10. Expression and localization of tubulin cofactors TBCD and TBCE in human gametes.

    Science.gov (United States)

    Jiménez-Moreno, Victoria; Agirregoitia, Ekaitz

    2017-06-01

    The tubulin cofactors TBCD and TBCE play an essential role in regulation of the microtubule dynamics in a wide variety of somatic cells, but little information is known about the expression of these cofactors in human sperm and oocytes. In this study, we focused on the investigation of the presence of, and the differential distribution of, the tubulin cofactors TBCD and TBCE in human sperm and during human oocyte maturation. We performed expression assays for TBCD and TBCE by reverse transcription-polymerase chain reaction (RT-PCR), western blot and immunofluorescence and verified the presence of both cofactors in human gametes. TBCD and TBCE were located mainly in the middle region and in the tail of the sperm while in the oocyte the localization was cytosolic. The mRNA of both tubulin cofactors were present in the human oocytes but not in sperm cells. This finding gives a first insight into where TBCD and TBCE could carry out their function in the continuous changes that the cytoskeleton experiences during gametogenesis and also prior to fertilization.

  11. A new model for separation between brain dopamine and serotonin transporters in {sup 123}I-{beta}-CIT SPECT measurements: normal values and sex and age dependence

    Energy Technology Data Exchange (ETDEWEB)

    Ryding, Erik; Rosen, Ingmar [Department of Clinical Neurophysiology, University Hospital, Lund (Sweden); Lindstroem, Mats; Bosson, Peter; Traeskman-Bendz, Lil [Department of Psychiatry, University Hospital, Lund (Sweden); Braadvik, Bjoern; Grabowski, Martin [Department of Neurology, University Hospital, Lund (Sweden)

    2004-08-01

    {sup 123}I-{beta}-CIT is a radioactive ligand for single-photon emission computed tomography (SPECT) imaging of the pre-synaptic (transporter) re-uptake sites for dopamine (DAT) and serotonin (5HTT), and it is widely used to visualize monoamine turnover. Since {sup 123}I-{beta}-CIT uptake occurs at 5HTT and DAT sites in conjunction with the presence of freely soluble {sup 123}I-{beta}-CIT in brain tissue, adequate separation of these three components is necessary. However, only partial separation is possible with current methods. Two main strategies have previously been used for {sup 123}I-{beta}-CIT component separation, based on the following considerations: (1) the faster uptake rate for 5HTT compared with DAT enables temporal separation by performing 5HTT imaging at 1-2 h and DAT imaging at 20-24 h; (2) blocking the 5HTT re-uptake with citalopram renders {sup 123}I-{beta}-CIT imaging DAT (non-5HTT) specific. In a new analytical model, we combined these two approaches with methods to isolate the passively dissolved {sup 123}I-{beta}-CIT in brain tissue from the monoamine transporter uptake, and to correct the 5HTT and DAT values for concomitant uptake. The new analytical model was used to study brain 5HTT and DAT in 23 normal subjects, with the aim of clarifying the effect of age and sex. A significant correlation between 5HTT and DAT values was found only in the thalamus, indicating successful component separation. Negative correlations between age and DAT were found for basal ganglia, thalami, brain stem and temporal lobes, but not for the frontal, parietal or occipital regions. No correlation with age was found for 5HTT. We found no sex difference for 5HTT or DAT. (orig.)

  12. [{sup 18}F]{beta}-CIT-FP is superior to [{sup 11}C]{beta}-CIT-FP for quantitation of the dopamine transporter

    Energy Technology Data Exchange (ETDEWEB)

    Lundkvist, Camilla; Halldin, Christer; Ginovart, Nathalie; Swahn, Carl-Gunnar; Farde, Lars

    1997-10-01

    {beta}-CIT-FP [N-(3-fluoropropyl)-2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)nortropane] is a cocaine analogue with high affinity for the dopamine transporter. Positron emission tomography (PET) studies with [O-methyl-{sup 11}C]{beta}-CIT-FP ([{sup 11}C]{beta}-CIT-FP) has shown that equilibrium conditions were approached but, however, not reached at the end of measurement. Moreover, metabolite studies of [{sup 11}C]{beta}-CIT-FP in monkey plasma demonstrated a lipophilic-labelled metabolite that may enter the brain. We therefore labelled {beta}-CIT-FP with fluorine-18 in a position that may avoid the formation of labelled lipophilic metabolites. The more long-lived radionuclide ({sup 18}F) was used to allow for measurements over longer time. [N-fluoropropyl-{sup 18}F]{beta}-CIT-FP ([{sup 18}F]{beta}-CIT-FP) was prepared by N-alkylation of nor-{beta}-CIT with [{sup 18}F]fluoropropyl bromide. PET studies were performed in cynomolgus monkeys. [{sup 18}F]{beta}-CIT-FP entered the brain rapidly. There was a high concentration of radioactivity in the striatum and much lower in the thalamus, neocortex, and cerebellum. The striatum-to-cerebellum ratio was about 5 at time of transient equilibrium, which occurred after 60 to 100 min. After pretreatment with GBR 12909, radioactivity in the striatum was markedly reduced, thus indicating specific [{sup 18}F]{beta}-CIT-FP binding to the dopamine transporter. The fraction of unchanged [{sup 18}F]{beta}-CIT-FP determined by HPLC was 10-15% after 140 min. No lipophilic labelled metabolites were detected. The absence of measurable lipophilic labelled metabolites and the occurrence of transient equilibrium within the time of the PET measurement indicate that [{sup 18}F]{beta}-CIT-FP is superior to [{sup 11}C]{beta}-CIT-FP as a PET radioligand for quantification of the dopamine transporter in the human brain.

  13. Anticancer activity of a novel small molecule tubulin inhibitor STK899704.

    Directory of Open Access Journals (Sweden)

    Krisada Sakchaisri

    Full Text Available We have identified the small molecule STK899704 as a structurally novel tubulin inhibitor. STK899704 suppressed the proliferation of cancer cell lines from various origins with IC50 values ranging from 0.2 to 1.0 μM. STK899704 prevented the polymerization of purified tubulin in vitro and also depolymerized microtubule in cultured cells leading to mitotic arrest, associated with increased Cdc25C phosphorylation and the accumulation of both cyclin B1 and polo-like kinase 1 (Plk1, and apoptosis. Unlike many anticancer drugs such as Taxol and doxorubicin, STK899704 effectively displayed antiproliferative activity against multidrug-resistant cancer cell lines. The proposed binding mode of STK899704 is at the interface between αβ-tubulin heterodimer overlapping with the colchicine-binding site. Our in vivo carcinogenesis model further showed that STK 899704 is potent in both the prevention and regression of tumors, remarkably reducing the number and volume of skin tumor by STK899704 treatment. Moreover, it was significant to note that the efficacy of STK899704 was surprisingly comparable to 5-fluorouracil, a widely used anticancer therapeutic. Thus, our results demonstrate the potential of STK899704 to be developed as an anticancer chemotherapeutic and an alternative candidate for existing therapies.

  14. Design, Synthesis and Biological Evaluation of 1,4-Disubstituted-3,4-dihydroisoquinoline Compounds as New Tubulin Polymerization Inhibitors

    Directory of Open Access Journals (Sweden)

    Ling Zhang

    2015-05-01

    Full Text Available A series of 1,4-disubstituted-3,4-dihydroisoquinoline derivatives designed as tubulin polymerization inhibitors were synthesized. Their cytotoxic activities against the CEM leukemia cell line were evaluated. Most of them displayed moderate cytotoxic activities, and compounds 21 and 32 showed good activities with IC50 of 4.10 and 0.64 μM, respectively. The most potent compound 32 was further confirmed to be able to inhibit tubulin polymerization, and its hypothetical binding mode with tubulin was obtained by molecular docking.

  15. Detection of Alzheimer’s disease amyloid-beta plaque deposition by deep brain impedance profiling

    Science.gov (United States)

    Béduer, Amélie; Joris, Pierre; Mosser, Sébastien; Fraering, Patrick C.; Renaud, Philippe

    2015-04-01

    Objective. Alzheimer disease (AD) is the most common form of neurodegenerative disease in elderly people. Toxic brain amyloid-beta (Aß) aggregates and ensuing cell death are believed to play a central role in the pathogenesis of the disease. In this study, we investigated if we could monitor the presence of these aggregates by performing in situ electrical impedance spectroscopy measurements in AD model mice brains. Approach. In this study, electrical impedance spectroscopy measurements were performed post-mortem in APPPS1 transgenic mice brains. This transgenic model is commonly used to study amyloidogenesis, a pathological hallmark of AD. We used flexible probes with embedded micrometric electrodes array to demonstrate the feasibility of detecting senile plaques composed of Aß peptides by localized impedance measurements. Main results. We particularly focused on deep brain structures, such as the hippocampus. Ex vivo experiments using brains from young and old APPPS1 mice lead us to show that impedance measurements clearly correlate with the percentage of Aβ plaque load in the brain tissues. We could monitor the effects of aging in the AD APPPS1 mice model. Significance. We demonstrated that a localized electrical impedance measurement constitutes a valuable technique to monitor the presence of Aβ-plaques, which is complementary with existing imaging techniques. This method does not require prior Aβ staining, precluding the risk of variations in tissue uptake of dyes or tracers, and consequently ensuring reproducible data collection.

  16. The Altered Hepatic Tubulin Code in Alcoholic Liver Disease.

    Science.gov (United States)

    Groebner, Jennifer L; Tuma, Pamela L

    2015-09-18

    The molecular mechanisms that lead to the progression of alcoholic liver disease have been actively examined for decades. Because the hepatic microtubule cytoskeleton supports innumerable cellular processes, it has been the focus of many such mechanistic studies. It has long been appreciated that α-tubulin is a major target for modification by highly reactive ethanol metabolites and reactive oxygen species. It is also now apparent that alcohol exposure induces post-translational modifications that are part of the natural repertoire, mainly acetylation. In this review, the modifications of the "tubulin code" are described as well as those adducts by ethanol metabolites. The potential cellular consequences of microtubule modification are described with a focus on alcohol-induced defects in protein trafficking and enhanced steatosis. Possible mechanisms that can explain hepatic dysfunction are described and how this relates to the onset of liver injury is discussed. Finally, we propose that agents that alter the cellular acetylation state may represent a novel therapeutic strategy for treating liver disease.

  17. Individualized quantification of brain {beta}-amyloid burden: results of a proof of mechanism phase 0 florbetaben PET trial in patients with Alzheimer's disease and healthy controls

    Energy Technology Data Exchange (ETDEWEB)

    Barthel, Henryk; Luthardt, Julia; Becker, Georg; Patt, Marianne; Sattler, Bernhard; Schildan, Andreas; Hesse, Swen; Meyer, Philipp M.; Sabri, Osama [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Hammerstein, Eva; Hartwig, Kristin; Gertz, Hermann-Josef [University of Leipzig, Department of Psychiatry, Leipzig (Germany); Eggers, Birk [Arzneimittelforschung Leipzig GmbH, Leipzig (Germany); Wolf, Henrike [University of Leipzig, Department of Psychiatry, Leipzig (Germany); University of Zurich, Department of Psychiatry, Zurich (Switzerland); Zimmermann, Torsten; Reischl, Joachim; Rohde, Beate; Reininger, Cornelia [Bayer Healthcare, Berlin (Germany)

    2011-09-15

    Complementing clinical findings with those generated by biomarkers - such as {beta}-amyloid-targeted positron emission tomography (PET) imaging - has been proposed as a means of increasing overall accuracy in the diagnosis of Alzheimer's disease (AD). Florbetaben ([{sup 18}F]BAY 94-9172) is a novel {beta}-amyloid PET tracer currently in global clinical development. We present the results of a proof of mechanism study in which the diagnostic efficacy, pharmacokinetics, safety and tolerability of florbetaben were assessed. The value of various quantitative parameters derived from the PET scans as potential surrogate markers of cognitive decline was also investigated. Ten patients with mild-moderate probable AD (DSM-IV and NINCDS-ADRDA criteria) and ten age-matched ({>=} 55 years) healthy controls (HCs) were administered a single dose of 300 MBq florbetaben, which contained a tracer mass dose of < 5 {mu}g. The 70-90 min post-injection brain PET data were visually analysed by three blinded experts. Quantitative assessment was also performed via MRI-based, anatomical sampling of predefined volumes of interest (VOI) and subsequent calculation of standardized uptake value (SUV) ratios (SUVRs, cerebellar cortex as reference region). Furthermore, single-case, voxelwise analysis was used to calculate individual ''whole brain {beta}-amyloid load''. Visual analysis of the PET data revealed nine of the ten AD, but only one of the ten HC brains to be {beta}-amyloid positive (p = 0.001), with high inter-reader agreement (weighted kappa {>=} 0.88). When compared to HCs, the neocortical SUVRs were significantly higher in the ADs (with descending order of effect size) in frontal cortex, lateral temporal cortex, occipital cortex, anterior and posterior cingulate cortices, and parietal cortex (p = 0.003-0.010). Voxel-based group comparison confirmed these differences. Amongst the PET-derived parameters, the Statistical Parametric Mapping-based whole brain

  18. Blocking Blood Flow to Solid Tumors by Destabilizing Tubulin: An Approach to Targeting Tumor Growth.

    Science.gov (United States)

    Pérez-Pérez, María-Jesús; Priego, Eva-María; Bueno, Oskía; Martins, Maria Solange; Canela, María-Dolores; Liekens, Sandra

    2016-10-13

    The unique characteristics of the tumor vasculature offer the possibility to selectively target tumor growth and vascularization using tubulin-destabilizing agents. Evidence accumulated with combretastatin A-4 (CA-4) and its prodrug CA-4P support the therapeutic value of compounds sharing this mechanism of action. However, the chemical instability and poor solubility of CA-4 demand alternative compounds that are able to surmount these limitations. This Perspective illustrates the different classes of compounds that behave similar to CA-4, analyzes their binding mode to αβ-tubulin according to recently available structural complexes, and includes described approaches to improve their delivery. In addition, dissecting the mechanism of action of CA-4 and analogues allows a closer insight into the advantages and drawbacks associated with these tubulin-destabilizing agents that behave as vascular disrupting agents (VDAs).

  19. Low dose tubulin-binding drugs rescue peroxisome trafficking deficit in patient-derived stem cells in Hereditary Spastic Paraplegia

    Directory of Open Access Journals (Sweden)

    Yongjun Fan

    2014-05-01

    Full Text Available Hereditary Spastic Paraplegia (HSP is a genetically heterogeneous group of disorders, diagnosed by progressive gait disturbances with muscle weakness and spasticity, for which there are no treatments targeted at the underlying pathophysiology. Mutations in spastin are a common cause of HSP. Spastin is a microtubule-severing protein whose mutation in mouse causes defective axonal transport. In human patient-derived olfactory neurosphere-derived (ONS cells, spastin mutations lead to lower levels of acetylated α-tubulin, a marker of stabilised microtubules, and to slower speed of peroxisome trafficking. Here we screened multiple concentrations of four tubulin-binding drugs for their ability to rescue levels of acetylated α-tubulin in patient-derived ONS cells. Drug doses that restored acetylated α-tubulin to levels in control-derived ONS cells were then selected for their ability to rescue peroxisome trafficking deficits. Automated microscopic screening identified very low doses of the four drugs (0.5 nM taxol, 0.5 nM vinblastine, 2 nM epothilone D, 10 µM noscapine that rescued acetylated α-tubulin in patient-derived ONS cells. These same doses rescued peroxisome trafficking deficits, restoring peroxisome speeds to untreated control cell levels. These results demonstrate a novel approach for drug screening based on high throughput automated microscopy for acetylated α-tubulin followed by functional validation of microtubule-based peroxisome transport. From a clinical perspective, all the drugs tested are used clinically, but at much higher doses. Importantly, epothilone D and noscapine can enter the central nervous system, making them potential candidates for future clinical trials.

  20. Low dose tubulin-binding drugs rescue peroxisome trafficking deficit in patient-derived stem cells in Hereditary Spastic Paraplegia

    Science.gov (United States)

    Fan, Yongjun; Wali, Gautam; Sutharsan, Ratneswary; Bellette, Bernadette; Crane, Denis I.; Sue, Carolyn M.; Mackay-Sim, Alan

    2014-01-01

    ABSTRACT Hereditary Spastic Paraplegia (HSP) is a genetically heterogeneous group of disorders, diagnosed by progressive gait disturbances with muscle weakness and spasticity, for which there are no treatments targeted at the underlying pathophysiology. Mutations in spastin are a common cause of HSP. Spastin is a microtubule-severing protein whose mutation in mouse causes defective axonal transport. In human patient-derived olfactory neurosphere-derived (ONS) cells, spastin mutations lead to lower levels of acetylated α-tubulin, a marker of stabilised microtubules, and to slower speed of peroxisome trafficking. Here we screened multiple concentrations of four tubulin-binding drugs for their ability to rescue levels of acetylated α-tubulin in patient-derived ONS cells. Drug doses that restored acetylated α-tubulin to levels in control-derived ONS cells were then selected for their ability to rescue peroxisome trafficking deficits. Automated microscopic screening identified very low doses of the four drugs (0.5 nM taxol, 0.5 nM vinblastine, 2 nM epothilone D, 10 µM noscapine) that rescued acetylated α-tubulin in patient-derived ONS cells. These same doses rescued peroxisome trafficking deficits, restoring peroxisome speeds to untreated control cell levels. These results demonstrate a novel approach for drug screening based on high throughput automated microscopy for acetylated α-tubulin followed by functional validation of microtubule-based peroxisome transport. From a clinical perspective, all the drugs tested are used clinically, but at much higher doses. Importantly, epothilone D and noscapine can enter the central nervous system, making them potential candidates for future clinical trials. PMID:24857849

  1. Astrocytic expression of the Alzheimer's disease beta-secretase (BACE1) is stimulus-dependent

    DEFF Research Database (Denmark)

    Hartlage-Rübsamen, Maike; Zeitschel, Ulrike; Apelt, Jenny

    2003-01-01

    The beta-site APP-cleaving enzyme (BACE1) is a prerequisite for the generation of beta-amyloid peptides, which give rise to cerebrovascular and parenchymal beta-amyloid deposits in the brain of Alzheimer's disease patients. BACE1 is neuronally expressed in the brains of humans and experimental...... paradigms studied. In contrast, BACE1 expression by reactive astrocytes was evident in chronic but not in acute models of gliosis. Additionally, we observed BACE1-immunoreactive astrocytes in proximity to beta-amyloid plaques in the brains of aged Tg2576 mice and Alzheimer's disease patients....

  2. Nuclear Tubulin: A Novel Target for Breast Cancer Chemotherapy

    Science.gov (United States)

    2001-05-01

    A. Castillo1, R.F. Luduena 3, and I. Meza 2 ’Departamentos de Biologia Celular and 2 Biomedicina Molecular, CINVESTA V del /PN, M6xico, D. F...resistance. J Biol Chem 270: 31269-31275. Hyams JS, Lloyd CW. 1994.-.The role of multiple tubulin isoforms in celular microtubule function. In: Raff E editor

  3. The Altered Hepatic Tubulin Code in Alcoholic Liver Disease

    Directory of Open Access Journals (Sweden)

    Jennifer L. Groebner

    2015-09-01

    Full Text Available The molecular mechanisms that lead to the progression of alcoholic liver disease have been actively examined for decades. Because the hepatic microtubule cytoskeleton supports innumerable cellular processes, it has been the focus of many such mechanistic studies. It has long been appreciated that α-tubulin is a major target for modification by highly reactive ethanol metabolites and reactive oxygen species. It is also now apparent that alcohol exposure induces post-translational modifications that are part of the natural repertoire, mainly acetylation. In this review, the modifications of the “tubulin code” are described as well as those adducts by ethanol metabolites. The potential cellular consequences of microtubule modification are described with a focus on alcohol-induced defects in protein trafficking and enhanced steatosis. Possible mechanisms that can explain hepatic dysfunction are described and how this relates to the onset of liver injury is discussed. Finally, we propose that agents that alter the cellular acetylation state may represent a novel therapeutic strategy for treating liver disease.

  4. Effect of naloxone hydrochloride on c-fos protein expression in brain and plasma beta-endorphin level in rats with diffuse brain injury and secondary brain insult

    Directory of Open Access Journals (Sweden)

    Jun-jie JING

    2012-09-01

    Full Text Available Objective To observe the changes of c-fos protein expression in brain and beta-endorphin (β-EP level in blood plasma in rats with diffuse brain injury (DBI and secondary brain insult (SBI after intraperitoneal injection of naloxone hydrochloride, and explore the role of c-fos andβ-EP in development of SBI in rats. Methods Seventy health male SD rats were enrolled in the present study and randomly divided into group A (intraperitoneally injected with 0.9% saline after DBI and SBI model was reproduced, group B (injected intraperitoneally with 1.0mg/kg naloxone hydrochloride after DBI and SBI model was reproduced, and group C (intraperitoneally injected with 1.0mg/kg naloxone hydrochloride after DBI and before SBI model was reproduced. The animals were sacrificed 3, 24 and 48 hours after injury, and the number of c-fos positive cells in brain and content of β-EP in blood plasma were determined by immunohistochemistry and radioimmunoassay respectively, the water content and number of injured neurons in brain tissue were measured by pathomorphological observation of the brain tissue. Results No significant difference was observed between group B and C for all the detection parameters. In group B and C, the water content in brain tissue at 3h and 24h was found to be decreased, while the number of injured neurons at 24h and 48h increased, number of c-fos positive cells in brain at 3h, 24h and 48h decreased, and content of β-EP in blood plasma at 3h and 24h decreased when compared with group A(P < 0.05. Conclusion Naloxone hydrochloride could decrease the c-fos expression in brain and β-EP level in blood plasma, alleviate the nerve injury, and protect neural function. The therapeutic effect of naloxone administered either after DBI and SBI or after DBI and before SBI was similar.

  5. Arabidopsis GCP3-interacting protein 1/MOZART 1 is an integral component of the γ-tubulin-containing microtubule nucleating complex.

    Science.gov (United States)

    Nakamura, Masayoshi; Yagi, Noriyoshi; Kato, Takehide; Fujita, Satoshi; Kawashima, Noriyuki; Ehrhardt, David W; Hashimoto, Takashi

    2012-07-01

    Microtubules in eukaryotic cells are nucleated from ring-shaped complexes that contain γ-tubulin and a family of homologous γ-tubulin complex proteins (GCPs), but the subunit composition of the complexes can vary among fungi, animals and plants. Arabidopsis GCP3-interacting protein 1 (GIP1), a small protein with no homology to the GCP family, interacts with GCP3 in vitro, and is a plant homolog of vertebrate mitotic-spindle organizing protein associated with a ring of γ-tubulin 1 (MOZART1), a recently identified component of the γ-tubulin complex in human cell lines. In this study, we characterized two closely related Arabidopsis GIP1s: GIP1a and GIP1b. Single mutants of gip1a and gip1b were indistinguishable from wild-type plants, but their double mutant was embryonic lethal, and showed impaired development of male gametophytes. Functional fusions of GIP1a with green fluorescent protein (GFP) were used to purify GIP1a-containing complexes from Arabidopsis plants, which contained all the subunits (except NEDD1) previously identified in the Arabidopsis γ-tubulin complexes. GIP1a and GIP1b interacted specifically with Arabidopsis GCP3 in yeast. GFP-GIP1a labeled mitotic microtubule arrays in a pattern largely consistent with, but partly distinct from, the localization of the γ-tubulin complex containing GCP2 or GCP3 in planta. In interphase cortical arrays, the labeled complexes were preferentially recruited to existing microtubules, from which new microtubules were efficiently nucleated. However, in contrast to complexes labeled with tagged GCP2 or GCP3, their recruitment to cortical areas with no microtubules was rarely observed. These results indicate that GIP1/MOZART1 is an integral component of a subset of the Arabidopsis γ-tubulin complexes. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

  6. Novel mutations in β-tubulin gene in Trichoderma harzianum mutants resistant to methyl benzimidazol-2-yl carbamate.

    Science.gov (United States)

    Li, M; Zhang, H Y; Liang, B

    2013-01-01

    Twelve-low resistant (LR) mutants of Trichoderma harzianum with the capability of grow fast at 0.8 μg/mL methyl benzimidazol-2-yl carbamate (MBC) were obtained using UV mutagenesis. MR and HR mutants which could grow fast at 10 and 100 μg/mL MBC, respectively, were isolated by step-up selection protocols in which UV-treated mutants were induced and mycelial sector screening was made in plates with growth medium. Subsequently, β-tubulin genes of 14 mutants were cloned to describe-the molecular lesion likely to be responsible-for MBC resistance. Comparison of the β-tubulin sequences of the mutant and sensitive strains of T. harzianum revealed 2 new MBC-binding sites differed from those in other plant pathogens. A single mutation at-amino acid 168, having Phe (TTC) instead of Ser (TCC)', was demonstrated for the HR mutant; a double mutation in amino acid 13 resulting in the substitution of Gly (GGC) by Val (GTG) was observed in β-tubulin gene of MR mutant. On the other hand, no substitutions were identified in the β-tubulin gene and its 5'-flanking regions in 12 LR mutants of T. harzianum.

  7. Antihelminthic benzimidazoles are novel HIF activators that prevent oxidative neuronal death via binding to tubulin.

    Science.gov (United States)

    Aleyasin, Hossein; Karuppagounder, Saravanan S; Kumar, Amit; Sleiman, Sama; Basso, Manuela; Ma, Thong; Siddiq, Ambreena; Chinta, Shankar J; Brochier, Camille; Langley, Brett; Haskew-Layton, Renee; Bane, Susan L; Riggins, Gregory J; Gazaryan, Irina; Starkov, Anatoly A; Andersen, Julie K; Ratan, Rajiv R

    2015-01-10

    Pharmacological activation of the adaptive response to hypoxia is a therapeutic strategy of growing interest for neurological conditions, including stroke, Huntington's disease, and Parkinson's disease. We screened a drug library with known safety in humans using a hippocampal neuroblast line expressing a reporter of hypoxia-inducible factor (HIF)-dependent transcription. Our screen identified more than 40 compounds with the ability to induce hypoxia response element-driven luciferase activity as well or better than deferoxamine, a canonical activator of hypoxic adaptation. Among the chemical entities identified, the antihelminthic benzimidazoles represented one pharmacophore that appeared multiple times in our screen. Secondary assays confirmed that antihelminthics stabilized the transcriptional activator HIF-1α and induced expression of a known HIF target gene, p21(cip1/waf1), in post-mitotic cortical neurons. The on-target effect of these agents in stimulating hypoxic signaling was binding to free tubulin. Moreover, antihelminthic benzimidazoles also abrogated oxidative stress-induced death in vitro, and this on-target effect also involves binding to free tubulin. These studies demonstrate that tubulin-binding drugs can activate a component of the hypoxic adaptive response, specifically the stabilization of HIF-1α and its downstream targets. Tubulin-binding drugs, including antihelminthic benzimidazoles, also abrogate oxidative neuronal death in primary neurons. Given their safety in humans and known ability to penetrate into the central nervous system, antihelminthic benzimidazoles may be considered viable candidates for treating diseases associated with oxidative neuronal death, including stroke.

  8. Effects of thyroid status on presynaptic. cap alpha. 2-adrenoceptor and. beta. -adrenoceptor binding in the rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Atterwill, C.K.; Bunn, S.J.; Atkinson, D.J. (Development Neurobiology Unit, London (UK). Inst. of Neurology); Smith, S.L.; Heal, D.J. (Radcliffe Infirmary, Oxford (UK))

    1984-01-01

    The effect of thyroid status on noradrenergic synaptic function in the mature brain was examined by measuring presynaptic ..cap alpha..2- and postsynaptic ..beta..-adrenoceptors. Repeated triiodothyronine (T/sub 3/) administration to rats (100..mu..g/kg x 14 days hyperthyroid) caused an 18% increase in striatal ..beta..-adrenoceptors as shown by (/sup 3/H)-dihydroalprenolol binding with no change in membranes from cerebral cortex or hypothalamus. In contrast, hypothyroidism (propylthiouracil, PTU x 14 days) produced significant 12% and 30% reductions in striatal and hypothalamic ..beta..-adrenoceptors respectively with no change in the cerebral cortex. Presynaptic ..cap alpha..2-adrenoceptor function was measured in the two dysthyroid states using the clonidine-induced hypoactivity model. Experimental hyperthyroidism increased the degree of clonidine-induced hypoactivity, and suggests increased presynaptic ..cap alpha..2-adrenoceptor function compared with control rats, whereas hypothyroidism suppressed presynaptic ..cap alpha..2-adrenoceptor function. These results show firstly that changes of thyroid status in the mature rat may produce homeostatic alterations at central noradrenergic synapses as reflected by changes in pre- and postsynaptic adrenoceptor function. Secondly, there appear to be T/sub 3/-induced changes in ..beta..-adrenoceptors in the striatum where changes in dopaminergic neuronal activity have previously been demonstrated.

  9. The structure of tubulin-binding cofactor A from Leishmania major infers a mode of association during the early stages of microtubule assembly

    Energy Technology Data Exchange (ETDEWEB)

    Barrack, Keri L.; Fyfe, Paul K.; Hunter, William N., E-mail: w.n.hunter@dundee.ac.uk [University of Dundee, Dow Street, Dundee DD1 5EH, Scotland (United Kingdom)

    2015-04-21

    The structure of a tubulin-binding cofactor from L. major is reported and compared with yeast, plant and human orthologues. Tubulin-binding cofactor A (TBCA) participates in microtubule formation, a key process in eukaryotic biology to create the cytoskeleton. There is little information on how TBCA might interact with β-tubulin en route to microtubule biogenesis. To address this, the protozoan Leishmania major was targeted as a model system. The crystal structure of TBCA and comparisons with three orthologous proteins are presented. The presence of conserved features infers that electrostatic interactions that are likely to involve the C-terminal tail of β-tubulin are key to association. This study provides a reagent and template to support further work in this area.

  10. Organotypic vibrosections from whole brain adult Alzheimer mice (overexpressing amyloid-precursor-protein with the Swedish-Dutch-Iowa mutations as a model to study clearance of beta-amyloid plaques

    Directory of Open Access Journals (Sweden)

    Christian eHumpel

    2015-04-01

    Full Text Available Alzheimer´s disease is a severe neurodegenerative disorder of the brain, pathologically characterized by extracellular beta-amyloid plaques, intraneuronal Tau inclusions, inflammation, reactive glial cells, vascular pathology and neuronal cell death. The degradation and clearance of beta-amyloid plaques is an interesting therapeutic approach, and the proteases neprilysin (NEP, insulysin and matrix metalloproteinases (MMP are of particular interest. The aim of this project was to establish and characterize a simple in vitro model to study the degrading effects of these proteases. Organoytpic brain vibrosections (120 µm thick were sectioned from adult (9 month old wildtype and transgenic mice (expressing amyloid precursor protein (APP harboring the Swedish K670N/M671L, Dutch E693Q, and Iowa D694N mutations; APP_SDI and cultured for 2 weeks. Plaques were stained by immunohistochemistry for beta-amyloid and Thioflavin S. Our data show that plaques were evident in 2 week old cultures from 9 month old transgenic mice. These plaques were surrounded by reactive GFAP+ astroglia and Iba1+ microglia. Incubation of fresh slices for 2 weeks with 1-0.1-0.01 µg/ml of NEP, insulysin, MMP-2 or MMP-9 showed that NEP, insulysin and MMP-9 markedly degradeded beta-amyloid plaques but only at the highest concentration. Our data provide for the first time a potent and powerful living brain vibrosection model containing a high number of plaques, which allows to rapidly and simply study the degradation and clearance of beta-amyloid plaques in vitro.

  11. Brain injury-associated biomarkers of TGF-beta1, S100B, GFAP, NF-L, tTG, AbetaPP, and tau were concomitantly enhanced and the UPS was impaired during acute brain injury caused by Toxocara canis in mice.

    Science.gov (United States)

    Liao, Chien-Wei; Fan, Chia-Kwung; Kao, Ting-Chang; Ji, Dar-Der; Su, Kua-Eyre; Lin, Yun-Ho; Cho, Wen-Long

    2008-06-24

    Because the outcomes and sequelae after different types of brain injury (BI) are variable and difficult to predict, investigations on whether enhanced expressions of BI-associated biomarkers (BIABs), including transforming growth factor beta1 (TGF-beta1), S100B, glial fibrillary acidic protein (GFAP), neurofilament light chain (NF-L), tissue transglutaminases (tTGs), beta-amyloid precursor proteins (AbetaPP), and tau are present as well as whether impairment of the ubiquitin-proteasome system (UPS) is present have been widely used to help delineate pathophysiological mechanisms in various BIs. Larvae of Toxocara canis can invade the brain and cause BI in humans and mice, leading to cerebral toxocariasis (CT). Because the parasitic burden is light in CT, it may be too cryptic to be detected in humans, making it difficult to clearly understand the pathogenesis of subtle BI in CT. Since the pathogenesis of murine toxocariasis is very similar to that in humans, it appears appropriate to use a murine model to investigate the pathogenesis of CT. BIAB expressions and UPS function in the brains of mice inoculated with a single dose of 250 T. canis embryonated eggs was investigated from 3 days (dpi) to 8 weeks post-infection (wpi) by Western blotting and RT-PCR. Results revealed that at 4 and 8 wpi, T. canis larvae were found to have invaded areas around the choroid plexus but without eliciting leukocyte infiltration in brains of infected mice; nevertheless, astrogliosis, an indicator of BI, with 78.9~142.0-fold increases in GFAP expression was present. Meanwhile, markedly increased levels of other BIAB proteins including TGF-beta1, S100B, NF-L, tTG, AbetaPP, and tau, with increases ranging 2.0~12.0-fold were found, although their corresponding mRNA expressions were not found to be present at 8 wpi. Concomitantly, UPS impairment was evidenced by the overexpression of conjugated ubiquitin and ubiquitin in the brain. Further studies are needed to determine whether there is an

  12. gamma-Tubulin has a conserved intrinsic property of self-polymerization into double stranded filaments and fibrillar networks

    Czech Academy of Sciences Publication Activity Database

    Chumová, Jana; Trögelová, Lucie; Kourová, Hana; Volc, Jindřich; Sulimenko, Vadym; Halada, Petr; Kučera, Ondřej; Benada, Oldřich; Kuchařová, A.; Klebanovych, Anastasiya; Dráber, Pavel; Daniel, G.; Binarová, Pavla

    2018-01-01

    Roč. 1865, č. 5 (2018), s. 734-748 ISSN 0167-4889 R&D Projects: GA ČR GA15-11657S; GA ČR GA16-25159S; GA ČR GA16-23702S; GA MŠk(CZ) LM2015062 Institutional support: RVO:61388971 ; RVO:68378050 ; RVO:67985882 Keywords : gamma-Tubulin * GCP-free gamma-tubulin * Filament self-assembly Subject RIV: CE - Biochemistry OBOR OECD: Microbiology Impact factor: 4.521, year: 2016

  13. Structural and functional features of lysine acetylation of plant and animal tubulins.

    Science.gov (United States)

    Rayevsky, Alexey V; Sharifi, Mohsen; Samofalova, Dariya A; Karpov, Pavel A; Blume, Yaroslav B

    2017-10-10

    The study of the genome and the proteome of different species and representatives of distinct kingdoms, especially detection of proteome via wide-scaled analyses has various challenges and pitfalls. Attempts to combine all available information together and isolate some common features for determination of the pathway and their mechanism of action generally have a highly complicated nature. However, microtubule (MT) monomers are highly conserved protein structures, and microtubules are structurally conserved from Homo sapiens to Arabidopsis thaliana. The interaction of MT elements with microtubule-associated proteins and post-translational modifiers is fully dependent on protein interfaces, and almost all MT modifications are well described except acetylation. Crystallography and interactome data using different approaches were combined to identify conserved proteins important in acetylation of microtubules. Application of computational methods and comparative analysis of binding modes generated a robust predictive model of acetylation of the ϵ-amino group of Lys40 in α-tubulins. In turn, the model discarded some probable mechanisms of interaction between elements of interest. Reconstruction of unresolved protein structures was carried out with modeling by homology to the existing crystal structure (PDBID: 1Z2B) from B. taurus using Swiss-model server, followed by a molecular dynamics simulation. Docking of the human tubulin fragment with Lys40 into the active site of α-tubulin acetyltransferase, reproduces the binding mode of peptidomimetic from X-ray structure (PDBID: 4PK3). © 2017 International Federation for Cell Biology.

  14. Phosphorylation of the yeast γ-tubulin Tub4 regulates microtubule function

    DEFF Research Database (Denmark)

    Lin, Tien-chen; Gombos, Linda; Neuner, Annett

    2011-01-01

    The yeast ¿-tubulin Tub4 is assembled with Spc97 and Spc98 into the small Tub4 complex. The Tub4 complex binds via the receptor proteins Spc72 and Spc110 to the spindle pole body (SPB), the functional equivalent of the mammalian centrosome, where the Tub4 complex organizes cytoplasmic and nuclear...... microtubules. Little is known about the regulation of the Tub4 complex. Here, we isolated the Tub4 complex with the bound receptors from yeast cells. Analysis of the purified Tub4 complex by mass spectrometry identified more than 50 phosphorylation sites in Spc72, Spc97, Spc98, Spc110 and Tub4. To examine...... the functional relevance of the phosphorylation sites, phospho-mimicking and non-phosphorylatable mutations in Tub4, Spc97 and Spc98 were analyzed. Three phosphorylation sites in Tub4 were found to be critical for Tub4 stability and microtubule organization. One of the sites is highly conserved in ¿-tubulins...

  15. A simple and fast method for fixation of cultured cell lines that preserves cellular structures containing gamma-tubulin.

    Science.gov (United States)

    Alvarado-Kristensson, Maria

    2018-01-01

    When using fluorescence microscope techniques to study cells, it is essential that the cell structure and contents are preserved after preparation of the samples, and that the preparation method employed does not create artefacts that can be perceived as cellular structure/components. γ-Tubulin forms filaments that in some cases are immunostained with an anti-γ-tubulin antibody, but this immunostaining is not reproducible [[1], [2

  16. Tubulins as therapeutic targets in cancer: from bench to bedside

    Czech Academy of Sciences Publication Activity Database

    Katsetos, C.D.; Dráber, Pavel

    2012-01-01

    Roč. 18, č. 19 (2012), s. 2778-2792 ISSN 1381-6128 R&D Projects: GA ČR GA204/09/1777; GA AV ČR KAN200520701; GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : microtubules * tubulin * cancer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.311, year: 2012

  17. Overexpression of γ-tubulin in non-small cell lung cancer

    Czech Academy of Sciences Publication Activity Database

    Maounis, N.F.; Dráberová, Eduarda; Mahera, E.; Chorti, M.; Caracciolo, V.; Sulimenko, Tetyana; Riga, D.; Trakas, N.; Emmanouilidou, A.; Giordano, A.; Dráber, Pavel; Katsetos, C.D.

    2012-01-01

    Roč. 27, č. 9 (2012), s. 1183-1194 ISSN 0213-3911 R&D Projects: GA ČR GA204/09/1777; GA ČR GAP302/10/1701; GA MŠk LC545 Institutional research plan: CEZ:AV0Z50520514 Keywords : gamma-tubulin * microtubules * NSCLC Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.281, year: 2012

  18. The effects of Beta-Endorphin: state change modification

    NARCIS (Netherlands)

    Veening, J.G.; Barendregt, H.P.

    2015-01-01

    Beta-endorphin (beta-END) is an opioid neuropeptide which has an important role in the development of hypotheses concerning the non-synaptic or paracrine communication of brain messages. This kind of communication between neurons has been designated volume transmission (VT) to differentiate it

  19. Distribution of gama-tubulin in cellulatr compartments of higher plant cells

    Czech Academy of Sciences Publication Activity Database

    Binarová, Pavla; Cenklová, Věra; Sulimenko, Vadym; Dryková, Denisa; Volc, Jindřich; Dráber, Pavel

    2003-01-01

    Roč. 27, - (2003), s. 167-169 ISSN 1065-6995 R&D Projects: GA ČR GA204/03/1013 Institutional research plan: CEZ:AV0Z5038910; CEZ:AV0Z5020903 Keywords : sds - page * gama-tubulin Subject RIV: EE - Microbiology, Virology Impact factor: 1.092, year: 2003

  20. Reversible Morphological Control of Tubulin-Encapsulating Giant Liposomes by Hydrostatic Pressure.

    Science.gov (United States)

    Hayashi, Masahito; Nishiyama, Masayoshi; Kazayama, Yuki; Toyota, Taro; Harada, Yoshie; Takiguchi, Kingo

    2016-04-19

    Liposomes encapsulating cytoskeletons have drawn much recent attention to develop an artificial cell-like chemical-machinery; however, as far as we know, there has been no report showing isothermally reversible morphological changes of liposomes containing cytoskeletons because the sets of various regulatory factors, that is, their interacting proteins, are required to control the state of every reaction system of cytoskeletons. Here we focused on hydrostatic pressure to control the polymerization state of microtubules (MTs) within cell-sized giant liposomes (diameters ∼10 μm). MT is the cytoskeleton formed by the polymerization of tubulin, and cytoskeletal systems consisting of MTs are very dynamic and play many important roles in living cells, such as the morphogenesis of nerve cells and formation of the spindle apparatus during mitosis. Using real-time imaging with a high-pressure microscope, we examined the effects of hydrostatic pressure on the morphology of tubulin-encapsulating giant liposomes. At ambient pressure (0.1 MPa), many liposomes formed protrusions due to tubulin polymerization within them. When high pressure (60 MPa) was applied, the protrusions shrank within several tens of seconds. This process was repeatedly inducible (around three times), and after the pressure was released, the protrusions regenerated within several minutes. These deformation rates of the liposomes are close to the velocities of migrating or shape-changing living cells rather than the shortening and elongation rates of the single MTs, which have been previously measured. These results demonstrate that the elongation and shortening of protrusions of giant liposomes is repeatedly controllable by regulating the polymerization state of MTs within them by applying and releasing hydrostatic pressure.

  1. Beta-thalassemia intermedia associated with moyamoya syndrome.

    Science.gov (United States)

    Göksel, Basak Karakurum; Ozdogu, Hakan; Yildirim, Tulin; Oğuzkurt, Levent; Asma, Suheyl

    2010-07-01

    Moyamoya syndrome (MMS) is a progressive disorder. We report a 19-year-old boy with beta-thalassemia who presented with a left hemiparesis. Brain MRI showed old middle cerebral artery and left frontal subcortical white matter infarcts. Brain magnetic resonance angiography and digital subtraction angiography revealed occlusion of the bilateral internal carotid arteries with a rich network of basal collateral vessels. To our knowledge this is the third report of beta-thalassemia intermedia and MMS, and the first report of a patient in Turkey. It emphasizes the potential for cerebral infarct due to anemia, protein S and thrombocytosis.

  2. Association of the interleukin 1 beta gene and brain spontaneous activity in amnestic mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Zhuang Liying

    2012-12-01

    Full Text Available Abstract Purpose The inflammatory response has been associated with the pathogenesis of Alzheimer’s disease (AD. The purpose of this study is to determine whether the rs1143627 polymorphism of the interleukin-1 beta (IL-1β gene moderates functional magnetic resonance imaging (fMRI-measured brain regional activity in amnestic mild cognitive impairment (aMCI. Methods Eighty older participants (47 with aMCI and 33 healthy controls were recruited for this study. All of the participants were genotyped for variant rs1143627 in the IL1B gene and were scanned using resting-state fMRI. Brain activity was assessed by amplitude of low-frequency fluctuation (ALFF. Results aMCI patients had abnormal ALFF in many brain regions, including decreases in the inferior frontal gyrus, the superior temporal lobe and the middle temporal lobe, and increases in the occipital cortex (calcarine, parietal cortex (Pcu and cerebellar cortex. The regions associated with an interaction of group X genotypes of rs1143627 C/T were the parietal cortex (left Pcu, frontal cortex (left superior, middle, and medial gyrus, right anterior cingulum, occipital cortex (left middle lobe, left cuneus and the bilateral posterior lobes of the cerebellum. Regarding the behavioral significance, there were significant correlations between ALFF in different regions of the brain and with the cognitive scores of each genotype group. Conclusions The present study provided evidence that aMCI patients had abnormal ALFF in many brain regions. Specifically, the rs1143627 C/T polymorphism of the IL1B gene may modulate regional spontaneous brain activity in aMCI patients.

  3. High LET Radiation Amplifies Centrosome Overduplication Through a Pathway of γ-Tubulin Monoubiquitination

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Mikio [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto (Japan); Hirayama, Ryoichi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Komatsu, Kenshi, E-mail: komatsu@house.rbc.kyoto-u.ac.jp [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto (Japan)

    2013-06-01

    Purpose: Radiation induces centrosome overduplication, leading to mitotic catastrophe and tumorigenesis. Because mitotic catastrophe is one of the major tumor cell killing factors in high linear energy transfer (LET) radiation therapy and long-term survivors from such treatment have a potential risk of secondary tumors, we investigated LET dependence of radiation-induced centrosome overduplication and the underlying mechanism. Methods and Materials: Carbon and iron ion beams (13-200 keV/μm) and γ-rays (0.5 keV/μm) were used as radiation sources. To count centrosomes after IR exposure, human U2OS and mouse NIH3T3 cells were immunostained with antibodies of γ-tubulin and centrin 2. Similarly, Nbs1-, Brca1-, Ku70-, and DNA-PKcs-deficient mouse cells and their counterpart wild-type cells were used for measurement of centrosome overduplication. Results: The number of excess centrosome-containing cells at interphase and the resulting multipolar spindle at mitosis were amplified with increased LET, reaching a maximum level of 100 keV/μm, followed by sharp decrease in frequency. Interestingly, Ku70 and DNA-PKcs deficiencies marginally affected the induction of centrosome overduplication, whereas the cell killings were significantly enhanced. This was in contrast to observation that high LET radiation significantly enhanced frequencies of centrosome overduplication in Nbs1- and Brca1-deficient cells. Because NBS1/BRCA1 is implicated in monoubiquitination of γ-tubulin, we subsequently tested whether it is affected by high LET radiation. As a result, monoubiquitination of γ-tubulin was abolished in 48 to 72 hours after exposure to high LET radiation, although γ-ray exposure slightly decreased it 48 hours postirradiation and was restored to a normal level at 72 hours. Conclusions: High LET radiation significantly reduces NBS1/BRCA1-mediated monoubiquitination of γ-tubulin and amplifies centrosome overduplication with a peak at 100 keV/μm. In contrast, Ku70 and DNA

  4. First demonstration of cerebrospinal fluid and plasma A beta lowering with oral administration of a beta-site amyloid precursor protein-cleaving enzyme 1 inhibitor in nonhuman primates.

    Science.gov (United States)

    Sankaranarayanan, Sethu; Holahan, Marie A; Colussi, Dennis; Crouthamel, Ming-Chih; Devanarayan, Viswanath; Ellis, Joan; Espeseth, Amy; Gates, Adam T; Graham, Samuel L; Gregro, Allison R; Hazuda, Daria; Hochman, Jerome H; Holloway, Katharine; Jin, Lixia; Kahana, Jason; Lai, Ming-tain; Lineberger, Janet; McGaughey, Georgia; Moore, Keith P; Nantermet, Philippe; Pietrak, Beth; Price, Eric A; Rajapakse, Hemaka; Stauffer, Shaun; Steinbeiser, Melissa A; Seabrook, Guy; Selnick, Harold G; Shi, Xiao-Ping; Stanton, Matthew G; Swestock, John; Tugusheva, Katherine; Tyler, Keala X; Vacca, Joseph P; Wong, Jacky; Wu, Guoxin; Xu, Min; Cook, Jacquelynn J; Simon, Adam J

    2009-01-01

    beta-Site amyloid precursor protein (APP)-cleaving enzyme (BACE) 1 cleavage of amyloid precursor protein is an essential step in the generation of the potentially neurotoxic and amyloidogenic A beta 42 peptides in Alzheimer's disease. Although previous mouse studies have shown brain A beta lowering after BACE1 inhibition, extension of such studies to nonhuman primates or man was precluded by poor potency, brain penetration, and pharmacokinetics of available inhibitors. In this study, a novel tertiary carbinamine BACE1 inhibitor, tertiary carbinamine (TC)-1, was assessed in a unique cisterna magna ported rhesus monkey model, where the temporal dynamics of A beta in cerebrospinal fluid (CSF) and plasma could be evaluated. TC-1, a potent inhibitor (IC(50) approximately 0.4 nM), has excellent passive membrane permeability, low susceptibility to P-glycoprotein transport, and lowered brain A beta levels in a mouse model. Intravenous infusion of TC-1 led to a significant but transient lowering of CSF and plasma A beta levels in conscious rhesus monkeys because it underwent CYP3A4-mediated metabolism. Oral codosing of TC-1 with ritonavir, a potent CYP3A4 inhibitor, twice daily over 3.5 days in rhesus monkeys led to sustained plasma TC-1 exposure and a significant and sustained reduction in CSF sAPP beta, A beta 40, A beta 42, and plasma A beta 40 levels. CSF A beta 42 lowering showed an EC(50) of approximately 20 nM with respect to the CSF [TC-1] levels, demonstrating excellent concordance with its potency in a cell-based assay. These results demonstrate the first in vivo proof of concept of CSF A beta lowering after oral administration of a BACE1 inhibitor in a nonhuman primate.

  5. Gamma-tubulin-containing abnormal centrioles are induced by insufficient Plk4 in human HCT116 colorectal cancer cells.

    Science.gov (United States)

    Kuriyama, Ryoko; Bettencourt-Dias, Monica; Hoffmann, Ingrid; Arnold, Marc; Sandvig, Lisa

    2009-06-15

    Cancer cells frequently induce aberrant centrosomes, which have been implicated in cancer initiation and progression. Human colorectal cancer cells, HCT116, contain aberrant centrioles composed of disorganized cylindrical microtubules and displaced appendages. These cells also express unique centrosome-related structures associated with a subset of centrosomal components, including gamma-tubulin, centrin and PCM1. During hydroxyurea treatment, these abnormal structures become more abundant and undergo a change in shape from small dots to elongated fibers. Although gamma-tubulin seems to exist as a ring complex, the abnormal structures do not support microtubule nucleation. Several lines of evidence suggest that the fibers correspond to a disorganized form of centriolar microtubules. Plk4, a mammalian homolog of ZYG-1 essential for initiation of centriole biogenesis, is not associated with the gamma-tubulin-specific abnormal centrosomes. The amount of Plk4 at each centrosome was less in cells with abnormal centrosomes than cells without gamma-tubulin-specific abnormal centrosomes. In addition, the formation of abnormal structures was abolished by expression of exogenous Plk4, but not SAS6 and Cep135/Bld10p, which are downstream regulators required for the organization of nine-triplet microtubules. These results suggest that HCT116 cells fail to organize the ninefold symmetry of centrioles due to insufficient Plk4.

  6. The Effects of Low-Dose Bisphenol A and Bisphenol F on Neural Differentiation of a Fetal Brain-Derived Neural Progenitor Cell Line.

    Science.gov (United States)

    Fujiwara, Yuki; Miyazaki, Wataru; Koibuchi, Noriyuki; Katoh, Takahiko

    2018-01-01

    Environmental chemicals are known to disrupt the endocrine system in humans and to have adverse effects on several organs including the developing brain. Recent studies indicate that exposure to environmental chemicals during gestation can interfere with neuronal differentiation, subsequently affecting normal brain development in newborns. Xenoestrogen, bisphenol A (BPA), which is widely used in plastic products, is one such chemical. Adverse effects of exposure to BPA during pre- and postnatal periods include the disruption of brain function. However, the effect of BPA on neural differentiation remains unclear. In this study, we explored the effects of BPA or bisphenol F (BPF), an alternative compound for BPA, on neural differentiation using ReNcell, a human fetus-derived neural progenitor cell line. Maintenance in growth factor-free medium initiated the differentiation of ReNcell to neuronal cells including neurons, astrocytes, and oligodendrocytes. We exposed the cells to BPA or BPF for 3 days from the period of initiation and performed real-time PCR for neural markers such as β III-tubulin and glial fibrillary acidic protein (GFAP), and Olig2. The β III-tubulin mRNA level decreased in response to BPA, but not BPF, exposure. We also observed that the number of β III-tubulin-positive cells in the BPA-exposed group was less than that of the control group. On the other hand, there were no changes in the MAP2 mRNA level. These results indicate that BPA disrupts neural differentiation in human-derived neural progenitor cells, potentially disrupting brain development.

  7. The Effects of Low-Dose Bisphenol A and Bisphenol F on Neural Differentiation of a Fetal Brain-Derived Neural Progenitor Cell Line

    Directory of Open Access Journals (Sweden)

    Yuki Fujiwara

    2018-02-01

    Full Text Available Environmental chemicals are known to disrupt the endocrine system in humans and to have adverse effects on several organs including the developing brain. Recent studies indicate that exposure to environmental chemicals during gestation can interfere with neuronal differentiation, subsequently affecting normal brain development in newborns. Xenoestrogen, bisphenol A (BPA, which is widely used in plastic products, is one such chemical. Adverse effects of exposure to BPA during pre- and postnatal periods include the disruption of brain function. However, the effect of BPA on neural differentiation remains unclear. In this study, we explored the effects of BPA or bisphenol F (BPF, an alternative compound for BPA, on neural differentiation using ReNcell, a human fetus-derived neural progenitor cell line. Maintenance in growth factor-free medium initiated the differentiation of ReNcell to neuronal cells including neurons, astrocytes, and oligodendrocytes. We exposed the cells to BPA or BPF for 3 days from the period of initiation and performed real-time PCR for neural markers such as β III-tubulin and glial fibrillary acidic protein (GFAP, and Olig2. The β III-tubulin mRNA level decreased in response to BPA, but not BPF, exposure. We also observed that the number of β III-tubulin-positive cells in the BPA-exposed group was less than that of the control group. On the other hand, there were no changes in the MAP2 mRNA level. These results indicate that BPA disrupts neural differentiation in human-derived neural progenitor cells, potentially disrupting brain development.

  8. Beta-secretase-cleaved amyloid precursor protein in Alzheimer brain: a morphologic study

    DEFF Research Database (Denmark)

    Sennvik, Kristina; Bogdanovic, N; Volkmann, Inga

    2004-01-01

    beta-amyloid (Abeta) is the main constituent of senile plaques seen in Alzheimer's disease. Abeta is derived from the amyloid precursor protein (APP) via proteolytic cleavage by proteases beta- and gamma-secretase. In this study, we examined content and localization of beta-secretase-cleaved APP...... the beta-sAPP immunostaining to be stronger and more extensive in gray matter in Alzheimer disease (AD) cases than controls. The axonal beta-sAPP staining was patchy and unevenly distributed for the AD cases, indicating impaired axonal transport. beta-sAPP was also found surrounding senile plaques...

  9. Luminal localization of α-tubulin K40 acetylation by cryo-EM analysis of fab-labeled microtubules.

    Directory of Open Access Journals (Sweden)

    Virupakshi Soppina

    Full Text Available The αβ-tubulin subunits of microtubules can undergo a variety of evolutionarily-conserved post-translational modifications (PTMs that provide functional specialization to subsets of cellular microtubules. Acetylation of α-tubulin residue Lysine-40 (K40 has been correlated with increased microtubule stability, intracellular transport, and ciliary assembly, yet a mechanistic understanding of how acetylation influences these events is lacking. Using the anti-acetylated tubulin antibody 6-11B-1 and electron cryo-microscopy, we demonstrate that the K40 acetylation site is located inside the microtubule lumen and thus cannot directly influence events on the microtubule surface, including kinesin-1 binding. Surprisingly, the monoclonal 6-11B-1 antibody recognizes both acetylated and deacetylated microtubules. These results suggest that acetylation induces structural changes in the K40-containing loop that could have important functional consequences on microtubule stability, bending, and subunit interactions. This work has important implications for acetylation and deacetylation reaction mechanisms as well as for interpreting experiments based on 6-11B-1 labeling.

  10. Regulation of microtubule nucleation mediated by gamma-tubulin complexes

    Czech Academy of Sciences Publication Activity Database

    Sulimenko, Vadym; Hájková, Zuzana; Klebanovych, Anastasiya; Dráber, Pavel

    2017-01-01

    Roč. 254, č. 3 (2017), s. 1187-1199 ISSN 0033-183X R&D Projects: GA MŠk(CZ) LD13015 Institutional support: RVO:68378050 Keywords : mitotic spindle formation * ring complex * fission yeast * organizing centers * protein complex * golgi-complex * cell-cycle * pole body * augmin * centrosome * Centrosomes * Microtubule nucleation * Microtubule-organizing centers * Non-centrosomal nucleation sites * Spindle pole bodies * gamma-Tubulin complexes Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Cell biology Impact factor: 2.870, year: 2016

  11. Interdisciplinary study for the evaluation of biochemical alterations on mussel Mytilus galloprovincialis exposed to a tributyltin-polluted area

    Energy Technology Data Exchange (ETDEWEB)

    Magi, Emanuele [University of Genoa, Department of Chemistry and Industrial Chemistry, Genoa (Italy); Department of Chemistry and Industrial Chemistry, Genoa (Italy); Liscio, Camilla; Pistarino, Erika; Santamaria, Barbara; Di Carro, Marina; Tiso, Micaela; Cosulich, M.E. [University of Genoa, Department of Chemistry and Industrial Chemistry, Genoa (Italy); Scaloni, Andrea; Renzone, Giovanni [National Research Council, Proteomic and Mass Spectrometry Laboratory, ISPAAM, Naples (Italy)

    2008-05-15

    An interdisciplinary approach was employed to monitor the concentration and the effects of butyltin compounds in mussels (Mytilus galloprovincialis). Tissues from animals exposed to a marine area (Vado Ligure harbour) with a high concentration of tributyltin (TBT) were analysed and compared with control samples. TBT concentrations were measured by gas chromatography-mass spectrometry and the protein pattern in gill tissues was studied by proteomic analysis. Several proteomic signatures associated with contaminant exposure were observed; spots that were significantly increased in all contaminated samples were identified by mass spectrometry as fragments of {beta}-tubulin. The degradation of {beta}-tubulin was then confirmed by western blot analysis with specific anti-{beta}-tubulin antibody. The effects observed on mussel gills after exposure in the TBT-polluted area are discussed. (orig.)

  12. The prion protein as a receptor for amyloid-beta

    NARCIS (Netherlands)

    Kessels, Helmut W.; Nguyen, Louis N.; Nabavi, Sadegh; Malinow, Roberto

    2010-01-01

    Increased levels of brain amyloid-beta, a secreted peptide cleavage product of amyloid precursor protein (APP), is believed to be critical in the aetiology of Alzheimer's disease. Increased amyloid-beta can cause synaptic depression, reduce the number of spine protrusions (that is, sites of synaptic

  13. Overexpression and Nucleolar Localization of γ-Tubulin Small Complex Proteins GCP2 and GCP3 in Glioblastoma

    Czech Academy of Sciences Publication Activity Database

    Dráberová, Eduarda; D'Agostino, L.; Caracciolo, V.; Sládková, Vladimíra; Sulimenko, Tetyana; Sulimenko, Vadym; Sobol, Margaryta; Maounis, N.F.; Tzelepis, E.; Mahera, E.; Křen, L.; Legido, A.; Giordano, A.; Moerk, S.; Hozák, Pavel; Dráber, Pavel; Katsetos, C.D.

    2015-01-01

    Roč. 74, č. 7 (2015), s. 723-742 ISSN 0022-3069 R&D Projects: GA MŠk LH12050; GA MZd NT14467; GA ČR GAP302/12/1673; GA TA ČR(CZ) TE01020118; GA MPO FR-TI3/588 Grant - others:GA AV ČR M200521203PIPP; St. Christopher's Hospital for Children Reunified Endowment(US) 323256 Institutional support: RVO:68378050 Keywords : Gamma-tubulin * Gamma-tubulin complex proteins * GCP2 * Glioma * Glioblastoma * Nucleolus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.432, year: 2015

  14. TGF-β-stimulated aberrant expression of class III β-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

    International Nuclear Information System (INIS)

    Chung, Eun Jee; Chun, Ji Na; Jung, Sun-Ah; Cho, Jin Won; Lee, Joon H.

    2011-01-01

    Highlights: ► TGF-β induces aberrant expression of βIII in RPE cells via the ERK pathway. ► TGF-β increases O-GlcNAc modification of βIII in RPE cells. ► Mature RPE cells have the capacity to express a neuron-associated gene by TGF-β. -- Abstract: The class III β-tubulin isotype (β III ) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III β-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-β (TGF-β) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-β on the aberrant expression of class III β-tubulin and the intracellular signaling pathway mediating these changes. TGF-β-induced aberrant expression and O-linked-β-N-acetylglucosamine (O-GlcNac) modification of class III β-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-β also stimulated phosphorylation of ERK. TGF-β-induced aberrant expression of class III β-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-β stimulated aberrant expression of class III β-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-β stimulation and provide useful information towards understanding the pathogenesis of proliferative vitreoretinal diseases.

  15. p27Kip1 Modulates Axonal Transport by Regulating α-Tubulin Acetyltransferase 1 Stability

    Directory of Open Access Journals (Sweden)

    Giovanni Morelli

    2018-05-01

    Full Text Available Summary: The protein p27Kip1 plays roles that extend beyond cell-cycle regulation during cerebral cortex development, such as the regulation of neuronal migration and neurite branching via signaling pathways that converge on the actin and microtubule cytoskeletons. Microtubule-dependent transport is essential for the maturation of neurons and the establishment of neuronal connectivity though synapse formation and maintenance. Here, we show that p27Kip1 controls the transport of vesicles and organelles along the axon of mice cortical projection neurons in vitro. Moreover, suppression of the p27Kip1 ortholog, dacapo, in Drosophila melanogaster disrupts axonal transport in vivo, leading to the reduction of locomotor activity in third instar larvae and adult flies. At the molecular level, p27Kip1 stabilizes the α-tubulin acetyltransferase 1, thereby promoting the acetylation of microtubules, a post-translational modification required for proper axonal transport. : Morelli et al. report that p27Kip1/Dacapo modulates the acetylation of microtubules in axons via stabilization of ATAT1, the main α-tubulin acetyltransferase. Its conditional loss leads to the reduction of bidirectional axonal transport of vesicles and mitochondria in vitro in mice and in vivo in Drosophila. Keywords: p27Kip1, dacapo, acetylation, axonal transport, ATAT1, alpha-tubulin, HDAC6, Drosophila, mouse, cerebral cortex

  16. Requirement of a novel splicing variant of human histone deacetylase 6 for TGF-{beta}1-mediated gene activation

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Yan [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States); Nguyen, Hong T. [Graduate Program in Biomedical Sciences, Tulane School of Medicine, New Orleans, LA 70112 (United States); Lasky, Joseph A. [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States); Cao, Subing [Graduate Program in Biomedical Sciences, Tulane School of Medicine, New Orleans, LA 70112 (United States); Li, Cui [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States); Xiangya Hospital, Central South University, Hunan 41008 (China); Hu, Jiyao; Guo, Xinyue; Burow, Matthew E. [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States); Shan, Bin, E-mail: bshan@tulane.edu [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States)

    2010-02-19

    Histone deacetylase 6 (HDAC6) belongs to the family of class IIb HDACs and predominantly deacetylates non-histone proteins in the cytoplasm via the C-terminal deacetylase domain of its two tandem deacetylase domains. HDAC6 modulates fundamental cellular processes via deacetylation of {alpha}-tubulin, cortactin, molecular chaperones, and other peptides. Our previous study indicates that HDAC6 mediates TGF-{beta}1-induced epithelial-mesenchymal transition (EMT) in A549 cells. In the current study, we identify a novel splicing variant of human HDAC6, hHDAC6p114. The hHDAC6p114 mRNA arises from incomplete splicing and encodes a truncated isoform of the hHDAC6p114 protein of 114 kDa when compared to the major isoform hHDAC6p131. The hHDAC6p114 protein lacks the first 152 amino acids from N-terminus in the hHDAC6p131 protein, which harbors a nuclear export signal peptide and 76 amino acids of the N-terminal deacetylase domain. hHDAC6p114 is intact in its deacetylase activity against {alpha}-tubulin. The expression hHDAC6p114 is elevated in a MCF-7 derivative that exhibits an EMT-like phenotype. Moreover, hHDAC6p114 is required for TGF-{beta}1-activated gene expression associated with EMT in A549 cells. Taken together, our results implicate that expression and function of hHDAC6p114 is differentially regulated when compared to hHDAC6p131.

  17. Control channels in the brain and their influence on brain executive functions

    Science.gov (United States)

    Meng, Qinglei; Choa, Fow-Sen; Hong, Elliot; Wang, Zhiguang; Islam, Mohammad

    2014-05-01

    In a computer network there are distinct data channels and control channels where massive amount of visual information are transported through data channels but the information streams are routed and controlled by intelligent algorithm through "control channels". Recent studies on cognition and consciousness have shown that the brain control channels are closely related to the brainwave beta (14-40 Hz) and alpha (7-13 Hz) oscillations. The high-beta wave is used by brain to synchronize local neural activities and the alpha oscillation is for desynchronization. When two sensory inputs are simultaneously presented to a person, the high-beta is used to select one of the inputs and the alpha is used to deselect the other so that only one input will get the attention. In this work we demonstrated that we can scan a person's brain using binaural beats technique and identify the individual's preferred control channels. The identified control channels can then be used to influence the subject's brain executive functions. In the experiment, an EEG measurement system was used to record and identify a subject's control channels. After these channels were identified, the subject was asked to do Stroop tests. Binaural beats was again used to produce these control-channel frequencies on the subject's brain when we recorded the completion time of each test. We found that the high-beta signal indeed speeded up the subject's executive function performance and reduced the time to complete incongruent tests, while the alpha signal didn't seem to be able to slow down the executive function performance.

  18. Dietary flavonoid fisetin binds to β-tubulin and disrupts microtubule dynamics in prostate cancer cells.

    Science.gov (United States)

    Mukhtar, Eiman; Adhami, Vaqar Mustafa; Sechi, Mario; Mukhtar, Hasan

    2015-10-28

    Microtubule targeting based therapies have revolutionized cancer treatment; however, resistance and side effects remain a major limitation. Therefore, novel strategies that can overcome these limitations are urgently needed. We made a novel discovery that fisetin, a hydroxyflavone, is a microtubule stabilizing agent. Fisetin binds to tubulin and stabilizes microtubules with binding characteristics far superior than paclitaxel. Surface plasmon resonance and computational docking studies suggested that fisetin binds to β-tubulin with superior affinity compared to paclitaxel. Fisetin treatment of human prostate cancer cells resulted in robust up-regulation of microtubule associated proteins (MAP)-2 and -4. In addition, fisetin treated cells were enriched in α-tubulin acetylation, an indication of stabilization of microtubules. Fisetin significantly inhibited PCa cell proliferation, migration, and invasion. Nudc, a protein associated with microtubule motor dynein/dynactin complex that regulates microtubule dynamics, was inhibited with fisetin treatment. Further, fisetin treatment of a P-glycoprotein overexpressing multidrug-resistant cancer cell line NCI/ADR-RES inhibited the viability and colony formation. Our results offer in vitro proof-of-concept for fisetin as a microtubule targeting agent. We suggest that fisetin could be developed as an adjuvant for treatment of prostate and other cancer types. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Rational design of biaryl pharmacophore inserted noscapine derivatives as potent tubulin binding anticancer agents

    Science.gov (United States)

    Santoshi, Seneha; Manchukonda, Naresh Kumar; Suri, Charu; Sharma, Manya; Sridhar, Balasubramanian; Joseph, Silja; Lopus, Manu; Kantevari, Srinivas; Baitharu, Iswar; Naik, Pradeep Kumar

    2015-03-01

    We have strategically designed a series of noscapine derivatives by inserting biaryl pharmacophore (a major structural constituent of many of the microtubule-targeting natural anticancer compounds) onto the scaffold structure of noscapine. Molecular interaction of these derivatives with α,β-tubulin heterodimer was investigated by molecular docking, molecular dynamics simulation, and binding free energy calculation. The predictive binding affinity indicates that the newly designed noscapinoids bind to tubulin with a greater affinity. The predictive binding free energy (ΔGbind, pred) of these derivatives (ranging from -5.568 to -5.970 kcal/mol) based on linear interaction energy (LIE) method with a surface generalized Born (SGB) continuum solvation model showed improved binding affinity with tubulin compared to the lead compound, natural α-noscapine (-5.505 kcal/mol). Guided by the computational findings, these new biaryl type α-noscapine congeners were synthesized from 9-bromo-α-noscapine using optimized Suzuki reaction conditions for further experimental evaluation. The derivatives showed improved inhibition of the proliferation of human breast cancer cells (MCF-7), human cervical cancer cells (HeLa) and human lung adenocarcinoma cells (A549), compared to natural noscapine. The cell cycle analysis in MCF-7 further revealed that these compounds alter the cell cycle profile and cause mitotic arrest at G2/M phase more strongly than noscapine. Tubulin binding assay revealed higher binding affinity to tubulin, as suggested by dissociation constant (Kd) of 126 ± 5.0 µM for 5a, 107 ± 5.0 µM for 5c, 70 ± 4.0 µM for 5d, and 68 ± 6.0 µM for 5e compared to noscapine (Kd of 152 ± 1.0 µM). In fact, the experimentally determined value of ΔGbind, expt (calculated from the Kd value) are consistent with the predicted value of ΔGbind, pred calculated based on LIE-SGB. Based on these results, one of the derivative 5e of this series was used for further toxicological

  20. BIALLELIC POLYMORPHISM IN THE INTRON REGION OF B-TUBULIN GENE OF CRYPTOSPORIDIUM PARASITES

    Science.gov (United States)

    Nucleotide sequencing of polymerase chain reaction-amplified intron region of the Cryptosporidium parvum B-tubulin gene in 26 human and 15 animal isolates revealed distinct genetic polymorphism between the human and bovine genotypes. The separation of 2 genotypes of C. parvum is...

  1. Predictive timing functions of cortical beta oscillations are impaired in Parkinson's disease and influenced by L-DOPA and deep brain stimulation of the subthalamic nucleus

    Directory of Open Access Journals (Sweden)

    A. Gulberti

    2015-01-01

    Full Text Available Cortex-basal ganglia circuits participate in motor timing and temporal perception, and are important for the dynamic configuration of sensorimotor networks in response to exogenous demands. In Parkinson's disease (PD patients, rhythmic auditory stimulation (RAS induces motor performance benefits. Hitherto, little is known concerning contributions of the basal ganglia to sensory facilitation and cortical responses to RAS in PD. Therefore, we conducted an EEG study in 12 PD patients before and after surgery for subthalamic nucleus deep brain stimulation (STN-DBS and in 12 age-matched controls. Here we investigated the effects of levodopa and STN-DBS on resting-state EEG and on the cortical-response profile to slow and fast RAS in a passive-listening paradigm focusing on beta-band oscillations, which are important for auditory–motor coupling. The beta-modulation profile to RAS in healthy participants was characterized by local peaks preceding and following auditory stimuli. In PD patients RAS failed to induce pre-stimulus beta increases. The absence of pre-stimulus beta-band modulation may contribute to impaired rhythm perception in PD. Moreover, post-stimulus beta-band responses were highly abnormal during fast RAS in PD patients. Treatment with levodopa and STN-DBS reinstated a post-stimulus beta-modulation profile similar to controls, while STN-DBS reduced beta-band power in the resting-state. The treatment-sensitivity of beta oscillations suggests that STN-DBS may specifically improve timekeeping functions of cortical beta oscillations during fast auditory pacing.

  2. Predictive timing functions of cortical beta oscillations are impaired in Parkinson's disease and influenced by L-DOPA and deep brain stimulation of the subthalamic nucleus.

    Science.gov (United States)

    Gulberti, A; Moll, C K E; Hamel, W; Buhmann, C; Koeppen, J A; Boelmans, K; Zittel, S; Gerloff, C; Westphal, M; Schneider, T R; Engel, A K

    2015-01-01

    Cortex-basal ganglia circuits participate in motor timing and temporal perception, and are important for the dynamic configuration of sensorimotor networks in response to exogenous demands. In Parkinson's disease (PD) patients, rhythmic auditory stimulation (RAS) induces motor performance benefits. Hitherto, little is known concerning contributions of the basal ganglia to sensory facilitation and cortical responses to RAS in PD. Therefore, we conducted an EEG study in 12 PD patients before and after surgery for subthalamic nucleus deep brain stimulation (STN-DBS) and in 12 age-matched controls. Here we investigated the effects of levodopa and STN-DBS on resting-state EEG and on the cortical-response profile to slow and fast RAS in a passive-listening paradigm focusing on beta-band oscillations, which are important for auditory-motor coupling. The beta-modulation profile to RAS in healthy participants was characterized by local peaks preceding and following auditory stimuli. In PD patients RAS failed to induce pre-stimulus beta increases. The absence of pre-stimulus beta-band modulation may contribute to impaired rhythm perception in PD. Moreover, post-stimulus beta-band responses were highly abnormal during fast RAS in PD patients. Treatment with levodopa and STN-DBS reinstated a post-stimulus beta-modulation profile similar to controls, while STN-DBS reduced beta-band power in the resting-state. The treatment-sensitivity of beta oscillations suggests that STN-DBS may specifically improve timekeeping functions of cortical beta oscillations during fast auditory pacing.

  3. Brain-computer interface signal processing at the Wadsworth Center: mu and sensorimotor beta rhythms.

    Science.gov (United States)

    McFarland, Dennis J; Krusienski, Dean J; Wolpaw, Jonathan R

    2006-01-01

    The Wadsworth brain-computer interface (BCI), based on mu and beta sensorimotor rhythms, uses one- and two-dimensional cursor movement tasks and relies on user training. This is a real-time closed-loop system. Signal processing consists of channel selection, spatial filtering, and spectral analysis. Feature translation uses a regression approach and normalization. Adaptation occurs at several points in this process on the basis of different criteria and methods. It can use either feedforward (e.g., estimating the signal mean for normalization) or feedback control (e.g., estimating feature weights for the prediction equation). We view this process as the interaction between a dynamic user and a dynamic system that coadapt over time. Understanding the dynamics of this interaction and optimizing its performance represent a major challenge for BCI research.

  4. Blood-brain barrier dysfunction and amyloid precursor protein accumulation in microvascular compartment following ischemia-reperfusion brain injury with 1-year survival.

    Science.gov (United States)

    Pluta, R

    2003-01-01

    This study examined the late microvascular consequences of brain ischemia due to cardiac arrest in rats. In reacted vibratome sections scattered foci of extravasated horseradish peroxidase were noted throughout the brain and did not appear to be restricted to any specific area of brain. Ultrastructural investigation of leaky sites frequently presented platelets adhering to the endothelium of venules and capillaries. Endothelial cells demonstrated pathological changes with evidence of perivascular astrocytic swelling. At the same time, we noted C-terminal of amyloid precursor protein/beta-amyloid peptide (CAPP/betaA) deposits in cerebral blood vessels, with a halo of CAPP/betaA immunoreactivity in the surrounding parenchyma suggested diffusion of CAPP/betaA out of the vascular compartment. Changes predominated in the hippocampus, cerebral and entorhinal cortex, corpus callosum, thalamus, basal ganglia and around the lateral ventricles. These data implicate delayed abnormal endothelial function of vessels following ischemia-reperfusion brain injury as a primary event in the pathogenesis of the recurrent cerebral infarction.

  5. Synthesis and activity of novel analogs of hemiasterlin as inhibitors of tubulin polymerization: modification of the A segment.

    Science.gov (United States)

    Yamashita, Ayako; Norton, Emily B; Kaplan, Joshua A; Niu, Chuan; Loganzo, Frank; Hernandez, Richard; Beyer, Carl F; Annable, Tami; Musto, Sylvia; Discafani, Carolyn; Zask, Arie; Ayral-Kaloustian, Semiramis

    2004-11-01

    Analogs of hemiasterlin (1) and HTI-286 (2), which contain various aromatic rings in the A segment, were synthesized as potential inhibitors of tubulin polymerization. The structure-activity relationships related to stereo- and regio-chemical effects of substituents on the aromatic ring in the A segment were studied. Analogs, which carry a meta-substituted phenyl ring in the A segment show comparable activity for inhibition of tubulin polymerization to 2, as well as in the cell proliferation assay using KB cells containing P-glycoprotein, compared to those of 1 and 2.

  6. Impaired dopaminergic neurotransmission in patients with traumatic brain injury: a SPECT study using 123I-beta-CIT and 123I-IBZM.

    Science.gov (United States)

    Donnemiller, E; Brenneis, C; Wissel, J; Scherfler, C; Poewe, W; Riccabona, G; Wenning, G K

    2000-09-01

    Structural imaging suggests that traumatic brain injury (TBI) may be associated with disruption of neuronal networks, including the nigrostriatal dopaminergic pathway. However, to date deficits in pre- and/or postsynaptic dopaminergic neurotransmission have not been demonstrated in TBI using functional imaging. We therefore assessed dopaminergic function in ten TBI patients using [123I]2-beta-carbomethoxy-3-beta-(4-iodophenyl)tropane (beta-CIT) and [123I]iodobenzamide (IBZM) single-photon emission tomography (SPET). Average Glasgow Coma Scale score (+/-SD) at the time of head trauma was 5.8+/-4.2. SPET was performed on average 141 days (SD +/-92) after TBI. The SPET images were compared with structural images using cranial computerised tomography (CCT) and magnetic resonance imaging (MRI). SPET was performed with an ADAC Vertex dual-head camera. The activity ratios of striatal to cerebellar uptake were used as a semiquantitative parameter of striatal dopamine transporter (DAT) and D2 receptor (D2R) binding. Compared with age-matched controls, patients with TBI had significantly lower striatal/cerebellar beta-CIT and IBZM binding ratios (PTBI despite relative structural preservation of the striatum. Further investigations of possible clinical correlates and efficacy of dopaminergic therapy in patients with TBI seem justified.

  7. Overexpressed HDAC8 in cervical cancer cells shows functional redundancy of tubulin deacetylation with HDAC6.

    Science.gov (United States)

    Vanaja, G R; Ramulu, Hemalatha Golaconda; Kalle, Arunasree M

    2018-05-02

    Histone deacetylases (HDACs) are involved in epigenetic gene regulation via deacetylation of acetylated lysine residues of both histone and non-histone proteins. Among the 18 HDACs identified in humans, HDAC8, a class I HDAC, is best understood structurally and enzymatically. However, its precise subcellular location, function in normal cellular physiology, its protein partners and substrates still remain elusive. The subcellular localization of HDAC8 was studied using immunofluorescence and confocal imaging. The binding parterns were identified employing immunoprecipitation (IP) followed by MALDI-TOF analysis and confirmed using in-silico protein-protein interaction studies, HPLC-based in vitro deacetylation assay, intrinsic fluorescence spectrophotometric analysis, Circular dichroism (CD) and Surface Plasmon Resonance (SPR). Functional characterization of the binding was carried out using immunoblot and knockdown by siRNA. Using one way ANOVA statistical significance (n = 3) was determined. Here, we show that HDAC8 and its phosphorylated form (pHDAC8) localized predominantly in the cytoplasm in cancerous, HeLa, and non-cancerous (normal), HEK293T, cells, although nucleolar localization was observed in HeLa cells. The study identified Alpha tubulin as a novel interacting partner of HDAC8. Further, the results indicated binding and deacetylation of tubulin at ac-lys40 by HDAC8. Knockdown of HDAC8 by siRNA, inhibition of HDAC8 and/or HDAC6 by PCI-34051 and tubastatin respectively, cell-migration, cell morphology and cell cycle analysis clearly explained HDAC8 as tubulin deacetylase in HeLa cells and HDAC6 in HEK 293 T cells. HDAC8 shows functional redundancy with HDAC6 when overexpressed in cervical cancer cells, HeLa, and deacetylaes ac-lys40 of alpha tubulin leading to cervical cancer proliferation and progression.

  8. Cortical Reorganization after Hand Immobilization: The beta qEEG Spectral Coherence Evidences

    Science.gov (United States)

    Fortuna, Marina; Teixeira, Silmar; Machado, Sérgio; Velasques, Bruna; Bittencourt, Juliana; Peressutti, Caroline; Budde, Henning; Cagy, Mauricio; Nardi, Antonio E.; Piedade, Roberto; Ribeiro, Pedro; Arias-Carrión, Oscar

    2013-01-01

    There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes. PMID:24278213

  9. Tubulin cytoskeleton during microsporogenesis in the male-sterile genotype of Allium sativum and fertile Allium ampeloprasum L.

    Science.gov (United States)

    Tchórzewska, Dorota; Deryło, Kamil; Błaszczyk, Lidia; Winiarczyk, Krystyna

    2015-12-01

    Microsporogenesis in garlic. The male-sterile Allium sativum (garlic) reproduces exclusively in the vegetative mode, and anthropogenic factors seem to be the cause of the loss of sexual reproduction capability. There are many different hypotheses concerning the causes of male sterility in A.sativum; however, the mechanisms underlying this phenomenon have not been comprehensively elucidated.Numerous attempts have been undertaken to understand the causes of male sterility, but the tubulin cytoskeleton in meiotically dividing cells during microsporogenesis has never been investigated in this species. Using sterile A.sativum genotype L13 and its fertile close relative A. ampeloprasum (leek), we have analysed the distribution of the tubulin cytoskeleton during microsporogenesis. We observed that during karyokinesis and cytokinesis, in both meiotic divisions I and II, the microtubular cytoskeleton in garlic L13 formed configurations that resembled tubulin arrangement typical of monocots. However, the tubulin cytoskeleton in garlic was distinctly poorer (composed of a few MT filaments) compared with that found in meiotically dividing cells in A. ampeloprasum. These differences did not affect the course of karyogenesis, chondriokinesis, and cytokinesis, which contributed to completion of microsporogenesis, but there was no further development of the male gametophyte. At the very beginning of the successive stage of development of fertile pollen grains, i.e. gametogenesis, there were disorders involving the absence of a normal cortical cytoskeleton and dramatically progressive degeneration of the cytoplasm in garlic. Therefore,we suggest that, due to disturbances in cortical cytoskeleton formation at the very beginning of gametogenesis, the intracellular transport governed by the cytoskeleton might be perturbed, leading to microspore decay in the male-sterile garlic genotype.

  10. Hypoparathyroidism and intracerebral calcification in patients with beta-thalassemia major

    Energy Technology Data Exchange (ETDEWEB)

    Karimi, M. [Iran-Shiraz-Namazee Hospital, Namazee Square, Hematology Research Center, Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz (Iran, Islamic Republic of)], E-mail: karimim@sums.ac.ir; Rasekhi, A.R. [Iran-Shiraz-Namazee Hospital, Namazee Square, Imaging Research Center, Department of Radiology, Shiraz University of Medical Sciences, Shiraz (Iran, Islamic Republic of)], E-mail: rasekhia@sums.ac.ir; Rasekh, M. [Iran-Shiraz-Namazee Hospital, Namazee Square, Department of Endocrinology and Metabolism, Shiraz University of Medical Sciences, Shiraz (Iran, Islamic Republic of)], E-mail: Rasekhm@sums.ac.ir; Nabavizadeh, S.A. [Iran-Shiraz-Namazee Hospital, Namazee Square, Imaging Research Center, Department of Radiology, Shiraz University of Medical Sciences, Shiraz (Iran, Islamic Republic of)], E-mail: nabavia@gmail.com; Assadsangabi, R. [Iran-Shiraz-Namazee Hospital, Namazee Square, Imaging Research Center, Department of Radiology, Shiraz University of Medical Sciences, Shiraz (Iran, Islamic Republic of)], E-mail: assadsangabi@yahoo.com; Amirhakimi, G.H. [Iran-Shiraz-Namazee Hospital, Namazee Square, Department of Endocrinology and Metabolism, Shiraz University of Medical Sciences, Shiraz (Iran, Islamic Republic of)], E-mail: amirhakimig@sums.ac.ir

    2009-06-15

    Background: Hypoparathyroidism is one of the most important endocrine complications of thalassemia major. This study was conducted to evaluate the prevalence of intracerebral calcifications in patients with thalassemia with and without hypoparathyroidism. Methods: 47 beta-thalassemia patients with hypoparathyroidism underwent a brain CT scan to investigate the presence and extent of intracerebral calcification. 30 age- and sex-matched beta-thalassemic patients with normal parathyroid function who had undergone brain CT for headache, or some other minor neurologic problems were also enrolled in the study serving as controls. The amount of intracerebral calcification, hematologic parameters, and some clinical findings were compared between both groups. Results: Intracerebral calcification was present in 54.2% of beta-thalassemia patients with hypoparathyroidism. The most frequent sites of calcification were basal ganglia, and frontoparietal areas of the brain. Thalami, internal capsule, cerebellum and posterior fossa were other less frequently calcified regions of the brain. In contrast, there was no evidence of intracerebral calcifications in the 30 thalassemic patients with normal parathyroid function. There was not a statistically significant difference between serum ferritin concentrations in thalassemia patient with hypoparathyroidism and those with normal parathyroid function (2781 vs. 2178, P > 0.05). Conclusion: Intracranial calcification is a common finding in thalassemia patients with hypoparathyroidism, it can be extensive and involves most regions of the brain.

  11. Hypoparathyroidism and intracerebral calcification in patients with beta-thalassemia major

    International Nuclear Information System (INIS)

    Karimi, M.; Rasekhi, A.R.; Rasekh, M.; Nabavizadeh, S.A.; Assadsangabi, R.; Amirhakimi, G.H.

    2009-01-01

    Background: Hypoparathyroidism is one of the most important endocrine complications of thalassemia major. This study was conducted to evaluate the prevalence of intracerebral calcifications in patients with thalassemia with and without hypoparathyroidism. Methods: 47 beta-thalassemia patients with hypoparathyroidism underwent a brain CT scan to investigate the presence and extent of intracerebral calcification. 30 age- and sex-matched beta-thalassemic patients with normal parathyroid function who had undergone brain CT for headache, or some other minor neurologic problems were also enrolled in the study serving as controls. The amount of intracerebral calcification, hematologic parameters, and some clinical findings were compared between both groups. Results: Intracerebral calcification was present in 54.2% of beta-thalassemia patients with hypoparathyroidism. The most frequent sites of calcification were basal ganglia, and frontoparietal areas of the brain. Thalami, internal capsule, cerebellum and posterior fossa were other less frequently calcified regions of the brain. In contrast, there was no evidence of intracerebral calcifications in the 30 thalassemic patients with normal parathyroid function. There was not a statistically significant difference between serum ferritin concentrations in thalassemia patient with hypoparathyroidism and those with normal parathyroid function (2781 vs. 2178, P > 0.05). Conclusion: Intracranial calcification is a common finding in thalassemia patients with hypoparathyroidism, it can be extensive and involves most regions of the brain.

  12. GMP-compliant automated synthesis of [{sup 18}F]AV-45 (Florbetapir F 18) for imaging {beta}-amyloid plaques in human brain

    Energy Technology Data Exchange (ETDEWEB)

    Yao, C.-H. [Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Taiwan (China); Lin, K.-J. [Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, 259 Wen-Hua 1st Road, Kweishan, Taoyuan 333, Taiwan (China); Weng, C.-C. [Department of Medical Imaging and Radiological Sciences, Chang Gung University, 259 Wen-Hua 1st Road, Kweishan, Taoyuan 333, Taiwan (China); Hsiao, I.-T. [Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, 259 Wen-Hua 1st Road, Kweishan, Taoyuan 333, Taiwan (China); Ting, Y.-S. [Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Taiwan (China); Yen, T.-C. [Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, 259 Wen-Hua 1st Road, Kweishan, Taoyuan 333, Taiwan (China); Jan, T.-R. [Department and Graduate Institute of Veterinary Medicine, National Taiwan University, Taipei, Taiwan (China); Skovronsky, Daniel [Avid Radiopharmaceuticals, Inc., Philadelphia, PA 19104 (United States); Kung, M.-P. [Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Taiwan (China); Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Wey, S.-P., E-mail: spwey@mail.cgu.edu.t [Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, 259 Wen-Hua 1st Road, Kweishan, Taoyuan 333, Taiwan (China)

    2010-12-15

    We report herein the Good Manufacturing Practice (GMP)-compliant automated synthesis of {sup 18}F-labeled styrylpyridine, AV-45 (Florbetapir), a novel tracer for positron emission tomography (PET) imaging of {beta}-amyloid (A{beta}) plaques in the brain of Alzheimer's disease patients. [{sup 18}F]AV-45 was prepared in 105 min using a tosylate precursor with Sumitomo modules for radiosynthesis under GMP-compliant conditions. The overall yield was 25.4{+-}7.7% with a final radiochemical purity of 95.3{+-}2.2% (n=19). The specific activity of [{sup 18}F]AV-45 reached as high as 470{+-}135 TBq/mmol (n=19). The present studies show that [{sup 18}F]AV-45 can be manufactured under GMP-compliant conditions and could be widely available for routine clinical use.

  13. THE EFFECT OF BETA GLUCAN OF SACCHAROMYCES CEREVISAE ON THE INCREASE OF THE NUMBER OF BRAIN CELLS IN SUBSTANTIA NIGRA BRAIN OF PARKINSON’S WISTAR STRAIN RAT (RATTUS NORVEGICUS MODEL INDUCED WITH ROTENONE

    Directory of Open Access Journals (Sweden)

    Masruroh Rahayu

    2015-01-01

    Full Text Available ackground and aims. One of many neurodegenerative diseases afflicting the elderly is Parkinson. Beta glucan from Saccharomyces cerevisae is very potential to be used as a regenerative therapy of Parkinson's disease. Beta glucan can increase the mobilization of hematopoietic stem cells (HSCs from the bone marrow into the damaged tissues. Hematopoietic stem cells (HSCs which have been mobilized can regenerate and differentiate into brain cells so that the symptoms of Parkinson would be reduced. This research aims to find out the effects of the addition of Saccharomyces cerevisae toward the number of brain cells in substantia nigra Parkinson’s rat model. Method. The research was experimental in vivo using the draft of randomized post test only controlled group design. There were five groups that become the sample in this research with 5 rats for each group, i.e. negative control group, positive control group, Treatment Group 1, 2 and 3 (Rotenone + Saccharomyces cerevisae 18 mg/kgBB, 36 mg/kgBB, 72 mg/kgBBfor 4 weeks. Variable measured in this study was the number of brain cells in substantia nigra. The results of this study showed that Treatment Group 3 (72 mg/kgBB was a group with the largest number of brain cells than the other treatment groups. Statistical data obtained showed that the average number of brain cells in negative control group was 192.00 cells; positive control amounted to 116.80 cells; Treatment 1 amounted to 135.40 cells; Treatment 2 amounted to 140.80 cells; and Treatment 3 amounted to 161.80 cells. Result. The result of ANOVA test showed a significant difference between groups (p< 0.05, while the correlation test result indicated a strong correlation between the dose of Saccharomyces cerevisae and the number of substantia nigra of rat’s brain cells (r = 0,818. Conclusion. From this research, it can be concluded that the addition of Saccharomyces cerevisae with a dose of 18mg/kgBB, 36mg/kgBBdan 72 mg/kgBB is able to increase

  14. Synthesis of 14C labelled electrophilic ligands of the colchicine binding site of tubulin: chloroacetates of demethylthiocolchicines and of N-acetylcolchinol; isothiocyanate of 9-deoxy-N-acetylcolchinol

    International Nuclear Information System (INIS)

    Boye, O.; Brossi, A.

    1993-01-01

    14 C-Chloroacetates of 2-demethylthiocolchicine 7 and of 3-demethylthiocolchicine 8 were synthesized and found to covalently bind with high specificity to the β-subunit of tubulin. The 14 C-chloroacetate of N-acetylcolchinol and the 14 C-isothiocyanate were also prepared and found to react covalently with tubulin but in a nonspecific manner. With the radiolabelled chloroacetates 7 and 8 two compounds are now available to further characterize the colchicine binding site on the β subunit of tubulin. (author)

  15. Increased central immunoreactive beta-endorphin content in patients with Wernicke-Korsakoff syndrome and in alcoholics.

    Science.gov (United States)

    Summers, J A; Pullan, P T; Kril, J J; Harper, C G

    1991-01-01

    beta-endorphin, adrenocorticotrophin, and alpha-melanocyte stimulating hormone were measured by radioimmunoassay in three areas of human brain at necropsy in seven subjects with Wernicke-Korsakoff syndrome and in 52 controls. Thiamin concentration in six brain areas was also measured. Mamillary body beta-endorphin concentrations were significantly increased in those with the syndrome compared with controls, and those controls with high alcohol intake showed increased mamillary body beta-endorphin compared with controls with low alcohol intake. Brain thiamin concentration was similar in both groups, with the exception of the brainstem, where it was reduced in subjects with Wernicke-Korsakoff syndrome. Thalamic beta-endorphin in controls was inversely correlated with thiamin in frontal white matter, frontal cortex, parietal white matter and parietal cortex, while beta-endorphin in the hypothalamus of patients was inversely correlated with thiamin in frontal cortex, parietal white matter, thalamus and brainstem. These results suggest that there is a disturbance of the endorphinergic system in Wernicke-Korsakoff syndrome which may be related to alcohol intake. PMID:1650797

  16. Utilization of D-beta-hydroxybutyrate and oleate as alternate energy fuels in brain cell cultures of newborn mice after hypoxia at different glucose concentrations.

    Science.gov (United States)

    Bossi, E; Kohler, E; Herschkowitz, N

    1989-11-01

    In dissociated whole brain cell cultures from newborn mice, we have previously shown that during glucose deprivation under normoxia, D-beta-hydroxybutyrate and oleic acid are increasingly used for energy production. We now asked whether this glucose dependency of the utilization of D-beta-hydroxybutyrate and oleic acid as alternate energy fuels is also present after a hypoxic phase. 3-Hydroxy[3-14C]butyrate or [U-14C]oleic acid were added to 7- and 14-d-old cultures and 14CO2-production compared after hypoxia in normal and glucose-deprived conditions. After hypoxia, the ability of the cells 7 d in culture to increase D-beta-hydroxybutyrate consumption in response to glucose deprivation is diminished, 14-d-old cells lose this ability. In contrast, after hypoxia, both 7- and 14-d-old cultures maintain or even improve the ability to increase oleate consumption, when glucose is lacking.

  17. Antivascular and antitumor properties of the tubulin-binding chalcone TUB091.

    Science.gov (United States)

    Canela, María-Dolores; Noppen, Sam; Bueno, Oskía; Prota, Andrea E; Bargsten, Katja; Sáez-Calvo, Gonzalo; Jimeno, María-Luisa; Benkheil, Mohammed; Ribatti, Domenico; Velázquez, Sonsoles; Camarasa, María-José; Díaz, J Fernando; Steinmetz, Michel O; Priego, Eva-María; Pérez-Pérez, María-Jesús; Liekens, Sandra

    2017-02-28

    We investigated the microtubule-destabilizing, vascular-targeting, anti-tumor and anti-metastatic activities of a new series of chalcones, whose prototype compound is (E)-3-(3''-amino-4''-methoxyphenyl)-1-(5'-methoxy-3',4'-methylendioxyphenyl)-2-methylprop-2-en-1-one (TUB091). X-ray crystallography showed that these chalcones bind to the colchicine site of tubulin and therefore prevent the curved-to-straight structural transition of tubulin, which is required for microtubule formation. Accordingly, TUB091 inhibited cancer and endothelial cell growth, induced G2/M phase arrest and apoptosis at 1-10 nM. In addition, TUB091 displayed vascular disrupting effects in vitro and in the chicken chorioallantoic membrane (CAM) assay at low nanomolar concentrations. A water-soluble L-Lys-L-Pro derivative of TUB091 (i.e. TUB099) showed potent antitumor activity in melanoma and breast cancer xenograft models by causing rapid intratumoral vascular shutdown and massive tumor necrosis. TUB099 also displayed anti-metastatic activity similar to that of combretastatin A4-phosphate. Our data indicate that this novel class of chalcones represents interesting lead molecules for the design of vascular disrupting agents (VDAs). Moreover, we provide evidence that our prodrug approach may be valuable for the development of anti-cancer drugs.

  18. Iodine-123 labelled N-(2-fluoroethyl)-2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)nortropane for dopamine transporter imaging in the living human brain

    Energy Technology Data Exchange (ETDEWEB)

    Kuikka, J.T. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); AAkerman, K. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Bergstroem, K.A. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Karhu, J. [Dept. of Clinical Neurophysiology, Kuopio Univ. Hospital (Finland); Hiltunen, J. [MAP Medical Technologies Oy, Tikkakoski (Finland); Haukka, J. [MAP Medical Technologies Oy, Tikkakoski (Finland); Heikkinen, J. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Tiihonen, J. [Dept. of Forensic Psychiatry, Niuvanniemi Hospital, Kuopio (Finland); Wang, S. [Research Biochemical International (RBI), Natick, MA (United States); Neumeyer, J.L. [Research Biochemical International (RBI), Natick, MA (United States)

    1995-07-01

    Here we report a pilot comparison of [{sup 123}I]{beta}-CIT and [{sup 123}I]{beta}-CIT-FP with a new tropane derivative, [{sup 123}I]N-(2-fluoroethyl)-2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)nortropane ([{sup 123}I]{beta}-CIT-FE), using SPET imaging in four healthy male subjects. Peak uptake of [{sup 123}I]{beta}-CIT-FE into the basal ganglia occurred very rapidly (0.5 h after injection of tracer), after which the striatal washout obeyed a bi-exponential form. The specific DAT binding of [{sup 123}I]{beta}-CIT-FE into the basal ganglia was somewhat less (0.785{+-}0.117) than that of [{sup 123}I]{beta}-CIT (0.922{+-}0.004) or [{sup 123}I]{beta}-CIT-FP (0.813{+-}0.047). All these tracers have excellent imaging quality in healthy control subjects. However, the relatively fast washout of [{sup 123}I]{beta}-CIT-FE and low temporal resolution of older SPET cameras may limit the use of this tracer to the measurement of the DAT density. (orig./UG)

  19. Induction of tumor cell death through targeting tubulin and evoking dysregulation of cell cycle regulatory proteins by multifunctional cinnamaldehydes.

    Science.gov (United States)

    Nagle, Amrita A; Gan, Fei-Fei; Jones, Gavin; So, Choon-Leng; Wells, Geoffrey; Chew, Eng-Hui

    2012-01-01

    Multifunctional trans-cinnamaldehyde (CA) and its analogs display anti-cancer properties, with 2-benzoyloxycinnamaldehyde (BCA) and 5-fluoro-2-hydroxycinnamaldehyde (FHCA) being identified as the ortho-substituted analogs that possess potent anti-tumor activities. In this study, BCA, FHCA and a novel analog 5-fluoro-2-benzoyloxycinnamaldehyde (FBCA), were demonstrated to decrease growth and colony formation of human colon-derived HCT 116 and mammary-derived MCF-7 carcinoma cells under non-adhesive conditions. The 2-benzoyloxy and 5-fluoro substituents rendered FBCA more potent than BCA and equipotent to FHCA. The cellular events by which these cinnamaldehydes caused G(2)/M phase arrest and halted proliferation of HCT 116 cells were thereby investigated. Lack of significant accumulation of mitosis marker phospho-histone H3 in cinnamaldehyde-treated cells indicated that the analogs arrested cells in G(2) phase. G(2) arrest was brought about partly by cinnamaldehyde-mediated depletion of cell cycle proteins involved in regulating G(2) to M transition and spindle assembly, namely cdk1, cdc25C, mad2, cdc20 and survivin. Cyclin B1 levels were found to be increased, which in the absence of active cdk1, would fail to drive cells into M phase. Concentrations of cinnamaldehydes that brought about dysregulation of levels of cell cycle proteins also caused tubulin aggregation, as evident from immunodetection of dose-dependent tubulin accumulation in the insoluble cell lysate fractions. In a cell-free system, reduced biotin-conjugated iodoacetamide (BIAM) labeling of tubulin protein pretreated with cinnamaldehydes was indicative of drug interaction with the sulfhydryl groups in tubulin. In conclusion, cinnamaldehydes treatment at proapoptotic concentrations caused tubulin aggregation and dysegulation of cell cycle regulatory proteins cdk1 and cdc25C that contributed at least in part to arresting cells at G(2) phase, resulting in apoptotic cell death characterized by emergence

  20. Effect of beta-endorphin imprinting during late pregnancy on the brain serotonin and plasma nocistatin levels of adult male rats.

    Science.gov (United States)

    Tekes, K; Gyenge, M; Hantos, M; Csaba, G

    2007-07-01

    Female rats were treated with 10 microg of beta-endorphin on the 19th day of pregnancy. Offspring were studied when five months old. Serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) content in four brain regions were determined by HPLC-EC and the nocistatin levels of blood plasma using RIA methods. In each brain region studied, the 5-HT levels were highly significantly reduced and that of 5-HIAA in three regions was highly significantly increased. When 5HIAA/5HT ratios, as a measure of serotonin turnover, were calculated, imprinted animals showed extremely high values. Plasma nocistatin level was also significantly elevated. The results call attention to the effect of perinatal endorphin imprinting and its long-term consequences (e.g., setting of aggressiveness, pain tolerance).

  1. Distribution of cytoskeletal proteins, integrins, leukocyte adhesion molecules and extracellular matrix proteins in plastic-embedded human and rat kidneys

    NARCIS (Netherlands)

    van Goor, H; Coers, W; van der Horst, MLC; Suurmeijer, AJH

    2001-01-01

    OBJECTIVE: To study the distribution of cytoskeletal proteins (actin, alpha -actinin, vinculin, beta -tubulin, keratin, vimentin, desmin), adhesion molecules for cell-matrix interations (very later antigens [VLA1-6], beta1, beta2 [CD18], vitronectin receptor [alphav beta3], CD 11b), leukocyte

  2. Once-weekly 22microg subcutaneous IFN-beta-1a in secondary progressive MS: a 3-year follow-up study on brain MRI measurements and serum MMP-9 levels

    DEFF Research Database (Denmark)

    Wu, X; Kuusisto, H; Dastidar, P

    2007-01-01

    : There was no obvious effect on the number of contrast medium-enhancing lesions, the volume of T1 or T2 lesions or level of serum MMP-9, nor was any effect detected on the relapse rate and the Expanded Disability Status Scale (EDSS). Brain atrophy progression was not affected by the treatment. CONCLUSION: The lack......OBJECTIVE: To study the effect of weekly injected subcutaneous interferon (IFN)-beta-1a 22 microg on the extent of brain lesions on magnetic resonance imaging (MRI) and the level of serum matrix metalloproteinase (MMP)-9 in patients with secondary progressive multiple sclerosis (SPMS). SUBJECTS...... of effect on MRI, clinical outcomes or the levels of MMP-9 indicates that subcutaneous administration of low-dose low-frequency IFN-beta-1a is insufficient in controlling either the inflammatory constitutes or the neurodegenerative changes of advanced SPMS. Udgivelsesdato: 2007-Jul...

  3. PET imaging of brain with the {beta}-amyloid probe, [{sup 11}C]6-OH-BTA-1, in a transgenic mouse model of Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Hiroshi [Fujita Health University, Department of Radiology, Aichi (Japan); National Institutes of Health, Molecular Imaging Branch, National Institute of Mental Health, Bethesda, Maryland (United States); Ye, Daniel; Cohen, Robert M. [National Institutes of Health, Geriatric Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland (United States); Ichise, Masanori; Liow, Jeih-San; Cai, Lisheng; Musachio, John L.; Hong, Jinsoo; Crescenzo, Mathew; Tipre, Dnyanesh; Lu, Jian-Qiang; Zoghbi, Sami; Vines, Douglass C.; Pike, Victor W.; Innis, Robert B. [National Institutes of Health, Molecular Imaging Branch, National Institute of Mental Health, Bethesda, Maryland (United States); Jacobowitz, David [USUHS, Department of Anatomy, Physiology, and Genetics, Bethesda, Maryland (United States); Seidel, Jurgen; Green, Michael V. [National Institutes of Health, Department of Nuclear Medicine, Warren Grant Magnuson Clinical Center, Bethesda, Maryland (United States); Katada, Kazuhiro [Fujita Health University, Department of Radiology, Aichi (Japan)

    2005-04-01

    The purpose of this study was to evaluate the capacity of [{sup 11}C]6-OH-BTA-1 and positron emission tomography (PET) to quantify {beta}-amyloid (A{beta}) plaques in the Tg2576 mouse model of Alzheimer's disease (AD). PET imaging was performed with the NIH ATLAS small animal scanner in six elderly transgenic mice (Tg2576; age 22.0{+-}1.8 months; 23.6{+-}2.6 g) overexpressing a mutated form of human {beta}-amyloid precursor protein (APP) known to result in the production of A{beta} plaques, and in six elderly wild-type litter mates (age 21.8{+-}1.6 months; 29.5{+-}4.7 g). Dynamic PET scans were performed for 30 min in each mouse under 1% isoflurane inhalation anesthesia after a bolus injection of 13-46 MBq of [{sup 11}C]6-OH-BTA-1. PET data were reconstructed with 3D OSEM. On the coronal PET image, irregular regions of interest (ROIs) were placed on frontal cortex (FR), parietal cortex (PA), striatum (ST), thalamus (TH), pons (PO), and cerebellum (CE), guided by a mouse stereotaxic atlas. Time-activity curves (TACs) (expressed as percent injected dose per gram normalized to body weight: % ID-kg/g) were obtained for FR, PA, ST, TH, PO, and CE. ROI-to-CE radioactivity ratios were also calculated. Following PET scans, sections of mouse brain prepared from anesthetized and fixative-perfused mice were stained with thioflavin-S. TACs for [{sup 11}C]6-OH-BTA-1 in all ROIs peaked early (at 30-55 s), with radioactivity washing out quickly thereafter in both transgenic and wild-type mice. Peak uptake in all regions was significantly lower in transgenic mice than in wild-type mice. During the later part of the washout phase (12-30 min), the mean FR/CE and PA/CE ratios were higher in transgenic than in wild-type mice (1.06{+-}0.04 vs 0.98{+-}0.07, p=0.04; 1.06{+-}0.09 vs 0.93{+-}0.08 p=0.02) while ST/CE, TH/CE, and PO/CE ratios were not. Ex vivo staining revealed widespread A{beta} plaques in cortex, but not in cerebellum of transgenic mice or in any brain regions of wild

  4. Broad substrate tolerance of tubulin tyrosine ligase enables one-step site-specific enzymatic protein labeling.

    Science.gov (United States)

    Schumacher, Dominik; Lemke, Oliver; Helma, Jonas; Gerszonowicz, Lena; Waller, Verena; Stoschek, Tina; Durkin, Patrick M; Budisa, Nediljko; Leonhardt, Heinrich; Keller, Bettina G; Hackenberger, Christian P R

    2017-05-01

    The broad substrate tolerance of tubulin tyrosine ligase is the basic rationale behind its wide applicability for chemoenzymatic protein functionalization. In this context, we report that the wild-type enzyme enables ligation of various unnatural amino acids that are substantially bigger than and structurally unrelated to the natural substrate, tyrosine, without the need for extensive protein engineering. This unusual substrate flexibility is due to the fact that the enzyme's catalytic pocket forms an extended cavity during ligation, as confirmed by docking experiments and all-atom molecular dynamics simulations. This feature enabled one-step C-terminal biotinylation and fluorescent coumarin labeling of various functional proteins as demonstrated with ubiquitin, an antigen binding nanobody, and the apoptosis marker Annexin V. Its broad substrate tolerance establishes tubulin tyrosine ligase as a powerful tool for in vitro enzyme-mediated protein modification with single functional amino acids in a specific structural context.

  5. Relationship of Resistance to Benzimidazole Fungicides with Mutation of β-Tubulin Gene in Venturia nashicola

    Directory of Open Access Journals (Sweden)

    Yeonsoo Kwak

    2017-06-01

    Full Text Available Pear scab caused by Venturia nashicola has been reported as an important disease of pear resulting in lowering the quality of pear fruits. In this study, it was conducted to investigate the relationship between resistance of V. nashicola and mutation of β-tubulin gene and the fungicide resistance in field isolate group in benzimidazole fungicides. Responce of V. nashicola to carbendazim could be classified into 3 groups as sensitive that does not grow at all on PDA amended with 0.16 μg/ml of carbendazim, low resistance that could not grow in 4.0 μg/ml medium, and high resistance that can grow even at 100 μg/ml. Thirty isolates of V. nashicola collected from 3 regions as Wonju, Naju, and Okcheon were highly resistant to carbendazim. Analysis of the nucleotide sequence of β-tubulin gene of V. nashicola showed that there was no difference in the nucleotide sequence between the sensitive and the low-resistant isolate, but GAG at codon 198 (glutamic acid was replaced with GCG (alanine in the high-resistant isolate. Among 10 isolates obtained from the Okcheon, 5 isolates showed the substitution of glycine for glutamic acid, which were resistant to carbendazim, but more sensitive to the mixture of carbendazim and diethofencarb than others. Through these results, all isolates of V. nashicola isolated in pear orchard were found to be resistant to benzimidazoles. Also, mutants E198A and E198G at β-tubulin were found to be important mechanisms of V. nashicola resistance against benzimidazole fungicides.

  6. Characterization of amyloid beta peptides from brain extracts of transgenic mice overexpressing the London mutant of human amyloid precursor protein.

    Science.gov (United States)

    Pype, Stefan; Moechars, Dieder; Dillen, Lieve; Mercken, Marc

    2003-02-01

    Alzheimer's disease (AD) is marked by the presence of neurofibrillary tangles and amyloid plaques in the brain of patients. To study plaque formation, we report on further quantitative and qualitative analysis of human and mouse amyloid beta peptides (Abeta) from brain extracts of transgenic mice overexpressing the London mutant of human amyloid precursor protein (APP). Using enzyme-linked immunosorbant assays (ELISAs) specific for either human or rodent Abeta, we found that the peptides from both species aggregated to form plaques. The ratios of deposited Abeta1-42/1-40 were in the order of 2-3 for human and 8-9 for mouse peptides, indicating preferential deposition of Abeta42. We also determined the identity and relative levels of other Abeta variants present in protein extracts from soluble and insoluble brain fractions. This was done by combined immunoprecipitation and mass spectrometry (IP/MS). The most prominent peptides truncated either at the carboxyl- or the amino-terminus were Abeta1-38 and Abeta11-42, respectively, and the latter was strongly enriched in the extracts of deposited peptides. Taken together, our data indicate that plaques of APP-London transgenic mice consist of aggregates of multiple human and mouse Abeta variants, and the human variants that we identified were previously detected in brain extracts of AD patients.

  7. Clinical evaluation of β-tubulin real-time PCR for rapid diagnosis of dermatophytosis, a comparison with mycological methods.

    Science.gov (United States)

    Motamedi, Marjan; Mirhendi, Hossein; Zomorodian, Kamiar; Khodadadi, Hossein; Kharazi, Mahboobeh; Ghasemi, Zeinab; Shidfar, Mohammad Reza; Makimura, Koichi

    2017-10-01

    Following our previous report on evaluation of the beta tubulin real-time PCR for detection of dermatophytosis, this study aimed to compare the real-time PCR assay with conventional methods for the clinical assessment of its diagnostic performance. Samples from a total of 853 patients with suspected dermatophyte lesions were subjected to direct examination (all samples), culture (499 samples) and real-time PCR (all samples). Fungal DNA was extracted directly from clinical samples using a conical steel bullet, followed by purification with a commercial kit and subjected to the Taq-Man probe-based real-time PCR. The study showed that among the 499 specimens for which all three methods were used, 156 (31.2%), 128 (25.6%) and 205 (41.0%) were found to be positive by direct microscopy, culture and real-time PCR respectively. Real-time PCR significantly increased the detection rate of dermatophytes compared with microscopy (288 vs 229) with 87% concordance between the two methods. The sensitivity, specificity, positive predictive value, and negative predictive value of the real-time PCR was 87.5%, 85%, 66.5% and 95.2% respectively. Although real-time PCR performed better on skin than on nail samples, it should not yet fully replace conventional diagnosis. © 2017 Blackwell Verlag GmbH.

  8. Towards Alzheimer's beta-amyloid vaccination.

    Science.gov (United States)

    Frenkel, D; Solomon, B

    2001-01-01

    Beta-amyloid pathology, the main hallmark of Alzheimer's disease (AD), has been linked to its conformational status and aggregation. We recently showed that site-directed monoclonal antibodies (mAbs) towards the N-terminal region of the human beta-amyloid peptide bind to preformed beta-amyloid fibrils (Abeta), leading to disaggregation and inhibition of their neurotoxic effect. Here we report the development of a novel immunization procedure to raise effective anti-aggregating amyloid beta-protein (AbetaP) antibodies, using as antigen filamentous phages displaying the only EFRH peptide found to be the epitope of these antibodies. Due to the high antigenicity of the phage no adjuvant is required to obtain high affinity anti-aggregating IgG antibodies in animals model, that exhibit identity to human AbetaP. Such antibodies are able to sequester peripheral AbetaP, thus avoiding passage through the blood brain barrier (BBB) and, as recently shown in a transgenic mouse model, to cross the BBB and dissolve already formed beta-amyloid plaques. To our knowledge, this is the first attempt to use as a vaccine a self-anti-aggregating epitope displayed on a phage, and this may pave the way to treat abnormal accumulation-peptide diseases, such as Alzheimer's disease or other amyloidogenic diseases. Copyright 2001 The International Association for Biologicals.

  9. Muscle plasticity related to changes in tubulin and αB-crystallin levels induced by eccentric contraction in rat skeletal muscles.

    Science.gov (United States)

    Jee, H; Ochi, E; Sakurai, T; Lim, J-Y; Nakazato, K; Hatta, H

    2016-09-01

    We used the model of eccentric contraction of the hindlimb muscle by Ochi et al. to examine the role of eccentric contraction in muscle plasticity. This model aims to focus on stimulated skeletal muscle responses by measuring tissue weights and tracing the quantities of αB-crystallin and tubulin. The medial gastrocnemius muscle (GCM) responded to electrically induced eccentric contraction (EIEC) with significant increases in tissue weight (p muscle weight after EIEC. EIEC in the GCM caused contractile-induced sustenance of the traced proteins, but the soleus muscle exhibited a remarkable decrease in α-tubulin and a 19% decrease in αB-crystallin. EIEC caused fast-to-slow myosin heavy chain (MHC) isoform type-oriented shift within both the GCM and soleus muscle. These results have shown that different MHC isoform type-expressing slow and fast muscles commonly undergo fast-to-slow type MHC isoform transformation. This suggests that different levels of EIEC affected each of the slow and fast muscles to induce different quantitative changes in the expression of αB-crystallin and α-tubulin.

  10. Protein interactions of gamma tubulin reveal its multiple roles in acentrosomal plant cells

    Czech Academy of Sciences Publication Activity Database

    Binarová, Pavla; Doskočilová, Anna; Kourová, Hana; Plíhal, Ondřej; Volc, Jindřich; Halada, Petr; Kohoutová, Lucie

    2010-01-01

    Roč. 21, č. 24 (2010), s. 2842-2842 ISSN 1059-1524. [ASCB Annual Meeting 2010. 11.12.2010-15.12.2010, Philadelphia] R&D Projects: GA MŠk LC545; GA AV ČR IAA500200719; GA ČR(CZ) GA204/07/1169 Institutional research plan: CEZ:AV0Z50200510 Keywords : g-tubulin * microtubules Subject RIV: EE - Microbiology, Virology

  11. Induction of tumor cell death through targeting tubulin and evoking dysregulation of cell cycle regulatory proteins by multifunctional cinnamaldehydes.

    Directory of Open Access Journals (Sweden)

    Amrita A Nagle

    Full Text Available Multifunctional trans-cinnamaldehyde (CA and its analogs display anti-cancer properties, with 2-benzoyloxycinnamaldehyde (BCA and 5-fluoro-2-hydroxycinnamaldehyde (FHCA being identified as the ortho-substituted analogs that possess potent anti-tumor activities. In this study, BCA, FHCA and a novel analog 5-fluoro-2-benzoyloxycinnamaldehyde (FBCA, were demonstrated to decrease growth and colony formation of human colon-derived HCT 116 and mammary-derived MCF-7 carcinoma cells under non-adhesive conditions. The 2-benzoyloxy and 5-fluoro substituents rendered FBCA more potent than BCA and equipotent to FHCA. The cellular events by which these cinnamaldehydes caused G(2/M phase arrest and halted proliferation of HCT 116 cells were thereby investigated. Lack of significant accumulation of mitosis marker phospho-histone H3 in cinnamaldehyde-treated cells indicated that the analogs arrested cells in G(2 phase. G(2 arrest was brought about partly by cinnamaldehyde-mediated depletion of cell cycle proteins involved in regulating G(2 to M transition and spindle assembly, namely cdk1, cdc25C, mad2, cdc20 and survivin. Cyclin B1 levels were found to be increased, which in the absence of active cdk1, would fail to drive cells into M phase. Concentrations of cinnamaldehydes that brought about dysregulation of levels of cell cycle proteins also caused tubulin aggregation, as evident from immunodetection of dose-dependent tubulin accumulation in the insoluble cell lysate fractions. In a cell-free system, reduced biotin-conjugated iodoacetamide (BIAM labeling of tubulin protein pretreated with cinnamaldehydes was indicative of drug interaction with the sulfhydryl groups in tubulin. In conclusion, cinnamaldehydes treatment at proapoptotic concentrations caused tubulin aggregation and dysegulation of cell cycle regulatory proteins cdk1 and cdc25C that contributed at least in part to arresting cells at G(2 phase, resulting in apoptotic cell death characterized by

  12. The synthesis of (R)- and (S)-[N-methyl-{sup 11}C]{beta}, {beta}-difluoromethamphetamine for the investigation of the binding mechanism of biogenic amines in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Gillings, N.M.; Gee, A.D. [PET Centre, Aarhus University Hospital, Aarhus C (Denmark); Inoue, O. [School of Allied Health Sciences, Osaka University Medical School, Osaka (Japan)

    1999-04-01

    In an attempt to elucidate the contribution of the extent of nitrogen protonation on the in vivo binding of methamphetamine in the brain, the enantiomers of [N-methyl-{sup 11}C]{beta},{beta}-difluoroamphetamine (4) were prepared for use in positron emission tomography (PET) studies. Thus, the enantiomers of {beta},{beta}-difluoroamphetamine were prepared from trans-{beta}-methylstyrene, via bromination, conversion into the azirine, fluorination and resolution as the tartrate salts. (R)- and (S)-{beta},{beta}-difluoroamphetamine (3) were then each labelled with carbon-11 (t{sub 1/2}=20.4 min) by N-methylation of the corresponding homochiral {beta},{beta}-difluoroamphetamine with [{sup 11}C]methyl iodide. The labelled products were each synthesised, purified and formulated in 35 min, starting from [{sup 11}C]carbon dioxide in 15-16% decay-corrected radiochemical yield, with a radiochemical purity of >99% and specific radioactivity of 50-150 GBq {mu}mol{sup -1} at end of synthesis.

  13. Aberrant prefrontal beta oscillations predict episodic memory encoding deficits in schizophrenia.

    Science.gov (United States)

    Meconi, Federica; Anderl-Straub, Sarah; Raum, Heidelore; Landgrebe, Michael; Langguth, Berthold; Bäuml, Karl-Heinz T; Hanslmayr, Simon

    Verbal episodic memory is one of the core cognitive functions affected in patients with schizophrenia (SZ). Although this verbal memory impairment in SZ is a well-known finding, our understanding about its underlying neurophysiological mechanisms is rather scarce. Here we address this issue by recording brain oscillations during a memory task in a sample of healthy controls and patients with SZ. Brain oscillations represent spectral fingerprints of specific neurocognitive operations and are therefore a promising tool to identify neurocognitive mechanisms that are affected by SZ. Healthy controls showed a prominent suppression of left prefrontal beta oscillatory activity during successful memory formation, which replicates several previous oscillatory memory studies. In contrast, patients failed to exhibit such a left prefrontal beta power suppression. Utilizing a new topographical pattern similarity approach, we further demonstrate that the degree of similarity between a patient's beta power decrease to that of the controls reliably predicted memory performance. This relationship between beta power decreases and memory was such that the patients' memory performance improved as they showed a more similar topographical beta desynchronization pattern compared to that of healthy controls. Together, these findings support left prefrontal beta desynchronization as the spectral fingerprint of verbal episodic memory formation, likely indicating deep semantic processing of verbal material. These findings also demonstrate that left prefrontal beta power suppression (or lack thereof) during memory encoding are a reliable biomarker for the observed encoding impairments in SZ in verbal memory.

  14. Aberrant prefrontal beta oscillations predict episodic memory encoding deficits in schizophrenia

    Directory of Open Access Journals (Sweden)

    Federica Meconi

    2016-01-01

    Full Text Available Verbal episodic memory is one of the core cognitive functions affected in patients with schizophrenia (SZ. Although this verbal memory impairment in SZ is a well-known finding, our understanding about its underlying neurophysiological mechanisms is rather scarce. Here we address this issue by recording brain oscillations during a memory task in a sample of healthy controls and patients with SZ. Brain oscillations represent spectral fingerprints of specific neurocognitive operations and are therefore a promising tool to identify neurocognitive mechanisms that are affected by SZ. Healthy controls showed a prominent suppression of left prefrontal beta oscillatory activity during successful memory formation, which replicates several previous oscillatory memory studies. In contrast, patients failed to exhibit such a left prefrontal beta power suppression. Utilizing a new topographical pattern similarity approach, we further demonstrate that the degree of similarity between a patient's beta power decrease to that of the controls reliably predicted memory performance. This relationship between beta power decreases and memory was such that the patients' memory performance improved as they showed a more similar topographical beta desynchronization pattern compared to that of healthy controls. Together, these findings support left prefrontal beta desynchronization as the spectral fingerprint of verbal episodic memory formation, likely indicating deep semantic processing of verbal material. These findings also demonstrate that left prefrontal beta power suppression (or lack thereof during memory encoding are a reliable biomarker for the observed encoding impairments in SZ in verbal memory.

  15. Beta burst dynamics in Parkinson's disease OFF and ON dopaminergic medication.

    Science.gov (United States)

    Tinkhauser, Gerd; Pogosyan, Alek; Tan, Huiling; Herz, Damian M; Kühn, Andrea A; Brown, Peter

    2017-11-01

    Exaggerated basal ganglia beta activity (13-35 Hz) is commonly found in patients with Parkinson's disease and can be suppressed by dopaminergic medication, with the degree of suppression being correlated with the improvement in motor symptoms. Importantly, beta activity is not continuously elevated, but fluctuates to give beta bursts. The percentage number of longer beta bursts in a given interval is positively correlated with clinical impairment in Parkinson's disease patients. Here we determine whether the characteristics of beta bursts are dependent on dopaminergic state. Local field potentials were recorded from the subthalamic nucleus of eight Parkinson's disease patients during temporary lead externalization during surgery for deep brain stimulation. The recordings took place with the patient quietly seated following overnight withdrawal of levodopa and after administration of levodopa. Beta bursts were defined by applying a common amplitude threshold and burst characteristics were compared between the two drug conditions. The amplitude of beta bursts, indicative of the degree of local neural synchronization, progressively increased with burst duration. Treatment with levodopa limited this evolution leading to a relative increase of shorter, lower amplitude bursts. Synchronization, however, was not limited to local neural populations during bursts, but also, when such bursts were cotemporaneous across the hemispheres, was evidenced by bilateral phase synchronization. The probability of beta bursts and the proportion of cotemporaneous bursts were reduced by levodopa. The percentage number of longer beta bursts in a given interval was positively related to motor impairment, while the opposite was true for the percentage number of short duration beta bursts. Importantly, the decrease in burst duration was also correlated with the motor improvement. In conclusion, we demonstrate that long duration beta bursts are associated with an increase in local and

  16. Identification of new 2,5-diketopiperazine derivatives as simultaneous effective inhibitors of αβ-tubulin and BCRP proteins: Molecular docking, Structure-Activity Relationships and virtual consensus docking studies

    Science.gov (United States)

    Fani, Najmeh; Sattarinezhad, Elham; Bordbar, Abdol-Khalegh

    2017-06-01

    In the first part of this paper, docking method was employed in order to study the binding mechanism of breast cancer resistance protein (BCRP) with a group of previously synthesized TPS-A derivatives which known as potent inhibitors of this protein to get insight into drug binding site of BCRP and to explore structure-activity relationship of these compounds. Molecular docking results showed that most of these compounds bind in the binding site of BCRP at the interface between the membrane and outer environment. In the second part, a group of designed TPS-A derivatives which showed good binding energies in the binding site of αβ-tubulin in the previous study were chosen to study their binding energies in the binding site of BCRP to investigate their simultaneous inhibitory effect on both αβ-tubulin and BCRP. The results showed that all of these compounds bind to the binding site of BCRP with relatively suitable binding energies and therefore could be potential inhibitors of both αβ-tubulin and BCRP proteins. Finally, virtual consensus docking method was utilized with the aim of design of new 2,5-diketopiperazine derivatives with significant inhibitory effect on both αβ-tubulin and BCRP proteins. For this purpose binding energies of a library of 2,5-diketopiperazine derivatives in the binding sites of αβ-tubulin and BCRP was investigated by using AutoDock and AutoDock vina tools. Molecular docking results revealed that a group of 36 compounds among them exhibit strong anti-tubulin and anti-BCRP activity.

  17. Gamma-tubulin in Leishmania: cell cycle-dependent changes in subcellular localization and heterogeneity of its isoforms

    Czech Academy of Sciences Publication Activity Database

    Libusová, Lenka; Sulimenko, Tetyana; Sulimenko, Vadym; Hozák, Pavel; Dráber, Pavel

    2004-01-01

    Roč. 295, - (2004), s. 375-386 ISSN 0014-4827 R&D Projects: GA MŠk ME 310; GA MŠk LN00A026 Keywords : gamma-tubulin * cell cycle * Leishmania Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.007, year: 2004

  18. Lactate fuels the human brain during exercise

    DEFF Research Database (Denmark)

    Quistorff, Bjørn; Secher, Niels H; Van Lieshout, Johannes J

    2008-01-01

    The human brain releases a small amount of lactate at rest, and even an increase in arterial blood lactate during anesthesia does not provoke a net cerebral lactate uptake. However, during cerebral activation associated with exercise involving a marked increase in plasma lactate, the brain takes up......)] from a resting value of 6 to exercise, cerebral activation associated with mental activity, or exposure to a stressful situation. The CMR decrease is prevented with combined beta(1)- and beta(2)-adrenergic receptor...

  19. PDGF-beta receptor expression and ventilatory acclimatization to hypoxia in the rat.

    Science.gov (United States)

    Alea, O A; Czapla, M A; Lasky, J A; Simakajornboon, N; Gozal, E; Gozal, D

    2000-11-01

    Activation of platelet-derived growth factor-beta (PDGF-beta) receptors in the nucleus of the solitary tract (nTS) modulates the late phase of the acute hypoxic ventilatory response (HVR) in the rat. We hypothesized that temporal changes in PDGF-beta receptor expression could underlie the ventilatory acclimatization to hypoxia (VAH). Normoxic ventilation was examined in adult Sprague-Dawley rats chronically exposed to 10% O(2), and at 0, 1, 2, 7, and 14 days, Northern and Western blots of the dorsocaudal brain stem were performed for assessment of PDGF-beta receptor expression. Although no significant changes in PDGF-beta receptor mRNA occurred over time, marked attenuation of PDGF-beta receptor protein became apparent after day 7 of hypoxic exposure. Such changes were significantly correlated with concomitant increases in normoxic ventilation, i.e., with VAH (r: -0.56, P < 0.005). In addition, long-term administration of PDGF-BB in the nTS via osmotic pumps loaded with either PDGF-BB (n = 8) or vehicle (Veh; n = 8) showed that although no significant changes in the magnitude of acute HVR occurred in Veh over time, the typical attenuation of HVR by PDGF-BB decreased over time. Furthermore, PDGF-BB microinjections did not attenuate HVR in acclimatized rats at 7 and 14 days of hypoxia (n = 10). We conclude that decreased expression of PDGF-beta receptors in the dorsocaudal brain stem correlates with the magnitude of VAH. We speculate that the decreased expression of PDGF-beta receptors is mediated via internalization and degradation of the receptor rather than by transcriptional regulation.

  20. Microtubules as mechanical force sensors.

    Science.gov (United States)

    Karafyllidis, Ioannis G; Lagoudas, Dimitris C

    2007-03-01

    Microtubules are polymers of tubulin subunits (dimers) arranged on a hexagonal lattice. Each tubulin dimer comprises two monomers, the alpha-tubulin and beta-tubulin, and can be found in two states. In the first state a mobile negative charge is located into the alpha-tubulin monomer and in the second into the beta-tubulin monomer. Each tubulin dimer is modeled as an electrical dipole coupled to its neighbors by electrostatic forces. The location of the mobile charge in each dimer depends on the location of the charges in the dimer's neighborhood. Mechanical forces that act on the microtubule affect the distances between the dimers and alter the electrostatic potential. Changes in this potential affect the mobile negative charge location in each dimer and the charge distribution in the microtubule. The net effect is that mechanical forces affect the charge distribution in microtubules. We propose to exploit this effect and use microtubules as mechanical force sensors. We model each dimer as a two-state quantum system and, following the quantum computation paradigm, we use discrete quantum random walk on the hexagonal microtubule lattice to determine the charge distribution. Different forces applied on the microtubule are modeled as different coin biases leading to different probability distributions of the quantum walker location, which are directly connected to different charge distributions. Simulation results show that there is a strong indication that microtubules can be used as mechanical force sensors and that they can also detect the force directions and magnitudes.

  1. Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

    1986-01-20

    Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-..beta.. endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I/sup 125/ h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables.

  2. Evidence for the association of the S100beta gene with low cognitive performance and dementia in the elderly

    DEFF Research Database (Denmark)

    Lambert, J-C; Ferreira, S; Gussekloo, J

    2007-01-01

    independent populations. Moreover, we detected a significant association of this SNP with increased risk of developing dementia or Alzheimer's disease (AD) in six independent populations, especially in women and in the oldest. Furthermore, we characterised a new primate-specific exon within intron 2 (the...... corresponding mRNA isoform was called S100beta2). S100beta2 expression was increased in AD brain compared with controls, and the rs2300403 SNP was associated with elevated levels of S100beta2 mRNA in AD brains, especially in women. Therefore, this genetic variant in S100beta increases the risk of low cognitive...

  3. Estimating direction in brain-behavior interactions: Proactive and reactive brain states in driving.

    Science.gov (United States)

    Garcia, Javier O; Brooks, Justin; Kerick, Scott; Johnson, Tony; Mullen, Tim R; Vettel, Jean M

    2017-04-15

    Conventional neuroimaging analyses have ascribed function to particular brain regions, exploiting the power of the subtraction technique in fMRI and event-related potential analyses in EEG. Moving beyond this convention, many researchers have begun exploring network-based neurodynamics and coordination between brain regions as a function of behavioral parameters or environmental statistics; however, most approaches average evoked activity across the experimental session to study task-dependent networks. Here, we examined on-going oscillatory activity as measured with EEG and use a methodology to estimate directionality in brain-behavior interactions. After source reconstruction, activity within specific frequency bands (delta: 2-3Hz; theta: 4-7Hz; alpha: 8-12Hz; beta: 13-25Hz) in a priori regions of interest was linked to continuous behavioral measurements, and we used a predictive filtering scheme to estimate the asymmetry between brain-to-behavior and behavior-to-brain prediction using a variant of Granger causality. We applied this approach to a simulated driving task and examined directed relationships between brain activity and continuous driving performance (steering behavior or vehicle heading error). Our results indicated that two neuro-behavioral states may be explored with this methodology: a Proactive brain state that actively plans the response to the sensory information and is characterized by delta-beta activity, and a Reactive brain state that processes incoming information and reacts to environmental statistics primarily within the alpha band. Published by Elsevier Inc.

  4. Brain MR finding of {beta}-fluoroethyl acetate rodenticide intoxication: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Young; Jung, Cheol Kyu; Lee, Seung Ro; Park, Dong Woo [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2008-05-15

    {beta}-fluoroethyl acetate rodenticide intoxication can manifest as several different clinical abnormalities such as respiratory, neurologic, cardiologic and fluid-electrolyte problems. We report here on the MR findings of a case that showed symmetric cytotoxic edema in the while matter of the cerebral hemispheres after the ingestion of {beta} - fluoroethyl acetate rodenticide by a woman who was attempting suicide.

  5. Depletion of GGA3 stabilizes BACE and enhances beta-secretase activity.

    Science.gov (United States)

    Tesco, Giuseppina; Koh, Young Ho; Kang, Eugene L; Cameron, Andrew N; Das, Shinjita; Sena-Esteves, Miguel; Hiltunen, Mikko; Yang, Shao-Hua; Zhong, Zhenyu; Shen, Yong; Simpkins, James W; Tanzi, Rudolph E

    2007-06-07

    Beta-site APP-cleaving enzyme (BACE) is required for production of the Alzheimer's disease (AD)-associated Abeta protein. BACE levels are elevated in AD brain, and increasing evidence reveals BACE as a stress-related protease that is upregulated following cerebral ischemia. However, the molecular mechanism responsible is unknown. We show that increases in BACE and beta-secretase activity are due to posttranslational stabilization following caspase activation. We also found that during cerebral ischemia, levels of GGA3, an adaptor protein involved in BACE trafficking, are reduced, while BACE levels are increased. RNAi silencing of GGA3 also elevated levels of BACE and Abeta. Finally, in AD brain samples, GGA3 protein levels were significantly decreased and inversely correlated with increased levels of BACE. In summary, we have elucidated a GGA3-dependent mechanism regulating BACE levels and beta-secretase activity. This mechanism may explain increased cerebral levels of BACE and Abeta following cerebral ischemia and existing in AD.

  6. INDUCTION OF INTERLEUKIN-1-BETA MESSENGER-RNA AFTER FOCAL CEREBRAL-ISCHEMIA IN THE RAT

    NARCIS (Netherlands)

    BUTTINI, M; SAUTER, A; BODDEKE, HWGM

    The expression of interleukin-1beta (IL-1beta) mRNA in the brain in response to cerebral ischaemia in rats was examined using in situ hybridization histochemistry. Focal cerebral ischaemia was induced in spontaneously hypertensive rats by permanent occlusion of the left middle cerebral artery

  7. Dual aminergic regulation of central beta adrenoceptors. Effect of atypical antidepressants and 5-hydroxytryptophan

    International Nuclear Information System (INIS)

    Manier, D.H.; Gillespie, D.D.; Sulser, F.

    1989-01-01

    Nonlinear regression analysis of agonist competition binding curves reveals that the [ 3 H]-dihydroalprenolol-labeled receptor population with low affinity for isoproterenol is increased by p-chlorophenylalanine (PCPA) and this increase is abolished by 5-hydroxytryptophan (5-HTP) in vivo. Desipramine (DMI) decreased the beta adrenoceptor population with high agonist affinity to the same degree in PCPA-treated animals as in control animals, thus explaining the reported discrepancy between beta adrenoceptor number and responsiveness of the beta adrenoceptor-coupled adenylate cyclase system. Mianserin also selectively reduced the beta adrenoceptor population with high agonist affinity in membrane preparations of normal animals, whereas fluoxetine selectively abolished the upregulation of the low affinity sites in reserpinized animals and had no effect on either receptor population from brain of normal animals. The results emphasize the importance of nonlinear regression analysis of agonist competition binding for the interpretation of drug action and encourage the pursuit of the molecular neurobiology of the serotonin (5-HT)/norepinephrine (NE) link in brain

  8. Dual aminergic regulation of central beta adrenoceptors. Effect of atypical antidepressants and 5-hydroxytryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Manier, D.H.; Gillespie, D.D.; Sulser, F.

    1989-06-01

    Nonlinear regression analysis of agonist competition binding curves reveals that the (/sup 3/H)-dihydroalprenolol-labeled receptor population with low affinity for isoproterenol is increased by p-chlorophenylalanine (PCPA) and this increase is abolished by 5-hydroxytryptophan (5-HTP) in vivo. Desipramine (DMI) decreased the beta adrenoceptor population with high agonist affinity to the same degree in PCPA-treated animals as in control animals, thus explaining the reported discrepancy between beta adrenoceptor number and responsiveness of the beta adrenoceptor-coupled adenylate cyclase system. Mianserin also selectively reduced the beta adrenoceptor population with high agonist affinity in membrane preparations of normal animals, whereas fluoxetine selectively abolished the upregulation of the low affinity sites in reserpinized animals and had no effect on either receptor population from brain of normal animals. The results emphasize the importance of nonlinear regression analysis of agonist competition binding for the interpretation of drug action and encourage the pursuit of the molecular neurobiology of the serotonin (5-HT)/norepinephrine (NE) link in brain.

  9. Fluid Mechanics of the Vascular Basement Membrane in the Brain

    Science.gov (United States)

    Coloma, Mikhail; Hui, Jonathan; Chiarot, Paul; Huang, Peter; Carare, Roxana; McLeod, Kenneth; Schaffer, David

    2013-11-01

    Beta-amyloid is a normal product of brain metabolic function and is found within the interstitial fluid of the brain. Failure of the clearance of beta-amyloid from the aging brain leads to its accumulation within the walls of arteries and to Alzheimer's disease. The vascular basement membrane (VBM) within the walls of cerebral arteries surrounds the spirally arranged smooth muscle cells and represents an essential pathway for removal of beta-amyloid from the brain. This process fails with the stiffening of arterial walls associated with aging. In this study we hypothesize that the deformation of the VBM associated with arterial pulsations drives the interstitial fluid to drain in the direction opposite of the arterial blood flow. This hypothesis is theoretically investigated by modeling the VBM as a thin, coaxial, fluid-filled porous medium surrounding a periodically deforming cylindrical tube. Flow and boundary conditions required to achieve such a backward clearance are derived through a control volume analysis of mass, momentum, and energy.

  10. Biallelic Mutations in TBCD, Encoding the Tubulin Folding Cofactor D, Perturb Microtubule Dynamics and Cause Early-Onset Encephalopathy

    NARCIS (Netherlands)

    Flex, Elisabetta; Niceta, Marcello; Cecchetti, Serena; Thiffault, Isabelle; Au, Margaret G.; Capuano, Alessandro; Piermarini, Emanuela; Ivanova, Anna A.; Francis, Joshua W.; Chillemi, Giovanni; Chandramouli, Balasubramanian; Carpentieri, Giovanna; Haaxma, Charlotte A.; Ciolfi, Andrea; Pizzi, Simone; Douglas, Ganka V.; Levine, Kara; Sferra, Antonella; Dentici, Maria Lisa; Pfundt, Rolph R.; Le Pichon, Jean-Baptiste; Farrow, Emily; Baas, Frank; Piemonte, Fiorella; Dallapiccola, Bruno; Graham, John M.; Saunders, Carol J.; Bertini, Enrico; Kahn, Richard A.; Koolen, David A.; Tartaglia, Marco

    2016-01-01

    Microtubules are dynamic cytoskeletal elements coordinating and supporting a variety of neuronal processes, including cell division, migration, polarity, intracellular trafficking, and signal transduction. Mutations in genes encoding tubulins and microtubule-associated proteins are known to cause

  11. Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

    International Nuclear Information System (INIS)

    Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

    1986-01-01

    Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-β endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I 125 h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables

  12. Live visualizations of single isolated tubulin protein self-assembly via tunneling current: effect of electromagnetic pumping during spontaneous growth of microtubule.

    Science.gov (United States)

    Sahu, Satyajit; Ghosh, Subrata; Fujita, Daisuke; Bandyopadhyay, Anirban

    2014-12-03

    As we bring tubulin protein molecules one by one into the vicinity, they self-assemble and entire event we capture live via quantum tunneling. We observe how these molecules form a linear chain and then chains self-assemble into 2D sheet, an essential for microtubule, --fundamental nano-tube in a cellular life form. Even without using GTP, or any chemical reaction, but applying particular ac signal using specially designed antenna around atomic sharp tip we could carry out the self-assembly, however, if there is no electromagnetic pumping, no self-assembly is observed. In order to verify this atomic scale observation, we have built an artificial cell-like environment with nano-scale engineering and repeated spontaneous growth of tubulin protein to its complex with and without electromagnetic signal. We used 64 combinations of plant, animal and fungi tubulins and several doping molecules used as drug, and repeatedly observed that the long reported common frequency region where protein folds mechanically and its structures vibrate electromagnetically. Under pumping, the growth process exhibits a unique organized behavior unprecedented otherwise. Thus, "common frequency point" is proposed as a tool to regulate protein complex related diseases in the future.

  13. Apc1 is required for maintenance of local brain organizers and dorsal midbrain survival.

    Science.gov (United States)

    Paridaen, Judith T M L; Danesin, Catherine; Elas, Abu Tufayal; van de Water, Sandra; Houart, Corinne; Zivkovic, Danica

    2009-07-15

    The tumor suppressor Apc1 is an intracellular antagonist of the Wnt/beta-catenin pathway, which is vital for induction and patterning of the early vertebrate brain. However, its role in later brain development is less clear. Here, we examined the mechanisms underlying effects of an Apc1 zygotic-effect mutation on late brain development in zebrafish. Apc1 is required for maintenance of established brain subdivisions and control of local organizers such as the isthmic organizer (IsO). Caudal expansion of Fgf8 from IsO into the cerebellum is accompanied by hyperproliferation and abnormal cerebellar morphogenesis. Loss of apc1 results in reduced proliferation and apoptosis in the dorsal midbrain. Mosaic analysis shows that Apc is required cell-autonomously for maintenance of dorsal midbrain cell fate. The tectal phenotype occurs independently of Fgf8-mediated IsO function and is predominantly caused by stabilization of beta-catenin and subsequent hyperactivation of Wnt/beta-catenin signalling, which is mainly mediated through LEF1 activity. Chemical activation of the Wnt/beta-catenin in wild-type embryos during late brain maintenance stages phenocopies the IsO and tectal phenotypes of the apc mutants. These data demonstrate that Apc1-mediated restriction of Wnt/beta-catenin signalling is required for maintenance of local organizers and tectal integrity.

  14. Orphan nuclear receptor TLX activates Wnt/beta-catenin signalling to stimulate neural stem cell proliferation and self-renewal.

    Science.gov (United States)

    Qu, Qiuhao; Sun, Guoqiang; Li, Wenwu; Yang, Su; Ye, Peng; Zhao, Chunnian; Yu, Ruth T; Gage, Fred H; Evans, Ronald M; Shi, Yanhong

    2010-01-01

    The nuclear receptor TLX (also known as NR2E1) is essential for adult neural stem cell self-renewal; however, the molecular mechanisms involved remain elusive. Here we show that TLX activates the canonical Wnt/beta-catenin pathway in adult mouse neural stem cells. Furthermore, we demonstrate that Wnt/beta-catenin signalling is important in the proliferation and self-renewal of adult neural stem cells in the presence of epidermal growth factor and fibroblast growth factor. Wnt7a and active beta-catenin promote neural stem cell self-renewal, whereas the deletion of Wnt7a or the lentiviral transduction of axin, a beta-catenin inhibitor, led to decreased cell proliferation in adult neurogenic areas. Lentiviral transduction of active beta-catenin led to increased numbers of type B neural stem cells in the subventricular zone of adult brains, whereas deletion of Wnt7a or TLX resulted in decreased numbers of neural stem cells retaining bromodeoxyuridine label in the adult brain. Both Wnt7a and active beta-catenin significantly rescued a TLX (also known as Nr2e1) short interfering RNA-induced deficiency in neural stem cell proliferation. Lentiviral transduction of an active beta-catenin increased cell proliferation in neurogenic areas of TLX-null adult brains markedly. These results strongly support the hypothesis that TLX acts through the Wnt/beta-catenin pathway to regulate neural stem cell proliferation and self-renewal. Moreover, this study suggests that neural stem cells can promote their own self-renewal by secreting signalling molecules that act in an autocrine/paracrine mode.

  15. Lithium ameliorates open-field and elevated plus maze behaviors, and brain phospho-glycogen synthase kinase 3-beta expression in fragile X syndrome model mice.

    Science.gov (United States)

    Chen, Xi; Sun, Weiwen; Pan, Ying; Yang, Quan; Cao, Kaiyi; Zhang, Jin; Zhang, Yizhi; Chen, Mincong; Chen, Feidi; Huang, Yueling; Dai, Lijun; Chen, Shengqiang

    2013-10-01

    To investigate whether lithium modifies open-field and elevated plus maze behavior, and brain phospho-glycogen synthase kinase 3 (P-GSK3beta) expression in Fmr1 knockout mice. One hundred and eighty FVB mice, including knockout and wild type, with an age of 30 days were used. An open-field and elevated plus maze was utilized to test behavior, while western blot was used to measure the P-GSK3beta expression. Six groups were formed: control (saline), lithium chloride 30, 60, 90, 120, and 200 mg/kg. The experiments were carried out in the Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China between January and June 2012. Lithium significantly decreased total distance, crossing, central area time, and center entry in the open-field test (popen-arm tracking, open-arm entry, and open-arm time in the elevated plus maze (popen-field and elevated plus maze behaviors of Fmr1 knockout mice. This effect may be related to its enhancement of P-GSK3beta expression. Our findings suggest that lithium might have a therapeutic effect in fragile X syndrome.

  16. SAS-4 is recruited to a dynamic structure in newly forming centrioles that is stabilized by the gamma-tubulin-mediated addition of centriolar microtubules.

    Science.gov (United States)

    Dammermann, Alexander; Maddox, Paul S; Desai, Arshad; Oegema, Karen

    2008-02-25

    Centrioles are surrounded by pericentriolar material (PCM), which is proposed to promote new centriole assembly by concentrating gamma-tubulin. Here, we quantitatively monitor new centriole assembly in living Caenorhabditis elegans embryos, focusing on the conserved components SAS-4 and SAS-6. We show that SAS-4 and SAS-6 are coordinately recruited to the site of new centriole assembly and reach their maximum levels during S phase. Centriolar SAS-6 is subsequently reduced by a mechanism intrinsic to the early assembly pathway that does not require progression into mitosis. Centriolar SAS-4 remains in dynamic equilibrium with the cytoplasmic pool until late prophase, when it is stably incorporated in a step that requires gamma-tubulin and microtubule assembly. These results indicate that gamma-tubulin in the PCM stabilizes the nascent daughter centriole by promoting microtubule addition to its outer wall. Such a mechanism may help restrict new centriole assembly to the vicinity of preexisting parent centrioles that recruit PCM.

  17. Triazolopyridinyl-acrylonitrile derivatives as antimicrotubule agents: Synthesis, in vitro and in silico characterization of antiproliferative activity, inhibition of tubulin polymerization and binding thermodynamics.

    Science.gov (United States)

    Briguglio, Irene; Laurini, Erik; Pirisi, Maria Antonietta; Piras, Sandra; Corona, Paola; Fermeglia, Maurizio; Pricl, Sabrina; Carta, Antonio

    2017-12-01

    In this paper we report the synthesis, in vitro anticancer activity, and the experimental/computational characterization of mechanism of action of a new series of E isomers of triazolo[4,5-b/c]pyridin-acrylonitrile derivatives (6c-g, 7d-e, 8d-e, 9c-f, 10d-e, 11d-e). All new compounds are endowed with moderate to interesting antiproliferative activity against 9 different cancer cell lines derived from solid and hematological human tumors. Fluorescence-based assays prove that these molecules interfere with tubulin polymerization. Furthermore, isothermal titration calorimetry (ITC) provides full tubulin/compound binding thermodynamics, thereby ultimately qualifying and quantifying the interactions of these molecular series with the target protein. Lastly, the analysis based on the tight coupling of in vitro and in silico modeling of the interactions between tubulin and the title compounds allows to propose a molecular rationale for their biological activity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Design, synthesis and molecular modeling of new 4-phenylcoumarin derivatives as tubulin polymerization inhibitors targeting MCF-7 breast cancer cells.

    Science.gov (United States)

    Batran, Rasha Z; Kassem, Asmaa F; Abbas, Eman M H; Elseginy, Samia A; Mounier, Marwa M

    2018-07-23

    A new set of 4-phenylcoumarin derivatives was designed and synthesized aiming to introduce new tubulin polymerization inhibitors as anti-breast cancer candidates. All the target compounds were evaluated for their cytotoxic effects against MCF-7 cell line, where compounds 2f, 3a, 3b, 3f, 7a and 7b, showed higher cytotoxic effect (IC 50  = 4.3-21.2 μg/mL) than the reference drug doxorubicin (IC 50  = 26.1 μg/mL), additionally, compounds 1 and 6b exhibited the same potency as doxorubicin (IC 50  = 25.2 and 28.0 μg/mL, respectively). The thiazolidinone derivatives 3a, 3b and 3f with potent and selective anticancer effects towards MCF-7 cells (IC 50  = 11.1, 16.7 and 21.2 μg/mL) were further assessed for tubulin polymerization inhibition effects which showed that the three compounds were potent tubulin polymerization suppressors with IC 50 values of 9.37, 2.89 and 6.13 μM, respectively, compared to the reference drug colchicine (IC 50  = 6.93 μM). The mechanistic effects on cell cycle progression and induction of apoptosis in MCF-7 cells were determined for compound 3a due to its potent and selective cytotoxic effects in addition to its promising tubulin polymerization inhibition potency. The results revealed that compound 3a induced cell cycle cessation at G2/M phase and accumulation of cells in pre-G1 phase and prevented its mitotic cycle, in addition to its activation of caspase-7 mediating apoptosis of MCF-7 cells. Molecular modeling studies for compounds 3a, 3b and 3f were carried out on tubulin crystallography, the results indicated that the compounds showed binding mode similar to the co-crystalized ligand; colchicine. Moreover, pharmacophore constructed models and docking studies revealed that thiazolidinone, acetamide and coumarin moieties are crucial for the activity. Molecular dynamics (MD) studies were carried out for the three compounds over 100 ps. MD results of compound 3a showed that it reached the stable state

  19. Rational design, synthesis, and biological evaluation of third generation α-noscapine analogues as potent tubulin binding anti-cancer agents.

    Directory of Open Access Journals (Sweden)

    Naresh Kumar Manchukonda

    Full Text Available Systematic screening based on structural similarity of drugs such as colchicine and podophyllotoxin led to identification of noscapine, a microtubule-targeted agent that attenuates the dynamic instability of microtubules without affecting the total polymer mass of microtubules. We report a new generation of noscapine derivatives as potential tubulin binding anti-cancer agents. Molecular modeling experiments of these derivatives 5a, 6a-j yielded better docking score (-7.252 to -5.402 kCal/mol than the parent compound, noscapine (-5.505 kCal/mol and its existing derivatives (-5.563 to -6.412 kCal/mol. Free energy (ΔG bind calculations based on the linear interaction energy (LIE empirical equation utilizing Surface Generalized Born (SGB continuum solvent model predicted the tubulin-binding affinities for the derivatives 5a, 6a-j (ranging from -4.923 to -6.189 kCal/mol. Compound 6f showed highest binding affinity to tubulin (-6.189 kCal/mol. The experimental evaluation of these compounds corroborated with theoretical studies. N-(3-brormobenzyl noscapine (6f binds tubulin with highest binding affinity (KD, 38 ± 4.0 µM, which is ~ 4.0 times higher than that of the parent compound, noscapine (KD, 144 ± 1.0 µM and is also more potent than that of the first generation clinical candidate EM011, 9-bromonoscapine (KD, 54 ± 9.1 µM. All these compounds exhibited substantial cytotoxicity toward cancer cells, with IC50 values ranging from 6.7 µM to 72.9 µM; compound 6f showed prominent anti-cancer efficacy with IC50 values ranging from 6.7 µM to 26.9 µM in cancer cells of different tissues of origin. These compounds perturbed DNA synthesis, delayed the cell cycle progression at G2/M phase, and induced apoptotic cell death in cancer cells. Collectively, the study reported here identified potent, third generation noscapinoids as new anti-cancer agents.

  20. Brain-computer interface for alertness estimation and improving

    Science.gov (United States)

    Hramov, Alexander; Maksimenko, Vladimir; Hramova, Marina

    2018-02-01

    Using wavelet analysis of the signals of electrical brain activity (EEG), we study the processes of neural activity, associated with perception of visual stimuli. We demonstrate that the brain can process visual stimuli in two scenarios: (i) perception is characterized by destruction of the alpha-waves and increase in the high-frequency (beta) activity, (ii) the beta-rhythm is not well pronounced, while the alpha-wave energy remains unchanged. The special experiments show that the motivation factor initiates the first scenario, explained by the increasing alertness. Based on the obtained results we build the brain-computer interface and demonstrate how the degree of the alertness can be estimated and controlled in real experiment.

  1. Beta-endorphin and alpha-n-acetyl beta-endorphin; synthesis, conformation and binding parameter

    Energy Technology Data Exchange (ETDEWEB)

    Lovegren, E.S.

    1986-01-01

    Beta-endorphin (EP) is a 31-residue opioid peptide found in many tissues, including the pituitary, brain and reproductive tract. Alpha-amino-acetyl beta-endorphin (AcEP) was characterized spectroscopically by proton nuclear magnetic resonance (NMR) and circular dichroism in deuterated water and trifluoroethanol (TFE). Both EP and AcEP bind to neuroblastoma N2a cells. This binding was not mediated through opiate receptors, and both peptides seemed to bind at common sites. Ovarian immunoreactive-EP levels were determined for immature and mature rates. These levels were found to be responsive to exogenous gonadotropin treatment in immature animals. A large percentage of the immunoreactive-EP is present in follicular fluid, and most of the endorphin-like peptides were acetylated, as measured by radioimmunoassay. Chromatogaphic analysis suggested at least three EP-like species: EP, a carboxy-terminally cleaved and an amino-terminally acetylated EP.

  2. DNA polymerase-beta is expressed early in neurons of Alzheimer's disease brain and is loaded into DNA replication forks in neurons challenged with beta-amyloid

    NARCIS (Netherlands)

    Copani, Agata; Hoozemans, Jeroen J. M.; Caraci, Filippo; Calafiore, Marco; van Haastert, Elise S.; Veerhuis, Robert; Rozemuller, Annemieke J. M.; Aronica, Eleonora; Sortino, Maria Angela; Nicoletti, Ferdinando

    2006-01-01

    Cultured neurons exposed to synthetic beta-amyloid (Abeta) fragments reenter the cell cycle and initiate a pathway of DNA replication that involves the repair enzyme DNA polymerase-beta (DNA pol-beta) before undergoing apoptotic death. In this study, by performing coimmunoprecipitation experiments

  3. Myc-nick: a cytoplasmic cleavage product of Myc that promotes alpha-tubulin acetylation and cell differentiation.

    Science.gov (United States)

    Conacci-Sorrell, Maralice; Ngouenet, Celine; Eisenman, Robert N

    2010-08-06

    The Myc oncoprotein family comprises transcription factors that control multiple cellular functions and are widely involved in oncogenesis. Here we report the identification of Myc-nick, a cytoplasmic form of Myc generated by calpain-dependent proteolysis at lysine 298 of full-length Myc. Myc-nick retains conserved Myc box regions but lacks nuclear localization signals and the bHLHZ domain essential for heterodimerization with Max and DNA binding. Myc-nick induces alpha-tubulin acetylation and altered cell morphology by recruiting histone acetyltransferase GCN5 to microtubules. During muscle differentiation, while the levels of full-length Myc diminish, Myc-nick and acetylated alpha-tubulin levels are increased. Ectopic expression of Myc-nick accelerates myoblast fusion, triggers the expression of myogenic markers, and permits Myc-deficient fibroblasts to transdifferentiate in response to MyoD. We propose that the cleavage of Myc by calpain abrogates the transcriptional inhibition of differentiation by full-length Myc and generates Myc-nick, a driver of cytoplasmic reorganization and differentiation. Copyright 2010 Elsevier Inc. All rights reserved.

  4. Relation between the 2{nu}{beta}{beta} and 0{nu}{beta}{beta} nuclear matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Petr [Kellogg Radiation Laboratory, Caltech, Pasadena, CA 91125 (United States); Simkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, SK-84248 Bratislava (Slovakia)

    2011-12-16

    A formal relation between the GT part of the nuclear matrix elements M{sub GT}{sup 0{nu}} of 0{nu}{beta}{beta} decay and the closure matrix elements M{sub cl}{sup 2{nu}} of 2{nu}{beta}{beta} decay is established. This relation is based on the integral representation of these quantities in terms of their dependence on the distance r between the two nucleons undergoing transformation. We also discuss the difficulties in determining the correct values of the closure 2{nu}{beta}{beta} decay matrix elements.

  5. Altered cellular distribution and subcellular sorting of gamma-tubulin in diffuse astrocytic gliomas and human glioblastoma cell lines

    Czech Academy of Sciences Publication Activity Database

    Katsetos, C.; Path, M.; Reddy, G.; Dráberová, Eduarda; Šmejkalová, Barbora; Del Valle, L.; Asfraf, Q.; Tadevosyan, A.; Yelin, K.; Maraziotis, T.; Mörk, S.; Mishra, O.; Legido, A.; Nissanov, J.; Baas, P.; De Chadarevian, J.; Dráber, Pavel

    2006-01-01

    Roč. 65, č. 5 (2006), s. 465-477 ISSN 0022-3069 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z5052915 Keywords : anaplastic changes * glioblastoma * gamma tubulin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.371, year: 2006

  6. Nicotinic {alpha}4{beta}2 receptor imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Pichika, Rama [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Easwaramoorthy, Balasubramaniam [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Collins, Daphne [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Christian, Bradley T. [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Shi, Bingzhi [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Narayanan, Tanjore K. [Department of Nuclear Medicine, Kettering Medical Center, Dayton, OH 45429 (United States); Potkin, Steven G. [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States); Mukherjee, Jogeshwar [Brain Imaging Center, Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-3960 (United States)]. E-mail: j.mukherjee@uci.edu

    2006-04-15

    The {alpha}4{beta}2 nicotinic acetylcholine receptor (nAChR) has been implicated in various neurodegenerative diseases. Optimal positron emission tomography (PET) imaging agents are therefore highly desired for this receptor. We report here the development and initial evaluation of 2-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine (nifene). In vitro binding affinity of nifene in rat brain homogenate using {sup 3}H-cytisine exhibited a K {sub i}=0.50 nM for the {alpha}4{beta}2 sites. The radiosynthesis of 2-{sup 18}F-fluoro-3-[2-((S)-3-pyrrolinyl)methoxy]pyridine ({sup 18}F-nifene) was accomplished in 2.5 h with an overall radiochemical yield of 40-50%, decay corrected. The specific activity was estimated to be approx. 37-185 GBq/{mu}mol. In vitro autoradiography in rat brain slices indicated selective binding of {sup 18}F-nifene to anteroventral thalamic (AVT) nucleus, thalamus, subiculum, striata, cortex and other regions consistent with {alpha}4{beta}2 receptor distribution. Rat cerebellum showed some binding, whereas regions in the hippocampus had the lowest binding. The highest ratio of >13 between AVT and cerebellum was measured for {sup 18}F-nifene in rat brain slices. The specific binding was reduced (>95%) by 300 {mu}M nicotine in these brain regions. Positron emission tomography imaging study of {sup 18}F-nifene (130 MBq) in anesthetized rhesus monkey was carried out using an ECAT EXACT HR+ scanner. PET study showed selective maximal uptake in the regions of the anterior medial thalamus, ventro-lateral thalamus, lateral geniculate, cingulate gyrus, temporal cortex including the subiculum. The cerebellum in the monkeys showed lower binding than the other regions. Thalamus-to-cerebellum ratio peaked at 30-35 min postinjection to a value of 2.2 and subsequently reduced. The faster binding profile of {sup 18}F-nifene indicates promise as a PET imaging agent and thus needs further evaluation.

  7. Stabilization of protein by freeze-drying in the presence of trehalose: a case study of tubulin

    Czech Academy of Sciences Publication Activity Database

    Dráber, Pavel; Sulimenko, Vadym; Sulimenko, Tetyana; Dráberová, Eduarda

    2014-01-01

    Roč. 1129, February (2014), s. 443-458 ISSN 1064-3745 R&D Projects: GA MŠk LH12050; GA AV ČR M200521203; GA ČR GAP302/10/1701; GA ČR GPP302/11/P709 Institutional support: RVO:68378050 Keywords : Freeze-drying * Microtubules * Stability * Trehalose * Tubulin Subject RIV: EB - Genetics ; Molecular Biology

  8. Catalpol ameliorates beta amyloid-induced degeneration of cholinergic neurons by elevating brain-derived neurotrophic factors.

    Science.gov (United States)

    Wang, Z; Liu, Q; Zhang, R; Liu, S; Xia, Z; Hu, Y

    2009-11-10

    The purpose of this work is to study the effect of catalpol, an iridoid from Rehmannia glutinosa on neurodegenerative changes induced by beta-amyloid peptide Abeta(25-35) or Abeta(25-35)+ibotenic acid and the underlying mechanism. Results showed that catalpol significantly improved the memory deficits in the neurodegenerative mouse model produced by injection of Abeta(25-35)+ibotenic acid to the nucleus magnocellularis basalis, yet it is neither a cholinesterase inhibitor nor a muscarinic (M) receptor agonist. Instead, the choline acetyl transferase (ChAT) activity and the M receptor density in brain were significantly decreased in the model mice and catalpol could significantly elevate their levels. Furthermore, the brain-derived neurotrophic factor (BDNF) content in brain was significantly decreased in the model mice and catalpol elevated it to normal level (83%+/-3% and 102%+/-2% of normal respectively). There is a significant positive correlation between BDNF content and memory. Primary culture of forebrain neurons revealed that aggregated Abeta(25-35) induced significant decrease of ChAT positive neuron number, neurite outgrowth length, and M receptor density, while catalpol added to the culture medium 2 h prior to Abeta addition showed significant dose dependent protective effect. Notably, 24 h and 48 h after the addition of Abeta to the cultured cells, the BDNF mRNA level in the neurons decreased to 76%+/-7% and 66%+/-3% of control without catalpol treatment, but became 128%+/-17% and 131%+/-23% of control with catalpol treatment. When the action of BDNF was inhibited by k252a in the cultured neurons, the protective effect of catalpol was completely (neurite outgrowth length) or partially (ChAT positive neuron number and the M receptor density) abolished. Taken together, catalpol improves memory and protects the forebrain neurons from neurodegeneration through increasing BDNF expression. Whether catalpol could reverse the neurodegenerative changes already

  9. Preferential reduction of binding of 125I-iodopindolol to beta-1 adrenoceptors in the amygdala of rat after antidepressant treatments

    International Nuclear Information System (INIS)

    Ordway, G.A.; Gambarana, C.; Tejani-Butt, S.M.; Areso, P.; Hauptmann, M.; Frazer, A.

    1991-01-01

    This study utilized quantitative receptor autoradiography to examine the effects of repeated administration of antidepressants to rats on the binding of the beta adrenoceptor antagonist, 125 I-iodopindolol ( 125 I-IPIN) to either beta-1 or beta-2 adrenoceptors in various regions of brain. Antidepressants were selected to represent various chemical and pharmacological classes including tricyclic compounds (desipramine and protriptyline), monoamine oxidase inhibitors (clorgyline, phenelzine and tranylcypromine), atypical antidepressants (mianserin and trazodone) and selective inhibitors of the uptake of serotonin (citalopram and sertraline). Additionally, rats were treated with various psychotropic drugs that lack antidepressant efficacy (cocaine, deprenyl, diazepam and haloperidol). Repeated treatment of rats with desipramine, protriptyline, clorgyline, phenelzine, tranylcypromine or mianserin reduced the binding of 125 I-IPIN to beta-1 adrenoceptors in many brain areas. Only in the basolateral and lateral nuclei of the amygdala did all six of these antidepressants significantly reduce 125 I-IPIN binding to beta-1 adrenoceptors. In these amygdaloid nuclei, the magnitude of the reduction in the binding of 125 I-IPIN caused by each of these drugs was comparable to or greater than the reduction in binding produced in any other region of brain. Reductions of binding of 125 I-IPIN after antidepressant treatments were not consistently observed in the cortex, the area of brain examined most often in homogenate binding studies. Only the monoamine oxidase inhibitors caused reductions in the binding of 125 I-IPIN to beta-2 adrenoceptors, and this effect was generally localized to the amygdala and hypothalamus

  10. Dietary flavonoid fisetin binds to β-tubulin and disrupts microtubule dynamics in prostate cancer cells

    OpenAIRE

    Mukhtar, Eiman; Adhami, Vaqar Mustafa; Sechi, Mario; Mukhtar, Hasan

    2015-01-01

    Microtubule targeting based therapies have revolutionized cancer treatment; however, resistance and side effects remain a major limitation. Therefore, novel strategies that can overcome these limitations are urgently needed. We made a novel discovery that fisetin, a hydroxyflavone, is a microtubule stabilizing agent. Fisetin binds to tubulin and stabilizes microtubules with binding characteristics far superior than paclitaxel. Surface plasmon resonance and computational docking studies sugges...

  11. Early inflammatory response in rat brain after peripheral thermal injury.

    Science.gov (United States)

    Reyes, Raul; Wu, Yimin; Lai, Qin; Mrizek, Michael; Berger, Jamie; Jimenez, David F; Barone, Constance M; Ding, Yuchuan

    2006-10-16

    Previous studies have shown that the cerebral complications associated with skin burn victims are correlated with brain damage. The aim of this study was to determine whether systemic thermal injury induces inflammatory responses in the brain. Sprague Dawley rats (n=28) were studied in thermal injury and control groups. Animals from the thermal injury (n=14) and control (n=14) group were anesthetized and submerged to the neck vertically in 85 degrees C water for 6 s producing a third degree burn affecting 60-70% of the animal body surface area. The controls were submerged in 37 degrees C water for 6 s. Early expression of tumor necrosis factor-alpha (TNF-alpha), interleukin 1-beta (IL-1beta), and intracellular cell adhesion molecules (ICAM-1) protein levels in serum were determined at 3 (n=7) and 7 h (n=7) by enzyme-linked immunoabsorbent assay (ELISA). mRNA of TNF-alpha, IL-1beta, and ICAM-1 in the brain was measured at the same time points with a real-time reverse transcriptase-polymerase chain reaction (RT-PCR). An equal animal number was used for controls. Systemic inflammatory responses were demonstrated by dramatic up-regulations (5-50 fold) of TNF-alpha, IL-1beta, and ICAM-1 protein level in serum at 7 h after the thermal injury. However, as early as 3 h after peripheral thermal injury, a significant increase (3-15 fold) in mRNA expression of TNF-alpha, IL-1beta and ICAM-1 was observed in brain homogenates, with increased levels remaining at 7 h after injury. This study demonstrated an early inflammatory response in the brain after severe peripheral thermal injury. The cerebral inflammatory reaction was associated with expression of systemic cytokines and an adhesion molecule.

  12. Activation of the endoplasmic reticulum stress response by the amyloid-beta 1-40 peptide in brain endothelial cells.

    Science.gov (United States)

    Fonseca, Ana Catarina R G; Ferreiro, Elisabete; Oliveira, Catarina R; Cardoso, Sandra M; Pereira, Cláudia F

    2013-12-01

    Neurovascular dysfunction arising from endothelial cell damage is an early pathogenic event that contributes to the neurodegenerative process occurring in Alzheimer's disease (AD). Since the mechanisms underlying endothelial dysfunction are not fully elucidated, this study was aimed to explore the hypothesis that brain endothelial cell death is induced upon the sustained activation of the endoplasmic reticulum (ER) stress response by amyloid-beta (Aβ) peptide, which deposits in the cerebral vessels in many AD patients and transgenic mice. Incubation of rat brain endothelial cells (RBE4 cell line) with Aβ1-40 increased the levels of several markers of ER stress-induced unfolded protein response (UPR), in a time-dependent manner, and affected the Ca(2+) homeostasis due to the release of Ca(2+) from this intracellular store. Finally, Aβ1-40 was shown to activate both mitochondria-dependent and -independent apoptotic cell death pathways. Enhanced release of cytochrome c from mitochondria and activation of the downstream caspase-9 were observed in cells treated with Aβ1-40 concomitantly with caspase-12 activation. Furthermore, Aβ1-40 activated the apoptosis effectors' caspase-3 and promoted the translocation of apoptosis-inducing factor (AIF) to the nucleus demonstrating the involvement of caspase-dependent and -independent mechanisms during Aβ-induced endothelial cell death. In conclusion, our data demonstrate that ER stress plays a significant role in Aβ1-40-induced apoptotic cell death in brain endothelial cells suggesting that ER stress-targeted therapeutic strategies might be useful in AD to counteract vascular defects and ultimately neurodegeneration. © 2013.

  13. Radioiodinated benzimidazole derivatives as single photon emission computed tomography probes for imaging of {beta}-amyloid plaques in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Cui Mengchao [Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan); Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875 (China); Ono, Masahiro, E-mail: ono@pharm.kyoto-u.ac.j [Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan); Kimura, Hiroyuki; Kawashima, Hidekazu [Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan); Liu Boli [Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875 (China); Saji, Hideo, E-mail: hsaji@pharm.kyoto-u.ac.j [Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan)

    2011-04-15

    Five iodinated 2-phenyl-1H-benzo[d]imidazole derivatives were synthesized and evaluated as potential probes for {beta}-amyloid (A{beta}) plaques. One of the compounds, 4-(6-iodo-1H-benzo[d]imidazol-2-yl)-N,N-dimethylaniline (12), showed excellent affinity for A{beta}{sub 1-42} aggregates (K{sub i}=9.8 nM). Autoradiography with sections of postmortem Alzheimer's disease (AD) brain revealed that a radioiodinated probe [{sup 125}I]12, labeled A{beta} plaques selectively with low nonspecific binding. Biodistribution experiments with normal mice injected intravenously with [{sup 125}I]12 showed high uptake [4.14 percent injected dose per gram (% ID/g) at 2 min] into and rapid clearance (0.15% ID/g at 60 min) from the brain, which may bring about a good signal-to-noise ratio and therefore achieve highly sensitive detection of A{beta} plaques. In addition, [{sup 125}I]12 labeled amyloid plaques in vivo in an AD transgenic model. The preliminary results strongly suggest that [{sup 125}I]12 bears characteristics suitable for detecting amyloid plaques in vivo. When labeled with {sup 123}I, it may be a useful SPECT imaging agent for A{beta} plaques in the brain of living AD patients.

  14. Long-term air pollution exposure is associated with neuroinflammation, an altered innate immune response, disruption of the blood-brain barrier, ultrafine particulate deposition, and accumulation of amyloid beta-42 and alpha-synuclein in children and young adults.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Solt, Anna C; Henríquez-Roldán, Carlos; Torres-Jardón, Ricardo; Nuse, Bryan; Herritt, Lou; Villarreal-Calderón, Rafael; Osnaya, Norma; Stone, Ida; García, Raquel; Brooks, Diane M; González-Maciel, Angelica; Reynoso-Robles, Rafael; Delgado-Chávez, Ricardo; Reed, William

    2008-02-01

    Air pollution is a serious environmental problem. We investigated whether residency in cities with high air pollution is associated with neuroinflammation/neurodegeneration in healthy children and young adults who died suddenly. We measured mRNA cyclooxygenase-2, interleukin-1beta, and CD14 in target brain regions from low (n = 12) or highly exposed residents (n = 35) aged 25.1 +/- 1.5 years. Upregulation of cyclooxygenase-2, interleukin-1beta, and CD14 in olfactory bulb, frontal cortex, substantia nigrae and vagus nerves; disruption of the blood-brain barrier; endothelial activation, oxidative stress, and inflammatory cell trafficking were seen in highly exposed subjects. Amyloid beta42 (Abeta42) immunoreactivity was observed in 58.8% of apolipoprotein E (APOE) 3/3 < 25 y, and 100% of the APOE 4 subjects, whereas alpha-synuclein was seen in 23.5% of < 25 y subjects. Particulate material (PM) was seen in olfactory bulb neurons, and PM < 100 nm were observed in intraluminal erythrocytes from lung, frontal, and trigeminal ganglia capillaries. Exposure to air pollution causes neuroinflammation, an altered brain innate immune response, and accumulation of Abeta42 and alpha-synuclein starting in childhood. Exposure to air pollution should be considered a risk factor for Alzheimer's and Parkinson's diseases, and carriers of the APOE 4 allele could have a higher risk of developing Alzheimer's disease if they reside in a polluted environment.

  15. Human histone deacetylase 6 shows strong preference for tubulin dimers over assembled microtubules

    Czech Academy of Sciences Publication Activity Database

    Škultétyová, Ĺubica; Ustinova, Kseniya; Kutil, Zsofia; Nováková, Zora; Pavlíček, Jiří; Mikesova, Jana; Trapl, Dalibor; Baranová, Petra; Havlínová, Barbora; Hubálek, Martin; Lánský, Zdeněk; Bařinka, Cyril

    2017-01-01

    Roč. 7, 2017 Sep 14 (2017), č. článku 11547. ISSN 2045-2322 R&D Projects: GA ČR GA15-19640S; GA ČR(CZ) GA15-17488S; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 ; RVO:61388963 Keywords : ALPHA-TUBULIN * IN-VIVO * MOLECULAR-BASIS * POSTTRANSLATIONAL MODIFICATION Subject RIV: CE - Biochemistry; CE - Biochemistry (UOCHB-X) OBOR OECD: Biochemistry and molecular biology; Biochemistry and molecular biology (UOCHB-X) Impact factor: 4.259, year: 2016

  16. Determination of pharmacological levels of harmane, harmine and harmaline in mammalian brain tissue, cerebrospinal fluid and plasma by high-performance liquid chromatography with fluorimetric detection.

    Science.gov (United States)

    Moncrieff, J

    1989-11-24

    Increased blood aldehyde levels, as occur in alcohol intoxication, could lead to the formation of beta-carbolines such as harmane by condensation with indoleamines. Endogenous beta-carbolines, therefore, should occur in specific brain areas where indoleamine concentrations are high, whilst exogenous beta-carbolines should exhibit an even distribution. The author presents direct and sensitive methods for assaying the beta-carbolines harmane, harmine and harmaline in brain tissue, cerebrospinal fluid and plasma at picogram sample concentrations using reversed-phase high-performance liquid chromatography with fluorimetric detection and minimal sample preparation. Using these assay methods, it was found that the distribution of beta-carbolines from a source exogenous to the brain results in a relatively even distribution within the brain tissue.

  17. Effects of oxidative stress on hyperglycaemia-induced brain malformations in a diabetes mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Ya [Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China (China); Wang, Guang [Division of Histology & Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University, Guangzhou 510632 (China); Han, Sha-Sha; He, Mei-Yao [Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China (China); Cheng, Xin; Ma, Zheng-Lai [Division of Histology & Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University, Guangzhou 510632 (China); Wu, Xia [Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China (China); Yang, Xuesong, E-mail: yang_xuesong@126.com [Division of Histology & Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University, Guangzhou 510632 (China); Liu, Guo-Sheng, E-mail: tlgs@jnu.edu.cn [Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China (China)

    2016-09-10

    Pregestational diabetes mellitus (PGDM) enhances the risk of fetal neurodevelopmental defects. However, the mechanism of hyperglycaemia-induced neurodevelopmental defects is not fully understood. In this study, several typical neurodevelopmental defects were identified in the streptozotocin-induced diabetes mouse model. The neuron-specific class III beta-tubulin/forkhead box P1-labelled neuronal differentiation was suppressed and glial fibrillary acidic protein-labelled glial cell lineage differentiation was slightly promoted in pregestational diabetes mellitus (PGDM) mice. Various concentrations of glucose did not change the U87 cell viability, but glial cell line-derived neurotrophic factor expression was altered with varying glucose concentrations. Mouse maternal hyperglycaemia significantly increased Tunel{sup +} apoptosis but did not dramatically affect PCNA{sup +} cell proliferation in the process. To determine the cause of increased apoptosis, we determined the SOD activity, the expression of Nrf2 as well as its downstream anti-oxidative factors NQO1 and HO1, and found that all of them significantly increased in PGDM fetal brains compared with controls. However, Nrf2 expression in U87 cells was not significantly changed by different glucose concentrations. In mouse telencephalon, we observed the co-localization of Tuj-1 and Nrf2 expression in neurons, and down-regulating of Nrf2 in SH-SY5Y cells altered the viability of SH-SY5Y cells exposed to high glucose concentrations. Taken together, the data suggest that Nrf2-modulated antioxidant stress plays a crucial role in maternal hyperglycaemia-induced neurodevelopmental defects. - Highlights: • Typical neurodevelopmental defects could be observed in STZ-treated mouse fetuses. • Nrf2 played a crucial role in hyperglycaemia-induced brain malformations. • The effects of hyperglycaemia on neurons and glia cells were not same.

  18. Effects of oxidative stress on hyperglycaemia-induced brain malformations in a diabetes mouse model

    International Nuclear Information System (INIS)

    Jin, Ya; Wang, Guang; Han, Sha-Sha; He, Mei-Yao; Cheng, Xin; Ma, Zheng-Lai; Wu, Xia; Yang, Xuesong; Liu, Guo-Sheng

    2016-01-01

    Pregestational diabetes mellitus (PGDM) enhances the risk of fetal neurodevelopmental defects. However, the mechanism of hyperglycaemia-induced neurodevelopmental defects is not fully understood. In this study, several typical neurodevelopmental defects were identified in the streptozotocin-induced diabetes mouse model. The neuron-specific class III beta-tubulin/forkhead box P1-labelled neuronal differentiation was suppressed and glial fibrillary acidic protein-labelled glial cell lineage differentiation was slightly promoted in pregestational diabetes mellitus (PGDM) mice. Various concentrations of glucose did not change the U87 cell viability, but glial cell line-derived neurotrophic factor expression was altered with varying glucose concentrations. Mouse maternal hyperglycaemia significantly increased Tunel"+ apoptosis but did not dramatically affect PCNA"+ cell proliferation in the process. To determine the cause of increased apoptosis, we determined the SOD activity, the expression of Nrf2 as well as its downstream anti-oxidative factors NQO1 and HO1, and found that all of them significantly increased in PGDM fetal brains compared with controls. However, Nrf2 expression in U87 cells was not significantly changed by different glucose concentrations. In mouse telencephalon, we observed the co-localization of Tuj-1 and Nrf2 expression in neurons, and down-regulating of Nrf2 in SH-SY5Y cells altered the viability of SH-SY5Y cells exposed to high glucose concentrations. Taken together, the data suggest that Nrf2-modulated antioxidant stress plays a crucial role in maternal hyperglycaemia-induced neurodevelopmental defects. - Highlights: • Typical neurodevelopmental defects could be observed in STZ-treated mouse fetuses. • Nrf2 played a crucial role in hyperglycaemia-induced brain malformations. • The effects of hyperglycaemia on neurons and glia cells were not same.

  19. Motor System Interactions in the Beta Band Decrease during Loss of Consciousness.

    Science.gov (United States)

    Swann, Nicole C; de Hemptinne, Coralie; Maher, Ryan B; Stapleton, Catherine A; Meng, Lingzhong; Gelb, Adrian W; Starr, Philip A

    2016-01-01

    Communication between brain areas and how they are influenced by changes in consciousness are not fully understood. One hypothesis is that brain areas communicate via oscillatory processes, utilizing network-specific frequency bands, that can be measured with metrics that reflect between-region interactions, such as coherence and phase amplitude coupling (PAC). To evaluate this hypothesis and understand how these interactions are modulated by state changes, we analyzed electrophysiological recordings in humans at different nodes of one well-studied brain network: the basal ganglia-thalamocortical loops of the motor system during loss of consciousness induced by anesthesia. We recorded simultaneous electrocorticography over primary motor cortex (M1) with local field potentials from subcortical motor regions (either basal ganglia or thalamus) in 15 movement disorder patients during anesthesia (propofol) induction as a part of their surgery for deep brain stimulation. We observed reduced coherence and PAC between M1 and the subcortical nuclei, which was specific to the beta band (∼18-24 Hz). The fact that this pattern occurs selectively in beta underscores the importance of this frequency band in the motor system and supports the idea that oscillatory interactions at specific frequencies are related to the capacity for normal brain function and behavior.

  20. Effects of stress and. beta. -funal trexamine pretreatment on morphine analgesia and opioid binding in rats

    Energy Technology Data Exchange (ETDEWEB)

    Adams, J.U.; Andrews, J.S.; Hiller, J.M.; Simon, E.J.; Holtzman, S.G.

    1987-12-28

    This study was essentially an in vivo protection experiment designed to test further the hypothesis that stress induces release of endogenous opiods which then act at opioid receptors. Rats that were either subjected to restraint stress for 1 yr or unstressed were injected ICV with either saline or 2.5 ..mu..g of ..beta..-funaltrexamine (..beta..-FNA), an irreversible opioid antagonist that alkylates the mu-opioid receptor. Twenty-four hours later, subjects were tested unstressed for morphine analgesia or were sacrificed and opioid binding in brain was determined. (/sup 3/H)D-Ala/sup 2/NMePhe/sup 4/-Gly/sup 5/(ol)enkephalin (DAGO) served as a specific ligand for mu-opioid receptors, and (/sup 3/H)-bremazocine as a general ligand for all opioid receptors. Rats injected with saline while stressed were significantly less sensitive to the analgesic action of morphine 24 hr later than were their unstressed counterparts. ..beta..-FNA pretreatment attenuated morphine analgesia in an insurmountable manner. Animals pretreated with ..beta..-FNA while stressed were significantly more sensitive to the analgesic effect of morphine than were animals that received ..beta..-FNA while unstressed. ..beta..-FNA caused small and similar decreases in (/sup 3/H)-DAGO binding in brain of both stressed and unstressed animals. 35 references, 2 figures, 2 tables.

  1. Deep brain stimulation modulates synchrony within spatially and spectrally distinct resting state networks in Parkinson's disease.

    Science.gov (United States)

    Oswal, Ashwini; Beudel, Martijn; Zrinzo, Ludvic; Limousin, Patricia; Hariz, Marwan; Foltynie, Tom; Litvak, Vladimir; Brown, Peter

    2016-05-01

    Chronic dopamine depletion in Parkinson's disease leads to progressive motor and cognitive impairment, which is associated with the emergence of characteristic patterns of synchronous oscillatory activity within cortico-basal-ganglia circuits. Deep brain stimulation of the subthalamic nucleus is an effective treatment for Parkinson's disease, but its influence on synchronous activity in cortico-basal-ganglia loops remains to be fully characterized. Here, we demonstrate that deep brain stimulation selectively suppresses certain spatially and spectrally segregated resting state subthalamic nucleus-cortical networks. To this end we used a validated and novel approach for performing simultaneous recordings of the subthalamic nucleus and cortex using magnetoencephalography (during concurrent subthalamic nucleus deep brain stimulation). Our results highlight that clinically effective subthalamic nucleus deep brain stimulation suppresses synchrony locally within the subthalamic nucleus in the low beta oscillatory range and furthermore that the degree of this suppression correlates with clinical motor improvement. Moreover, deep brain stimulation relatively selectively suppressed synchronization of activity between the subthalamic nucleus and mesial premotor regions, including the supplementary motor areas. These mesial premotor regions were predominantly coupled to the subthalamic nucleus in the high beta frequency range, but the degree of deep brain stimulation-associated suppression in their coupling to the subthalamic nucleus was not found to correlate with motor improvement. Beta band coupling between the subthalamic nucleus and lateral motor areas was not influenced by deep brain stimulation. Motor cortical coupling with subthalamic nucleus predominantly involved driving of the subthalamic nucleus, with those drives in the higher beta frequency band having much shorter net delays to subthalamic nucleus than those in the lower beta band. These observations raise the

  2. D-piece modifications of the hemiasterlin analog HTI-286 produce potent tubulin inhibitors.

    Science.gov (United States)

    Zask, Arie; Birnberg, Gary; Cheung, Katherine; Kaplan, Joshua; Niu, Chuan; Norton, Emily; Yamashita, Ayako; Beyer, Carl; Krishnamurthy, Girija; Greenberger, Lee M; Loganzo, Frank; Ayral-Kaloustian, Semiramis

    2004-08-16

    Modifications of the D-piece carboxylic acid group of the hemiasterlin analog HTI-286 gave tubulin inhibitors which were potent cytotoxic agents in taxol resistant cell lines expressing P-glycoprotein. Amides derived from proline had potency comparable to HTI-286. Reduction of the carboxylic acid to ketones and alcohols or its conversion to acidic heterocycles also gave potent analogs. Synthetic modifications of the carboxylic acid could be carried out selectively using a wide range of synthetic reagents. Proline analog 3 was found to be effective in a human xenograft model in athymic mice.

  3. Beta-amyloid precursor protein transgenic mice that harbor diffuse A beta deposits but do not form plaques show increased ischemic vulnerability: role of inflammation

    Czech Academy of Sciences Publication Activity Database

    Koistinaho, M.; Kettunen, M. I.; Goldsteins, G.; Keinänen, R.; Salminen, A.; Ort, Michael; Bureš, Jan; Liu, D.; Kauppinen, R. A.; Higgins, L. S.; Koistinaho, J.

    2002-01-01

    Roč. 99, č. 3 (2002), s. 1610-1615 ISSN 0027-8424 R&D Projects: GA ČR GA309/00/1656 Institutional research plan: CEZ:AV0Z5011922 Keywords : Beta-amyloid * Alzheimer disease * brain ischemia Subject RIV: FH - Neurology Impact factor: 10.701, year: 2002

  4. Nuclear gamma-tubulin associates with nucleoli and interacts with tumor suppressor protein C53

    Czech Academy of Sciences Publication Activity Database

    Hořejší, Barbora; Vinopal, Stanislav; Sládková, Vladimíra; Dráberová, Eduarda; Sulimenko, Vadym; Sulimenko, Tetyana; Vosecká, Věra; Philimonenko, Anatoly; Hozák, Pavel; Katsetos, C.D.; Dráber, Pavel

    2012-01-01

    Roč. 227, č. 1 (2012), s. 367-382 ISSN 0021-9541 R&D Projects: GA ČR GA204/09/1777; GA ČR(CZ) GD204/09/H084; GA ČR GAP302/10/1701; GA MŠk LC545; GA AV ČR KAN200520701; GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : nucleolus * gamma-tubulin * C53 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.218, year: 2012

  5. Association of ABCB1, β tubulin I, and III with multidrug resistance of MCF7/DOC subline from breast cancer cell line MCF7.

    Science.gov (United States)

    Li, Wentao; Zhai, Baoping; Zhi, Hui; Li, Yuhong; Jia, Linjiao; Ding, Chao; Zhang, Bin; You, Wei

    2014-09-01

    Docetaxel is a first-line chemotherapeutic agent for treating advanced breast cancer. The development of chemoresistance or multidrug resistance (MDR), however, results in breast cancer chemotherapy failure. This study aims to explore the molecular mechanisms underlying docetaxel-resistance in treatment of breast cancer. The docetaxel-resistant subline MCF7/DOC, derived from the parental sensitive breast cancer cell line MCF7, was established by intermittent exposure to moderate concentrations of docetaxel, followed by examination of its phenotypes. The MCF7/DOC subline showed cross resistance against paclitaxel, doxorubicin, methotrexate, and 5-Fu. Compared to the parental MCF7, MCF7/DOC cells were enlarged with heterogeneous sizes and a cobblestone and polygonal appearance. They were arrested at G2/M phase and proliferated slowly. The colony formation potential of MCF7/DOC in soft agar was significantly increased. MCF7/DOC cells showed reduced intracellular accumulation and increased efflux of rhodamine 123. The mRNA expression level of adenosine triphosphate binding cassette (ABC) transporter family, i.e., ABCB1, ABCC1, ABCC2, ABCG2, and β tubulin isotypes were characterized by quantitative PCR. High-level expression of ABCB1, βI, and βIII tubulin mRNA in MCF7/DOC was detected. Downregulation of ABCB1, βI, and βIII tubulin mediated by three combined siRNAs resulted in stronger growth inhibition of MCF7/DOC than inhibition of the expression of individual genes. ABCB1, βI, and βIII tubulin might contribute to the MDR of MCF7/DOC and be potential therapeutic targets for overcoming MDR of breast cancer.

  6. 1-Methyl-beta-carboline (harmane), a potent endogenous inhibitor of benzodiazepine receptor binding.

    Science.gov (United States)

    Rommelspacher, H; Nanz, C; Borbe, H O; Fehske, K J; Müller, W E; Wollert, U

    1980-10-01

    The interaction of several beta-carbolines with specific [3H]-flunitrazepam binding to benzodiazepine receptors in rat brain membranes was investigated. Out of the investigated compounds, harmane and norharmane were the most potent inhibitors of specific [3H]-flunitrazepam binding, with IC50-values in the micromolar range. All other derivatives, including harmine, harmaline, and several tetrahydroderivatives were at least ten times less potent. Harmane has been previously found in rat brain and human urine, so it is the most potent endogenous inhibitor of specific [3H]-flunitrazepam binding known so far, with a several fold higher affinity for the benzodiazepine receptor than inosine and hypoxanthine. Thus, we suggest that harmane or other related beta-carbolines could be potential candidates as endogenous ligands of the benzodiazepine receptor.

  7. Effects of sertraline on brain current source of the high beta frequency band: analysis of electroencephalography during audiovisual erotic stimulation in males with premature ejaculation.

    Science.gov (United States)

    Kwon, O Y; Kam, S C; Choi, J H; Do, J M; Hyun, J S

    2011-01-01

    To identify the effects of sertraline, a selective serotonin reuptake inhibitor, for the treatment of premature ejaculation (PE), changes in brain current-source density (CSD) of the high beta frequency band (22-30 Hz) induced by sertraline administration were investigated during audiovisual erotic stimulation. Eleven patients with PE (36.9±7.8 yrs) and 11 male volunteers (24.2±1.9 years) were enrolled. Scalp electroencephalography (EEG) was conducted twice: once before sertraline administration and then again 4 h after the administration of 50 mg sertraline. Statistical non-parametric maps were obtained using the EEG segments to detect the current-density differences in the high beta frequency bands (beta-3, 22-30 Hz) between the EEGs before and after sertraline administration in the patient group and between the patient group and controls after the administration of sertraline during the erotic video sessions. Comparing between before and after sertraline administration in the patients with PE, the CSD of the high beta frequency band at 4 h after sertraline administration increased significantly in both superior frontal gyri and the right medial frontal gyrus (P<0.01). The CSD of the beta-3 band of the patients with PE were less activated significantly in the middle and superior temporal gyrus, lingual and fusiform gyrus, inferior occipital gyrus and cuneus of the right cerebral hemisphere compared with the normal volunteers 4 h after sertraline administration (P<0.01). In conclusion, sertraline administration increased the CSD in both the superior frontal and right middle temporal gyrus in patients with PE. The results suggest that the increased neural activity in these particular cerebral regions after sertraline administration may be associated with inhibitory effects on ejaculation in patients with PE.

  8. Aspergillus contaminans

    Science.gov (United States)

    Aspergillus contaminans is described as a new species from the fingernail of a patient with an infected nail. Phylogenetic analysis of four loci (ITS, calmodulin, beta tubulin and RNA polymerase beta, second largest subunit) showed that this species is most closely related to A. carlsbadensis from A...

  9. Availability of neurotransmitter glutamate is diminished when beta-hydroxybutyrate replaces glucose in cultured neurons.

    Science.gov (United States)

    Lund, Trine M; Risa, Oystein; Sonnewald, Ursula; Schousboe, Arne; Waagepetersen, Helle S

    2009-07-01

    Ketone bodies serve as alternative energy substrates for the brain in cases of low glucose availability such as during starvation or in patients treated with a ketogenic diet. The ketone bodies are metabolized via a distinct pathway confined to the mitochondria. We have compared metabolism of [2,4-(13)C]beta-hydroxybutyrate to that of [1,6-(13)C]glucose in cultured glutamatergic neurons and investigated the effect of neuronal activity focusing on the aspartate-glutamate homeostasis, an essential component of the excitatory activity in the brain. The amount of (13)C incorporation and cellular content was lower for glutamate and higher for aspartate in the presence of [2,4-(13)C]beta-hydroxybutyrate as opposed to [1,6-(13)C]glucose. Our results suggest that the change in aspartate-glutamate homeostasis is due to a decreased availability of NADH for cytosolic malate dehydrogenase and thus reduced malate-aspartate shuttle activity in neurons using beta-hydroxybutyrate. In the presence of glucose, the glutamate content decreased significantly upon activation of neurotransmitter release, whereas in the presence of only beta-hydroxybutyrate, no decrease in the glutamate content was observed. Thus, the fraction of the glutamate pool available for transmitter release was diminished when metabolizing beta-hydroxybutyrate, which is in line with the hypothesis of formation of transmitter glutamate via an obligatory involvement of the malate-aspartate shuttle.

  10. In vitro and ex vivo distribution of [3H]harmane, an endogenous beta-carboline, in rat brain.

    Science.gov (United States)

    Anderson, Neil J; Tyacke, Robin J; Husbands, Stephen M; Nutt, David J; Hudson, Alan L; Robinson, Emma S J

    2006-03-01

    The endogenous beta-carboline, harmane, has been shown to bind to monoamine oxidase A (MAO-A) and a separate, high affinity, non-MAO site. Research in our laboratory has shown that harmane is an active component of clonidine-displacing substance (CDS), the proposed endogenous ligand for imidazoline binding sites (IBS). In the present study we have investigated the distribution of [3H]harmane in rat brain, and related the binding profile to the distribution of the MAO-A selective ligand [3H]Ro41-1049 and the I2BS ligand [3H]2-BFI. The in vivo distribution of [3H]harmane following intravenous administration was also investigated. Receptor autoradiography revealed a highly significant correlation for the distribution of [3H]harmane and [3H]Ro41-1049, and a significant correlation for [3H]harmane and the I2BS ligand [3H]2-BFI. The in vivo distribution of [3H]harmane suggests that the ligand accumulates in the adrenal gland and throughout the brain with the primary route of excretion occurring via the duodenum. In conclusion, these studies have shown that [3H]harmane labels a population of binding sites that reflect the distribution of MAO-A. Further evidence for a non-MAO, IBS [3H]harmane population has not been shown but the high level of expression of the MAO-A site is likely to have masked the much smaller population of I2BS.

  11. N-Heterocyclic (4-Phenylpiperazin-1-yl)methanones Derived from Phenoxazine and Phenothiazine as Highly Potent Inhibitors of Tubulin Polymerization

    DEFF Research Database (Denmark)

    Prinz, Helge; Ridder, Ann-Kathrin; Vogel, Kirsten

    2017-01-01

    We report here a series of 27 10-(4-phenylpiperazin-1-yl)methanones derived from tricyclic heterocycles which were screened for effects on tumor cell growth, inhibition of tubulin polymerization, and induction of cell cycle arrest. Several analogues, among them the 10-(4-(3-methoxyphenyl)piperazi...

  12. Neurine, an acetylcholine autolysis product, elevates secreted amyloid-beta protein precursor and amyloid-beta peptide levels, and lowers neuronal cell viability in culture: a role in Alzheimer's disease?

    Science.gov (United States)

    Tweedie, David; Brossi, Arnold; Chen, DeMoa; Ge, Yuan-Wen; Bailey, Jason; Yu, Qian-Sheng; Kamal, Mohammad A; Sambamurti, Kumar; Lahiri, Debomoy K; Greig, Nigel H

    2006-09-01

    Classical hallmarks of Alzheimer's disease (AD) are a synaptic loss, cholinergic neuron death, and abnormal protein deposition, particularly of toxic amyloid-beta peptide (Abeta) that is derived from amyloid-beta protein precursor (AbetaPP) by the action of beta- and gamma-secretases. The trigger(s) initiating the biochemical cascades that underpin these hallmarks have yet to be fully elucidated. The typical forebrain cholinergic cell demise associated with AD brain results in a loss of presynaptic cholinergic markers and acetylcholine (ACh). Neurine (vinyl-trimethyl-ammonium hydroxide) is a breakdown product of ACh, consequent to autolysis and is an organic poison found in cadavre brain. The time- and concentration-dependent actions of neurine were assessed in human neuroblastoma (NB, SK-N-SH) cells in culture by quantifying cell viability by lactate dehydrogenase (LDH) and MTS assay, and AbetaPP and Abeta levels by Western blot and ELISA. NB cells displayed evidence of toxicity to neurine at > or = 3 mg/ml, as demonstrated by elevated LDH levels in the culture media and a reduced cell viability shown by the MTS assay. Using subtoxic concentrations of neurine, elevations in AbetaPP and Abeta1-40 peptide levels were detected in conditioned media samples.

  13. BETA digital beta radiometer

    International Nuclear Information System (INIS)

    Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

    1989-01-01

    Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

  14. Minocycline does not affect amyloid beta phagocytosis by human microglial cells

    NARCIS (Netherlands)

    Familian, Atoosa; Eikelenboom, Piet; Veerhuis, Robert

    2007-01-01

    Activated microglia accumulate in amyloid beta (Abeta) plaques containing amyloid associated factors SAP and C1q in Alzheimer's disease (AD) brain. Microglia are involved in AD pathogenesis by promoting Abeta plaque formation and production of pro-inflammatory cytokines. On the other hand,

  15. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  16. Mixed heterolobosean and novel gregarine lineage genes from culture ATCC 50646: Long-branch artefacts, not lateral gene transfer, distort α-tubulin phylogeny.

    Science.gov (United States)

    Cavalier-Smith, Thomas

    2015-04-01

    Contradictory and confusing results can arise if sequenced 'monoprotist' samples really contain DNA of very different species. Eukaryote-wide phylogenetic analyses using five genes from the amoeboflagellate culture ATCC 50646 previously implied it was an undescribed percolozoan related to percolatean flagellates (Stephanopogon, Percolomonas). Contrastingly, three phylogenetic analyses of 18S rRNA alone, did not place it within Percolozoa, but as an isolated deep-branching excavate. I resolve that contradiction by sequence phylogenies for all five genes individually, using up to 652 taxa. Its 18S rRNA sequence (GQ377652) is near-identical to one from stained-glass windows, somewhat more distant from one from cooling-tower water, all three related to terrestrial actinocephalid gregarines Hoplorhynchus and Pyxinia. All four protein-gene sequences (Hsp90; α-tubulin; β-tubulin; actin) are from an amoeboflagellate heterolobosean percolozoan, not especially deeply branching. Contrary to previous conclusions from trees combining protein and rRNA sequences or rDNA trees including Eozoa only, this culture does not represent a major novel deep-branching eukaryote lineage distinct from Heterolobosea, and thus lacks special significance for deep eukaryote phylogeny, though the rDNA sequence is important for gregarine phylogeny. α-Tubulin trees for over 250 eukaryotes refute earlier suggestions of lateral gene transfer within eukaryotes, being largely congruent with morphology and other gene trees. Copyright © 2015. Published by Elsevier GmbH.

  17. Molecular biology of the mammalian brain

    International Nuclear Information System (INIS)

    Morrison, M.R.; Griffin, W.S.T.

    1985-01-01

    The authors' characterization of abundant mRNAs by analysis of their in vitro translation products has provided detailed information on the changes in steady-state mRNA levels taking place during brain and neuroblastoma differentiation as well as on more general aspects of mRNA structure and utilization in the nervous system. Quantitation of specific mRNAs using radiolabelled recombinant DNA probes has confirmed that the measurements of translationally active tubulin and actin mRNAs by this method are indeed an accurate indication of their steady-state levels. The technology is now available to characterize neuropathology at the cellular level. Analysis of mRNA changes in diseased brain are of obvious relevance in documenting gross pathological changes in transcription patterns. In situ hybridization and immunohistochemistry can now be used, perhaps even in combination with computer reconstruction to investigate more critically the specific cell losses so characteristic of diseases such as Huntington's, Parkinson's, amyotrophic lateral sclerosis, multiple sclerosis, and Alzheimer's. In situ hybridization of probes to mRNAs encoding specific neurotransmitter enzymes and abundant ''housekeeping'' proteins can now be used to determine whether the remaining cells in affected brain areas are transcriptionally normal. Furthermore, this technique can also be used to document the transcriptional changes in cell types not presently identified as compromised and thus will pinpoint more precisely the initial cell targets of disease

  18. Zinc and Copper Effects on Stability of Tubulin and Actin Networks in Dendrites and Spines of Hippocampal Neurons.

    Science.gov (United States)

    Perrin, Laura; Roudeau, Stéphane; Carmona, Asuncion; Domart, Florelle; Petersen, Jennifer D; Bohic, Sylvain; Yang, Yang; Cloetens, Peter; Ortega, Richard

    2017-07-19

    Zinc and copper ions can modulate the activity of glutamate receptors. However, labile zinc and copper ions likely represent only the tip of the iceberg and other neuronal functions are suspected for these metals in their bound state. We performed synchrotron X-ray fluorescence imaging with 30 nm resolution to image total biometals in dendrites and spines from hippocampal neurons. We found that zinc is distributed all along the dendrites while copper is mainly pinpointed within the spines. In spines, zinc content is higher within the spine head while copper is higher within the spine neck. Such specific distributions suggested metal interactions with cytoskeleton proteins. Zinc supplementation induced the increase of β-tubulin content in dendrites. Copper supplementation impaired the β-tubulin and F-actin networks. Copper chelation resulted in the decrease of F-actin content in dendrites, drastically reducing the number of F-actin protrusions. These results indicate that zinc is involved in microtubule stability whereas copper is essential for actin-dependent stability of dendritic spines, although copper excess can impair the dendritic cytoskeleton.

  19. Lipid raft facilitated ligation of K-{alpha}1-tubulin by specific antibodies on epithelial cells: Role in pathogenesis of chronic rejection following human lung transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Tiriveedhi, Venkataswarup; Angaswamy, Nataraju [Department of Surgery, Pathology and Immunology, Washington University School of Medicine, St. Louis, MO (United States); Weber, Joseph [Department of Medicine, Washington University School of Medicine, St. Louis, MO (United States); Mohanakumar, T., E-mail: kumart@wustl.edu [Department of Surgery, Pathology and Immunology, Washington University School of Medicine, St. Louis, MO (United States)

    2010-08-20

    Research highlights: {yields} Addition of KAT Abs (+) sera to NHBE culture causes upregulation of growth factors. {yields} Cholesterol depletion causes down regulation of growth factor expression. {yields} Cholesterol depletion is accompanied by loss of membrane bound caveolin. {yields} Thus, we demonstrate lipid raft are critical for efficient ligation of the KAT Abs. -- Abstract: Long term function of human lung allografts is hindered by development of chronic rejection manifested as Bronchiolitis Obliterans Syndrome (BOS). We have previously identified the development of antibodies (Abs) following lung transplantation to K-{alpha}1-tubulin (KAT), an epithelial surface gap junction cytoskeletal protein, in patients who develop BOS. However, the biochemical and molecular basis of the interactions and signaling cascades mediated by KAT Abs are yet to be defined. In this report, we investigated the biophysical basis of the epithelial cell membrane surface interaction between KAT and its specific Abs. Towards this, we analyzed the role of the lipid raft-domains in the membrane interactions which lead to cell signaling and ultimately increased growth factor expression. Normal human bronchial epithelial (NHBE) cells, upon specific ligation with Abs to KAT obtained either from the serum of BOS(+) patients or monoclonal KAT Abs, resulted in upregulation of growth factors VEGF, PDGF, and bFGF (6.4 {+-} 1.1-, 3.2 {+-} 0.9-, and 3.4 {+-} 1.1-fold increase, respectively) all of which are important in the pathogenesis of BOS. To define the role for lipid raft in augmenting surface interactions, we analyzed the changes in the growth factor expression pattern upon depletion and enrichment with lipid raft following the ligation of the epithelial cell membranes with Abs specific for KAT. NHBE cells cultured in the presence of {beta}-methyl cyclodextran ({beta}MCD) had significantly reduced growth factor expression (1.3 {+-} 0.3, vs {beta}MCD untreated being 6.4 {+-} 1.1-fold

  20. Increased beta rhythm as an indicator of inhibitory mechanisms in tourette syndrome.

    Science.gov (United States)

    Niccolai, Valentina; van Dijk, Hanneke; Franzkowiak, Stephanie; Finis, Jennifer; Südmeyer, Martin; Jonas, Melanie; Thomalla, Götz; Siebner, Hartwig Roman; Müller-Vahl, Kirsten; Münchau, Alexander; Schnitzler, Alfons; Biermann-Ruben, Katja

    2016-03-01

    Inhibitory oscillatory mechanisms subserving tic compensation have been put forward in Tourette syndrome. Modulation of the beta rhythm (15-25 Hz) as the well-established oscillatory movement execution-inhibition indicator was tested during a cognitive-motor task in patients with Tourette syndrome. Performing a Go/NoGo task, 12 patients with Tourette syndrome and 12 matched controls were recorded using whole-head magnetoencephalography. Compared to healthy participants, patients showed less beta suppression in the sensorimotor area and enhanced beta power in parieto-occipital brain regions contralaterally to the response hand. Average beta power and power gain correlated negatively with tic severity. Increased motor inhibitory as well as visuomotor attentional processes are likely to subserve tic compensation. Correlational results suggest that stronger inhibitory compensation accompanies less tic severity. © 2016 International Parkinson and Movement Disorder Society.

  1. Genetic disruption of tubulin acetyltransferase, αTAT1, inhibits proliferation and invasion of colon cancer cells through decreases in Wnt1/β-catenin signaling

    International Nuclear Information System (INIS)

    Oh, Somi; You, Eunae; Ko, Panseon; Jeong, Jangho; Keum, Seula; Rhee, Sangmyung

    2017-01-01

    Microtubules are required for diverse cellular processes, and abnormal regulation of microtubule dynamics is closely associated with severe diseases including malignant tumors. In this study, we report that α-tubulin N-acetyltransferase (αTAT1), a regulator of α-tubulin acetylation, is required for colon cancer proliferation and invasion via regulation of Wnt1 and its downstream genes expression. Public transcriptome analysis showed that expression of ATAT1 is specifically upregulated in colon cancer tissue. A knockout (KO) of ATAT1 in the HCT116 colon cancer cell line, using the CRISPR/Cas9 system showed profound inhibition of proliferative and invasive activities of these cancer cells. Overexpression of αTAT1 or the acetyl-mimic K40Q α-tubulin mutant in αTAT1 KO cells restored the invasiveness, indicating that microtubule acetylation induced by αTAT1 is critical for HCT116 cell invasion. Analysis of colon cancer-related gene expression in αTAT1 KO cells revealed that the loss of αTAT1 decreased the expression of WNT1. Mechanistically, abrogation of tubulin acetylation by αTAT1 knockout inhibited localization of β-catenin to the plasma membrane and nucleus, thereby resulting in the downregulation of Wnt1 and of its downstream genes including CCND1, MMP-2, and MMP-9. These results suggest that αTAT1-mediated Wnt1 expression via microtubule acetylation is important for colon cancer progression. - Highlights: • Ablation of αTAT1 inhibits HCT116 colon cancer cell invasion. • αTAT1/acetylated microtubules regulate expression of Wnt1/β-catenin target genes. • Acetylated microtubules regulate cellular localization of β-catenin. • Loss of αTAT1 prevents Wnt1 from inducing β-catenin-dependent and -independent pathways.

  2. A Novel Dual HDAC6 and Tubulin Inhibitor, MPT0B451, Displays Anti-tumor Ability in Human Cancer Cells in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Yi-Wen Wu

    2018-03-01

    Full Text Available The combination cancer therapy is a new strategy to circumvent drug resistance for the treatment of high metastasis and advanced malignancies. Herein, we developed a synthesized compound MPT0B451 that display inhibitory effect against histone deacetylase (HDAC 6 and tubulin assembly. Our data demonstrated that MPT0B451 significantly inhibited cancer cell growths in HL-60 and PC-3 cells due to inhibition of HDAC activity. MPT0B451 also markedly increased caspase-mediated apoptosis in these cells. The cell cycle analysis showed mitotic arrest induced by MPT0B451 with enhanced expression of G2/M transition proteins. Moreover, molecular docking analysis supported MPT0B451 as a dual HDAC6 and tubulin inhibitor. Finally, MPT0B451 led to tumor growth inhibition (TGI in HL-60 and PC-3 xenograft models. These findings indicated that MPT0B451 has dual inhibition effects for HDAC6 and tubulin, and also contributed to G2/M arrest followed by apoptotic induction. Together, our results suggested that MPT0B451 may serve as a potent anti-cancer treatment regimen in human prostate cancer and acute myeloid leukemia.

  3. Pediatric respiratory and systemic effects of chronic air pollution exposure: nose, lung, heart, and brain pathology.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Franco-Lira, Maricela; Torres-Jardón, Ricardo; Henriquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Valencia-Salazar, Gildardo; González-Maciel, Angelica; Reynoso-Robles, Rafael; Villarreal-Calderón, Rafael; Reed, William

    2007-01-01

    Exposures to particulate matter and gaseous air pollutants have been associated with respiratory tract inflammation, disruption of the nasal respiratory and olfactory barriers, systemic inflammation, production of mediators of inflammation capable of reaching the brain and systemic circulation of particulate matter. Mexico City (MC) residents are exposed to significant amounts of ozone, particulate matter and associated lipopolysaccharides. MC dogs exhibit brain inflammation and an acceleration of Alzheimer's-like pathology, suggesting that the brain is adversely affected by air pollutants. MC children, adolescents and adults have a significant upregulation of cyclooxygenase-2 (COX2) and interleukin-1beta (IL-1beta) in olfactory bulb and frontal cortex, as well as neuronal and astrocytic accumulation of the 42 amino acid form of beta -amyloid peptide (Abeta 42), including diffuse amyloid plaques in frontal cortex. The pathogenesis of Alzheimer's disease (AD) is characterized by brain inflammation and the accumulation of Abeta 42, which precede the appearance of neuritic plaques and neurofibrillary tangles, the pathological hallmarks of AD. Our findings of nasal barrier disruption, systemic inflammation, and the upregulation of COX2 and IL-1beta expression and Abeta 42 accumulation in brain suggests that sustained exposures to significant concentrations of air pollutants such as particulate matter could be a risk factor for AD and other neurodegenerative diseases.

  4. Brain aging, Alzheimer's disease, and mitochondria

    Science.gov (United States)

    Swerdlow, Russell H.

    2011-01-01

    The relationship between brain aging and Alzheimer’s disease (AD) is contentious. One view holds AD results when brain aging surpasses a threshold. The other view postulates AD is not a consequence of brain aging. This review discusses this conundrum from the perspective of different investigative lines that have tried to address it, as well as from the perspective of the mitochondrion, an organelle that appears to play a role in both AD and brain aging. Specific issues addressed include the question of whether AD and brain aging should be conceptually lumped or split, the extent to which AD and brain aging potentially share common molecular mechanisms, whether beta amyloid should be primarily considered a marker of AD or simply brain aging, and the definition of AD itself. PMID:21920438

  5. New Insights in the Amyloid-Beta Interaction with Mitochondria

    Directory of Open Access Journals (Sweden)

    Carlos Spuch

    2012-01-01

    Full Text Available Biochemical and morphological alterations of mitochondria may play an important role in the pathogenesis of Alzheimer’s disease (AD. Particularly, mitochondrial dysfunction is a hallmark of amyloid-beta-induced neuronal toxicity in Alzheimer’s disease. The recent emphasis on the intracellular biology of amyloid-beta and its precursor protein (APP has led researchers to consider the possibility that mitochondria-associated and mitochondrial amyloid-beta may directly cause neurotoxicity. Both proteins are known to localize to mitochondrial membranes, block the transport of nuclear-encoded mitochondrial proteins to mitochondria, interact with mitochondrial proteins, disrupt the electron transport chain, increase reactive oxygen species production, cause mitochondrial damage, and prevent neurons from functioning normally. In this paper, we will outline current knowledge of the intracellular localization of amyloid-beta. Moreover, we summarize evidence from AD postmortem brain as well as animal AD models showing that amyloid-beta triggers mitochondrial dysfunction through a number of pathways such as impairment of oxidative phosphorylation, elevation of reactive oxygen species production, alteration of mitochondrial dynamics, and interaction with mitochondrial proteins. Thus, this paper supports the Alzheimer cascade mitochondrial hypothesis such as the most important early events in this disease, and probably one of the future strategies on the therapy of this neurodegenerative disease.

  6. Differential expression of gamma-tubulin and class III beta-tubulin in meduloblastoma cell lines

    Czech Academy of Sciences Publication Activity Database

    Caracciolo, V.; D´Agostino, L.; Dráberová, Eduarda; Sládková, Vladimíra; Agamanolis, D.; De Chaderevian, J.P.; Legido, A.; Giordano, A.; Dráber, Pavel; Katsetos, C.

    2010-01-01

    Roč. 69, č. 5 (2010), s. 558-558 ISSN 0022-3069. [Annual Meeting of the American-Association-of-Neuropathologists /86./. 10.06.10-13.06.10, Phidadelphia] Institutional research plan: CEZ:AV0Z50520514

  7. Interactions between two beta-sheets. Energetics of beta/beta packing in proteins.

    Science.gov (United States)

    Chou, K C; Némethy, G; Rumsey, S; Tuttle, R W; Scheraga, H A

    1986-04-20

    The analysis of the interactions between regularly folded segments of the polypeptide chain contributes to an understanding of the energetics of protein folding. Conformational energy-minimization calculations have been carried out to determine the favorable ways of packing two right-twisted beta-sheets. The packing of two five-stranded beta-sheets was investigated, with the strands having the composition CH3CO-(L-Ile)6-NHCH3 in one beta-sheet and CH3CO-(L-Val)6-NHCH3 in the other. Two distinct classes of low-energy packing arrangements were found. In the class with lowest energies, the strands of the two beta-sheets are aligned nearly parallel (or antiparallel) with each other, with a preference for a negative orientation angle, because this arrangement corresponds to the best complementary packing of the two twisted saddle-shaped beta-sheets. In the second class, with higher interaction energies, the strands of the two beta-sheets are oriented nearly perpendicular to each other. While the surfaces of the two beta-sheets are not complementary in this arrangement, there is good packing between the corner of one beta-sheet and the interior part of the surface of the other, resulting in a favorable energy of packing. Both classes correspond to frequently observed orientations of beta-sheets in proteins. In proteins, the second class of packing is usually observed when the two beta-sheets are covalently linked, i.e. when a polypeptide strand passes from one beta-sheet to the other, but we have shown here that a large contribution to the stabilization of this packing arrangement arises from noncovalent interactions.

  8. Interaction with beta-arrestin determines the difference in internalization behavor between beta1- and beta2-adrenergic receptors.

    Science.gov (United States)

    Shiina, T; Kawasaki, A; Nagao, T; Kurose, H

    2000-09-15

    The beta(1)-adrenergic receptor (beta(1)AR) shows the resistance to agonist-induced internalization. As beta-arrestin is important for internalization, we examine the interaction of beta-arrestin with beta(1)AR with three different methods: intracellular trafficking of beta-arrestin, binding of in vitro translated beta-arrestin to intracellular domains of beta(1)- and beta(2)ARs, and inhibition of betaAR-stimulated adenylyl cyclase activities by beta-arrestin. The green fluorescent protein-tagged beta-arrestin 2 translocates to and stays at the plasma membrane by beta(2)AR stimulation. Although green fluorescent protein-tagged beta-arrestin 2 also translocates to the plasma membrane, it returns to the cytoplasm 10-30 min after beta(1)AR stimulation. The binding of in vitro translated beta-arrestin 1 and beta-arrestin 2 to the third intracellular loop and the carboxyl tail of beta(1)AR is lower than that of beta(2)AR. The fusion protein of beta-arrestin 1 with glutathione S-transferase inhibits the beta(1)- and beta(2)AR-stimulated adenylyl cyclase activities, although inhibition of the beta(1)AR-stimulated activity requires a higher concentration of the fusion protein than that of the beta(2)AR-stimulated activity. These results suggest that weak interaction of beta(1)AR with beta-arrestins explains the resistance to agonist-induced internalization. This is further supported by the finding that beta-arrestin can induce internalization of beta(1)AR when beta-arrestin 1 does not dissociate from beta(1)AR by fusing to the carboxyl tail of beta(1)AR.

  9. Synthesis of 2-aryl-1,2,4-oxadiazolo-benzimidazoles: Tubulin polymerization inhibitors and apoptosis inducing agents.

    Science.gov (United States)

    Kamal, Ahmed; Reddy, T Srinivasa; Vishnuvardhan, M V P S; Nimbarte, Vijaykumar D; Subba Rao, A V; Srinivasulu, Vunnam; Shankaraiah, Nagula

    2015-08-01

    A new series of 2-aryl 1,2,4-oxadiazolo-benzimidazole conjugates have been synthesized and evaluated for their antiproliferative activity in the sixty cancer cell line panel of the National Cancer Institute (NCI). Compounds 5l (NSC: 761109/1) and 5x (NSC: 761814/1) exhibited remarkable cytotoxic activity against most of the cancer cell lines in the one dose assay and were further screened at five dose concentrations (0.01, 0.1, 1, 10 and 100 μM) which showed GI50 values in the range of 0.79-28.2 μM. Flow cytometric data of these compounds showed increased cells in G2/M phase, which is suggestive of G2/M cell cycle arrest. Further, compounds 5l and 5x showed inhibition of tubulin polymerization and disruption of the formation of microtubules. These compounds induce apoptosis by DNA fragmentation and chromatin condensation as well as by mitochondrial membrane depolarization. In addition, structure activity relationship studies within the series are also discussed. Molecular docking studies of compounds 5l and 5x into the colchicine-binding site of the tubulin, revealed the possible mode of interaction by these compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Brain fibronectin expression in prenatally irradiated mice

    International Nuclear Information System (INIS)

    Meznarich, H.K.; McCoy, L.S.; Bale, T.L.; Stiegler, G.L.; Sikov, M.R.

    1993-01-01

    Activation of gene transcription by radiation has been recently demonstrated in vivo. However, little is known on the specificity of these alterations on gene transcription. Prenatal irradiation is a known teratogen that affects the developing mammalian central nervous system (CNS). Altered neuronal migration has been suggested as a mechanism for abnormal development of prenatally irradiated brains. Fibronectin (FN), an extracellular glycoprotein, is essential for neural crest cell migration and neural cell growth. In addition, elevated levels of FN have been found in the extracellular matrix of irradiated lung. To test whether brain FN is affected by radiation, either FN level in insoluble matrix fraction or expression of FN mRNA was examined pre- and postnatally after irradiation. Mice (CD1), at 13 d of gestation (DG), served either as controls or were irradiated with 14 DG, 17 DG, or 5,6, or 14 d postnatal. Brain and liver were collected from offspring and analyzed for either total FN protein levels or relative mRNAs for FN and tubulin. Results of prenatal irradiation on reduction of postnatal brain weight relative to whole are comparable to that reported by others. Insoluble matrix fraction (IMF) per gram of brain, liver, lung, and heart weight was not significantly different either between control and irradiated groups or between postnatal stages, suggesting that radiation did not affect the IMF. However, total amounts of FN in brain IMF at 17 DG were significantly different (p < .02) between normal (1.66 ± 0.80 μg) and irradiated brains (0.58 ± 0.22 μg). FN mRNA was detectable at 13, 14, and 17 DG, but was not detectable at 6 and 14 d postnatal, indicating that FN mRNA is developmentally regulated. 41 refs., 4 figs., 3 tabs

  11. Hdac6 knock-out increases tubulin acetylation but does not modify disease progression in the R6/2 mouse model of Huntington's disease.

    Directory of Open Access Journals (Sweden)

    Anna Bobrowska

    Full Text Available Huntington's disease (HD is a progressive neurodegenerative disorder for which there is no effective disease modifying treatment. Following-on from studies in HD animal models, histone deacetylase (HDAC inhibition has emerged as an attractive therapeutic option. In parallel, several reports have demonstrated a role for histone deacetylase 6 (HDAC6 in the modulation of the toxicity caused by the accumulation of misfolded proteins, including that of expanded polyglutamine in an N-terminal huntingtin fragment. An important role for HDAC6 in kinesin-1 dependent transport of brain-derived neurotrophic factor (BDNF from the cortex to the striatum has also been demonstrated. To elucidate the role that HDAC6 plays in HD progression, we evaluated the effects of the genetic depletion of HDAC6 in the R6/2 mouse model of HD. Loss of HDAC6 resulted in a marked increase in tubulin acetylation throughout the brain. Despite this, there was no effect on the onset and progression of a wide range of behavioural, physiological, molecular and pathological HD-related phenotypes. We observed no change in the aggregate load or in the levels of soluble mutant exon 1 transprotein. HDAC6 genetic depletion did not affect the efficiency of BDNF transport from the cortex to the striatum. Therefore, we conclude that HDAC6 inhibition does not modify disease progression in R6/2 mice and HDAC6 should not be prioritized as a therapeutic target for HD.

  12. Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study

    International Nuclear Information System (INIS)

    Suarez, S.V.; Changeux, J.P.; Granon, S.; Amadon, A.; Giacomini, E.; Le Bihan, D.; Wiklund, A.

    2009-01-01

    Rationale: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity β2-containing nicotinic receptors (β2*nAChRs) are located. Objectives We intend to see which brain circuits are activated when nicotine is given in animals naive for nicotine and whether the β2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. Materials and methods: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and β2 knockout (KO) mice. Results: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, β2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via α7 nicotinic receptors. Conclusions: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on β2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice. (authors)

  13. Defective tubulin organization and proplatelet formation in murine megakaryocytes lacking Rac1 and Cdc42

    DEFF Research Database (Denmark)

    Pleines, Irina; Dütting, Sebastian; Cherpokova, Deya

    2013-01-01

    Blood platelets are anuclear cell fragments that are essential for blood clotting. Platelets are produced by bone marrow megakaryocytes (MKs), which extend protrusions, or so-called proplatelets, into bone marrow sinusoids. Proplatelet formation requires a profound reorganization of the MK actin...... normally in vivo but displayed highly abnormal morphology and uncontrolled fragmentation. Consistently, a lack of Rac1/Cdc42 virtually abrogated proplatelet formation in vitro. Strikingly, this phenotype was associated with severely defective tubulin organization, whereas actin assembly and structure were...

  14. (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G2/M arrest, and triggers apoptosis in human leukemia HL-60 cells

    International Nuclear Information System (INIS)

    Magalhães, Hemerson I.F.; Wilke, Diego V.; Bezerra, Daniel P.; Cavalcanti, Bruno C.; Rotta, Rodrigo; Lima, Dênis P. de; Beatriz, Adilson; Moraes, Manoel O.; Diniz-Filho, Jairo; Pessoa, Claudia

    2013-01-01

    (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC 50 values in the nanomolar range. Cell cycle arrest in G 2 /M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation, loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G 2 /M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G 2 /M phase of the cell cycle. • PHT induces caspase-dependent apoptosis

  15. Enhanced IL-1beta production in response to the activation of hippocampal glial cells impairs neurogenesis in aged mice.

    Science.gov (United States)

    Kuzumaki, Naoko; Ikegami, Daigo; Imai, Satoshi; Narita, Michiko; Tamura, Rie; Yajima, Marie; Suzuki, Atsuo; Miyashita, Kazuhiko; Niikura, Keiichi; Takeshima, Hideyuki; Ando, Takayuki; Ushijima, Toshikazu; Suzuki, Tsutomu; Narita, Minoru

    2010-09-01

    A variety of mechanisms that contribute to the accumulation of age-related damage and the resulting brain dysfunction have been identified. Recently, decreased neurogenesis in the hippocampus has been recognized as one of the mechanisms of age-related brain dysfunction. However, the molecular mechanism of decreased neurogenesis with aging is still unclear. In the present study, we investigated whether aging decreases neurogenesis accompanied by the activation of microglia and astrocytes, which increases the expression of IL-1beta in the hippocampus, and whether in vitro treatment with IL-1beta in neural stem cells directly impairs neurogenesis. Ionized calcium-binding adaptor molecule 1 (Iba1)-positive microglia and glial fibrillary acidic protein (GFAP)-positive astrocytes were increased in the dentate gyrus of the hippocampus of 28-month-old mice. Furthermore, the mRNA level of IL-1beta was significantly increased without related histone modifications. Moreover, a significant increase in lysine 9 on histone H3 (H3K9) trimethylation at the promoter of NeuroD (a neural progenitor cell marker) was observed in the hippocampus of aged mice. In vitro treatment with IL-1beta in neural stem cells prepared from whole brain of E14.5 mice significantly increased H3K9 trimethylation at the NeuroD promoter. These findings suggest that aging may decrease hippocampal neurogenesis via epigenetic modifications accompanied by the activation of microglia and astrocytes with the increased expression of IL-1beta in the hippocampus.

  16. Complexes of membrane-associated gamma-tubulin with Fyn kinase and phosphoinositide 3-kinase in differentiating cells

    Czech Academy of Sciences Publication Activity Database

    Sulimenko, Vadym; Macůrek, Libor; Dráberová, Eduarda; Richterová, Věra; Sulimenko, Tetyana; Dráberová, Lubica; Marková, Vladimíra; Dráber, Pavel

    2009-01-01

    Roč. 276, č. 1 (2009), s. 253-253 ISSN 1742-464X. [FEBS Congress /34/. 04.07.2009-09.07.2009, Praha] R&D Projects: GA MŠk 1M0506; GA MŠk LC545; GA ČR GA204/05/2375; GA ČR GA304/04/1273 Institutional research plan: CEZ:AV0Z50520514 Keywords : detergent -resistant membrane * Fyn * PI3K gamma-tubulin Subject RIV: EB - Genetics ; Molecular Biology

  17. Structural derivatives of pindolol: relationship between in vivo and in vitro potencies for their interaction with central beta-adrenergic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Tejani-Butt, S.M.; Brunswick, D.J.

    1987-08-24

    Although (-)-/sup 125/I-iodopindolol (IPIN) can be used to label beta-adrenergic receptors in the central nervous system (CNS) in vivo, use of this ligand for receptor imaging studies in humans may be limited due to its relatively poor penetration into the CNS. A series of derivatives related to pindolol was therefore studied in an effort to determine the factors that might influence the penetration and interaction of these compounds with central beta-adrenergic receptors in vivo. Evaluation of the ability of these derivatives to displace the binding of IPIN in the brain upon systemic administration provides an assessment of whether the derivatives penetrate and interact with central beta-adrenergic receptors in vivo. Multiple regression analyses showed that the most important factor which influences the ability of the pindolol derivatives to penetrate into the brain and interact with beta-adrenergic receptors in vivo is the affinity of the derivatives for binding to beta-adrenergic receptors in vitro. Both lipophilicity and the molecular weights of the derivatives are important secondary factors which influence their in vivo potency. 15 references, 4 figures, 1 table.

  18. Structural derivatives of pindolol: relationship between in vivo and in vitro potencies for their interaction with central beta-adrenergic receptors

    International Nuclear Information System (INIS)

    Tejani-Butt, S.M.; Brunswick, D.J.

    1987-01-01

    Although (-)- 125 I-iodopindolol (IPIN) can be used to label beta-adrenergic receptors in the central nervous system (CNS) in vivo, use of this ligand for receptor imaging studies in humans may be limited due to its relatively poor penetration into the CNS. A series of derivatives related to pindolol was therefore studied in an effort to determine the factors that might influence the penetration and interaction of these compounds with central beta-adrenergic receptors in vivo. Evaluation of the ability of these derivatives to displace the binding of IPIN in the brain upon systemic administration provides an assessment of whether the derivatives penetrate and interact with central beta-adrenergic receptors in vivo. Multiple regression analyses showed that the most important factor which influences the ability of the pindolol derivatives to penetrate into the brain and interact with beta-adrenergic receptors in vivo is the affinity of the derivatives for binding to beta-adrenergic receptors in vitro. Both lipophilicity and the molecular weights of the derivatives are important secondary factors which influence their in vivo potency. 15 references, 4 figures, 1 table

  19. The ontogeny of seizures induced by leucine-enkephalin and beta-endorphin.

    Science.gov (United States)

    Snead, O C; Stephens, H

    1984-06-01

    Rats ranging in postnatal age from 6 hours to 28 days were implanted with cortical and depth electrodes as well as an indwelling cannula in the lateral ventricle. We then administered varying amounts of the opiate peptides leucine-enkephalin and beta-endorphin intracerebroventricularly with continuous electroencephalographic monitoring. Leucine-enkephalin produced electrical seizure activity in rats as young as 2 days. beta-Endorphin administration was associated with seizures at the fifth postnatal day, with a high incidence of apnea resulting in death in animals as young as 6 hours. An adult seizure response to beta-endorphin and leucine-enkephalin was seen at 15 and 28 days of age, respectively. Naloxone blocked the seizure produced by these opiate peptides in all age groups. The data indicate that the opiate peptides are potent epileptogenic compounds in developing brain, that seizures induced by leucine-enkephalin differ from those caused by beta-endorphin, and that petit mal-like seizure activity can be an adult response in the rodent.

  20. Effect of beta and gamma neurofeedback on memory and intelligence in the elderly.

    Science.gov (United States)

    Staufenbiel, S M; Brouwer, A-M; Keizer, A W; van Wouwe, N C

    2014-01-01

    Recent research showed a correlation between cognitive decline and a decrease of EEG gamma activity. In the present double-blind randomized control study, we investigated whether gamma and beta neurofeedback protocols, that have been shown to modulate performance on cognitive control and memory in young adults, also leads to increased brain activity and cognitive performance in elderly. Twenty older adults either performed eight 30-min gamma neurofeedback session or beta neurofeedback session within a period of 21 days. Cognitive performance was determined before and after the training through an IQ and memory task and we added a subjective well-being questionnaire. Both neurofeedback training protocols resulted in a significant increase of the brain activity within each training session, suggesting that the aging brain is still trainable. However, we found no effects on cognitive performance or transfer of the feedback beyond the trainings. We discuss several possible reasons for the lack of training on rest measurements and cognition and ways to improve the feedback protocols for future studies. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Adrenergic receptors in frontal cortex in human brain.

    Science.gov (United States)

    Cash, R; Raisman, R; Ruberg, M; Agid, Y

    1985-02-05

    The binding of three adrenergic ligands ([3H]prazosin, [3H]clonidine, [3H]dihydroalprenolol) was studied in the frontal cortex of human brain. alpha 1-Receptors, labeled by [3H]prazosin, predominated. [3H]Clonidine bound to two classes of sites, one of high affinity and one of low affinity. Guanosine triphosphate appeared to lower the affinity of [3H]clonidine for its receptor. [3H]Dihydroalprenolol bound to three classes of sites: the beta 1-receptor, the beta 2-receptor and a receptor with low affinity which represented about 40% of the total binding, but which was probably a non-specific site; the beta 1/beta 2 ratio was 1/2.

  2. Brain perfusion SPECT correlates with CSF biomarkers in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Habert, Marie-Odile [UMR-S 678, Universite Pierre et Marie Curie-Paris 6, INSERM, Paris (France); CHU Pitie-Salpetriere, AP-HP, Department of Nuclear Medicine, Paris (France); Hopital Pitie-Salpetriere, Department of Nuclear Medicine, Paris (France); Souza, Leonardo Cruz de; Dubois, Bruno; Sarazin, Marie [CHU Pitie-Salpetriere, AP-HP, Research and Resource Memory Centre and INSERM U610, Paris (France); Lamari, Foudil; Jardel, Claude [CHU Pitie-Salpetriere, AP-HP, Department of Metabolic Biochemistry, Paris (France); Daragon, Nelle; Desarnaud, Serge [CHU Pitie-Salpetriere, AP-HP, Department of Nuclear Medicine, Paris (France)

    2010-03-15

    Our aim was to study the correlations between cerebrospinal fluid (CSF) biomarker levels such as {beta}-amyloid 42 (A{beta}{sub 42}), total and phosphorylated tau protein (T-tau and P-tau) and brain perfusion SPECT in Alzheimer's disease (AD) using a voxel-based methodology. Patients (n = 31) with clinical features of AD (n = 25) or amnestic mild cognitive impairment (aMCI) (n = 6) were retrospectively included. All subjects underwent the same clinical, neuropsychological and neuroimaging tests. They had a lumbar puncture and a brain perfusion ({sup 99m}Tc-ECD) SPECT within a time interval of 10 ({+-}26) days. Correlations between CSF biomarker concentrations and perfusion were studied using SPM2 software. Individual normalised regional activity values were extracted from the eligible clusters for calculation of correlation coefficients. No significant correlation was found between A{beta}{sub 42} concentrations and brain perfusion. A significant correlation (p < 0.01, corrected) was found between T-tau or P-tau concentrations and perfusion in the left parietal cortex. Our results suggest a strong correlation between T-tau and P-tau levels and decreased brain perfusion in regions typically affected by neuropathological changes in AD. (orig.)

  3. Analysis of the 3’ untranslated regions of α-tubulin and S-crystallin mRNA and the identification of CPEB in dark- and light-adapted octopus retinas

    Science.gov (United States)

    Kelly, Shannan; Yamamoto, Hideki

    2008-01-01

    Purpose We previously reported the differential expression and translation of mRNA and protein in dark- and light-adapted octopus retinas, which may result from cytoplasmic polyadenylation element (CPE)–dependent mRNA masking and unmasking. Here we investigate the presence of CPEs in α-tubulin and S-crystallin mRNA and report the identification of cytoplasmic polyadenylation element binding protein (CPEB) in light- and dark-adapted octopus retinas. Methods 3’-RACE and sequencing were used to isolate and analyze the 3’-UTRs of α-tubulin and S-crystallin mRNA. Total retinal protein isolated from light- and dark-adapted octopus retinas was subjected to western blot analysis followed by CPEB antibody detection, PEP-171 inhibition of CPEB, and dephosphorylation of CPEB. Results The following CPE-like sequence was detected in the 3’-UTR of isolated long S-crystallin mRNA variants: UUUAACA. No CPE or CPE-like sequences were detected in the 3’-UTRs of α-tubulin mRNA or of the short S-crystallin mRNA variants. Western blot analysis detected CPEB as two putative bands migrating between 60-80 kDa, while a third band migrated below 30 kDa in dark- and light-adapted retinas. Conclusions The detection of CPEB and the identification of the putative CPE-like sequences in the S-crystallin 3’-UTR suggest that CPEB may be involved in the activation of masked S-crystallin mRNA, but not in the regulation of α-tubulin mRNA, resulting in increased S-crystallin protein synthesis in dark-adapted octopus retinas. PMID:18682811

  4. Insulin Resistance as a Link between Amyloid-Beta and Tau Pathologies in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Roger J. Mullins

    2017-05-01

    Full Text Available Current hypotheses and theories regarding the pathogenesis of Alzheimer’s disease (AD heavily implicate brain insulin resistance (IR as a key factor. Despite the many well-validated metrics for systemic IR, the absence of biomarkers for brain-specific IR represents a translational gap that has hindered its study in living humans. In our lab, we have been working to develop biomarkers that reflect the common mechanisms of brain IR and AD that may be used to follow their engagement by experimental treatments. We present two promising biomarkers for brain IR in AD: insulin cascade mediators probed in extracellular vesicles (EVs enriched for neuronal origin, and two-dimensional magnetic resonance spectroscopy (MRS measures of brain glucose. As further evidence for a fundamental link between brain IR and AD, we provide a novel analysis demonstrating the close spatial correlation between brain expression of genes implicated in IR (using Allen Human Brain Atlas data and tau and beta-amyloid pathologies. We proceed to propose the bold hypotheses that baseline differences in the metabolic reliance on glycolysis, and the expression of glucose transporters (GLUT and insulin signaling genes determine the vulnerability of different brain regions to Tau and/or Amyloid beta (Aβ pathology, and that IR is a critical link between these two pathologies that define AD. Lastly, we provide an overview of ongoing clinical trials that target IR as an angle to treat AD, and suggest how biomarkers may be used to evaluate treatment efficacy and target engagement.

  5. HSV presence in brains of individuals without dementia: the TASTY brain series

    Directory of Open Access Journals (Sweden)

    Jan Olsson

    2016-11-01

    Full Text Available Herpes simplex virus (HSV type 1 affects a majority of the population and recent evidence suggests involvement in Alzheimer's disease aetiology. We investigated the prevalence of HSV type 1 and 2 in the Tampere Autopsy Study (TASTY brain samples using PCR and sero-positivity in plasma, and associations with Alzheimer's disease neuropathology. HSV was shown to be present in human brain tissue in 11/584 (1.9% of samples in the TASTY cohort, of which six had Alzheimer's disease neuropathological amyloid beta (Aβ aggregations. Additionally, serological data revealed 86% of serum samples tested were IgG-positive for HSV. In conclusion, we report epidemiological evidence of the presence of HSV in brain tissue free from encephalitis symptoms in a cohort most closely representing the general population (a minimum prevalence of 1.9%. Whereas 6/11 samples with HSV DNA in the brain tissue had Aβ aggregations, most of those with Aβ aggregations did not have HSV present in the brain tissue.

  6. Neural mechanisms of mental schema: a triplet of delta, low beta/spindle and ripple oscillations.

    Science.gov (United States)

    Ohki, Takefumi; Takei, Yuichi

    2018-02-06

    Schemas are higher-level knowledge structures that integrate and organise lower-level representations. As internal templates, schemas are formed according to how events are perceived, interpreted and remembered. Although these higher-level units are assumed to play a fundamental role in our daily life from an early age, the neuronal basis and mechanisms of schema formation and use remain largely unknown. It is important to elucidate how the brain constructs and maintains these higher-level units. In order to examine the possible neural underpinnings of schema, we recapitulate previous work and discuss their findings related to schemas as the brain template. We specifically focused on low beta/spindle oscillations, which are assumed to be the key components of schemas, and propose that the brain template is implemented with a triplet of neural oscillations, that is delta, low beta/spindle and ripple oscillations. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  7. Expression of a truncated receptor protein tyrosine phosphatase kappa in the brain of an adult transgenic mouse

    DEFF Research Database (Denmark)

    Shen, P; Canoll, P D; Sap, J

    1999-01-01

    processes such as axonal growth and target recognition, as has been demonstrated for certain Drosophila RPTPs. The brain distribution of RPTP-kappa-expressing cells has not been determined, however. In a gene-trap mouse model with a beta-gal+neo (beta-geo) insertion in the endogenous RPTP-kappa gene......-6596]. Nevertheless, since the transgene's expression is driven by the endogenous RPTP-kappa promoter, distribution of the truncated RPTP-kappa/beta-geo fusion protein should reflect the regional and cellular expression of wild-type RPTP-kappa, and thus may identify sites where RPTP-kappa is important. Towards...... that goal, we have used this mouse model to map the distribution of the truncated RPTP-kappa/beta-geo fusion protein in the adult mouse brain using beta-galactosidase as a marker enzyme. Visualization of the beta-galactosidase activity revealed a non-random pattern of expression, and identified cells...

  8. Music genre preference and tempo alter alpha and beta waves in human non-musicians

    Directory of Open Access Journals (Sweden)

    Hunter Gentry

    2013-10-01

    Full Text Available This study examined the effects of music genre and tempo on brain activation patterns in 10 nonmusicians.Two genres (rock and jazz and three tempos (slowed, medium/normal, andquickened were examined using EEG recording and analyzed through Fast Fourier Transform(FFT analysis. When participants listened to their preferred genre, an increase in alpha waveamplitude was observed. Alpha waves were not significantly affected by tempo. Beta waveamplitude increased significantly as the tempo increased. Genre had no effect on beta waves. Thefindings of this study indicate that genre preference and artificially modified tempo do affectalpha and beta wave activation in non-musicians listening to preselected songs.

  9. Specific recognition of the C-terminal end of A beta 42 by a high affinity monoclonal antibody

    DEFF Research Database (Denmark)

    Axelsen, Trine Veje; Holm, Arne; Birkelund, Svend

    2009-01-01

    The neurotoxic peptide A beta(42) is derived from the amyloid precursor protein by proteolytic cleavage and is deposited in the brain of patients suffering from Alzheimer's disease (AD). In this study we generate a high affinity monoclonal antibody that targets the C-terminal end of A beta(42......) with high specificity. By this is meant that the paratope of the antibody must enclose the C-terminal end of A beta(42) including the carboxy-group of amino acid 42, and not just recognize a linear epitope in the C-terminal part of A beta. This has been accomplished by using a unique antigen construct made...... by the Ligand Presenting Assembly technology (LPA technology). This strategy results in dimeric presentation of the free C-terminal end of A beta(42). The generated Mab A beta1.1 is indeed specific for the C-terminal end of A beta(42) to which it binds with high affinity. Mab A beta1.1 recognizes the epitope...

  10. Cross-frequency coupling of brain oscillations in studying motivation and emotion.

    Science.gov (United States)

    Schutter, Dennis J L G; Knyazev, Gennady G

    2012-03-01

    Research has shown that brain functions are realized by simultaneous oscillations in various frequency bands. In addition to examining oscillations in pre-specified bands, interactions and relations between the different frequency bandwidths is another important aspect that needs to be considered in unraveling the workings of the human brain and its functions. In this review we provide evidence that studying interdependencies between brain oscillations may be a valuable approach to study the electrophysiological processes associated with motivation and emotional states. Studies will be presented showing that amplitude-amplitude coupling between delta-alpha and delta-beta oscillations varies as a function of state anxiety and approach-avoidance-related motivation, and that changes in the association between delta-beta oscillations can be observed following successful psychotherapy. Together these studies suggest that cross-frequency coupling of brain oscillations may contribute to expanding our understanding of the neural processes underlying motivation and emotion.

  11. Absence of beta-amyloid in cortical cataracts of donors with and without Alzheimer's disease.

    Science.gov (United States)

    Michael, Ralph; Rosandić, Jurja; Montenegro, Gustavo A; Lobato, Elvira; Tresserra, Francisco; Barraquer, Rafael I; Vrensen, Gijs F J M

    2013-01-01

    Eye lenses from human donors with and without Alzheimer's disease (AD) were studied to evaluate the presence of amyloid in cortical cataract. We obtained 39 lenses from 21 postmortem donors with AD and 15 lenses from age-matched controls provided by the Banco de Ojos para Tratamientos de la Ceguera (Barcelona, Spain). For 17 donors, AD was clinically diagnosed by general physicians and for 4 donors the AD diagnosis was neuropathologically confirmed. Of the 21 donors with AD, 6 had pronounced bilateral cortical lens opacities and 15 only minor or no cortical opacities. As controls, 7 donors with pronounced cortical opacities and 8 donors with almost transparent lenses were selected. All lenses were photographed in a dark field stereomicroscope. Histological sections were analyzed using a standard and a more sensitive Congo red protocol, thioflavin staining and beta-amyloid immunohistochemistry. Brain tissue from two donors, one with cerebral amyloid angiopathy and another with advanced AD-related changes and one cornea with lattice dystrophy were used as positive controls for the staining techniques. Thioflavin, standard and modified Congo red staining were positive in the control brain tissues and in the dystrophic cornea. Beta-amyloid immunohistochemistry was positive in the brain tissues but not in the cornea sample. Lenses from control and AD donors were, without exception, negative after Congo red, thioflavin, and beta-amyloid immunohistochemical staining. The results of the positive control tissues correspond well with known observations in AD, amyloid angiopathy and corneas with lattice dystrophy. The absence of staining in AD and control lenses with the techniques employed lead us to conclude that there is no beta-amyloid in lenses from donors with AD or in control cortical cataracts. The inconsistency with previous studies of Goldstein et al. (2003) and Moncaster et al. (2010), both of which demonstrated positive Congo red, thioflavin, and beta

  12. (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G{sub 2}/M arrest, and triggers apoptosis in human leukemia HL-60 cells

    Energy Technology Data Exchange (ETDEWEB)

    Magalhães, Hemerson I.F. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Centro de Ciências da Saúde, Departamento de Ciências Farmacêuticas, Universidade Federal da Paraíba, João Pessoa, Paraíba (Brazil); Wilke, Diego V. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Bezerra, Daniel P., E-mail: danielpbezerra@gmail.com [Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia (Brazil); Cavalcanti, Bruno C. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Rotta, Rodrigo; Lima, Dênis P. de; Beatriz, Adilson [Centro de Ciências Exatas e Tecnológicas (Laboratório LP4), Universidade Federal do Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul (Brazil); Moraes, Manoel O.; Diniz-Filho, Jairo [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Pessoa, Claudia, E-mail: c_pessoa@yahoo.com [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil)

    2013-10-01

    (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC{sub 50} values in the nanomolar range. Cell cycle arrest in G{sub 2}/M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation, loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G{sub 2}/M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G{sub 2}/M phase of the cell cycle. • PHT induces caspase-dependent apoptosis.

  13. Neuropeptide processing in regional brain slices: Effect of conformation and sequence

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.W.; Bijl, W.A.; van Nispen, J.W.; Brendel, K.; Davis, T.P. (Univ. of Arizona, Tucson (USA))

    1990-05-01

    The central enzymatic stability of des-enkephalin-gamma-endorphin and its synthetic analogs (cycloN alpha 6, C delta 11)beta-endorphin-(6-17) and (Pro7, Lys(Ac)9)-beta-endorphin(6-17) was studied in vitro using a newly developed, regionally dissected rat brain slice, time course incubation procedure. Tissue slice viability was estimated as the ability of the brain slice to take up or release gamma-(3H)aminobutyric acid after high K+ stimulation. Results demonstrated stability of uptake/release up to 5 hr of incubation, suggesting tissue viability over this period. The estimated half-life of peptides based on the results obtained in our incubation protocol suggest that the peptides studied are metabolized at different rates in the individual brain regions tested. A good correlation exists between the high enzyme activity of neutral endopeptidase and the rapid degradation of des-enkephalin-gamma-endorphin and (cycloN alpha 6, C delata 11)beta-endorphin-(6-17) in caudate putamen. Proline substitution combined with lysine acetylation appears to improve resistance to enzymatic metabolism in caudate putamen and hypothalamus. However, cyclization of des-enkephalin-gamma-endorphin forming an amide bond between the alpha-NH2 of the N-terminal threonine and the gamma-COOH of glutamic acid did not improve peptide stability in any brain region tested. The present study has shown that the brain slice technique is a valid and unique approach to study neuropeptide metabolism in small, discrete regions of rat brain where peptides, peptidases and receptors are colocalized and that specific structural modifications can improve peptide stability.

  14. Effect of. beta. -endorphin on catecholamine levels in rat hypothalamus and cerebral cortex

    Energy Technology Data Exchange (ETDEWEB)

    Slavnov, V.N.; Valueva, G.V.; Markov, V.V.; Luchitskii, E.V.

    1986-10-01

    The authors studied the effect of beta-endorphin on catecholamine concentrations in the hypothalmus and cerebral cortex in rats, as a contribution to the explanation of the mechanism of action of this peptide on certain pituitary trophic functions. Concentrations of dopamine, noradrenalin, and adrenalin were determined by a radioenzymatic method. A Mark 3 scintillation system was used for radiometric investigation of the samples. The results of these experiments indicate that beta-endorphin has a marked effect on brain catecholamine levels mainly in the hypothalamus.

  15. Small heat shock protein HspB8: its distribution in Alzheimer's disease brains and its inhibition of amyloid-beta protein aggregation and cerebrovascular amyloid-beta toxicity.

    NARCIS (Netherlands)

    Wilhelmus, M.M.M.; Boelens, W.C.; Otte-Holler, I.; Kamps, B.; Kusters, B.; Maat-Schieman, M.L.; Waal, R.M.W. de; Verbeek, M.M.

    2006-01-01

    Alzheimer's disease (AD) is characterized by pathological lesions, such as senile plaques (SPs) and cerebral amyloid angiopathy (CAA), both predominantly consisting of a proteolytic cleavage product of the amyloid-beta precursor protein (APP), the amyloid-beta peptide (Abeta). CAA is also the major

  16. Sequence swapping does not result in conformation swapping for the beta4/beta5 and beta8/beta9 beta-hairpin turns in human acidic fibroblast growth factor.

    Science.gov (United States)

    Kim, Jaewon; Lee, Jihun; Brych, Stephen R; Logan, Timothy M; Blaber, Michael

    2005-02-01

    The beta-turn is the most common type of nonrepetitive structure in globular proteins, comprising ~25% of all residues; however, a detailed understanding of effects of specific residues upon beta-turn stability and conformation is lacking. Human acidic fibroblast growth factor (FGF-1) is a member of the beta-trefoil superfold and contains a total of five beta-hairpin structures (antiparallel beta-sheets connected by a reverse turn). beta-Turns related by the characteristic threefold structural symmetry of this superfold exhibit different primary structures, and in some cases, different secondary structures. As such, they represent a useful system with which to study the role that turn sequences play in determining structure, stability, and folding of the protein. Two turns related by the threefold structural symmetry, the beta4/beta5 and beta8/beta9 turns, were subjected to both sequence-swapping and poly-glycine substitution mutations, and the effects upon stability, folding, and structure were investigated. In the wild-type protein these turns are of identical length, but exhibit different conformations. These conformations were observed to be retained during sequence-swapping and glycine substitution mutagenesis. The results indicate that the beta-turn structure at these positions is not determined by the turn sequence. Structural analysis suggests that residues flanking the turn are a primary structural determinant of the conformation within the turn.

  17. Epithelial to mesenchymal transition-related proteins ZEB1, β-catenin, and β-tubulin-III in idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Chilosi, Marco; Caliò, Anna; Rossi, Andrea; Gilioli, Eliana; Pedica, Federica; Montagna, Licia; Pedron, Serena; Confalonieri, Marco; Doglioni, Claudio; Ziesche, Rolf; Grubinger, Markus; Mikulits, Wolfgang; Poletti, Venerino

    2017-01-01

    Epithelial to mesenchymal transition has been suggested as a relevant contributor to pulmonary fibrosis, but how and where this complex process is triggered in idiopathic pulmonary fibrosis is not fully understood. Beta-tubulin-III (Tubβ3), ZEB1, and β-catenin are partially under the negative control of miR-200, a family of micro-RNAs playing a major role in epithelial to mesenchymal transition, that are reduced in experimental lung fibrosis and idiopathic pulmonary fibrosis. We wonder whether in situ expression of these proteins is increased in idiopathic pulmonary fibrosis, to better understand the significance of miR-200 feedback loop and epithelial to mesenchymal transition. We investigated the immunohistochemical and immunofluorescent expression and precise location of ZEB1, Tubβ3, and β-catenin in tissue samples from 34 idiopathic pulmonary fibrosis cases and 21 controls (5 normal lungs and 16 other interstitial lung diseases). In 100% idiopathic pulmonary fibrosis samples, the three proteins were concurrently expressed in fibroblastic foci, as well in damaged epithelial cells overlying these lesions and in pericytes within neo-angiogenesis areas. These results were also confirmed by immunofluorescence assay. In controls the abnormal expression of the three proteins was absent or limited. This is the first study that relates concurrent expression of Tubβ3, ZEB1, and β-catenin to abnormal epithelial and myofibroblast differentiation in idiopathic pulmonary fibrosis, providing indirect but robust evidence of miR-200 deregulation and epithelial to mesenchymal transition activation in idiopathic pulmonary fibrosis. The abnormal expression and localization of these proteins in bronchiolar fibro-proliferative lesions are unique for idiopathic pulmonary fibrosis, and might represent a disease-specific marker in challenging lung biopsies.

  18. SNP analyses of growth factor genes EGF, TGF{beta}-1, and HGF reveal haplotypic association of EGF with autism

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Takao; Thanseem, Ismail; Kawai, Masayoshi; Sekine, Yoshimoto [Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Nakamura, Kazuhiko; Anitha, Ayyappan; Suda, Shiro [Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Yamada, Kazuo [Laboratory of Molecular Psychiatry, RIKEN Brain Science Institute, Saitama (Japan); Tsujii, Masatsugu [Faculty of Sociology, Chukyo University, Toyota, Aichi (Japan); [The Osaka-Hamamatsu Joint Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu (Japan); Iwayama, Yoshimi; Hattori, Eiji; Toyota, Tomoko; Yoshikawa, Takeo [Laboratory of Molecular Psychiatry, RIKEN Brain Science Institute, Saitama (Japan); Miyachi, Taishi; Tsuchiya, Kenji; Sugihara, Gen-ichi; Matsuzaki, Hideo [The Osaka-Hamamatsu Joint Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu (Japan); Iwata, Yasuhide; Suzuki, Katsuaki [Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Mori, Norio [Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); [The Osaka-Hamamatsu Joint Research Center for Child Mental Development, Graduate School of Medicine, Osaka University (Japan); Ouchi, Yasuomi [The Osaka-Hamamatsu Joint Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu (Japan); [The Positron Medical Center, Hamamatsu Medical Center, Hamamatsu (Japan); Sugiyama, Toshiro [Aichi Children' s Health and Medical Center, Obu, Aichi (Japan); Takei, Nori [The Osaka-Hamamatsu Joint Research Center for Child Mental Development, Hamamatsu University School of Medicine, Hamamatsu (Japan)

    2007-09-07

    Autism is a pervasive neurodevelopmental disorder diagnosed in early childhood. Growth factors have been found to play a key role in the cellular differentiation and proliferation of the central and peripheral nervous systems. Epidermal growth factor (EGF) is detected in several regions of the developing and adult brain, where, it enhances the differentiation, maturation, and survival of a variety of neurons. Transforming growth factor-{beta} (TGF{beta}) isoforms play an important role in neuronal survival, and the hepatocyte growth factor (HGF) has been shown to exhibit neurotrophic activity. We examined the association of EGF, TGF{beta}1, and HGF genes with autism, in a trio association study, using DNA samples from families recruited to the Autism Genetic Resource Exchange; 252 trios with a male offspring scored for autism were selected for the study. Transmission disequilibrium test revealed significant haplotypic association of EGF with autism. No significant SNP or haplotypic associations were observed for TGF{beta}1 or HGF. Given the role of EGF in brain and neuronal development, we suggest a possible role of EGF in the pathogenesis of autism.

  19. Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Damstrup, L; Rygaard, K; Spang-Thomsen, M

    1993-01-01

    A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis......(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell...... lines express TGF beta-receptors and also produce TGF beta mRNAs....

  20. Antiproliferative effects of TSA, PXD‑101 and MS‑275 in A2780 and MCF7 cells: Acetylated histone H4 and acetylated tubulin as markers for HDACi potency and selectivity.

    Science.gov (United States)

    Androutsopoulos, Vasilis P; Spandidos, Demetrios A

    2017-12-01

    Inhibition of histone deacetylase enzymes (HDACs) has been well documented as an attractive target for the development of chemotherapeutic drugs. The present study investigated the effects of two prototype hydroxamic acid HDAC inhibitors, namely Trichostatin A (TSA) and Belinostat (PXD‑101) and the benzamide Entinostat (MS‑275) in A2780 ovarian carcinoma and MCF7 breast adenocarcinoma cells. The three HDACi inhibited the proliferation of A2780 and MCF7 cells at comparable levels, below the µM range. Enzyme inhibition assays in a cell‑free system showed that TSA was the most potent inhibitor of total HDAC enzyme activity followed by PXD‑101 and MS‑275. Incubation of A2780 and MCF7 cells with the hydroxamates TSA and PXD‑101 for 24 h resulted in a dramatic increase of acetylated tubulin induction (up to 30‑fold for TSA). In contrast to acetylated tubulin, western blot analysis and flow cytometry indicated that the induction of acetylated histone H4 was considerably smaller. The benzamide MS‑275 exhibited nearly a 2‑fold induction of acetylated histone H4 and an even smaller induction of acetylated tubulin in A2780 and MCF7 cells. Taken together, these data suggest that although the three HDACi were equipotent in inhibiting proliferation of MCF7 and A2780 cells, only the benzamide MS‑275 did not induce acetylated tubulin expression, a marker of class IIb HDACs.

  1. Complexes of gamma-tubulin with nonreceptor protein tyrosine kinases Src and Fyn in differentiating P19 embryonal carcinoma cells

    Czech Academy of Sciences Publication Activity Database

    Kukharskyy, Vitaliy; Sulimenko, Vadym; Macůrek, Libor; Sulimenko, Tetyana; Dráberová, Eduarda; Dráber, Pavel

    2004-01-01

    Roč. 298, - (2004), s. 218-228 ISSN 0014-4827 R&D Projects: GA AV ČR IAA5052004; GA ČR GA304/00/0553; GA ČR GA304/04/1273; GA MŠk LN00A026 Keywords : gamma-tubulin * P19 cells * Fyn and Src kinase Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.007, year: 2004

  2. Entrainment of prefrontal beta oscillations induces an endogenous echo and impairs memory formation.

    Science.gov (United States)

    Hanslmayr, Simon; Matuschek, Jonas; Fellner, Marie-Christin

    2014-04-14

    Brain oscillations across all frequency bands play a key role for memory formation. Specifically, desynchronization of local neuronal assemblies in the left inferior prefrontal cortex (PFC) in the beta frequency (∼18 Hz) has been shown to be central for encoding of verbal memories. However, it remains elusive whether prefrontal beta desynchronization is causally relevant for memory formation and whether these endogenous beta oscillations can be entrained by external stimulation. By using combined EEG-TMS (transcranial magnetic stimulation), we here address these fundamental questions in human participants performing a word-list learning task. Confirming our predictions, memory encoding was selectively impaired when the left inferior frontal gyrus (IFG) was driven at beta (18.7 Hz) compared to stimulation at other frequencies (6.8 Hz and 10.7 Hz) and to ineffective sham stimulation (18.7 Hz). Furthermore, a sustained oscillatory "echo" in the left IFG, which outlasted the stimulation period by approximately 1.5 s, was observed solely after beta stimulation. The strength of this beta echo was related to memory impairment on a between-subjects level. These results show endogenous oscillatory entrainment effects and behavioral impairment selectively in beta frequency for stimulation of the left IFG, demonstrating an intimate causal relationship between prefrontal beta desynchronization and memory formation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Insulin inhibits amyloid beta-induced cell death in cultured human brain pericytes

    NARCIS (Netherlands)

    Rensink, Annemieke A M; Otte-Höller, Irene; de Boer, Roelie; Bosch, Remko R; ten Donkelaar, Hans J; de Waal, Robert M W; Verbeek, Marcel M; Kremer, Berry

    Amyloid-beta (Abeta) deposition in the cerebral arterial and capillary walls is one of the characteristics of Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis-Dutch type. In vitro, Abeta1-40, carrying the "Dutch" mutation (DAbeta1-40), induced reproducible degeneration of

  4. Disruption of Ttll5/stamp gene (tubulin tyrosine ligase-like protein 5/SRC-1 and TIF2-associated modulatory protein gene) in male mice causes sperm malformation and infertility.

    Science.gov (United States)

    Lee, Geun-Shik; He, Yuanzheng; Dougherty, Edward J; Jimenez-Movilla, Maria; Avella, Matteo; Grullon, Sean; Sharlin, David S; Guo, Chunhua; Blackford, John A; Awasthi, Smita; Zhang, Zhenhuan; Armstrong, Stephen P; London, Edra C; Chen, Weiping; Dean, Jurrien; Simons, S Stoney

    2013-05-24

    TTLL5/STAMP (tubulin tyrosine ligase-like family member 5) has multiple activities in cells. TTLL5 is one of 13 TTLLs, has polyglutamylation activity, augments the activity of p160 coactivators (SRC-1 and TIF2) in glucocorticoid receptor-regulated gene induction and repression, and displays steroid-independent growth activity with several cell types. To examine TTLL5/STAMP functions in whole animals, mice were prepared with an internal deletion that eliminated several activities of the Stamp gene. This mutation causes both reduced levels of STAMP mRNA and C-terminal truncation of STAMP protein. Homozygous targeted mutant (Stamp(tm/tm)) mice appear normal except for marked decreases in male fertility associated with defects in progressive sperm motility. Abnormal axonemal structures with loss of tubulin doublets occur in most Stamp(tm/tm) sperm tails in conjunction with substantial reduction in α-tubulin polyglutamylation, which closely correlates with the reduction in mutant STAMP mRNA. The axonemes in other structures appear unaffected. There is no obvious change in the organs for sperm development of WT versus Stamp(tm/tm) males despite the levels of WT STAMP mRNA in testes being 20-fold higher than in any other organ examined. This defect in male fertility is unrelated to other Ttll genes or 24 genes previously identified as important for sperm function. Thus, STAMP appears to participate in a unique, tissue-selective TTLL-mediated pathway for α-tubulin polyglutamylation that is required for sperm maturation and motility and may be relevant for male fertility.

  5. Disruption of Ttll5/Stamp Gene (Tubulin Tyrosine Ligase-like Protein 5/SRC-1 and TIF2-associated Modulatory Protein Gene) in Male Mice Causes Sperm Malformation and Infertility*

    Science.gov (United States)

    Lee, Geun-Shik; He, Yuanzheng; Dougherty, Edward J.; Jimenez-Movilla, Maria; Avella, Matteo; Grullon, Sean; Sharlin, David S.; Guo, Chunhua; Blackford, John A.; Awasthi, Smita; Zhang, Zhenhuan; Armstrong, Stephen P.; London, Edra C.; Chen, Weiping; Dean, Jurrien; Simons, S. Stoney

    2013-01-01

    TTLL5/STAMP (tubulin tyrosine ligase-like family member 5) has multiple activities in cells. TTLL5 is one of 13 TTLLs, has polyglutamylation activity, augments the activity of p160 coactivators (SRC-1 and TIF2) in glucocorticoid receptor-regulated gene induction and repression, and displays steroid-independent growth activity with several cell types. To examine TTLL5/STAMP functions in whole animals, mice were prepared with an internal deletion that eliminated several activities of the Stamp gene. This mutation causes both reduced levels of STAMP mRNA and C-terminal truncation of STAMP protein. Homozygous targeted mutant (Stamptm/tm) mice appear normal except for marked decreases in male fertility associated with defects in progressive sperm motility. Abnormal axonemal structures with loss of tubulin doublets occur in most Stamptm/tm sperm tails in conjunction with substantial reduction in α-tubulin polyglutamylation, which closely correlates with the reduction in mutant STAMP mRNA. The axonemes in other structures appear unaffected. There is no obvious change in the organs for sperm development of WT versus Stamptm/tm males despite the levels of WT STAMP mRNA in testes being 20-fold higher than in any other organ examined. This defect in male fertility is unrelated to other Ttll genes or 24 genes previously identified as important for sperm function. Thus, STAMP appears to participate in a unique, tissue-selective TTLL-mediated pathway for α-tubulin polyglutamylation that is required for sperm maturation and motility and may be relevant for male fertility. PMID:23558686

  6. Alzheimer's disease amyloid-beta links lens and brain pathology in Down syndrome.

    Directory of Open Access Journals (Sweden)

    Juliet A Moncaster

    2010-05-01

    Full Text Available Down syndrome (DS, trisomy 21 is the most common chromosomal disorder and the leading genetic cause of intellectual disability in humans. In DS, triplication of chromosome 21 invariably includes the APP gene (21q21 encoding the Alzheimer's disease (AD amyloid precursor protein (APP. Triplication of the APP gene accelerates APP expression leading to cerebral accumulation of APP-derived amyloid-beta peptides (Abeta, early-onset AD neuropathology, and age-dependent cognitive sequelae. The DS phenotype complex also includes distinctive early-onset cerulean cataracts of unknown etiology. Previously, we reported increased Abeta accumulation, co-localizing amyloid pathology, and disease-linked supranuclear cataracts in the ocular lenses of subjects with AD. Here, we investigate the hypothesis that related AD-linked Abeta pathology underlies the distinctive lens phenotype associated with DS. Ophthalmological examinations of DS subjects were correlated with phenotypic, histochemical, and biochemical analyses of lenses obtained from DS, AD, and normal control subjects. Evaluation of DS lenses revealed a characteristic pattern of supranuclear opacification accompanied by accelerated supranuclear Abeta accumulation, co-localizing amyloid pathology, and fiber cell cytoplasmic Abeta aggregates (approximately 5 to 50 nm identical to the lens pathology identified in AD. Peptide sequencing, immunoblot analysis, and ELISA confirmed the identity and increased accumulation of Abeta in DS lenses. Incubation of synthetic Abeta with human lens protein promoted protein aggregation, amyloid formation, and light scattering that recapitulated the molecular pathology and clinical features observed in DS lenses. These results establish the genetic etiology of the distinctive lens phenotype in DS and identify the molecular origin and pathogenic mechanism by which lens pathology is expressed in this common chromosomal disorder. Moreover, these findings confirm increased Abeta

  7. Effects of dietary alpha-tocopherol and beta-carotene on lipid peroxidation induced by methyl mercuric chloride in mice

    DEFF Research Database (Denmark)

    Andersen, H R; Andersen, O

    1993-01-01

    -Tocopherol did not protect against CH3HgCl induced lipid peroxidation in the brain. Excess dietary beta-carotene further enhanced CH3HgCl induced lipid peroxidation in liver, kidney and brain. CH3HgCl significantly decreased the activity of total glutathione peroxidase (T-GSH-Px) and Se-dependent glutathione...

  8. Beta-energy averaging and beta spectra

    International Nuclear Information System (INIS)

    Stamatelatos, M.G.; England, T.R.

    1976-07-01

    A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

  9. Interleukin-1 receptors in mouse brain: Characterization and neuronal localization

    International Nuclear Information System (INIS)

    Takao, T.; Tracey, D.E.; Mitchell, W.M.; De Souza, E.B.

    1990-01-01

    The cytokine interleukin-1 (IL-1) has a variety of effects in brain, including induction of fever, alteration of slow wave sleep, and alteration of neuroendocrine activity. To examine the potential sites of action of IL-1 in brain, we used iodine-125-labeled recombinant human interleukin-1 [( 125I]IL-1) to identify and characterize IL-1 receptors in crude membrane preparations of mouse (C57BL/6) hippocampus and to study the distribution of IL-1-binding sites in brain using autoradiography. In preliminary homogenate binding and autoradiographic studies, [125I]IL-1 alpha showed significantly higher specific binding than [125I]IL-1 beta. Thus, [125I]IL-1 alpha was used in all subsequent assays. The binding of [125I]IL-1 alpha was linear over a broad range of membrane protein concentrations, saturable, reversible, and of high affinity, with an equilibrium dissociation constant value of 114 +/- 35 pM and a maximum number of binding sites of 2.5 +/- 0.4 fmol/mg protein. In competition studies, recombinant human IL-1 alpha, recombinant human IL-1 beta, and a weak IL-1 beta analog. IL-1 beta +, inhibited [125I]IL-1 alpha binding to mouse hippocampus in parallel with their relative bioactivities in the T-cell comitogenesis assay, with inhibitory binding affinity constants of 55 +/- 18, 76 +/- 20, and 2940 +/- 742 pM, respectively; rat/human CRF and human tumor necrosis factor showed no effect on [125I]IL-1 alpha binding. Autoradiographic localization studies revealed very low densities of [125I]IL-1 alpha-binding sites throughout the brain, with highest densities present in the molecular and granular layers of the dentate gyrus of the hippocampus and in the choroid plexus. Quinolinic acid lesion studies demonstrated that the [125I]IL-1 alpha-binding sites in the hippocampus were localized to intrinsic neurons

  10. Evidence for a new lineage of primary ambrosia fungi in Geosmithia Pitt (Ascomycota: Hypocreales)

    Czech Academy of Sciences Publication Activity Database

    Kolařík, Miroslav; Kirkendall, L.

    2010-01-01

    Roč. 114, č. 8 (2010), s. 676-689 ISSN 1878-6146 Institutional research plan: CEZ:AV0Z50200510 Keywords : beta-Tubulin * Cnesinus lecontei * Eupagiocerus dentipes Subject RIV: EE - Microbiology, Virology

  11. Altered brain rhythms and functional network disruptions involved in patients with generalized fixation-off epilepsy

    OpenAIRE

    Solana Sánchez, Ana Beatriz; Hernández Tamames, J.A.; Molina, E.; Martínez, K.; Pineda Pardo, José Ángel; Bruña Fernandez, Ricardo; Toledano, Rafael; San Antonio-Arce, Victoria; Garcia Morales, Irene; Gil Nagel, Antonio; Alfayate, E.; Álvarez Linera, Juan; Pozo Guerrero, Francisco del

    2012-01-01

    Fixation-off sensitivity (FOS) denotes the forms of epilepsy elicited by elimination of fixation. FOS-IGE patients are rare cases [1]. In a previous work [2] we showed that two FOS-IGE patients had different altered EEG rhythms when closing eyes; only beta band was altered in patient 1 while theta, alpha and beta were altered in patient 2. In the present work, we explain the relationship between the altered brain rhythms in these patients and the disruption in functional brain net...

  12. Frontal theta and beta synchronizations for monetary reward increase visual working memory capacity.

    Science.gov (United States)

    Kawasaki, Masahiro; Yamaguchi, Yoko

    2013-06-01

    Visual working memory (VWM) capacity is affected by motivational influences; however, little is known about how reward-related brain activities facilitate the VWM systems. To investigate the dynamic relationship between VWM- and reward-related brain activities, we conducted time-frequency analyses using electroencephalograph (EEG) data obtained during a monetary-incentive delayed-response task that required participants to memorize the position of colored disks. In case of a correct answer, participants received a monetary reward (0, 10 or 50 Japanese yen) announced at the beginning of each trial. Behavioral results showed that VWM capacity under high-reward condition significantly increased compared with that under low- or no-reward condition. EEG results showed that frontal theta (6 Hz) amplitudes enhanced during delay periods and positively correlated with VWM capacity, indicating involvement of theta local synchronizations in VWM. Moreover, frontal beta activities (24 Hz) were identified as reward-related activities, because delay-period amplitudes correlated with increases in VWM capacity between high-reward and no-reward conditions. Interestingly, cross-frequency couplings between frontal theta and beta phases were observed only under high-reward conditions. These findings suggest that the functional dynamic linking between VWM-related theta and reward-related beta activities on the frontal regions plays an integral role in facilitating increases in VWM capacity.

  13. Activities of UDP-glucuronyltransferase, beta-glucuronidase and deiodinase types I and II in hyper- and hypothyroid rats

    OpenAIRE

    Heide, S.M. van der; Joosten, B.H.G.M.; Everts, M.E.; Klaren, P.H.M.

    2004-01-01

    We have investigated the hypothesis that uridine 5'-diphosphate (UDP)-glucuronyltransferases (UGTs) and beta-glucuronidase are jointly involved in a mechanism for the storage and mobilization of iodothyronine metabolites in liver, kidney, heart and brain. Specifically, we predicted UGT activities to decrease and increase respectively, and beta-glucuronidase activity to increase and decrease respectively in hypo- and hyperthyroidism. To this end we have studied the effects of thyroid status on...

  14. Speculative Betas

    OpenAIRE

    Harrison Hong; David Sraer

    2012-01-01

    We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r...

  15. Labelling of. beta. -endorphin (. beta. -END) and. beta. -lipotropin (. beta. -LPH) by /sup 125/I

    Energy Technology Data Exchange (ETDEWEB)

    Deby-Dupont, G.; Joris, J.; Franchimont, P. (Universite de Liege (Belgique)); Reuter, A.M.; Vrindts-Gevaert, Y. (Institut des Radioelements, Fleurus (Belgique))

    1983-01-01

    5 ..mu..g of human ..beta..-endorphin were labelled with 2 mCi /sup 125/I by the chloramine T technique. After two gel filtrations on Sephadex G-15 and on Sephadex G-50 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer was obtained with a specific activity about 150 ..mu..Ci/..mu..g.Kept at + 4/sup 0/C, the tracer remained utilizable for 30 days without loss of immunoreactivity. The labelling with lactoperoxydase and the use of another gel filtration method (filtration on Aca 202) gave a /sup 125/I ..beta..-END tracer with the same immunoreactivity. The binding of this tracer to the antibody of an anti-..beta..-END antiserum diluted at 1/8000 was 32% with a non specific binding of 2%. 5 ..mu..g of human ..beta..-lipotropin were labelled with 0.5 mCi /sup 125/I by the lactoperoxydase method. After two gel filtrations on Sephadex G-25 and on Sephadex G-75 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer with a specific activity of 140 ..mu..Ci/..mu..g was obtained. It remained utilizable for 30 days when kept at + 4/sup 0/C. Gel filtration on Aca 202 did not give good purification, while gel filtration on Aca 54 was good but slower than on Sephadex G-75. The binding to antibody in absence of unlabelled ..beta..-LPH was 32% for an anti-..beta..-LPH antiserum diluted at 1/4000. The non specific binding was 2.5%.

  16. Increased beta rhythm as an indicator of inhibitory mechanisms in tourette syndrome

    DEFF Research Database (Denmark)

    Niccolai, Valentina; van Dijk, Hanneke; Franzkowiak, Stephanie

    2016-01-01

    BACKGROUND: Inhibitory oscillatory mechanisms subserving tic compensation have been put forward in Tourette syndrome. Modulation of the beta rhythm (15-25 Hz) as the well-established oscillatory movement execution-inhibition indicator was tested during a cognitive-motor task in patients with Tour......BACKGROUND: Inhibitory oscillatory mechanisms subserving tic compensation have been put forward in Tourette syndrome. Modulation of the beta rhythm (15-25 Hz) as the well-established oscillatory movement execution-inhibition indicator was tested during a cognitive-motor task in patients...... in parieto-occipital brain regions contralaterally to the response hand. Average beta power and power gain correlated negatively with tic severity. CONCLUSIONS: Increased motor inhibitory as well as visuomotor attentional processes are likely to subserve tic compensation. Correlational results suggest...... that stronger inhibitory compensation accompanies less tic severity. © 2016 International Parkinson and Movement Disorder Society....

  17. Alternative-splicing in the exon-10 region of GABA(A receptor beta(2 subunit gene: relationships between novel isoforms and psychotic disorders.

    Directory of Open Access Journals (Sweden)

    Cunyou Zhao

    Full Text Available BACKGROUND: Non-coding single nucleotide polymorphisms (SNPs in GABRB2, the gene for beta(2-subunit of gamma-aminobutyric acid type A (GABA(A receptor, have been associated with schizophrenia (SCZ and quantitatively correlated to mRNA expression and alternative splicing. METHODS AND FINDINGS: Expression of the Exon 10 region of GABRB2 from minigene constructs revealed this region to be an "alternative splicing hotspot" that readily gave rise to differently spliced isoforms depending on intron sequences. This led to a search in human brain cDNA libraries, and the discovery of two novel isoforms, beta(2S1 and beta(2S2, bearing variations in the neighborhood of Exon-10. Quantitative real-time PCR analysis of postmortem brain samples showed increased beta(2S1 expression and decreased beta(2S2 expression in both SCZ and bipolar disorder (BPD compared to controls. Disease-control differences were significantly correlated with SNP rs187269 in BPD males for both beta(2S1 and beta(2S2 expressions, and significantly correlated with SNPs rs2546620 and rs187269 in SCZ males for beta(2S2 expression. Moreover, site-directed mutagenesis indicated that Thr(365, a potential phosphorylation site in Exon-10, played a key role in determining the time profile of the ATP-dependent electrophysiological current run-down. CONCLUSION: This study therefore provided experimental evidence for the importance of non-coding sequences in the Exon-10 region in GABRB2 with respect to beta(2-subunit splicing diversity and the etiologies of SCZ and BPD.

  18. Sailing to and Docking at the Immune Synapse: Role of Tubulin Dynamics and Molecular Motors

    Directory of Open Access Journals (Sweden)

    Noa Beatriz Martín-Cófreces

    2018-05-01

    Full Text Available The different cytoskeleton systems and their connecting molecular motors move vesicles and intracellular organelles to shape cells. Polarized cells with specialized functions display an exquisite spatio-temporal regulation of both cytoskeletal and organelle arrangements that support their specific tasks. In particular, T cells rapidly change their shape and cellular function through the establishment of cell surface and intracellular polarity in response to a variety of cues. This review focuses on the contribution of the microtubule-based dynein/dynactin motor complex, the tubulin and actin cytoskeletons, and different organelles to the formation of the antigen-driven immune synapse.

  19. Amyloid beta(1-40-induced astrogliosis and the effect of genistein treatment in rat: a three-dimensional confocal morphometric and proteomic study.

    Directory of Open Access Journals (Sweden)

    Maryam Bagheri

    Full Text Available Astrocytes are highly involved in regulation and homeostasis of the extracellular environment in the healthy brain. In pathological conditions, these cells play a major role in the inflammatory response seen in CNS tissues, which is called reactive astrogliosis and includes hypertrophy and proliferation of astrocytes. Here, we performed 3D confocal microscopy to evaluate the morphological response of reactive astrocytes positive for glial fibrillary acidic protein (GFAP in rats, to the presence of Aβ(1-40 in the rat brain before and after treatment with genistein. In 50 astrocytes per animal, we measured the volume and surface area for the nucleus, cell body, the entire cell, the tissue covered by single astrocytes and quantified the number and length of branches, the density of the astrocytes and the intensity of GFAP immunoreactivity. Injecting Aβ(1-40 into the brain of rats caused astrogliosis indicated by increased values for all measured parameters. Mass spectrometric analysis of hippocampal tissue in Aβ(1-40-injected brain showed decreased amounts of tubulins, enolases and myelin basic protein, and increased amounts of dihydropyrimidinase-related protein 2. In Aβ(1-40-injected rats pretreated with genistein, GFAP intensity was decreased to the sham-operated group level, and Aβ(1-40-induced astrogliosis was significantly ameliorated.

  20. Identification of endogenous opioid receptor components in rat brain using a monoclonal antibody

    Energy Technology Data Exchange (ETDEWEB)

    Bero, L.A.; Roy, S.; Lee, N.M.

    1988-11-01

    A monoclonal antibody generated against the tertiary structure of a partially purified opioid binding protein was used to probe the structure of the dynorphin and beta-endorphin receptors. The Fab fragment 3B4F11 inhibited completely the binding of 125I-beta-endorphin and (3H)dynorphin to rat brain P2 membranes with IC50 values of 26 ng/ml and 40 ng/ml, respectively. To explore further the interaction of 3B4F11 with the beta-endorphin receptor, the effect of the Fab fragment on 125I-beta-endorphin cross-linking to rat brain membranes was examined. 125I-beta-endorphin was covalently bound to three major species of approximate molecular weights 108,000, 73,000, and 49,000. The delta-selective ligand D-Pen2, D-pen5enkephalin was least effective at inhibiting the cross-linking of beta-endorphin, whereas the micro-selective ligand Tyr-D-Ala-Gly-NMe-Phe-Gly-ol and kappa-selective ligand U50488 inhibited beta-endorphin cross-linking to the 108,000 and 73,000 Da species. Both 3B4F11 and beta-endorphin prevented the covalent binding of 125I-beta-endorphin to all three labeled species. These findings suggest that micro and kappa receptor types might have some structural similarities, whereas the delta receptor type might differ in molecular size. In addition, the micro, kappa, and delta ligands might have different primary sequences, whereas their tertiary structures might share regions of molecular homology with all three receptor constituents labeled by 125I-beta-endorphin. 3B4F11 will be a valuable tool for the purification and isolation of the several components of the beta-endorphin receptor complex.

  1. [Research of anti-aging mechanism of ginsenoside Rg1 on brain].

    Science.gov (United States)

    Li, Cheng-peng; Zhang, Meng-si; Liu, Jun; Geng, Shan; Li, Jing; Zhu, Jia-hong; Zhang, Yan-yan; Jia, Yan-yan; Wang, Lu; Wang, Shun-he; Wang, Ya-ping

    2014-11-01

    Neurodegenerative disease is common and frequently occurs in elderly patients. Previous studies have shown that ginsenoside Rg1 was able to inhibit senescent of brain, but the mechanism on the brain during the treatment remains elucidated. To study the mechanism of ginsenoside Rg1 in the process of anti-aging of brain, forty male SD rats were randomly divided into normal group, Rg1 normal group, brain aging model group and Rg1 brain aging model group, each group with 10 rats (brain aging model group: subcutaneous injection of D-galactose (120 mg kg(-1)), qd for 42 consecutive days; Rg1 brain aging model group: while copying the same test as that of brain aging model group, begin intraperitoneal injection of ginsenosides Rg1 (20 mg x kg(-1)) qd for 27 d from 16 d. Rg1 normal group: subcutaneous injection of the same amount of saline; begin intraperitoneal injection of ginsenosides Rg1 (20 mg x kg(-1)) qd for 27 d from 16 d. Normal: injected with an equal volume of saline within the same time. Perform the related experiment on the second day after finishing copying the model or the completion of the first two days of drug injections). Learning and memory abilities were measured by Morris water maze. The number of senescent cells was detected by SA-beta-Gal staining while the level of IL-1 and IL-6 proinflammatory cytokines in hippocampus were detected by ELISA. The activities of SOD, contents of GSH in hippo- campus were quantified by chromatometry. The change of telomerase activities and telomerase length were performed by TRAP-PCR and southern blotting assay, respectively. It is pointed that, in brain aging model group, the spatial learning and memory capacities were weaken, SA-beta-Gal positive granules increased in section of brain tissue, the activity of antioxidant enzyme SOD and the contents of GSH decreased in hippocampus, the level of IL-1 and IL-6 increased in hippocampus, while the length of telomere and the activity of telomerase decreased in hippocampus

  2. Comparison of Trazodone, Diazepame and Dibenzepine Influences on Rat Brain Beta-Endorphins Content

    Directory of Open Access Journals (Sweden)

    Radivoj Jadrić

    2007-08-01

    Full Text Available The aim of our study was to establish the extent of influence of different psychotropic drugs to brain β-endorphins in experimental animals. The study was performed on albino Wistar rats (weight 250 g, treated with different psychoactive drugs. RIA technique was employed for quantification of brain β-endorphins. Brain β-endorphins were higher in experiment group treated with trazodone (929 pg/g ± 44,43; X±SD, and dibenzepine (906,63 pg/g ± 74,06, yet with lower brain content in rats treated with diazepame (841,55 pg/g ± 68,47, compared to brain β-endorphins content of control group treated with saline solution (0,95% NaCl (873,5 pg/g ± 44,89. Significant differences were obtained comparing brain β-endorphins of trazodone vs. diaze-pame treated animals, with diazepame group having lower values (p<0,02. This study showed differences in changes of rat brain β-endorphins contents when different psy-choactive drugs are used. Therefore, we consider that β-endorphins could be used for evaluation of effects of psychoactive drugs, as a useful parameter in therapy with these psycho pharmaceuticals.

  3. Distinct spatio-temporal profiles of beta-oscillations within visual and sensorimotor areas during action recognition as revealed by MEG.

    Science.gov (United States)

    Pavlidou, Anastasia; Schnitzler, Alfons; Lange, Joachim

    2014-05-01

    The neural correlates of action recognition have been widely studied in visual and sensorimotor areas of the human brain. However, the role of neuronal oscillations involved during the process of action recognition remains unclear. Here, we were interested in how the plausibility of an action modulates neuronal oscillations in visual and sensorimotor areas. Subjects viewed point-light displays (PLDs) of biomechanically plausible and implausible versions of the same actions. Using magnetoencephalography (MEG), we examined dynamic changes of oscillatory activity during these action recognition processes. While both actions elicited oscillatory activity in visual and sensorimotor areas in several frequency bands, a significant difference was confined to the beta-band (∼20 Hz). An increase of power for plausible actions was observed in left temporal, parieto-occipital and sensorimotor areas of the brain, in the beta-band in successive order between 1650 and 2650 msec. These distinct spatio-temporal beta-band profiles suggest that the action recognition process is modulated by the degree of biomechanical plausibility of the action, and that spectral power in the beta-band may provide a functional interaction between visual and sensorimotor areas in humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Transthyretin protects against A-beta peptide toxicity by proteolytic cleavage of the peptide: a mechanism sensitive to the Kunitz protease inhibitor.

    Directory of Open Access Journals (Sweden)

    Rita Costa

    Full Text Available Alzheimer's disease (AD is a neurodegenerative disorder characterized by the deposition of amyloid beta-peptide (A-Beta in the brain. Transthyretin (TTR is a tetrameric protein of about 55 kDa mainly produced in the liver and choroid plexus of the brain. The known physiological functions of TTR are the transport of thyroid hormone T(4 and retinol, through binding to the retinol binding protein. TTR has also been established as a cryptic protease able to cleave ApoA-I in vitro. It has been described that TTR is involved in preventing A-Beta fibrilization, both by inhibiting and disrupting A-Beta fibrils, with consequent abrogation of toxicity. We further characterized the nature of the TTR/A-Beta interaction and found that TTR, both recombinant or isolated from human sera, was able to proteolytically process A-Beta, cleaving the peptide after aminoacid residues 1, 2, 3, 10, 13, 14,16, 19 and 27, as determined by mass spectrometry, and reversed phase chromatography followed by N-terminal sequencing. A-Beta peptides (1-14 and (15-42 showed lower amyloidogenic potential than the full length counterpart, as assessed by thioflavin binding assay and ultrastructural analysis by transmission electron microscopy. A-Beta cleavage by TTR was inhibited in the presence of an alphaAPP peptide containing the Kunitz Protease Inhibitor (KPI domain but not in the presence of the secreted alphaAPP derived from the APP isoform 695 without the KPI domain. TTR was also able to degrade aggregated forms of A-Beta peptide. Our results confirmed TTR as a protective molecule in AD, and prompted A-Beta proteolysis by TTR as a protective mechanism in this disease. TTR may prove to be a useful therapeutic agent for preventing or retarding the cerebral amyloid plaque formation implicated in AD pathology.

  5. Synthesis and Antitumor Molecular Mechanism of Agents Based on Amino 2-(3′,4′,5′-Trimethoxybenzoyl)-benzo[b]furan: Inhibition of Tubulin and Induction of Apoptosis

    Science.gov (United States)

    Baraldi, Pier Giovanni; Lopez-Cara, Carlota; Cruz-Lopez, Olga; Carrion, Maria Dora; Salvador, Maria Kimatrai; Bermejo, Jaime; Estévez, Sara; Estévez, Francisco; Balzarini, Jan; Brancale, Andrea; Ricci, Antonio; Chen, Longchuan; Kim, Jae Gwan; Hamel, Ernest

    2011-01-01

    Induction of apoptosis is a promising strategy that could lead to the discovery of new molecules active in cancer chemotherapy. This property is generally observed when cells are treated with agents that target microtubules, dynamic structures that play a crucial role in cell division. Small molecules such as benzo[b]furans are attractive as inhibitors of tubulin polymerization. A new class of inhibitors of tubulin polymerization based on the 2-(3′,4′,5′-trimethoxybenzoyl)benzo[b]furan molecular skeleton, with the amino group placed at different positions on the benzene ring, were synthesized and evaluated for antiproliferative activity, inhibition of tubulin polymerization, and cell-cycle effects. The methoxy substitution pattern on the benzene portion of the benzo[b]furan moiety played an important role in affecting antiproliferative activity. In the series of 5-amino derivatives, the greatest inhibition of cell growth oc curred if the methoxy substituent is placed at the C6 position, whereas C7 substitution decreases potency. The most promising compound in this series is 2-(3′,4′,5′-trimethoxybenzoyl)-3-methyl-5-amino-6-methoxybenzo[b]furan (3h), which inhibits cancer cell growth at nanomolar concentrations (IC50=16–24 nm), and interacts strongly with tubulin by binding to the colchicine site. Sub-G1 apoptotic cells in cultures of HL-60 and U937 cells were observed by flow cytometric analysis after treatment with 3h in a concentration-dependent manner. We also show that compound 3h induces apoptosis by activation of caspase-3, -8, and -9, and this is associated with cytochrome c release from mitochondria. The introduction of an α-bromoacryloyl group increased antiproliferative activity with respect to the parent amino derivatives. PMID:21805646

  6. CRMP5 regulates generation and survival of newborn neurons in olfactory and hippocampal neurogenic areas of the adult mouse brain.

    Directory of Open Access Journals (Sweden)

    Alexandra Veyrac

    Full Text Available The Collapsin Response Mediator Proteins (CRMPS are highly expressed in the developing brain, and in adult brain areas that retain neurogenesis, ie: the olfactory bulb (OB and the dentate gyrus (DG. During brain development, CRMPs are essentially involved in signaling of axon guidance and neurite outgrowth, but their functions in the adult brain remain largely unknown. CRMP5 has been initially identified as the target of auto-antibodies involved in paraneoplasic neurological diseases and further implicated in a neurite outgrowth inhibition mediated by tubulin binding. Interestingly, CRMP5 is also highly expressed in adult brain neurogenic areas where its functions have not yet been elucidated. Here we observed in both neurogenic areas of the adult mouse brain that CRMP5 was present in proliferating and post-mitotic neuroblasts, while they migrate and differentiate into mature neurons. In CRMP5(-/- mice, the lack of CRMP5 resulted in a significant increase of proliferation and neurogenesis, but also in an excess of apoptotic death of granule cells in the OB and DG. These findings provide the first evidence that CRMP5 is involved in the generation and survival of newly generated neurons in areas of the adult brain with a high level of activity-dependent neuronal plasticity.

  7. Perimovement decrease of alpha/beta oscillations in the human nucleus accumbens.

    Science.gov (United States)

    Stenner, Max-Philipp; Dürschmid, Stefan; Rutledge, Robb B; Zaehle, Tino; Schmitt, Friedhelm C; Kaufmann, Jörn; Voges, Jürgen; Heinze, Hans-Jochen; Dolan, Raymond J; Schoenfeld, Mircea Ariel

    2016-10-01

    The human nucleus accumbens is thought to play an important role in guiding future action selection via an evaluation of current action outcomes. Here we provide electrophysiological evidence for a more direct, i.e., online, role during action preparation. We recorded local field potentials from the nucleus accumbens in patients with epilepsy undergoing surgery for deep brain stimulation. We found a consistent decrease in the power of alpha/beta oscillations (10-30 Hz) before and around the time of movements. This perimovement alpha/beta desynchronization was observed in seven of eight patients and was present both before instructed movements in a serial reaction time task as well as before self-paced, deliberate choices in a decision making task. A similar beta decrease over sensorimotor cortex and in the subthalamic nucleus has been directly related to movement preparation and execution. Our results support the idea of a direct role of the human nucleus accumbens in action preparation and execution. Copyright © 2016 the American Physiological Society.

  8. Synthesis, radiolabeling and baboon SPECT imaging of 2{beta}-carbomethoxy-3{beta}-(3'-[{sup 123}I]iodophenyl)tropane ([{sup 123}I]YP256) as a serotonin transporter radiotracer

    Energy Technology Data Exchange (ETDEWEB)

    Bois, Frederic; Baldwin, Ronald M.; Amici, Louis; Al-Tikriti, Mohammed S. [Yale University, School of Medicine, VA Connecticut HCS (116A2), West Haven, CT 06516 (United States); Kula, Nora; Baldessarini, Ross [Department of Psychiatry and Neuroscience Program, Harvard Medical School, Mailman Research Center McLean Division of Massachusetts General Hospital, Belmont, MA 02478 (United States); Innis, Robert B.; Staley, Julie K. [Yale University, School of Medicine, VA Connecticut HCS (116A2), West Haven, CT 06516 (United States); Tamagnan, Gilles D. [Yale University, School of Medicine, VA Connecticut HCS (116A2), West Haven, CT 06516 (United States); Institute for Neurodegenerative Disorders, New Haven, CT 06510 (United States)], E-mail: gtamagnan@indd.org

    2008-01-15

    To develop a potential SPECT probe to evaluate the integrity of the serotoninergic system (5-HTT) whose dysfunction is linked to several disease conditions such as Parkinson's disease, Alzheimer's disease and depression, we report the synthesis, radiolabeling and in vivo baboon imaging of 2{beta}-carbomethoxy-3{beta}-(3'-[{sup 123}I]iodophenyl) tropane (YP256, ). The radiolabeling was performed by iododestannylation using sodium [{sup 123}I]iodide and peracetic acid. Although the ligand displayed high selectivity for 5-HTT over dopamine transporter in vitro, SPECT imaging in baboons did not reveal selective 5-HTT accumulation in brain in vivo.

  9. Sodium Channel Voltage-Gated Beta 2 Plays a Vital Role in Brain Aging Associated with Synaptic Plasticity and Expression of COX5A and FGF-2.

    Science.gov (United States)

    XiYang, Yan-Bin; Wang, You-Cui; Zhao, Ya; Ru, Jin; Lu, Bing-Tuan; Zhang, Yue-Ning; Wang, Nai-Chao; Hu, Wei-Yan; Liu, Jia; Yang, Jin-Wei; Wang, Zhao-Jun; Hao, Chun-Guang; Feng, Zhong-Tang; Xiao, Zhi-Cheng; Dong, Wei; Quan, Xiong-Zhi; Zhang, Lian-Feng; Wang, Ting-Hua

    2016-03-01

    The role of sodium channel voltage-gated beta 2 (SCN2B) in brain aging is largely unknown. The present study was therefore designed to determine the role of SCN2B in brain aging by using the senescence-accelerated mice prone 8 (SAMP8), a brain senescence-accelerated animal model, together with the SCN2B transgenic mice. The results showed that SAMP8 exhibited impaired learning and memory functions, assessed by the Morris water maze test, as early as 8 months of age. The messenger RNA (mRNA) and protein expressions of SCN2B were also upregulated in the prefrontal cortex at this age. Treatment with traditional Chinese anti-aging medicine Xueshuangtong (Panax notoginseng saponins, PNS) significantly reversed the SCN2B expressions in the prefrontal cortex, resulting in improved learning and memory. Moreover, SCN2B knockdown transgenic mice were generated and bred to determine the roles of SCN2B in brain senescence. A reduction in the SCN2B level by 60.68% resulted in improvement in the hippocampus-dependent spatial recognition memory and long-term potential (LTP) slope of field excitatory postsynaptic potential (fEPSP), followed by an upregulation of COX5A mRNA levels and downregulation of fibroblast growth factor-2 (FGF-2) mRNA expression. Together, the present findings indicated that SCN2B could play an important role in the aging-related cognitive deterioration, which is associated with the regulations of COX5A and FGF-2. These findings could provide the potential strategy of candidate target to develop antisenescence drugs for the treatment of brain aging.

  10. Effects of Acanthopanax senticosus on Brain Injury Induced by Simulated Spatial Radiation in Mouse Model Based on Pharmacokinetics and Comparative Proteomics

    Directory of Open Access Journals (Sweden)

    Yingyu Zhou

    2018-01-01

    Full Text Available The active compounds in Acanthopanax senticosus (AS have different pharmacokinetic characteristics in mouse models. Cmax and AUC of Acanthopanax senticosus polysaccharides (ASPS were significantly reduced in radiation-injured mice, suggesting that the blood flow of mouse was blocked or slowed, due to the pathological state of ischemia and hypoxia, which are caused by radiation. In contrast, the ability of various metabolizing enzymes to inactivate, capacity of biofilm transport decrease, and lessening of renal blood flow accounts for radiation, resulting in the accumulation of syringin and eleutheroside E in the irradiated mouse. Therefore, there were higher pharmacokinetic parameters—AUC, MRT, and t1/2 of the two compounds in radiation-injured mouse, when compared with normal mouse. In order to investigate the intrinsic mechanism of AS on radiation injury, AS extract’s protective effects on brain, the main part of mouse that suffered from radiation, were explored. The function of AS extract in repressing expression changes of radiation response proteins in prefrontal cortex (PFC of mouse brain included tubulin protein family (α-, β-tubulin subunits, dihydropyrimidinase-related protein 2 (CRMP2, γ-actin, 14-3-3 protein family (14-3-3ζ, ε, heat shock protein 90β (HSP90β, and enolase 2. The results demonstrated the AS extract had positive effects on nerve cells’ structure, adhesion, locomotion, fission, and phagocytosis, through regulating various action pathways, such as Hippo, phagosome, PI3K/Akt (phosphatidylinositol 3 kinase/protein kinase B, Neurotrophin, Rap1 (Ras-related protein RAP-1A, gap junction glycolysis/gluconeogenesis, and HIF-1 (Hypoxia-inducible factor 1 signaling pathways to maintain normal mouse neurological activity. All of the results indicated that AS may be a promising alternative medicine for the treatment of radiation injury in mouse brain. It would be tested that whether the bioactive ingredients of AS could

  11. Assessment of affinities of beta-CIT, beta-CIT-FE, and beta-CIT-FP for monoamine transporters permanently expressed in cell lines

    International Nuclear Information System (INIS)

    Okada, Tomoya; Fujita, Masahiro; Shimada, Shoichi; Sato, Kohji; Schloss, Patrick; Watanabe, Yoshiyuki; Itoh, Yasushi; Tohyama, Masaya; Nishimura, Tsunehiko

    1998-01-01

    We investigated the effects of three cocaine analogs, beta-CIT (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-tropane), beta-CIT-FE (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(2-fluoroethyl)-nortropane), and beta-CIT-FP (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane), on the uptake of [ 3 H]dopamine(DA), serotonin(5-HT), and 1-norepinephrine (NE) using cell lines permanently expressing DA, 5-HT, and NE transporters, respectively, to determine their affinities for these three transporters. We generated cell lines stably expressing DA, 5-HT, and NE transporters, respectively, by the Chen-Okayama method, and then tested the abilities of (-)cocaine, beta-CIT, beta-CIT-FE, beta-CIT-FP, and clomipramine to inhibit the uptake of [ 3 H]DA, 5-HT, and 1-NE. Ki values of beta-CIT, beta-CIT-FE, and beta-CIT-FP for [ 3 H]DA, 5-HT, 1-NE uptake were 6, 29, and 33 nM, 91, 133, and 130 nM, and 28, 113 and 70 nM, respectively, whereas those of cocaine and clomipramine were 316, 581, and 176 nM and > 10,000, 437, and 851 nM, respectively. Beta-CIT, beta-CIT-FE, and beta-CIT-FP were shown to be potent DA, 5-HT, and NE uptake inhibitors. Beta-CIT and beta-CIT-FP were highly potent and selective dopamine uptake inhibitors, and therefore might be useful for imaging of DA transporter with single photon emission computed tomography (SPECT) or positron emission tomography (PET)

  12. The role of beta-endorphin in the pathophysiology of major depression.

    Science.gov (United States)

    Hegadoren, K M; O'Donnell, T; Lanius, R; Coupland, N J; Lacaze-Masmonteil, N

    2009-10-01

    A role for beta-endorphin (beta-END) in the pathophysiology of major depressive disorder (MDD) is suggested by both animal research and studies examining clinical populations. The major etiological theories of depression include brain regions and neural systems that interact with opioid systems and beta-END. Recent preclinical data have demonstrated multiple roles for beta-END in the regulation of complex homeostatic and behavioural processes that are affected during a depressive episode. Additionally, beta-END inputs to regulatory pathways involving feeding behaviours, motivation, and specific types of motor activity have important implications in defining the biological foundations for specific depressive symptoms. Early research linking beta-END to MDD did so in the context of the hypothalamic-pituitary-adrenal (HPA) axis activity, where it was suggested that HPA axis dysregulation may account for depressive symptoms in some individuals. The primary aims of this paper are to use both preclinical and clinical research (a) to critically review data that explores potential roles for beta-END in the pathophysiology of MDD and (b) to highlight gaps in the literature that limit further development of etiological theories of depression and testable hypotheses. In addition to examining methodological and theoretical challenges of past clinical studies, we summarize studies that have investigated basal beta-END levels in MDD and that have used challenge tests to examine beta-END responses to a variety of experimental paradigms. A brief description of the synthesis, location in the CNS and behavioural pharmacology of this neuropeptide is also provided to frame this discussion. Given the lack of clinical improvement observed with currently available antidepressants in a significant proportion of depressed individuals, it is imperative that novel mechanisms be investigated for antidepressant potential. We conclude that the renewed interest in elucidating the role of beta

  13. Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest

    Science.gov (United States)

    Tian, Fangyun; Liu, Tiecheng; Xu, Gang; Li, Duan; Ghazi, Talha; Shick, Trevor; Sajjad, Azeem; Wang, Michael M.; Farrehi, Peter; Borjigin, Jimo

    2018-01-01

    Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO2-mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG) and electroencephalogram (EEG) signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients. PMID:29487541

  14. Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest

    Directory of Open Access Journals (Sweden)

    Fangyun Tian

    2018-02-01

    Full Text Available Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO2-mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG and electroencephalogram (EEG signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients.

  15. Molecular karyotype and chromosomal localization of genes encoding ß-tubulin, cysteine proteinase, hsp 70 and actin in Trypanosoma rangeli

    Directory of Open Access Journals (Sweden)

    CB Toaldo

    2001-01-01

    Full Text Available The molecular karyotype of nine Trypanosoma rangeli strains was analyzed by contour-clamped homogeneous electric field electrophoresis, followed by the chromosomal localization of ß-tubulin, cysteine proteinase, 70 kDa heat shock protein (hsp 70 and actin genes. The T. rangeli strains were isolated from either insects or mammals from El Salvador, Honduras, Venezuela, Colombia, Panama and southern Brazil. Also, T. cruzi CL-Brener clone was included for comparison. Despite the great similarity observed among strains from Brazil, the molecular karyotype of all T. rangeli strains analyzed revealed extensive chromosome polymorphism. In addition, it was possible to distinguish T. rangeli from T. cruzi by the chromosomal DNA electrophoresis pattern. The localization of ß-tubulin genes revealed differences among T. rangeli strains and confirmed the similarity between the isolates from Brazil. Hybridization assays using probes directed to the cysteine proteinase, hsp 70 and actin genes discriminated T. rangeli from T. cruzi, proving that these genes are useful molecular markers for the differential diagnosis between these two species. Numerical analysis based on the molecular karyotype data revealed a high degree of polymorphism among T. rangeli strains isolated from southern Brazil and strains isolated from Central and the northern South America. The T. cruzi reference strain was not clustered with any T. rangeli strain.

  16. Specific binding of beta-endorphin to normal human erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Chenet, B.; Hollis, V. Jr.; Kang, Y.; Simpkins, C.

    1986-03-05

    Beta-endorphin (BE) exhibits peripheral functions which may not be mediated by interactions with receptors in the brain. Recent studies have demonstrated binding of BE to both opioid and non-opioid receptors on lymphocytes and monocytes. Abood has reported specific binding of /sup 3/H-dihydromorphine in erythrocytes. Using 5 x 10/sup -11/M /sup 125/I-beta-endorphin and 10/sup -5/M unlabeled BE, they have detected 50% specific binding to human erythrocytes. This finding is supported by results from immunoelectron microscopy using rabbit anti-BE antibody and biotinylated secondary antibody with avidin-biotin complexes horseradish peroxidase. Binding is clearly observed and is confined to only one side of the cells. Conclusions: (1) BE binding to human erythrocytes was demonstrated by radioreceptor assay and immunoelectron microscopy, and (2) BE binding sites exist on only one side of the cells.

  17. {sup 18}F-labeled RGD peptide: initial evaluation for imaging brain tumor angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xiaoyuan; Park, Ryan; Shahinian, Anthony H.; Tohme, Michel; Khankaldyyan, Vazgen; Bozorgzadeh, Mohammed H.; Bading, James R.; Moats, Rex; Laug, Walter E.; Conti, Peter S. E-mail: pconti@usc.edu

    2004-02-01

    Brain tumors are highly angiogenesis dependent. The cell adhesion receptor integrin {alpha}{sub v}{beta}{sub 3} is overexpressed in glioma and activated endothelial cells and plays an important role in brain tumor growth, spread and angiogenesis. Suitably labeled {alpha}{sub v}{beta}{sub 3}-integrin antagonists may therefore be useful for imaging brain tumor associated angiogenesis. Cyclic RGD peptide c(RGDyK) was labeled with {sup 18}F via N-succinimidyl-4-[{sup 18}F]fluorobenzoate through the side-chain {epsilon}-amino group of the lysine residue. The radiotracer was evaluated in vivo for its tumor targeting efficacy and pharmacokinetics in subcutaneously implanted U87MG and orthotopically implanted U251T glioblastoma nude mouse models by means of microPET, quantitative autoradiography and direct tissue sampling. The N-4-[{sup 18}F]fluorobenzoyl-RGD ([{sup 18}F]FB-RGD) was produced in less than 2 h with 20-25% decay-corrected yields and specific activity of 230 GBq/{mu}mol at end of synthesis. The tracer showed very rapid blood clearance and both hepatobiliary and renal excretion. Tumor-to-muscle uptake ratio at 30 min was approximately 5 in the subcutaneous U87MG tumor model. MicroPET imaging with the orthotopic U251T brain tumor model revealed very high tumor-to-brain ratio, with virtually no uptake in the normal brain. Successful blocking of tumor uptake of [{sup 18}F]FB-RGD in the presence of excess amount of c(RGDyK) revealed receptor specific activity accumulation. Hence, N-4-[{sup 18}F]fluorobenzoyl labeled cyclic RGD peptide [{sup 18}F]FB-RGD is a potential tracer for imaging {alpha}{sub v}{beta}{sub 3}-integrin positive tumors in brain and other anatomic locations.

  18. TLR-activated repression of Fe-S cluster biogenesis drives a metabolic shift and alters histone and tubulin acetylation.

    Science.gov (United States)

    Tong, Wing-Hang; Maio, Nunziata; Zhang, De-Liang; Palmieri, Erika M; Ollivierre, Hayden; Ghosh, Manik C; McVicar, Daniel W; Rouault, Tracey A

    2018-05-22

    Given the essential roles of iron-sulfur (Fe-S) cofactors in mediating electron transfer in the mitochondrial respiratory chain and supporting heme biosynthesis, mitochondrial dysfunction is a common feature in a growing list of human Fe-S cluster biogenesis disorders, including Friedreich ataxia and GLRX5-related sideroblastic anemia. Here, our studies showed that restriction of Fe-S cluster biogenesis not only compromised mitochondrial oxidative metabolism but also resulted in decreased overall histone acetylation and increased H3K9me3 levels in the nucleus and increased acetylation of α-tubulin in the cytosol by decreasing the lipoylation of the pyruvate dehydrogenase complex, decreasing levels of succinate dehydrogenase and the histone acetyltransferase ELP3, and increasing levels of the tubulin acetyltransferase MEC17. Previous studies have shown that the metabolic shift in Toll-like receptor (TLR)-activated myeloid cells involves rapid activation of glycolysis and subsequent mitochondrial respiratory failure due to nitric oxide (NO)-mediated damage to Fe-S proteins. Our studies indicated that TLR activation also actively suppresses many components of the Fe-S cluster biogenesis machinery, which exacerbates NO-mediated damage to Fe-S proteins by interfering with cluster recovery. These results reveal new regulatory pathways and novel roles of the Fe-S cluster biogenesis machinery in modifying the epigenome and acetylome and provide new insights into the etiology of Fe-S cluster biogenesis disorders.

  19. Endogenous brain IL-1 mediates LPS-induced anorexia and hypothalamic cytokine expression.

    Science.gov (United States)

    Layé, S; Gheusi, G; Cremona, S; Combe, C; Kelley, K; Dantzer, R; Parnet, P

    2000-07-01

    The present study was designed to determine the role of endogenous brain interleukin (IL)-1 in the anorexic response to lipopolysaccharide (LPS). Intraperitoneal administration of LPS (5-10 microgram/mouse) induced a dramatic, but transient, decrease in food intake, associated with an enhanced expression of proinflammatory cytokine mRNA (IL-1beta, IL-6, and tumor necrosis factor-alpha) in the hypothalamus. This dose of LPS also increased plasma levels of IL-1beta. Intracerebroventricular pretreatment with IL-1 receptor antagonist (4 microgram/mouse) attenuated LPS-induced depression of food intake and totally blocked the LPS-induced enhanced expression of proinflammatory cytokine mRNA measured in the hypothalamus 1 h after treatment. In contrast, LPS-induced increases in plasma levels of IL-1beta were not altered. These findings indicate that endogenous brain IL-1 plays a pivotal role in the development of the hypothalamic cytokine response to a systemic inflammatory stimulus.

  20. Biosynthesis and release of beta-endorphin-, N-acetyl beta-endorphin-, beta-endorphin-(1-27)-, and N-acetyl beta-endorphin-(1-27)-like peptides by rat pituitary neurointermediate lobe: beta-endorphin is not further processed by anterior lobe

    International Nuclear Information System (INIS)

    Liotta, A.S.; Yamaguchi, H.; Krieger, D.T.

    1981-01-01

    Continuous labeling and pulse-chase techniques were employed to study the synthesis and secretion of multiple forms of immunoreactive beta-endorphin by cultured dispersed rat anterior lobe cells and intact neurointermediate pituitary lobe. Intact neurointermediate lobes incorporated radiolabeled amino acids into four to six forms of immunoreactive beta-endorphin. Four of these forms were physicochemically similar to authentic beta-endorphin, N-acetylated beta-endorphin, beta-endorphin-(1-27), and N-acetylated beta-endorphin-(1-27). Pulse-chase studies indicated that a beta-lipotropin-like molecule served as a metabolic intermediate for a beta-endorphin-like molecule. As beta-endorphin-like material accumulated in the cell, some of it was N-acetylated (approximately 18% at 2 hr chase and approximately 65% at 18 hr chase). At later chase times, beta-endorphin-(1-27)- and N-acetylated beta-endorphin-(1-27)-like peptides were the predominant molecular species detected. All endorphin forms were detected in unlabeled tissue maintained in culture or tissue continuously labeled for 72 hr and were released into the medium under basal, stimulatory (10(-8) M norepinephrine), or inhibitory (10(-7) M dopamine) incubation conditions. In all cases, beta-endorphin-(1-27)-like species were the predominant forms (more than 70% of total) present in the cells and released into the medium. In contrast, approximately 90% of radiolabeled immunoreactive beta-endorphin extracted from anterior lobe cells and medium similarly incubated appeared to represent the authentic beta-endorphin molecule. Continuous labeling (72 hr) revealed the beta-lipotropin/beta-endorphin molar ratio to be approximately 4. We conclude that, in anterior lobe, most of the beta-endorphin is not processed further and is released intact, while in neurointermediate lobe, it serves as a biosynthetic intermediate

  1. The Neuroprotective Functions of Transforming Growth Factor Beta Proteins

    Directory of Open Access Journals (Sweden)

    Gábor Lovas

    2012-07-01

    Full Text Available Transforming growth factor beta (TGF-β proteins are multifunctional cytokines whose neural functions are increasingly recognized. The machinery of TGF-β signaling, including the serine kinase type transmembrane receptors, is present in the central nervous system. However, the 3 mammalian TGF-β subtypes have distinct distributions in the brain suggesting different neural functions. Evidence of their involvement in the development and plasticity of the nervous system as well as their functions in peripheral organs suggested that they also exhibit neuroprotective functions. Indeed, TGF-β expression is induced following a variety of types of brain tissue injury. The neuroprotective function of TGF-βs is most established following brain ischemia. Damage in experimental animal models of global and focal ischemia was shown to be attenuated by TGF-βs. In addition, support for their neuroprotective actions following trauma, sclerosis multiplex, neurodegenerative diseases, infections, and brain tumors is also accumulating. The review will also describe the potential mechanisms of neuroprotection exerted by TGF-βs including anti-inflammatory, -apoptotic, -excitotoxic actions as well as the promotion of scar formation, angiogenesis, and neuroregeneration. The participation of these mechanisms in the neuroprotective effects of TGF-βs during different brain lesions will also be discussed.

  2. Quantification of alpha-tubulin isotypes by sandwich ELISA with signal amplification through biotinyl-tyramide or immuno-PCR

    Czech Academy of Sciences Publication Activity Database

    Dráberová, Eduarda; Stegurová, Lucie; Sulimenko, Vadym; Hájková, Zuzana; Dráber, Petr; Dráber, Pavel

    2013-01-01

    Roč. 395, 1-2 (2013), s. 63-70 ISSN 0022-1759 R&D Projects: GA AV ČR KAN200520701; GA ČR GAP302/12/1673; GA ČR GPP302/11/P709; GA ČR GAP302/10/1759; GA ČR GA301/09/1826; GA MŠk(CZ) LD13015; GA MŠk LD12073 Institutional support: RVO:68378050 Keywords : alpha-tubulin isotypes * biotinyl-tyramide * ELISA * immuno-PCR * mast cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.005, year: 2013

  3. [Study of dopamine transporter imaging on the brain of children with autism].

    Science.gov (United States)

    Sun, Xiaomian; Yue, Jing; Zheng, Chongxun

    2008-04-01

    This study was conducted to evaluate the applicability of 99mTc-2beta-[ N, N'-bis (2-mercaptoethyl) ethylenediamino]methyl,3beta(4-chlorophenyl)tropane(TRODAT-1) dopamine transporter(DAT) SPECT imaging in children with autism, and thus to provide an academic basis for the etiology, mechanism and clinical therapy of autism. Ten autistic children and ten healthy controls were examined with 99mTc-TRODAT-1 DAT SPECT imaging. Striatal specific uptake of 99mTc-TRODAT-1 was calculated with region of interest analysis according to the ratics between striatum and cerebellum [(STR-BKG)/BKG]. There was no statistically significant difference in semiquantitative dopamine transporter between the bilateral striata of autistic children (P=0.562), and between those of normal controls (p=0.573); Dopamine transporter in the brain of patients with autism increased significantly as compared with that in the brain of normal controls (P=0.017). Dopaminergic nervous system is dysfunctioning in the brain of children with autism, and DAT 99mTc-TRODAT-1 SPECT imaging on the brain will help the imaging diagnosis of childhcod autism.

  4. Effects of dietary [alpha]-tocopherol and [beta]-carotene on lipid peroxidation induced by methyl mercuric chloride in mice

    Energy Technology Data Exchange (ETDEWEB)

    Raun Andersen, H; Andersen, O [Department of Environmental Medicine, University of Odense, Odense (Denmark)

    1993-01-01

    Exposure of male CBA mice to methyl mercuric chloride, CH[sub 3]HgCl, (10-40 mg/l in drinking water) for 2 weeks resulted in dose-related Hg deposition and enhanced lipid peroxidation in liver, kidney and brain. Mice were fed well-defined semisynthetic diets containing different levels of [alpha]-tocopherol (10, 100 or 1000 mg/kg) or [beta]-carotene (1000, 10,000 or 100,000 IU/kg) for four weeks, two groups on each diet. The concentration of [alpha]-tocopherol and [beta]-carotene used corresponded to deficient, normal and high levels. During the last two weeks, one group on each diet was given 40 mg CH[sub 3]HgCl/l of drinking water. High dietary [alpha]-tocopherol protected against CH[sub 3]HgCl induced hepatic lipid peroxidation, whereas the [alpha]-tocopherol deficient diet further enhanced CH[sub 3]HgCl induced hepatic lipid peroxidation. Similar, though statistically non-significant effects occurred in the kidneys, [alpha]-tocopherol did not protect against CH[sub 3]HgCl induced lipid peroxidation in the brain. Excess dietary [beta]-carotene further enhanced CH[sub 3]HgCl induced lipid peroxidation in liver, kidney and brain. CH[sub 3]HgCl significantly decreased the activity of total glutathione peroxidase (T-GSH-Px) and Se-dependent glutathione peroxidase (Se-GSH-Px) in the kidneys in all dietary groups. High dietary [alpha]-tocopherol enhanced the activity of Se-GSH-Px in liver and kidney compared to the activity in mice fed the normal level of [alpha]-tocopherol. This occurred in mice exposed to CH[sub 3]-HgCl as well as in unexposed mice, and the difference between CH[sub 3]HgCl exposed and unexposed mice was not diminished. High dietary [alpha]-tocopherol increased the activity of both Se-GSH-Px and T-GSH-Px in the brain of CH[sub 3]HgCl-exposed mice. The dietary level of [beta]-carotene did not affect the activity of the two enzymes in the organs investigated. (au) (43 refs.).

  5. The role of mutated amyloid beta 1-42 stimulating dendritic cells in a PDAPP transgenic mouse

    Directory of Open Access Journals (Sweden)

    LI Jia-lin

    2012-06-01

    Full Text Available Background Amyloid plaque is one of the pathological hallmarks of Alzheimer's disease (AD. Anti-beta-amyloid (Aβ immunotherapy is effective in removing brain Aβ, but has shown to be associated with detrimental effects. To avoid severe adverse effects such as meningoencephalitis induced by amyloid beta vaccine with adjuvant, and take advantage of amyloid beta antibody's therapeutic effect on Alzheimer's disease sufficiently, our group has developed a new Alzheimer vaccine with mutated amyloid beta 1-42 peptide stimulating dendritic cells (DC. Our previous work has confirmed that DC vaccine can induce adequate anti-amyloid beta antibody in PDAPP Tg mice safely and efficiently. The DC vaccine can improve impaired learning and memory in the Alzheimer's animal model, and did not cause microvasculitis, microhemorrhage or meningoencephalitis in the animal model. However, the exact mechanism of immunotherapy which reduces Aβ deposition remains unknown. In this report, we studied the mechanism of the vaccine, thinking that this may have implications for better understanding of the pathogenesis of Alzheimer's disease. Methods A new Alzheimer vaccine with mutated amyloid beta 1-42 peptide stimulating DC which were obtained from C57/B6 mouse bone marrow was developed. Amyloid beta with Freund's adjuvant was inoculated at the same time to act as positive control. After the treatment was done, the samples of brains were collected, fixed, cut. Immunohistochemical staining was performed to observe the expression of the nuclear hormone liver X receptor (LXR, membrane-bound protein tyrosine phosphatase (CD45, the ATP-binding cassette family of active transporters (ABCA1, receptor for advanced glycation end products (RAGE, β-site APP-cleaving enzyme (BACE and Aβ in mouse brain tissue. Semi-quantitative analysis was used to defect CA1, CA2, CA3, DG, Rad in hippocampus region and positive neuron in cortex region. Results Aβ was significantly reduced in the

  6. Reduced beta band connectivity during number estimation in autism

    Directory of Open Access Journals (Sweden)

    Katrin A. Bangel

    2014-01-01

    Full Text Available Recent evidence suggests that disruption of integrative processes in sensation and perception may play a critical role in cognitive and behavioural atypicalities characteristic of ASD. In line with this, ASD is associated with altered structural and functional brain connectivity and atypical patterns of inter-regional communication which have been proposed to contribute to cognitive difficulties prevalent in this group. The present MEG study used atlas-guided source space analysis of inter-regional phase synchronization in ASD participants, as well as matched typically developing controls, during a dot number estimation task. This task included stimuli with globally integrated forms (animal shapes as well as randomly-shaped stimuli which lacked a coherent global pattern. Early task-dependent increases in inter-regional phase synchrony in theta, alpha and beta frequency bands were observed. Reduced long-range beta-band phase synchronization was found in participants with ASD at 70–145 ms during presentation of globally coherent dot patterns. This early reduction in task-dependent inter-regional connectivity encompassed numerous areas including occipital, parietal, temporal, and frontal lobe regions. These results provide the first evidence for inter-regional phase synchronization during numerosity estimation, as well as its alteration in ASD, and suggest that problems with communication among brain areas may contribute to difficulties with integrative processes relevant to extraction of meaningful ‘Gestalt’ features in this population.

  7. Regulation of microtubule nucleation from membranes by complexes of membrane-bound gamma-tubulin with Fyn kinase and phosphoinositide 3-kinase

    Czech Academy of Sciences Publication Activity Database

    Macůrek, Libor; Dráberová, Eduarda; Richterová, Věra; Sulimenko, Vadym; Sulimenko, Tetyana; Dráberová, Lubica; Marková, Vladimíra; Dráber, Pavel

    2008-01-01

    Roč. 416, č. 3 (2008), s. 421-430 ISSN 0264-6021 R&D Projects: GA MŠk LC545; GA ČR GA204/05/2375; GA ČR GA304/04/1273; GA MŠk(CZ) 1M0520 Institutional research plan: CEZ:AV0Z50520514 Keywords : detergent -resistant membrane * Fyn * PI3K gamma-tubulin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.371, year: 2008

  8. Purification of beta-acetylglucosaminase and beta-galactosidase from ram testis.

    Science.gov (United States)

    Caygill, J C; Roston, C P; Jevons, F R

    1966-02-01

    1. The presence of beta-galactosidase (EC 3.2.1.23) in an acetic acid extract of ram testis is reported. Some properties of the crude enzyme preparation were studied. 2. The purification of beta-acetylglucosaminase (EC 3.2.1.30) and of beta-galactosidase from the ram-testis extract by ammonium sulphate precipitation and chromatography on a CM-cellulose column is described. 3. The final purifications of the separated enzymes achieved were for the beta-acetylglucosaminase 35 times and for the beta-galactosidase 99 times. 4. The possibility of using DEAE-cellulose and Sephadex G-200 to purify the enzymes was investigated.

  9. Levels of alpha- and beta-secretase cleaved amyloid precursor protein in the cerebrospinal fluid of Alzheimer's disease patients

    DEFF Research Database (Denmark)

    Sennvik, K; Fastbom, J; Blomberg, M

    2000-01-01

    Alternative cleavage of the amyloid precursor protein (APP) results in generation and secretion of both soluble APP (sAPP) and beta-amyloid (Abeta). Abeta is the main component of the amyloid depositions in the brains of Alzheimer's disease (AD) patients. Using Western blotting, we compared...... the levels of alpha-secretase cleaved sAPP, beta-secretase cleaved sAPP and total sAPP, in cerebrospinal fluid (CSF) from 13 sporadic AD patients and 13 healthy controls. Our findings show significant amounts of beta-secretase cleaved sAPP in CSF. There was no statistically significant difference...... in the levels of beta-secretase cleaved sAPP between AD patients and controls. The levels of alpha-secretase cleaved sAPP and total sAPP were, however, found to be significantly lower in the AD patients than in the controls....

  10. Brain Phosphorus Magnetic Resonance Spectroscopy Imaging of Sleep Homeostasis and Restoration in Drug Dependence

    Directory of Open Access Journals (Sweden)

    George H. Trksak

    2007-01-01

    Full Text Available Numerous reports have documented a high occurrence of sleep difficulties in drug-dependent populations, prompting researchers to characterize sleep profiles and physiology in drug abusing populations. This mini-review examines studies indicating that drug-dependent populations exhibit alterations in sleep homeostatic and restoration processes in response to sleep deprivation. Sleep deprivation is a principal sleep research tool that results in marked physiological challenge, which provides a means to examine sleep homeostatic processes in response to extended wakefulness. A report from our laboratory demonstrated that following recovery sleep from sleep deprivation, brain high-energy phosphates particularly beta–nucleoside triphosphate (beta-NTP are markedly increased as measured with phosphorus magnetic resonance spectroscopy (MRS. A more recent study examined the effects of sleep deprivation in opiate-dependent methadone-maintained (MM subjects. The study demonstrated increases in brain beta-NTP following recovery sleep. Interestingly, these increases were of a markedly greater magnitude in MM subjects compared to control subjects. A similar study examined sleep deprivation in cocaine-dependent subjects demonstrating that cocaine-dependent subjects exhibit greater increases in brain beta-NTP following recovery sleep when compared to control subjects. The studies suggest that sleep deprivation in both MM subjects and cocaine-dependent subjects is characterized by greater changes in brain ATP levels than control subjects. Greater enhancements in brain ATP following recovery sleep may reflect a greater disruption to or impact of sleep deprivation in drug dependent subjects, whereby sleep restoration processes may be unable to properly regulate brain ATP and maintain brain high-energy equilibrium. These studies support the notion of a greater susceptibility to sleep loss in drug dependent populations. Additional sleep studies in drug abusing

  11. Apc1 is required for maintenance of local brain organizers and dorsal midbrain survival.

    NARCIS (Netherlands)

    Paridaen, J.T.M.; Danesin, C.; Elas, A.T.; van de Water, S.G.P.; Houart, C.; Zivkovic, D.

    2009-01-01

    The tumor suppressor Apc1 is an intracellular antagonist of the Wnt/beta-catenin pathway, which is vital for induction and patterning of the early vertebrate brain. However, its role in later brain development is less clear. Here, we examined the mechanisms underlying effects of an Apc1

  12. Differential expression of largemouth bass (Micropterus salmoides) estrogen receptor isotypes alpha, beta, and gamma by estradiol.

    Science.gov (United States)

    Sabo-Attwood, Tara; Kroll, Kevin J; Denslow, Nancy D

    2004-04-15

    The expression levels of three estrogen receptor (ER) isotypes alpha, beta, and gamma were quantified in female largemouth bass (Micropterus salmoides) (LMB) liver, ovary, brain, and pituitary tissues. ER alpha and beta expression predominated in the liver, while ERs beta and gamma predominated in the other tissues. Temporally in females, ER alpha was highly up-regulated, ER gamma was slightly up-regulated, and ER beta levels remained unchanged in the liver when plasma 17-beta estradiol (E2) and vitellogenin (Vtg) levels were elevated in the spring. In ovarian tissue from these same fish, all three ERs were maximally expressed in the fall, during early oocyte development and prior to peak plasma E2 levels. When males were injected with E2, ER alpha was highly inducible, ER gamma was moderately up-regulated, and ER beta levels were not affected. None of the ER isotypes were induced by E2 in gonadal tissues. These results combined suggest that the ERs themselves are not regulated in the same manner by E2, and furthermore, do not contribute equally to the transcriptional regulation of genes involved in fish reproduction such as Vtg.

  13. Insulin in the brain: sources, localization and functions.

    Science.gov (United States)

    Ghasemi, Rasoul; Haeri, Ali; Dargahi, Leila; Mohamed, Zahurin; Ahmadiani, Abolhassan

    2013-02-01

    Historically, insulin is best known for its role in peripheral glucose homeostasis, and insulin signaling in the brain has received less attention. Insulin-independent brain glucose uptake has been the main reason for considering the brain as an insulin-insensitive organ. However, recent findings showing a high concentration of insulin in brain extracts, and expression of insulin receptors (IRs) in central nervous system tissues have gathered considerable attention over the sources, localization, and functions of insulin in the brain. This review summarizes the current status of knowledge of the peripheral and central sources of insulin in the brain, site-specific expression of IRs, and also neurophysiological functions of insulin including the regulation of food intake, weight control, reproduction, and cognition and memory formation. This review also considers the neuromodulatory and neurotrophic effects of insulin, resulting in proliferation, differentiation, and neurite outgrowth, introducing insulin as an attractive tool for neuroprotection against apoptosis, oxidative stress, beta amyloid toxicity, and brain ischemia.

  14. Affinity purification and partial characterization of the zonulin/zonula occludens toxin (Zot) receptor from human brain.

    Science.gov (United States)

    Lu, R; Wang, W; Uzzau, S; Vigorito, R; Zielke, H R; Fasano, A

    2000-01-01

    The intercellular tight junctions (TJs) of endothelial cells represent the limiting structure for the permeability of the blood-brain barrier (BBB). Although the BBB has been recognized as being the interface between the bloodstream and the brain, little is known about its regulation. Zonulin and its prokaryotic analogue, zonula occludens toxin (Zot) elaborated by Vibrio cholerae, both modulate intercellular TJs by binding to a specific surface receptor with subsequent activation of an intracellular signaling pathway involving phospholipase C and protein kinase C activation and actin polymerization. Affinity column purification revealed that human brain plasma membrane preparations contain two Zot binding proteins of approximately 55 and approximately 45 kDa. Structural and kinetic studies, including saturation and competitive assays, identified the 55-kDa protein as tubulin, whereas the 45-kDa protein represents the zonulin/Zot receptor. Biochemical characterization provided evidence that this receptor is a glycoprotein containing multiple sialic acid residues. Comparison of the N-terminal sequence of the zonulin/Zot receptor with other protein sequences by BLAST analysis revealed a striking similarity with MRP-8, a 14-kDa member of the S-100 family of calcium binding proteins. The discovery and characterization of this receptor from human brain may significantly contribute to our knowledge on the pathophysiological regulation of the BBB.

  15. Functional modulation of cerebral gamma-aminobutyric acidA receptor/benzodiazepine receptor/chloride ion channel complex with ethyl beta-carboline-3-carboxylate: Presence of independent binding site for ethyl beta-carboline-3-carboxylate

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, J.; Kuriyama, K. (Kyoto Prefectural Univ. of Medicine (Japan))

    1990-05-01

    Effect of ethyl beta-carboline-3-carboxylate (beta-CCE) on the function of gamma-aminobutyric acid (GABA)A receptor/benzodiazepine receptor/chloride ion channel complex was studied. Beta-CCE noncompetitively and competitively inhibited (3H)flunitrazepam binding to benzodiazepine receptor, but not (3H)muscimol binding to GABAA receptor as well as t-(3H)butylbicycloorthobenzoate (( 3H) TBOB) binding to chloride ion channel, in particulate fraction of the mouse brain. Ro15-1788 also inhibited competitively (3H) flunitrazepam binding. On the other hand, the binding of beta-(3H)CCE was inhibited noncompetitively and competitively by clonazepam and competitively by Ro15-1788. In agreement with these results, benzodiazepines-stimulated (3H)muscimol binding was antagonized by beta-CCE and Ro15-1788. Gel column chromatography for the solubilized fraction from cerebral particulate fraction by 0.2% sodium deoxycholate (DOC-Na) in the presence of 1 M KCl indicated that beta-(3H)CCE binding site was eluted in the same fraction (molecular weight, 250,000) as the binding sites for (3H)flunitrazepam, (3H)muscimol and (3H)TBOB. GABA-stimulated 36Cl- influx into membrane vesicles prepared from the bovine cerebral cortex was stimulated and attenuated by flunitrazepam and beta-CCE, respectively. These effects of flunitrazepam and beta-CCE on the GABA-stimulated 36Cl- influx were antagonized by Ro15-1788. The present results suggest that the binding site for beta-CCE, which resides on GABAA receptor/benzodiazepine receptor/chloride ion channel complex, may be different from that for benzodiazepine. Possible roles of beta-CCE binding site in the allosteric inhibitions on benzodiazepine binding site as well as on the functional coupling between chloride ion channel and GABAA receptor are also suggested.

  16. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets........S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...

  17. Conversion of beta-methylbutyric acid to beta-hydroxy-beta-methylbutyric acid by Galactomyces reessii.

    OpenAIRE

    Lee, I Y; Nissen, S L; Rosazza, J P

    1997-01-01

    beta-Hydroxy-beta-methylbutyric acid (HMB) has been shown to increase strength and lean mass gains in humans undergoing resistance-exercise training. HMB is currently marketed as a calcium salt of HMB, and thus, environmentally sound and inexpensive methods of manufacture are being sought. This study investigates the microbial conversion of beta-methylbutyric acid (MBA) to HMB by cultures of Galactomyces reessii. Optimal concentrations of MBA were in the range of 5 to 20 g/liter for HMB produ...

  18. [O-methyl-{sup 11}C]{beta}-CIT-FP, a potential radioligand for quantitation of the dopamine transporter: Preparation, autoradiography, metabolite studies, and positron emission tomography examinations

    Energy Technology Data Exchange (ETDEWEB)

    Lundkvist, Camilla; Halldin, Christer; Swahn, Carl-Gunnar; Hall, Haakan; Karlsson, Per; Nakashima, Yoshifumi; Wang, Shaoyin; Milius, Richard A.; Neumeyer, John L.; Farde, Lars

    1995-10-01

    {beta}-CIT-FP [N-(3-fluoropropyl)-2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)nortropane] is a cocaine analogue with a high affinity for the dopamine transporter. [O-methyl-{sup 11}C]{beta}-CIT-FP ([{sup 11}C]{beta}-CIT-FP) was prepared byO -alkylation of the free acid with [{sup 11}C]methyl iodide. The total radiochemical yield of [{sup 11}C]{beta}-CIT-FP was 50 to 60% with an overall synthesis time of 30 min. The radiochemical purity was >99%, and the specific radioactivity at time of injection was about 37 GBq/{mu}mol (1000 Ci/mmol). Autoradiographic examination of [{sup 11}C]{beta}-CIT-FP binding in human brain postmortem demonstrated specific binding in the caudate nucleus and putamen. Positron emission tomography (PET) examination of [{sup 11}C]{beta}-CIT-FP in a Cynomolgus monkey demonstrated accumulation in the striatum with a striatum-to-cerebellum ratio of about 8 after 60 min. Equilibrium in the striatum was attained within 70 to 90 min. The radioactivity ratios of thalamus/cerebellum and neocortex/cerebellum were about 2 and 1.5, respectively. In a displacement experiment, radioactivity in the striatum but not in the cerebellum was reduced after injection of {beta}-CIT, indicating that striatal radioactivity following injection of [{sup 11}C]{beta}-CIT-FP is associated with dopamine transporter sites and that the binding is reversible. The fraction of the total radioactivity in plasma representing [{sup 11}C]{beta}-CIT-FP determined by high-performance liquid chromatography (HPLC) was 84% at 15 min and 50% at 95 min. [{sup 11}C]{beta}-CIT-FP should be a useful PET radioligand for the quantitation of dopamine transporters in the human brain in vivo.

  19. Distribution of protein kinase Mzeta and the complete protein kinase C isoform family in rat brain

    DEFF Research Database (Denmark)

    Naik, M U; Benedikz, Eirikur; Hernandez, I

    2000-01-01

    Protein kinase C (PKC) is a multigene family of at least ten isoforms, nine of which are expressed in brain (alpha, betaI, betaII, gamma, delta, straightepsilon, eta, zeta, iota/lambda). Our previous studies have shown that many of these PKCs participate in synaptic plasticity in the CA1 region...

  20. Alzheimer's disease risk gene CD33 inhibits microglial uptake of amyloid beta.

    Science.gov (United States)

    Griciuc, Ana; Serrano-Pozo, Alberto; Parrado, Antonio R; Lesinski, Andrea N; Asselin, Caroline N; Mullin, Kristina; Hooli, Basavaraj; Choi, Se Hoon; Hyman, Bradley T; Tanzi, Rudolph E

    2013-05-22

    The transmembrane protein CD33 is a sialic acid-binding immunoglobulin-like lectin that regulates innate immunity but has no known functions in the brain. We have previously shown that the CD33 gene is a risk factor for Alzheimer's disease (AD). Here, we observed increased expression of CD33 in microglial cells in AD brain. The minor allele of the CD33 SNP rs3865444, which confers protection against AD, was associated with reductions in both CD33 expression and insoluble amyloid beta 42 (Aβ42) levels in AD brain. Furthermore, the numbers of CD33-immunoreactive microglia were positively correlated with insoluble Aβ42 levels and plaque burden in AD brain. CD33 inhibited uptake and clearance of Aβ42 in microglial cell cultures. Finally, brain levels of insoluble Aβ42 as well as amyloid plaque burden were markedly reduced in APP(Swe)/PS1(ΔE9)/CD33(-/-) mice. Therefore, CD33 inactivation mitigates Aβ pathology and CD33 inhibition could represent a novel therapy for AD. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Activities of UDP-glucuronyltransferase, beta-glucuronidase and deiodinase types I and II in hyper- and hypothyroid rats

    NARCIS (Netherlands)

    Heide, S.M. van der; Joosten, B.H.G.M.; Everts, M.E.; Klaren, P.H.M.

    2004-01-01

    We have investigated the hypothesis that uridine 5'-diphosphate (UDP)-glucuronyltransferases (UGTs) and beta-glucuronidase are jointly involved in a mechanism for the storage and mobilization of iodothyronine metabolites in liver, kidney, heart and brain. Specifically, we predicted UGT activities to

  2. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward......-looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...

  3. Considerations of beta and electron transport in internal dose calculations. Final progress report, 1994 -1998

    International Nuclear Information System (INIS)

    Bolch, W.E.

    1998-01-01

    This research focused on the following major tasks: improved dosimetric models of the head and brain; development of improved skeletal dosimetry models; development of dosimetric techniques for nonuniform activity distributions; pediatric dosimetry phantoms and radionuclide S values; microdosimetry of beta emitters in radioimmunotherapy; and mechanisms of molecular radiation damage

  4. Validity of in vivo [123I]beta-CIT SPECT in detecting MDMA-induced neurotoxicity in rats

    NARCIS (Netherlands)

    de Win, Maartje M. L.; de Jeu, Rogier A. M.; de Bruin, Kora; Habraken, Jan B. A.; Reneman, Liesbeth; Booij, Jan; den Heeten, Gerard J.

    2004-01-01

    This study investigated the ability of a high-resolution pinhole single-photon emission computed tomography (SPECT) system, with [(123)I]beta-CIT as a radiotracer, to detect 3,4-methelenedioxymethamphetamine (MDMA, 'Ecstasy')-induced loss of serotonin transporters (SERTs) in the living rat brain. In

  5. Genetic variation in codons 167, 198 and 200 of the beta-tubulin gene in whipworms (Trichuris spp.) from a range of domestic animals and wildlife

    DEFF Research Database (Denmark)

    Hansen, Tina Vicky Alstrup; Nejsum, Peter; Olsen, Annette

    2013-01-01

    A recurrent problem in the control of whipworm (Trichuris spp.) infections in many animal species and man is the relatively low efficacy of treatment with a single application of benzimidazoles (BZs). The presence of single nucleotide polymorphisms (SNPs) in codons 167, 198 and 200 in the beta...

  6. Enantioselective synthesis of alpha,beta-disubstituted-beta-amino acids.

    Science.gov (United States)

    Sibi, Mukund P; Prabagaran, Narayanasamy; Ghorpade, Sandeep G; Jasperse, Craig P

    2003-10-01

    Highly diastereoselective and enantioselective addition of N-benzylhydroxylamine to imides 17 and 20-30 produces alpha,beta-trans-disubstituted N-benzylisoxazolidinones 19 and 31-41. These reactions proceed in 60-96% ee with 93-99% de's using 5 mol % of Mg(NTf2)2 and ligand 18. The product isoxazolidinones can be hydrogenolyzed directly to provide alpha,beta-disubstituted-beta-amino acids.

  7. Glycogen synthase kinase 3 beta alters anxiety-, depression-, and addiction-related behaviors and neuronal activity in the nucleus accumbens shell

    Science.gov (United States)

    Crofton, Elizabeth J.; Nenov, Miroslav N.; Zhang, Yafang; Scala, Federico; Page, Sean A.; McCue, David L.; Li, Dingge; Hommel, Jonathan D.; Laezza, Fernanda; Green, Thomas A.

    2017-01-01

    Psychiatric disorders such as anxiety, depression and addiction are often comorbid brain pathologies thought to share common mechanistic biology. As part of the cortico-limbic circuit, the nucleus accumbens shell (NAcSh) plays a fundamental role in integrating information in the circuit, such that modulation of NAcSh circuitry alters anxiety, depression, and addiction-related behaviors. Intracellular kinase cascades in the NAcSh have proven important mediators of behavior. To investigate glycogen-synthase kinase 3 (GSK3) beta signaling in the NAcSh in vivo we knocked down GSK3beta expression with a novel adeno-associated viral vector (AAV2) and assessed changes in anxiety- and depression-like behavior and cocaine self-administration in GSK3beta knockdown rats. GSK3beta knockdown reduced anxiety-like behavior while increasing depression-like behavior and cocaine self-administration. Correlative electrophysiological recordings in acute brain slices were used to assess the effect of AAV-shGSK3beta on spontaneous firing and intrinsic excitability of tonically active interneurons (TANs), cells required for input and output signal integration in the NAcSh and for processing reward-related behaviors. Loose-patch recordings showed that TANs transduced by AAV-shGSK3beta exhibited reduction in tonic firing and increased spike half width. When assessed by whole-cell patch clamp recordings these changes were mirrored by reduction in action potential firing and accompanied by decreased hyperpolarization-induced depolarizing sag potentials, increased action potential current threshold, and decreased maximum rise time. These results suggest that silencing of GSK3beta in the NAcSh increases depression- and addiction-related behavior, possibly by decreasing intrinsic excitability of TANs. However, this study does not rule out contributions from other neuronal sub-types. PMID:28126496

  8. Time Course of Brain Network Reconfiguration Supporting Inhibitory Control.

    Science.gov (United States)

    Popov, Tzvetan; Westner, Britta U; Silton, Rebecca L; Sass, Sarah M; Spielberg, Jeffrey M; Rockstroh, Brigitte; Heller, Wendy; Miller, Gregory A

    2018-05-02

    Hemodynamic research has recently clarified key nodes and links in brain networks implementing inhibitory control. Although fMRI methods are optimized for identifying the structure of brain networks, the relatively slow temporal course of fMRI limits the ability to characterize network operation. The latter is crucial for developing a mechanistic understanding of how brain networks shift dynamically to support inhibitory control. To address this critical gap, we applied spectrally resolved Granger causality (GC) and random forest machine learning tools to human EEG data in two large samples of adults (test sample n = 96, replication sample n = 237, total N = 333, both sexes) who performed a color-word Stroop task. Time-frequency analysis confirmed that recruitment of inhibitory control accompanied by slower behavioral responses was related to changes in theta and alpha/beta power. GC analyses revealed directionally asymmetric exchanges within frontal and between frontal and parietal brain areas: top-down influence of superior frontal gyrus (SFG) over both dorsal ACC (dACC) and inferior frontal gyrus (IFG), dACC control over middle frontal gyrus (MFG), and frontal-parietal exchanges (IFG, precuneus, MFG). Predictive analytics confirmed a combination of behavioral and brain-derived variables as the best set of predictors of inhibitory control demands, with SFG theta bearing higher classification importance than dACC theta and posterior beta tracking the onset of behavioral response. The present results provide mechanistic insight into the biological implementation of a psychological phenomenon: inhibitory control is implemented by dynamic routing processes during which the target response is upregulated via theta-mediated effective connectivity within key PFC nodes and via beta-mediated motor preparation. SIGNIFICANCE STATEMENT Hemodynamic neuroimaging research has recently clarified regional structures in brain networks supporting inhibitory control. However, due to

  9. Iodine-123 labelled nor-{beta}-CIT binds to the serotonin transporter in vivo as assessed by biodistribution studies in rats

    Energy Technology Data Exchange (ETDEWEB)

    Booij, J.; Knol, R.J.J.; Reneman, L.; De Bruin, K.; Van Royen, E.A. [Dept. of Nuclear Medicine, Univ. of Amsterdam (Netherlands); Janssen, A.G.M. [Amersham Cygne and Eindhoven University of Technology (Netherlands)

    1998-12-01

    Iodine-123 labelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)nortropane (nor-{beta}-CIT), a radioiodinated cocaine analogue, was evaluated as an agent for the in vivo labelling of serotonin transporters by biodistribution studies in rats. Intravenous injection of [{sup 123}I]nor-{beta}-CIT resulted in high accumulation of radioactivity in brain areas with high densities of serotonin (hypothalamus) and dopamine transporters (striatum), although the binding was less pronounced in the hypothalamus. While binding of [{sup 123}I]nor-{beta}-CIT in the hypothalamus was blocked significantly by fluvoxamine (a selective serotonin transporter blocker) but not by GBR12,909 (a selective dopamine transporter blocker), the opposite was observed in the striatum. The results of this study indicate that [{sup 123}I]nor-{beta}-CIT, although not being a selective radioligand, binds specifically to serotonin transporters in the hypothalamus in vivo and thus suggest that [{sup 123}I]nor-{beta}-CIT promises to be a suitable radioligand for single-photon emission tomography imaging of serotonin transporters in humans. (orig.) With 1 fig., 2 tabs., 15 refs.

  10. Anti-amyloid beta protein antibody passage across the blood-brain barrier in the SAMP8 mouse model of Alzheimer's disease: an age-related selective uptake with reversal of learning impairment.

    Science.gov (United States)

    Banks, William A; Farr, Susan A; Morley, John E; Wolf, Kathy M; Geylis, Valeria; Steinitz, Michael

    2007-08-01

    Amyloid beta protein (Abeta) levels are elevated in the brain of Alzheimer's disease patients. Anti-Abeta antibodies can reverse the histologic and cognitive impairments in mice which overexpress Abeta. Passive immunization appears safer than vaccination and treatment of patients will likely require human rather than xenogenic antibodies. Effective treatment will likely require antibody to cross the blood-brain barrier (BBB). Unfortunately, antibodies typically cross the BBB very poorly and accumulate less well in brain than even albumin, a substance nearly totally excluded from the brain. We compared the ability of two anti-Abeta human monoclonal IgM antibodies, L11.3 and HyL5, to cross the BBB of young CD-1 mice to that of young and aged SAMP8 mice. The SAMP8 mouse has a spontaneous mutation that induces an age-related, Abeta-dependent cognitive deficit. There was preferential uptake of intravenously administered L11.3 in comparison to HyL5, albumin, and a control human monoclonal IgM (RF), especially by hippocampus and olfactory bulb in aged SAMP8 mice. Injection of L11.3 into the brains of aged SAMP8 mice reversed both learning and memory impairments in aged SAMP8 mice, whereas IgG and IgM controls were ineffective. Pharmacokinetic analysis predicted that an intravenous dose 1000 times higher than the brain injection dose would reverse cognitive impairments. This predicted intravenous dose reversed the impairment in learning, but not memory, in aged SAMP8 mice. In conclusion, an IgM antibody was produced that crosses the BBB to reverse cognitive impairment in a murine model of Alzheimer's disease.

  11. Species differences in the localization and number of CNS beta adrenergic receptors: Rat versus guinea pig

    International Nuclear Information System (INIS)

    Booze, R.M.; Crisostomo, E.A.; Davis, J.N.

    1989-01-01

    The localization and number of beta adrenergic receptors were directly compared in the brains of rats and guinea pigs. The time course of association and saturability of [125I]cyanopindolol (CYP) binding to slide-mounted tissue sections was similar in rats (Kd = 17 pM) and guinea pigs (Kd = 20 pM). The beta-1 and beta-2 receptor subtypes were examined through the use of highly selective unlabeled receptor antagonists, ICI 118,551 (50 nM) and ICI 89,406 (70 nM). Dramatic species differences between rats and guinea pigs were observed in the neuroanatomical regional localization of the beta adrenergic receptor subtypes. For example, in the thalamus prominent beta-1 and beta-2 receptor populations were identified in the rat; however, the entire thalamus of the guinea pig had few, if any, beta adrenergic receptors of either subtype. Hippocampal area CA1 had high levels of beta-2 adrenergic receptors in both rats and guinea pigs but was accompanied by a widespread distribution of beta-2 adrenergic receptors only in rats. Quantitative autoradiographic analyses of 25 selected neuroanatomical regions (1) confirmed the qualitative differences in CNS beta adrenergic receptor localization, (2) determined that guinea pigs had significantly lower levels of beta adrenergic receptors than rats and (3) indicated a differential pattern of receptor subtypes between the two species. Knowledge of species differences in receptor patterns may be useful in designing effective experiments as well as in exploring the relationships between receptor and innervation patterns. Collectively, these data suggest caution be used in extrapolation of the relationships of neurotransmitters and receptors from studies of a single species

  12. Large-scale network dynamics of beta-band oscillations underlie auditory perceptual decision-making

    Directory of Open Access Journals (Sweden)

    Mohsen Alavash

    2017-06-01

    Full Text Available Perceptual decisions vary in the speed at which we make them. Evidence suggests that translating sensory information into perceptual decisions relies on distributed interacting neural populations, with decision speed hinging on power modulations of the neural oscillations. Yet the dependence of perceptual decisions on the large-scale network organization of coupled neural oscillations has remained elusive. We measured magnetoencephalographic signals in human listeners who judged acoustic stimuli composed of carefully titrated clouds of tone sweeps. These stimuli were used in two task contexts, in which the participants judged the overall pitch or direction of the tone sweeps. We traced the large-scale network dynamics of the source-projected neural oscillations on a trial-by-trial basis using power-envelope correlations and graph-theoretical network discovery. In both tasks, faster decisions were predicted by higher segregation and lower integration of coupled beta-band (∼16–28 Hz oscillations. We also uncovered the brain network states that promoted faster decisions in either lower-order auditory or higher-order control brain areas. Specifically, decision speed in judging the tone sweep direction critically relied on the nodal network configurations of anterior temporal, cingulate, and middle frontal cortices. Our findings suggest that global network communication during perceptual decision-making is implemented in the human brain by large-scale couplings between beta-band neural oscillations. The speed at which we make perceptual decisions varies. This translation of sensory information into perceptual decisions hinges on dynamic changes in neural oscillatory activity. However, the large-scale neural-network embodiment supporting perceptual decision-making is unclear. We addressed this question by experimenting two auditory perceptual decision-making situations. Using graph-theoretical network discovery, we traced the large-scale network

  13. In-trap decay spectroscopy for {beta}{beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Thomas

    2011-01-18

    The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

  14. Uptake of [3H]colchicine into brain and liver of mouse, rat, and chick

    International Nuclear Information System (INIS)

    Bennett, E.L.; Alberti, M.H.; Flood, J.F.

    1981-01-01

    The uptake of [ring A-4- 3 H] colchicine and [ring C-methoxy- 3 H]colchicine has been compared in mice from 1 to 24 hr after administration. Less radioactivity was found in brain after administration of ring-labeled colchicine than after administration of the methoxy-labeled colchicine. Three hr after administration of ring-labeled colchicine, 5% of the label was in liver and about 0.01% of the label was present in brain. Forty percent of the brain radioactivity was bound to tubulin as determined by vinblastine precipitation. After 3 hr, an average of 8% of the radioactivity from methoxy-labeled colchicine was found in the liver and 0.16% in brain. However, less than 5% of the activity in brain was precipitated by vinblastine, and the colchicine equivalent was comparable to that found after administration of the ring-labeled colchicine. The amount of colchicine entering mouse brain after subcutaneous injection is comparable to the minimum behaviorally effective dose when administered to the caudate. The metabolism of [ring C-methoxy- 3 H] and [ring A- 3 H]colchicine was also studied in rats. The general pattern was similar to mice; less radioactivity was found in brain after administration of the ring-labeled alkaloid than after administration of methoxy-labeled colchicine. Again, 40-50% of ring-labeled colchicine was precipitated by vinblastine. A much smaller percentage of the methoxy-labeled drug was precipitated by vinblastine than of the ring A-labeled colchicine. These experiments, together with behavioral experiments, support the hypotheses that structural alterations in synapses by recently synthesized proteins which are transported down the axons and dendrites may be an essential process for long-term memory formation

  15. Aspergillus pragensis sp nov discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi

    DEFF Research Database (Denmark)

    Lyskova, Pavlina; Hubka, Vit; Kolarik, Miroslav

    2014-01-01

    The identity of nine clinical isolates recovered from Czech patients and presumptively identified as Aspergillus sp. section Candidi based on colony morphology was revised using sequences of beta-tubulin, calmodulin gene sequence, and internal transcribed spacer rDNA. Six isolates were from suspe...

  16. Phylogeny and systematics of the genus Calonectria

    NARCIS (Netherlands)

    Lombard, L.; Crous, P.W.; Wingfield, B.D.; Wingfield, M.J.

    2010-01-01

    Species of Calonectria are important plant pathogens, several of which have a worldwide distribution. Contemporary taxonomic studies on these fungi have chiefly relied on DNA sequence comparisons of the beta-tubulin gene region. Despite many new species being described, there has been no

  17. New and revisited species in Aspergillus section Nigri

    DEFF Research Database (Denmark)

    Varga, J.; Frisvad, Jens Christian; Kocsube, S.

    2011-01-01

    based on either beta-tubulin or calmodulin sequence data. Aspergillus eucalypticola produced pyranonigrin A, funalenone, aurasperone B and other naphtho-gamma-pyrones. Aspergillus neoniger is also a biseriate species isolated from desert sand in Namibia, and mangrove water in Venezuela, which produces...

  18. Taxonomy of Penicillium citrinum and related species

    NARCIS (Netherlands)

    Houbraken, J.; Frisvad, J.C.; Samson, R.A.

    2010-01-01

    Penicillium citrinum and related species have been examined using a combination of partial beta-tubulin, calmodulin and ITS sequence data, extrolite patterns and phenotypic characters. It is concluded that seven species belong to the series Citrina. Penicillium sizovae and Penicillium steckii are

  19. Four new species of Emericella from the Mediterranean region of Europe.

    NARCIS (Netherlands)

    Zalar, P.; Frisvad, J.C.; Gunde-Cimerman, N.; Varga, J.; Samson, R.A.

    2008-01-01

    Four new species of Emericella, E. discophora, E. filifera, E. olivicola and E. stella-maris, are proposed. Their new taxonomic status was determined applying a polyphasic taxonomic approach using phenotypic (morphology and extrolite profiles) and molecular (sequences of ITS, beta-tubulin and

  20. BetaTPred: prediction of beta-TURNS in a protein using statistical algorithms.

    Science.gov (United States)

    Kaur, Harpreet; Raghava, G P S

    2002-03-01

    beta-turns play an important role from a structural and functional point of view. beta-turns are the most common type of non-repetitive structures in proteins and comprise on average, 25% of the residues. In the past numerous methods have been developed to predict beta-turns in a protein. Most of these prediction methods are based on statistical approaches. In order to utilize the full potential of these methods, there is a need to develop a web server. This paper describes a web server called BetaTPred, developed for predicting beta-TURNS in a protein from its amino acid sequence. BetaTPred allows the user to predict turns in a protein using existing statistical algorithms. It also allows to predict different types of beta-TURNS e.g. type I, I', II, II', VI, VIII and non-specific. This server assists the users in predicting the consensus beta-TURNS in a protein. The server is accessible from http://imtech.res.in/raghava/betatpred/

  1. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    -section. An investment strategy that goes long stocks with high jump betas and short stocks with low jump betas produces significant average excess returns. These higher risk premiums for the discontinuous and overnight market betas remain significant after controlling for a long list of other firm characteristics......Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross......-section of expected returns. Based on a novel highfrequency dataset of almost one-thousand individual stocks over two decades, we find that the two rough betas associated with intraday discontinuous and overnight returns entail significant risk premiums, while the intraday continuous beta is not priced in the cross...

  2. Plasma beta-endorphin, beta-lipotropin and corticotropin in polycystic ovarian disease.

    Science.gov (United States)

    Laatikainen, T; Salminen, K; Virtanen, T; Apter, D

    1987-04-01

    In 9 women with polycystic ovarian disease (PCOD) and in 11 control subjects at the follicular phase of the normal cycle, blood samples were collected at 15-min intervals during a 2 h period of bed rest for the assay of beta-endorphin, beta-lipotropin, corticotropin, cortisol and prolactin. During the study period, the plasma levels of these hormones decreased more significantly in the PCOD than in the control group, suggesting that the PCOD patients had a more significant stress response to the puncture of the vein than the control subjects. The second hour of the study period was considered to represent resting levels of hormones. The mean resting levels (+/- S.E.) of the hormones between the PCOD and control groups, respectively, were as follows: beta-E, 2.0 +/- 0.4 vs. 1.1 +/- 0.1 pmol/l, p less than 0.05; beta-LPH, 3.4 +/- 0.6 vs. 2.1 +/- 0.5 pmol/l, N.S.; corticotropin, 2.0 +/- 0.3 vs. 1.1 +/- 0.5 pmol/l, p less than 0.05; cortisol, 176 +/- 24 vs. 128 +/- 16, N.S.; and prolactin; 3.9 +/- 0.6 vs. 5.6 +/- 1.2 ng/ml, N.S. These results confirm the previous findings on increased circulating levels of beta-E in PCOD. A concomitant increase of the plasma level of corticotropin suggests that the basal secretion of both beta-E and corticotropin from the anterior pituitary gland is increased in women with PCOD.

  3. Molecular Characterization of Natural Fungal Flora in Black Olives: From Field to Table

    Directory of Open Access Journals (Sweden)

    Nisa Ozsoy

    2017-08-01

    Full Text Available In this study, molecular markers were used to determine fungal flora in black olive fruits from field surveys to the table, following the fermentation process. Field samples were collected from different locations of Canakkale province, including Gokceada (Imbros, where organic farming is employed. Some of the fruits from field samples were used for black table olive production and then fungal flora was tracked during the fermentation process. Fungal isolation was also conducted on some commercial samples. Fifty seven isolates from field samples, 56 isolates from the fermentation process and 17 isolates from commercial products were obtained. Among these isolates, 41 Alternaria, 43 Penicillium, 19 Aspergillus, 8 Monascus and 19 other genera were determined using amplified sizes of the Beta-tubulin gene region. Species level identification was carried out based on sequences of Beta-tubulin amplicons, which provided accurate identification, especially where the genera were morphologically highly similar. The occurrence and prevalence of fungal species changed in fungal collections from the field to the fermentation process. While Alternaria alternata was common in field samples, they were absent during fermentation. Many of these identified species, such as Penicillium expansum, Aspergillus niger and Monascus pilosus, which are known as potential toxin producers such as aflatoxin, ochratoxin A and citrinin, were found both in natural and fermented samples, even at the end of the fermentation process. These results showed that some fungal species which survive on olives from the field to the table are potential toxin producers and can be successfully characterized by amplification and sequencing of Beta-tubulin gene.

  4. On the importance of targeting parasite stem cells in anti-echinococcosis drug development

    Directory of Open Access Journals (Sweden)

    Brehm Klaus

    2014-01-01

    Full Text Available The life-threatening diseases alveolar and cystic echinococcoses are caused by larvae of the tapeworms Echinococcus multilocularis and E. granulosus, respectively. In both cases, intermediate hosts, such as humans, are infected by oral uptake of oncosphere larvae, followed by asexual multiplication and almost unrestricted growth of the metacestode within host organs. Besides surgery, echinococcosis treatment relies on benzimidazole-based chemotherapy, directed against parasite beta-tubulin. However, since beta-tubulins are highly similar between cestodes and humans, benzimidazoles can only be applied at parasitostatic doses and are associated with adverse side effects. Mostly aiming at identifying alternative drug targets, the nuclear genome sequences of E. multilocularis and E. granulosus have recently been characterized, revealing a large number of druggable targets that are expressed by the metacestode. Furthermore, recent cell biological investigations have demonstrated that E. multilocularis employs pluripotent stem cells, called germinative cells, which are the only parasite cells capable of proliferation and which give rise to all differentiated cells. Hence, the germinative cells are the crucial cell type mediating proliferation of E. multilocularis, and most likely also E. granulosus, within host organs and should also be responsible for parasite recurrence upon discontinuation of chemotherapy. Interestingly, recent investigations have also indicated that germinative cells might be less sensitive to chemotherapy because they express a beta-tubulin isoform with limited affinity to benzimidazoles. In this article, we briefly review the recent findings concerning Echinococcus genomics and stem cell research and propose that future research into anti-echinococcosis drugs should also focus on the parasite’s stem cell population.

  5. Alzheimer’s Disease Risk Gene CD33 Inhibits Microglial Uptake of Amyloid Beta

    Science.gov (United States)

    Griciuc, Ana; Serrano-Pozo, Alberto; Parrado, Antonio R.; Lesinski, Andrea N.; Asselin, Caroline N.; Mullin, Kristina; Hooli, Basavaraj; Choi, Se Hoon; Hyman, Bradley T.; Tanzi, Rudolph E.

    2013-01-01

    SUMMARY The transmembrane protein CD33 is a sialic acid-binding immunoglobulin-like lectin that regulates innate immunity but has no known functions in the brain. We have previously shown that the CD33 gene is a risk factor for Alzheimer’s disease (AD). Here, we observed increased expression of CD33 in microglial cells in AD brain. The minor allele of the CD33 SNP rs3865444, which confers protection against AD, was associated with reductions in both CD33 expression and insoluble amyloid beta 42 (Aβ42) levels in AD brain. Furthermore, the numbers of CD33-immunoreactive microglia were positively correlated with insoluble Aβ42 levels and plaque burden in AD brain. CD33 inhibited uptake and clearance of Aβ42 in microglial cell cultures. Finally, brain levels of insoluble Aβ42 as well as amyloid plaque burden were markedly reduced in APPSwe/PS1ΔE9/CD33−/− mice. Therefore, CD33 inactivation mitigates Aβ pathology and CD33 inhibition could represent a novel therapy for AD. PMID:23623698

  6. An experimental test of stroke recovery by implanting a hyaluronic acid hydrogel carrying a Nogo receptor antibody in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Ma Jun [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Tian Weiming [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Hou Shaoping [Beijing Institute of Neuroscience, Capital University of Medical Sciences, Beijing 100054 (China); Xu Qunyuan [Beijing Institute of Neuroscience, Capital University of Medical Sciences, Beijing 100054 (China); Spector, Myron [Tissue Engineering, VA Boston Healthcare System, Harvard Medical School, Boston, MA (United States); Cui Fuzhai [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2007-12-15

    The objective of the study was to determine the effects of a hyaluronic-acid-based (HA-based) hydrogel implant, carrying a polyclonal antibody to the Nogo-66 receptor (NgR), on adult rats that underwent middle cerebral artery occlusion (MCAO). Behavioral tests of a forelimb-reaching task suggested that the disabled function of the impaired forelimb in this stroke model was ameliorated by the implant to a certain extent. These behavioral findings were correlated with immunohistochemical results of investigating the distribution of NgR antibody, neurofilaments (NF) and neuron-specific class III {beta}-tubulin (TuJ1) in the brain sections. The porous hydrogel functioned as a scaffold to deliver the NgR antibody, support cell migration and development. In addition, it was found NF-positive and TuJ1-positive expressions were distributed in the implanted hydrogel. Collectively, the results demonstrate the promise of the HA hydrogel as a scaffold material and the delivery vehicle of the NgR antibody for the repair of defects and the support of neural regeneration in the brain.

  7. TBCD links centriologenesis, spindle microtubule dynamics, and midbody abscission in human cells.

    Directory of Open Access Journals (Sweden)

    Mónica López Fanarraga

    2010-01-01

    Full Text Available Microtubule-organizing centers recruit alpha- and beta-tubulin polypeptides for microtubule nucleation. Tubulin synthesis is complex, requiring five specific cofactors, designated tubulin cofactors (TBCs A-E, which contribute to various aspects of microtubule dynamics in vivo. Here, we show that tubulin cofactor D (TBCD is concentrated at the centrosome and midbody, where it participates in centriologenesis, spindle organization, and cell abscission. TBCD exhibits a cell-cycle-specific pattern, localizing on the daughter centriole at G1 and on procentrioles by S, and disappearing from older centrioles at telophase as the protein is recruited to the midbody. Our data show that TBCD overexpression results in microtubule release from the centrosome and G1 arrest, whereas its depletion produces mitotic aberrations and incomplete microtubule retraction at the midbody during cytokinesis. TBCD is recruited to the centriole replication site at the onset of the centrosome duplication cycle. A role in centriologenesis is further supported in differentiating ciliated cells, where TBCD is organized into "centriolar rosettes". These data suggest that TBCD participates in both canonical and de novo centriolar assembly pathways.

  8. On Fuzzy {beta}-I-open sets and Fuzzy {beta}-I-continuous functions

    Energy Technology Data Exchange (ETDEWEB)

    Keskin, Aynur [Department of Mathematics, Faculty of Science and Arts, Selcuk University, Campus, 42075 Konya (Turkey)], E-mail: akeskin@selcuk.edu.tr

    2009-11-15

    In this paper, first of all we obtain some properties and characterizations of fuzzy {beta}-I-open sets. After that, we also define the notion of {beta}-I-closed sets and obtain some properties. Lastly, we introduce the notions of fuzzy {beta}-I-continuity with the help of fuzzy {beta}-I-open sets to obtain decomposition of fuzzy continuity.

  9. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...... microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

  10. Characteristics of MR imaging of brain stem glioma for the treatment of combination chemotherapy with interferon-. beta. and ACNU in addition to radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wakabayashi, Toshihiko; Yoshida, Jun; Sugita, Kenichiro (Nagoya Univ. (Japan). Faculty of Medicine)

    1990-08-01

    In an attempt to improve the prognosis of brain stem glioma patients, a new treatment using a combination of chemotherapy of interferon-{beta}, ACNU, (1) - (4 - Amino - 2 - methyl - 5 - primidinyl) - methyl - 3 - (2-chloroethyl) - 3 -nitrosourea hydrochloride, and radiation, so called IAR therapy, was utilized on 19 patients who were diagnosed through CT and/or MRI findings as having pontine glioma. Eight of these patients were given IAR therapy at four week intervals and the changes were checked on MRI. The MRI response was classified into 3 types, that is, type 1: diffuse low intensity lesion on T{sub 1} WI changing to isodensity and tumor mass disappearing rapidly; type 2: located high intensity lesion in low intensity on T{sub 1} WI once appearing on decreasing the whole tumor size, then this lesion disappearing gradually; type 3: spotted low and/or iso mosaic intensity lesion appearing on and after treatment, with little change in tumor mass. The type 1 patients showed rapid improvement of neurological deficits and good recovery was obtained. Type 2 patients also recovered well but at recurrent periods tended to show disseminated sings intraspinally. The type 3 patients did not recover from neurological deficits well. But there were no significant differences of prognosis among these 3 types. Furthermore, MRI showed more precise data than CT scan on brain stem lesions and seemed to be more useful for diagnosis and follow-up treatment than CT scan. Though it is suggested that IAR combination therapy should be respected as the first choice for the treatment of brain stem glioma, it is strongly requested that some maintenance therapy is established for continuing the reduction time after induction of complete or partial remission with IAR therapy. (author).

  11. Development and characterization of a TAPIR-like mouse monoclonal antibody to amyloid-beta.

    Science.gov (United States)

    Wang, Jun; Hara, Hideo; Makifuchi, Takao; Tabira, Takeshi

    2008-06-01

    Tissue amyloid plaque immuno-reactive (TAPIR) antibody was better related to the effect of immunotherapy in Alzheimer's disease (AD) than ELISA antibody. Here we used a hybridoma technique to develop a TAPIR-like anti-human amyloid-beta (Abeta) mouse monoclonal antibody. The obtained monoclonal antibody, 3.4A10, was an IgG2b isotype and recognized N-terminal portion of Abeta1-42 without binding denatured or native amyloid-beta protein precursor. It had higher affinity to Abeta1-42 than to Abeta1-40 by Biacore affinity analysis and stained preferably the peripheral part of senile plaques and recognized the plaque core less than 4G8. It inhibited the Abeta1-42 fibril formation as well as degraded pre-aggregated Abeta1-42 peptide in a thioflavin T fluorescence spectrophotometry assay. The in vivo studies showed that 3.4A10 treatment decreased amyloid burden compared to the control group and significantly reduced Abeta42 levels rather than Abeta40 levels in brain lysates as well as the Abeta*56 oligomer (12mer) in TBS fraction of the brain lysates. 3.4A10 entered brain and decorated some plaques, which is surrounded by more Iba1-positive microglia. 3.4A10 therapy did not induce lymphocytic infiltration and obvious increase in microhemorrhage. We conclude that 3.4A10 is a TAPIR-like anti-human amyloid monoclonal antibody, and has a potential of therapeutic application for AD.

  12. N-Benzylhydroxylamine addition to beta-aryl enoates. Enantioselective synthesis of beta-aryl-beta-amino acid precursors

    Science.gov (United States)

    Sibi; Liu

    2000-10-19

    Chiral Lewis acid catalyzed N-benzylhydroxylamine addition to pyrrolidinone-derived enoates afforded beta-aryl-beta-amino acid derivatives in high enantiomeric purity with moderate to very good chemical efficiency.

  13. PERIPHERAL LIPOPOLYSACCHARIDE STIMULATION INDUCES INTERLEUKIN-1-BETA MESSENGER-RNA IN RAT-BRAIN MICROGLIAL CELLS

    NARCIS (Netherlands)

    BUTTINI, M; BODDEKE, H

    The inflammatory cytokine interleukin-1 acts as an endogenous pyrogen in organisms affected by infectious diseases and has been shown to influence the activity of the central nervous system. Using in situ hybridization histochemistry, we have examined the cellular source of interleukin-1 beta in rat

  14. Aspergillus bertholletius sp. nov. from Brazil Nuts

    DEFF Research Database (Denmark)

    Taniwaki, Marta H.; Pitt, John I.; Iamanaka, Beatriz T.

    2012-01-01

    During a study on the mycobiota of brazil nuts (Bertholletia excelsa) in Brazil, a new Aspergillus species, A. bertholletius, was found, and is described here. A polyphasic approach was applied using morphological characters, extrolite data as well as partial beta-tubulin, calmodulin and ITS sequ...

  15. Proteomic analysis of Brassica alboglabra in Response to Herbicide ...

    African Journals Online (AJOL)

    Aishah

    2013-05-15

    May 15, 2013 ... compared to the untreated group which include HSC-cognate binding proteins, adenosylmethionine synthetase and beta-tubulin involved in defence mechanism in plants. Little is known about the function of other proteins identified which include knox-like proteins and hypothetical protein. Further.

  16. Sustained effects of ecstasy on the human brain: a prospective neuroimaging study in novel users.

    Science.gov (United States)

    de Win, Maartje M L; Jager, Gerry; Booij, Jan; Reneman, Liesbeth; Schilt, Thelma; Lavini, Cristina; Olabarriaga, Sílvia D; den Heeten, Gerard J; van den Brink, Wim

    2008-11-01

    Previous studies have suggested toxic effects of recreational ecstasy use on the serotonin system of the brain. However, it cannot be excluded that observed differences between users and non-users are the cause rather than the consequence of ecstasy use. As part of the Netherlands XTC Toxicity (NeXT) study, we prospectively assessed sustained effects of ecstasy use on the brain in novel ecstasy users using repeated measurements with a combination of different neuroimaging parameters of neurotoxicity. At baseline, 188 ecstasy-naive volunteers with high probability of first ecstasy use were examined. After a mean period of 17 months follow-up, neuroimaging was repeated in 59 incident ecstasy users and 56 matched persistent ecstasy-naives and their outcomes were compared. Neuroimaging included [(123)I]beta-carbomethoxy-3beta-(4-iodophenyl)tropane (CIT) SPECT to measure serotonin transporter densities as indicators of serotonergic function; (1)H-MR spectroscopy ((1)H-MRS) to measure brain metabolites as indicators of neuronal damage; diffusion tensor imaging (DTI) to measure the apparent diffusion coefficient and fractional anisotropy (FA) of the diffusional motion of water molecules in the brain as indicators of axonal integrity; and perfusion weighted imaging (PWI) to measure regional relative cerebral blood volume (rrCBV) which indicates brain perfusion. With this approach, both structural ((1)H-MRS and DTI) and functional ([(123)I]beta-CIT SPECT and PWI) aspects of neurotoxicity were combined. Compared to persistent ecstasy-naives, novel low-dose ecstasy users (mean 6.0, median 2.0 tablets) showed decreased rrCBV in the globus pallidus and putamen; decreased FA in thalamus and frontoparietal white matter; increased FA in globus pallidus; and increased apparent diffusion coefficient in the thalamus. No changes in serotonin transporter densities and brain metabolites were observed. These findings suggest sustained effects of ecstasy on brain microvasculature, white

  17. Beta Emission and Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-13

    Bremsstrahlung is continuous radiation produced by beta particles decelerating in matter; different beta emitters have different endpoint energies; high-energy betas interacting with high-Z materials will more likely produce bremsstrahlung; depending on the data, sometimes all you can say is that a beta emitter is present.

  18. Expression of a truncated receptor protein tyrosine phosphatase kappa in the brain of an adult transgenic mouse

    DEFF Research Database (Denmark)

    Shen, P; Canoll, P D; Sap, J

    1999-01-01

    that goal, we have used this mouse model to map the distribution of the truncated RPTP-kappa/beta-geo fusion protein in the adult mouse brain using beta-galactosidase as a marker enzyme. Visualization of the beta-galactosidase activity revealed a non-random pattern of expression, and identified cells......-6596]. Nevertheless, since the transgene's expression is driven by the endogenous RPTP-kappa promoter, distribution of the truncated RPTP-kappa/beta-geo fusion protein should reflect the regional and cellular expression of wild-type RPTP-kappa, and thus may identify sites where RPTP-kappa is important. Towards...

  19. Prediction of treatment outcome in patients with obsessive-compulsive disorder with Low-Resolution Brain Electromagnetic Tomography: a prospective EEG study

    Directory of Open Access Journals (Sweden)

    Daniela eKrause

    2016-01-01

    Full Text Available The issue of predicting treatment response and identifying, in advance, which patient will profit from treating obsessive-compulsive disorder (OCD seems to be an elusive goal. This prospective study investigated brain electric activity (using Low-Resolution Brain Electromagnetic Tomography (LORETA for the purpose of predicting response to treatment. Forty-one unmedicated patients with a DSM-IV diagnosis of OCD were included. A resting 32-channel EEG was obtained from each participant before and after ten weeks of standardized treatment with sertraline and behavioral therapy. LORETA was used to localize the sources of brain electrical activity. At week ten, patients were divided into responders and non-responders (according to a reduction of symptom severity > 50% on the Y-BOCS. LORETA analysis revealed that at baseline responders showed compared to non-responders a significantly lower brain electric activity within the beta 1 (t=2.86, p<0.05, 2 (t=2.81, p<0.05 and 3 (t=2.76, p<0.05 frequency bands and ROI analysis confirmed a reduced activity in alpha 2 (t=2.06, p<0.05 in the anterior cingulate cortex (ACC. When baseline LORETA data were compared to follow-up data, the analysis showed in the responder group a significantly lower brain electrical resting activity in the beta 1 (t=3.17. p<0.05 and beta 3 (t=3.11. p<0.05 frequency bands and equally for the ROI analysis of the orbitofrontal cortex (OFC in the alpha 2 (t=2.15. p<0.05 frequency band. In the group of non-responders the opposite results were found. In addition, a positive correlation between frequency alpha 2 (rho=0.40, p=0.010, beta 3 (rho=0.42, p=0.006, delta (rho=0.33, p=0.038, theta (rho=0.34, p=0.031, alpha 1 (rho=0.38, p=0.015 and beta1 (rho=0.34, p=0.028 of the OFC and the bands delta (rho=0.33, p=0.035, alpha 1 (rho=0.36, p=0.019, alpha 2 (rho=0.34, p=0.031 and beta 3 (rho=0.38, p=0.015 of the ACC with a reduction of the Y-BOCS scores was identified.Our results suggest that

  20. Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

    CERN Document Server

    Brown, B A; Horoi, M

    2015-01-01

    The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

  1. Multiscale neural connectivity during human sensory processing in the brain

    Science.gov (United States)

    Maksimenko, Vladimir A.; Runnova, Anastasia E.; Frolov, Nikita S.; Makarov, Vladimir V.; Nedaivozov, Vladimir; Koronovskii, Alexey A.; Pisarchik, Alexander; Hramov, Alexander E.

    2018-05-01

    Stimulus-related brain activity is considered using wavelet-based analysis of neural interactions between occipital and parietal brain areas in alpha (8-12 Hz) and beta (15-30 Hz) frequency bands. We show that human sensory processing related to the visual stimuli perception induces brain response resulted in different ways of parieto-occipital interactions in these bands. In the alpha frequency band the parieto-occipital neuronal network is characterized by homogeneous increase of the interaction between all interconnected areas both within occipital and parietal lobes and between them. In the beta frequency band the occipital lobe starts to play a leading role in the dynamics of the occipital-parietal network: The perception of visual stimuli excites the visual center in the occipital area and then, due to the increase of parieto-occipital interactions, such excitation is transferred to the parietal area, where the attentional center takes place. In the case when stimuli are characterized by a high degree of ambiguity, we find greater increase of the interaction between interconnected areas in the parietal lobe due to the increase of human attention. Based on revealed mechanisms, we describe the complex response of the parieto-occipital brain neuronal network during the perception and primary processing of the visual stimuli. The results can serve as an essential complement to the existing theory of neural aspects of visual stimuli processing.

  2. Grasping hand verbs: oscillatory beta and alpha correlates of action-word processing.

    Directory of Open Access Journals (Sweden)

    Valentina Niccolai

    Full Text Available The grounded cognition framework proposes that sensorimotor brain areas, which are typically involved in perception and action, also play a role in linguistic processing. We assessed oscillatory modulation during visual presentation of single verbs and localized cortical motor regions by means of isometric contraction of hand and foot muscles. Analogously to oscillatory activation patterns accompanying voluntary movements, we expected a somatotopically distributed suppression of beta and alpha frequencies in the motor cortex during processing of body-related action verbs. Magnetoencephalographic data were collected during presentation of verbs that express actions performed using the hands (H or feet (F. Verbs denoting no bodily movement (N were used as a control. Between 150 and 500 msec after visual word onset, beta rhythms were suppressed in H and F in comparison with N in the left hemisphere. Similarly, alpha oscillations showed left-lateralized power suppression in the H-N contrast, although at a later stage. The cortical oscillatory activity that typically occurs during voluntary movements is therefore found to somatotopically accompany the processing of body-related verbs. The combination of a localizer task with the oscillatory investigation applied to verb reading as in the present study provides further methodological possibilities of tracking language processing in the brain.

  3. Production of beta-xylanase and beta-xylosidase by the extremely halophilic archaeon Halorhabdus utahensis

    DEFF Research Database (Denmark)

    Wainø, M.; Ingvorsen, K.

    2003-01-01

    -xylosidase stabilities, approximately 55% and 83% of the initial beta-xylanase and beta-xylosidase activities, respectively, remained after 24 h incubation at 20% NaCl. The enzymes were also shown to be slightly thermophilic: P-xylanase activity exhibiting two optima at 55degrees and 70degreesC, while beta......The extremely halophilic archaeon, Halorhabdus utahensis, isolated from the Great Salt Lake, Utah, produced beta-xylanase and beta-xylosidase activities. Both enzymes were active over a broad NaCl range from near zero to 30% NaCl when tested with culture broth. A broad NaCl optimum was observed...... for beta-xylanase activity between 5% and 15% NaCl, while beta-xylosidase activity was highest at 5% NaCl. Almost half of the maximum activities remained at 27%-30% NaCl for both enzyme activities. When dialyzed culture supernatant and culture broth were employed for determination of beta-xylanase and beta...

  4. Role of beta-adrenoceptors in memory consolidation: beta3-adrenoceptors act on glucose uptake and beta2-adrenoceptors on glycogenolysis.

    Science.gov (United States)

    Gibbs, Marie E; Hutchinson, Dana S; Summers, Roger J

    2008-09-01

    Noradrenaline, acting via beta(2)- and beta(3)-adrenoceptors (AR), enhances memory formation in single trial-discriminated avoidance learning in day-old chicks by mechanisms involving changes in metabolism of glucose and/or glycogen. Earlier studies of memory consolidation in chicks implicated beta(3)- rather than beta(2)-ARs in enhancement of memory consolidation by glucose, but did not elucidate whether stimulation of glucose uptake or of glycolysis was responsible. This study examines the role of glucose transport in memory formation using central injection of the nonselective facilitative glucose transporter (GLUT) inhibitor cytochalasin B, the endothelial/astrocytic GLUT-1 inhibitor phloretin and the Na(+)/energy-dependent endothelial glucose transporter (SGLT) inhibitor phlorizin. Cytochalasin B inhibited memory when injected into the mesopallium (avian cortex) either close to or between 25 and 45 min after training, whereas phloretin and phlorizin only inhibited memory at 30 min. This suggested that astrocytic/endothelial (GLUT-1) transport is critical at the time of consolidation, whereas a different transporter, probably the neuronal glucose transporter (GLUT-3), is important at the time of training. Inhibition of glucose transport by cytochalasin B, phloretin, or phlorizin also interfered with beta(3)-AR-mediated memory enhancement 20 min posttraining, whereas inhibition of glycogenolysis interfered with beta(2)-AR agonist enhancement of memory. We conclude that in astrocytes (1) activities of both GLUT-1 and SGLT are essential for memory consolidation 30 min posttraining; (2) neuronal GLUT-3 is essential at the time of training; and (3) beta(2)- and beta(3)-ARs consolidate memory by different mechanisms; beta(3)-ARs stimulate central glucose transport, whereas beta(2)-ARs stimulate central glycogenolysis.

  5. Low-beta investment strategies

    OpenAIRE

    Korn, Olaf; Kuntz, Laura-Chloé

    2015-01-01

    This paper investigates investment strategies that exploit the low-beta anomaly. Although the notion of buying low-beta stocks and selling high-beta stocks is natural, a choice is necessary with respect to the relative weighting of high-beta stocks and low-beta stocks in the investment portfolio. Our empirical results for US large-cap stocks show that this choice is very important for the risk-return characteristics of the resulting portfolios and their sensitivities to common risk factors. W...

  6. Ellagic acid promotes A{beta}42 fibrillization and inhibits A{beta}42-induced neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ying [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Yang, Shi-gao; Du, Xue-ting; Zhang, Xi; Sun, Xiao-xia; Zhao, Min [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Sun, Gui-yuan, E-mail: sungy2004@sohu.com [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Liu, Rui-tian, E-mail: rtliu@tsinghua.edu.cn [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China)

    2009-12-25

    Smaller, soluble oligomers of {beta}-amyloid (A{beta}) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of A{beta} oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against A{beta} neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on A{beta}42 aggregation and neurotoxicity in vitro. EA promoted A{beta} fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited A{beta} aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in A{beta}42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic A{beta} aggregates to render them harmless, our MTT results showed that EA could significantly reduce A{beta}42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.

  7. Microtubules as a Critical Target for Arsenic Toxicity in Lung Cells in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Yinzhi Zhao

    2012-02-01

    Full Text Available To understand mechanisms for arsenic toxicity in the lung, we examined effects of sodium m-arsenite (As3+ on microtubule (MT assembly in vitro (0–40 µM, in cultured rat lung fibroblasts (RFL6, 0–20 µM for 24 h and in the rat animal model (intratracheal instillation of 2.02 mg As/kg body weight, once a week for 5 weeks. As3+ induced a dose-dependent disassembly of cellular MTs and enhancement of the free tubulin pool, initiating an autoregulation of tubulin synthesis manifest as inhibition of steady-state mRNA levels of βI-tubulin in dosed lung cells and tissues. Spindle MT injuries by As3+ were concomitant with chromosomal disorientations. As3+ reduced the binding to tubulin of [3H]N-ethylmaleimide (NEM, an -SH group reagent, resulting in inhibition of MT polymerization in vitro with bovine brain tubulins which was abolished by addition of dithiothreitol (DTT suggesting As3+ action upon tubulin through -SH groups. In response to As3+, cells elevated cellular thiols such as metallothionein. Taxol, a tubulin polymerization agent, antagonized both As3+ and NEM induced MT depolymerization. MT–associated proteins (MAPs essential for the MT stability were markedly suppressed in As3+-treated cells. Thus, tubulin sulfhydryls and MAPs are major molecular targets for As3+ damage to the lung triggering MT disassembly cascades.

  8. Rapid synthesis of beta zeolites

    Science.gov (United States)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  9. Effects of enriched uranium on developing brain damage of neonatal rats

    Energy Technology Data Exchange (ETDEWEB)

    Guixiong, Gu; Shoupeng, Zhu; Liuyi, Wang; Shuqin, Yang; Lingli, Zhu [Suzhou Medical College, Suzhou (China)

    2001-04-01

    The model of irradiation-induced brain damage in vivo was settled first of all. The micro-auto-radiographic tracing showed that when the rat's brain at postnatal day after lateral ventricle injection with enriched uranium {sup 235}U the radionuclides were mainly accumulated in the nucleus. At the same time autoradiographic tracks appeared in the cytoplasm and interval between cells. The effects of cerebrum exposure to alpha irradiation by enriched uranium on somatic growth and neuro-behavior development of neonatal rats were examined by determination of multiple parameters. In the growth and development of the neonatal rat's cerebrum exposure to enriched uranium, the somatic growth such as body weight and brain weight increase was lower significantly. The data indicated that the neonatal wistar rats having cerebrum exposure to alpha irradiation by enriched uranium showed delayed growth and abnormal neuro-behavior. The changes of neuron specific enolase (NSE), interleukin-1 {beta} (IL- {beta}), superoxide dismutase (SOD), and endothelin (ET) in cerebellum, cerebral cortex, hippocampus, diencephalons of the rat brain after expose to alpha irradiation by enriched uranium were examined with radioimmunoassay. The results showed that SOD and ET can be elevated by the low dose irradiation of enriched uranium, and can be distinctly inhibited by the high dose. The data in view of biochemistry indicated firstly that alpha irradiation from enriched uranium on the developing brain damage of neonatal rats were of sensibility, fragility and compensation in nervous cells.

  10. Active-site-directed inactivation of Aspergillus oryzae beta-galactosidase with beta-D-galactopyranosylmethyl-p-nitrophenyltriazene.

    Science.gov (United States)

    Mega, T; Nishijima, T; Ikenaka, T

    1990-04-01

    beta-D-Galactopyranosylmethyl-p-nitrophenyltriazene (beta-GalMNT), a specific inhibitor of beta-galactosidase, was isolated as crystals by HPLC and its chemical and physicochemical characteristics were examined. Aspergillus oryzae beta-galactosidase was inactivated by the compound. We studied the inhibition mechanism in detail. The inhibitor was hydrolyzed by the enzyme to p-nitroaniline and an active intermediate (beta-galactopyranosylmethyl carbonium or beta-galactopyranosylmethyldiazonium), which inactivated the enzyme. The efficiency of inactivation of the enzyme (the ratio of moles of inactivated enzyme to moles of beta-GalMNT hydrolyzed by the enzyme) was 3%; the efficiency of Escherichia coli beta-galactosidase was 49%. In spite of the low efficiency, the rate of inactivation of A. oryzae enzyme was not very different from that of the E. coli enzyme, because the former hydrolyzed beta-GalMNT faster than the latter did. A. oryzae beta-galactosidase was also inactivated by p-chlorophenyl, p-tolyl, and m-nitrophenyl derivatives of beta-galactopyranosylmethyltriazene. However, E. coli beta-galactosidase was not inactivated by these triazene derivatives. The results showed that the inactivation of A. oryzae and E. coli beta-galactosidases by beta-GalMNT was an enzyme-activated and active-site-directed irreversible inactivation. The possibility of inactivation by intermediates produced nonenzymatically was ruled out for E. coli, but not for the A. oryzae enzyme.

  11. UPTAKE OF [3H]-COLCHICINE INTO BRAIN AND LIVER OF MOUSE, RAT, AND CHICK

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Edward L.; Alberti, Marie Hebert; Flood, James F.

    1980-07-01

    The uptake of [ring A-4-{sup 3}H] colchicine and [ring C-methoxy-{sup 3}H]colchicine has been compared in mice from 1 to 24 hr after administration. Less radioactivity was found in brain after administration of ring-labeled colchicine than after administration of the methoxy-labeled colchicine. Three hr after administration of ring-labeled colchicine, 5% of the label was in liver and about 0.01% of the label was present in brain. Forty percent of the brain radioactivity was bound to tubulin as determined by vinblastine precipitation. After 3 hr, an average of 8% of the radioactivity from methoxy-labeled colchicine was found in the liver and 0.16% in brain. However, less than 5% of the activity in brain was precipitated by vinblastine, and the colchicine equivalent was comparable to that found after administration of the ring-labeled colchicine. The amount of colchicine entering mouse brain after subcutaneous injection is comparable to the minimum behaviorally effective dose when administered to the caudate. The metabolism of [ring C-methoxy-{sup 3}H] and [ring A-{sup 3}H]colchicine was also studied in rats. the general pattern was similar to mice; less radioactivity was found in brain after administration of the ring-labeled alkoloid than after administration of methoxy-labeled colchicine. Again, 40-50% of ring-labeled colchicine was precipitated by vinblastine. A much smaller percentage of the methoxy-labeled drug was precipitated by vinblastine than of the ring A-labeled colchicine. These experiments, together with behavioral experiments [7], support the hypotheses that structural alteration in synapses by recently synthesized proteins which are transported down the axons and dendrites may be an essential process for long-term memory formation.

  12. Maternal plasma concentrations of beta-lipotrophin, beta-endorphin and gamma-lipotrophin throughout pregnancy.

    Science.gov (United States)

    Browning, A J; Butt, W R; Lynch, S S; Shakespear, R A

    1983-12-01

    Plasma beta-LPH, beta-EP and gamma-LPH concentrations were measured by radioimmunoassay in 10 pregnant women from 12 weeks gestation until term and in nine women in the early follicular phase of the cycle. There was a progressive and significant rise in the concentration of all three peptides throughout pregnancy and by 32 weeks the concentrations of beta-LPH and beta-EP were greater than the corresponding concentrations in the follicular phase: gamma-LPH was greater than in the follicular phase by the end of pregnancy in those women who were delivered after 40 weeks. The ratio of beta-LPH to gamma-LPH did not change significantly throughout pregnancy, but there was a progressive fall in the beta-LPH/beta-EP ratio. The possible presence of a 'big LPH' to explain this finding is discussed.

  13. Biological markers of amyloid beta-related mechanisms in Alzheimer's disease.

    LENUS (Irish Health Repository)

    Hampel, Harald

    2010-06-01

    Recent research progress has given detailed knowledge on the molecular pathogenesis of Alzheimer\\'s disease (AD), which has been translated into an intense, ongoing development of disease-modifying treatments. Most new drug candidates are targeted on inhibiting amyloid beta (Abeta) production and aggregation. In drug development, it is important to co-develop biomarkers for Abeta-related mechanisms to enable early diagnosis and patient stratification in clinical trials, and to serve as tools to identify and monitor the biochemical effect of the drug directly in patients. Biomarkers are also requested by regulatory authorities to serve as safety measurements. Molecular aberrations in the AD brain are reflected in the cerebrospinal fluid (CSF). Core CSF biomarkers include Abeta isoforms (Abeta40\\/Abeta42), soluble APP isoforms, Abeta oligomers and beta-site APP-cleaving enzyme 1 (BACE1). This article reviews recent research advances on core candidate CSF and plasma Abeta-related biomarkers, and gives a conceptual review on how to implement biomarkers in clinical trials in AD.

  14. Biological markers of amyloid beta-related mechanisms in Alzheimer's disease.

    LENUS (Irish Health Repository)

    Hampel, Harald

    2012-02-01

    Recent research progress has given detailed knowledge on the molecular pathogenesis of Alzheimer\\'s disease (AD), which has been translated into an intense, ongoing development of disease-modifying treatments. Most new drug candidates are targeted on inhibiting amyloid beta (Abeta) production and aggregation. In drug development, it is important to co-develop biomarkers for Abeta-related mechanisms to enable early diagnosis and patient stratification in clinical trials, and to serve as tools to identify and monitor the biochemical effect of the drug directly in patients. Biomarkers are also requested by regulatory authorities to serve as safety measurements. Molecular aberrations in the AD brain are reflected in the cerebrospinal fluid (CSF). Core CSF biomarkers include Abeta isoforms (Abeta40\\/Abeta42), soluble APP isoforms, Abeta oligomers and beta-site APP-cleaving enzyme 1 (BACE1). This article reviews recent research advances on core candidate CSF and plasma Abeta-related biomarkers, and gives a conceptual review on how to implement biomarkers in clinical trials in AD.

  15. Optimized formation of detergent micelles of beta-carotene and retinal production using recombinant human beta,beta-carotene 15,15'-monooxygenase.

    Science.gov (United States)

    Kim, Nam-Hee; Kim, Yeong-Su; Kim, Hye-Jung; Oh, Deok-Kun

    2008-01-01

    The formation of beta-carotene detergent micelles and their conversion into retinal by recombinant human beta,beta-carotene 15,15'-monooxygenase was optimized under aqueous conditions. Toluene was the most hydrophobic among the organic solvents tested; thus, it was used to dissolve beta-carotene, which is a hydrophobic compound. Tween 80 was selected as the detergent because it supported the highest level of retinal production among all of the detergents tested. The maximum production of retinal was achieved in detergent micelles containing 200 mg/L of beta-carotene and 2.4% (w/v) Tween 80. Under these conditions, the recombinant enzyme produced 97 mg/L of retinal after 16 h with a conversion yield of 48.5% (w/w). The amount of retinal produced, which is the highest ever reported, is a result of the ability of our system to dissolve large amounts of beta-carotene.

  16. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades...... in the expansion of the beta cell mass in human pregnancy, and the relative roles of endocrine factors and nutrients....

  17. Phagocytosis of haemozoin (malarial pigment enhances metalloproteinase-9 activity in human adherent monocytes: Role of IL-1beta and 15-HETE

    Directory of Open Access Journals (Sweden)

    Giribaldi Giuliana

    2008-08-01

    possibly responsible for increase of both IL-1beta production and MMP-9 activity. Conclusion Results indicate that specific lipoperoxide derivatives generated by HZ may play a role in modulating production of IL-1beta and MMP-9 expression and activity in HZ/trophozoite-fed human monocytes. Results may clarify aspects of cerebral malaria pathogenesis, since MMP-9, a metalloproteinase able to disrupt the basal lamina is possibly involved in generation of hallmarks of cerebral malaria, such as blood-brain barrier endothelium dysfunction, localized haemorrhages and extravasation of phagocytic cells and parasitized RBCs into brain tissues.

  18. Brain alpha- and beta-globin expression after intracerebral hemorrhage

    OpenAIRE

    He, Yangdong; Hua, Ya; Lee, Jin-Yul; Liu, Wenquan; Keep, Richard F; Wang, Michael M.; Xi, Guohua

    2010-01-01

    Our recent study has demonstrated that hemoglobin (Hb) is present in cerebral neurons and neuronal Hb is inducible after cerebral ischemia. In the present study, we examined the effects of intracerebral hemorrhage (ICH) on the mRNA levels of the α-globin (HbA) and the β-globin (HbB) components of Hb and Hb protein in the brain in vivo and in vitro. In vivo, male Sprague-Dawley rats received either a needle insertion (sham) or an infusion of autologous whole blood into the basal ganglia and we...

  19. Beta spectrometry

    International Nuclear Information System (INIS)

    Dryak, P.; Zderadicka, J.; Plch, J.; Kokta, L.; Novotna, P.

    1977-01-01

    For the purpose of beta spectrometry, a semiconductor spectrometer with one Si(Li) detector cooled with liquid nitrogen was designed. Geometrical detection efficiency is about 10% 4 sr. The achieved resolution for 624 keV conversion electrons of sup(137m)Ba is 2.6 keV (FWHM). A program was written in the FORTRAN language for the correction of the deformation of the measured spectra by backscattering in the analysis of continuous beta spectra. The method permits the determination of the maximum energy of the beta spectrum with an accuracy of +-5 keV. (author)

  20. DMPD: Immunoreceptor-like signaling by beta 2 and beta 3 integrins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17913496 Immunoreceptor-like signaling by beta 2 and beta 3 integrins. Jakus Z, Fod...) Show Immunoreceptor-like signaling by beta 2 and beta 3 integrins. PubmedID 17913496 Title Immunoreceptor-...like signaling by beta 2 and beta 3 integrins. Authors Jakus Z, Fodor S, Abram CL

  1. Identification of active anti-inflammatory principles of beta- beta ...

    African Journals Online (AJOL)

    chromatography. Components of the extracts were identified by thin layer chromatography (TLC) scanner and UV-visible spectroscopy, using scopoletin as standard. Results: ... basic coumarin skeleton ring structure reduce ... Figure 2: Thin-layer chromatogram: (1) Ethanol extract; (2) Dichloromethane fraction; (3) Beta-beta.

  2. Dimers of beta 2-glycoprotein I mimic the in vitro effects of beta 2-glycoprotein I-anti-beta 2-glycoprotein I antibody complexes

    NARCIS (Netherlands)

    Lutters, B. C.; Meijers, J. C.; Derksen, R. H.; Arnout, J.; de Groot, P. G.

    2001-01-01

    Anti-beta(2)-glycoprotein I antibodies are thought to cause lupus anticoagulant activity by forming bivalent complexes with beta(2)-glycoprotein I (beta(2)GPI). To test this hypothesis, chimeric fusion proteins were constructed of the dimerization domain (apple 4) of factor XI and beta(2)GPI. Both a

  3. Exercise- and cold-induced changes in plasma beta-endorphin and beta-lipotropin in men and women.

    Science.gov (United States)

    Viswanathan, M; Van Dijk, J P; Graham, T E; Bonen, A; George, J C

    1987-02-01

    The plasma beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH) response of men, eumenorrheic women, and amenorrheic women (n = 6) to 1 h of rest or to a bicycle ergometer test [20 min at 30% maximum O2 uptake (VO2max), 20 min at 60% VO2max, and at 90% VO2max to exhaustion] was studied in both normal (22 degrees C) and cold (5 degrees C) environments. beta-EP and beta-LPH was measured by radioimmunoassay in venous samples collected every 20 min during rest or after each exercise bout. Exhaustive exercise at ambient temperature (Ta) 22 degrees C induced significant increases in plasma beta-EP and beta-LPH in all subjects as did work at 60% VO2max in amenorrheic and eumenorrheic women. During work at Ta 5 degrees C, the relative increase in beta-EP and beta-LPH was suppressed in eumenorrheic women and completely prevented in amenorrheic women. Although significant lowering of beta-EP and beta-LPH was observed in men and eumenorrheic women during rest at 5 degrees C, amenorrheic women maintained precold exposure levels. These findings suggest that plasma beta-EP and beta-LPH may reflect a thermoregulatory response to heat load. There appears to be a sexual dimorphism in exercise- and cold-induced release of beta-EP and beta-LPH and amenorrhea may be accompanied by alterations in these responses.

  4. Beta-amyloidolysis and glutathione in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Lasierra-Cirujeda J

    2013-04-01

    Full Text Available J Lasierra-Cirujeda,1 P Coronel,2 MJ Aza,3 M Gimeno2 1CM Hematológico SC, Logroño, La Rioja, Spain; 2Tedec-Meiji Farma, SA, Alcalá de Henares, Madrid, Spain; 3Pharmaceutical Act, Ministry of Health, Regional Government, La Rioja, Spain Abstract: In this review, we hypothesized the importance of the interaction between the brain glutathione (GSH system, the proteolytic tissue plasminogen activator (t-PA/plasminogen/plasmin system, regulated by plasminogen activator inhibitor (PAI-1, and neuroserpin in the pathogenesis of Alzheimer's disease. The histopathological characteristic hallmark that gives personality to the diagnosis of Alzheimer's disease is the accumulation of neurofibroid tangles located intracellularly in the brain, such as the protein tau and extracellular senile plaques made primarily of amyloidal substance. These formations of complex etiology are intimately related to GSH, brain protective antioxidants, and the proteolytic system, in which t-PA plays a key role. There is scientific evidence that suggests a relationship between aging, a number of neurodegenerative disorders, and the excessive production of reactive oxygen species and accompanying decreased brain proteolysis. The plasminogen system in the brain is an essential proteolytic mechanism that effectively degrades amyloid peptides ("beta-amyloidolysis" through action of the plasmin, and this physiologic process may be considered to be a means of prevention of neurodegenerative disorders. In parallel to the decrease in GSH levels seen in aging, there is also a decrease in plasmin brain activity and a progressive decrease of t-PA activity, caused by a decrease in the expression of the t-PA together with an increase of the PAI-1 levels, which rise to an increment in the production of amyloid peptides and a lesser clearance of them. Better knowledge of the GSH mechanism and cerebral proteolysis will allow us to hypothesize about therapeutic practices. Keywords: glutathione

  5. beta-Thalassemia present in cis to a new beta-chain structural variant, Hb Vicksburg [beta 75 (E19)Leu leads to 0].

    Science.gov (United States)

    Adams, J G; Steinberg, M H; Newman, M V; Morrison, W T; Benz, E J; Iyer, R

    1981-01-01

    Hemoglobin Vicksburg was discovered in a 6-year-old Black boy who had been anemic since infancy. Examination of his hemolysate revealed 87.5% Hb F, 2.4% Hb A2, and 7.6% Hb Vicksburg, which had the electrophoretic and chromatographic properties of Hb A. Structural analysis of Hb Vicksburg demonstrated a deletion of leucine at beta 75(E19), a new variant. Hb Vicksburg was neither unstable nor subject to posttranslational degradation. The alpha/non-alpha biosynthetic ratio was 2.6. Because the proband appeared to be a mixed heterozygote for Hb Vicksburg and beta 0-thalassemia, Hb Vicksburg should have comprised the major portion of the hemolysate. Thus, Hb Vicksburg was synthesized at a rate considerably lower than would be expected on the basis of gene dosage. There was no reason to suspect abnormal translation of beta Vicksburg mRNA; in individuals with Hb St. Antoine (beta 74 and beta 75 deleted), the abnormal hemoglobin comprised 25% of the hemolysate in the simple heterozygote yet was unstable. Deletion of beta 75, therefore, would not in itself appear to lead to diminished synthesis. There was a profound deficit of beta Vicksburg mRNA when measured by liquid hybridization analysis with beta cDNA. The most plausible explanation for the low output of Hb Vicksburg is that a mutation for beta +-thalassemia is present in cis to the structural mutation.

  6. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...

  7. beta-Carotene in breast milk and serum is increased after a single beta-carotene dose.

    Science.gov (United States)

    Canfield, L M; Giuliano, A R; Neilson, E M; Yap, H H; Graver, E J; Cui, H A; Blashill, B M

    1997-07-01

    Normal lactating mothers were administered a single dose of 60 or 210 mg beta-carotene and changes in serum and milk retinol, alpha-tocopherol, and carotenoids were monitored for 8 d. Average serum beta-carotene concentrations increased 4.1- and 4.0-fold after the 60- and 210-mg doses, respectively. Milk beta-carotene concentrations increased 4.1- and 3.0-fold after the 60- and 210-mg doses, respectively. Maximum serum concentrations were reached 24 h after both supplements, although concentrations of milk beta-carotene continued to rise for 2-3 d. After 8 d, both serum and milk beta-carotene continued to rise for 2-3 d. After 8 d, both serum and milk beta-carotene concentrations remained about twofold higher than baseline concentrations. Increases in serum or milk beta-carotene concentrations were not dose-dependent. Initial serum and milk concentrations of beta-carotene predicted increases after supplementation, and increases in serum beta-carotene concentrations predicted those in milk. Concentrations of milk carotenoids were less than one-tenth their respective concentrations in serum. Lutein, beta-cryptoxanthin, lycopene, alpha-carotene, retinol, and alpha-tocopherol concentrations in serum or milk did not change significantly after beta-carotene supplementation. Retinol esters account for most of the retinol equivalents in the milk of well-nourished mothers. Initial and maximum concentrations of beta-carotene in serum and milk were strongly correlated for individual mothers. Collectively, the data showed that a single 60-mg supplement of beta-carotene sustained elevated beta-carotene concentrations in serum and milk for > 1 wk in normal mothers but did not affect concentrations of other major carotenoids, retinol, or alpha-tocopherol.

  8. The common inhalation anesthetic isoflurane induces caspase activation and increases amyloid beta-protein level in vivo.

    Science.gov (United States)

    Xie, Zhongcong; Culley, Deborah J; Dong, Yuanlin; Zhang, Guohua; Zhang, Bin; Moir, Robert D; Frosch, Matthew P; Crosby, Gregory; Tanzi, Rudolph E

    2008-12-01

    An estimated 200 million patients worldwide have surgery each year. Anesthesia and surgery have been reported to facilitate emergence of Alzheimer's disease. The commonly used inhalation anesthetic isoflurane has previously been reported to induce apoptosis, and to increase levels and aggregation of Alzheimer's disease-associated amyloid beta-protein (Abeta) in cultured cells. However, the in vivo relevance has not been addressed. We therefore set out to determine effects of isoflurane on caspase activation and levels of beta-site amyloid precursor protein-cleaving enzyme (BACE) and Abeta in naive mice, using Western blot, immunohistochemistry, and reverse transcriptase polymerase chain reaction. Here we show for the first time that a clinically relevant isoflurane anesthesia (1.4% isoflurane for 2 hours) leads to caspase activation and modest increases in levels of BACE 6 hours after anesthesia in mouse brain. Isoflurane anesthesia induces caspase activation, and increases levels of BACE and Abeta up to 24 hours after anesthesia. Isoflurane may increase BACE levels by reducing BACE degradation. Moreover, the Abeta aggregation inhibitor, clioquinol, was able to attenuate isoflurane-induced caspase-3 activation in vivo. Given that transient insults to brain may lead to long-term brain damage, these findings suggest that isoflurane may promote Alzheimer's disease neuropathogenesis and, as such, have implications for use of isoflurane in humans, pending human study confirmation.

  9. Beta Thalassemia (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Beta Thalassemia KidsHealth / For Parents / Beta Thalassemia What's in this ... Symptoms Diagnosis Treatment Print en español Beta talasemia Thalassemias Thalassemias are a group of blood disorders that ...

  10. Amyloid-beta aggregates cause alterations of astrocytic metabolic phenotype: impact on neuronal viability

    OpenAIRE

    Allaman, Igor; Gavillet, Mathilde; Bélanger, Mireille; Laroche, Thierry; Viertl, David; Lashuel, Hilal A.; Magistretti, Pierre J.

    2010-01-01

    Amyloid-beta (Abeta) peptides play a key role in the pathogenesis of Alzheimer's disease and exert various toxic effects on neurons; however, relatively little is known about their influence on glial cells. Astrocytes play a pivotal role in brain homeostasis, contributing to the regulation of local energy metabolism and oxidative stress defense, two aspects of importance for neuronal viability and function. In the present study, we explored the effects of Abeta peptides on glucose metabolism ...

  11. Systematic Risk on Istanbul Stock Exchange: Traditional Beta Coefficient Versus Downside Beta Coefficient

    Directory of Open Access Journals (Sweden)

    Gülfen TUNA

    2013-03-01

    Full Text Available The aim of this study is to test the validity of Downside Capital Asset Pricing Model (D-CAPM on the ISE. At the same time, the explanatory power of CAPM's traditional beta and D-CAPM's downside beta on the changes in the average return values are examined comparatively. In this context, the monthly data for seventy three stocks that are continuously traded on the ISE for the period 1991-2009 is used. Regression analysis is applied in this study. The research results have shown that D-CAPM is valid on the ISE. In addition, it is obtained that the power of downside beta coefficient is higher than traditional beta coefficient on explaining the return changes. Therefore, it can be said that the downside beta is superior to traditional beta in the ISE for chosen period.

  12. Interferon beta and vitamin D synergize to induce immunoregulatory receptors on peripheral blood monocytes of multiple sclerosis patients.

    Directory of Open Access Journals (Sweden)

    Anne Waschbisch

    Full Text Available Immunoglobulin-like transcript (ILT 3 and 4 are inhibitory receptors that modulate immune responses. Their expression has been reported to be affected by interferon, offering a possible mechanism by which this cytokine exerts its therapeutic effect in multiple sclerosis, a condition thought to involve excessive immune activity. To investigate this possibility, we measured expression of ILT3 and ILT4 on immune cells from multiple sclerosis patients, and in post-mortem brain tissue. We also studied the ability of interferon beta, alone or in combination with vitamin D, to induce upregulation of these receptors in vitro, and compared expression levels between interferon-treated and untreated multiple sclerosis patients. In vitro interferon beta treatment led to a robust upregulation of ILT3 and ILT4 on monocytes, and dihydroxyvitamin D3 increased expression of ILT3 but not ILT4. ILT3 was abundant in demyelinating lesions in postmortem brain, and expression on monocytes in the cerebrospinal fluid was higher than in peripheral blood, suggesting that the central nervous system milieu induces ILT3, or that ILT3 positive monocytes preferentially enter the brain. Our data are consistent with involvement of ILT3 and ILT4 in the modulation of immune responsiveness in multiple sclerosis by both interferon and vitamin D.

  13. Integrins beta 5, beta 3 and alpha v are apically distributed in endometrial epithelium.

    Science.gov (United States)

    Aplin, J D; Spanswick, C; Behzad, F; Kimber, S J; Vićovac, L

    1996-07-01

    Several adhesion molecules have been shown to occur at the surface of endometrial cells. One of these is the integrin alpha v subunit which associates with various beta chains including beta 5. We demonstrate the presence of integrin beta 5 polypeptide in human endometrial epithelial cells throughout the menstrual cycle using immunocytochemistry with monospecific antibodies, and at the mRNA level by thermal amplification from endometrial cDNA. Integrin beta 5 is also found in a population of bone marrow-derived cells. A notable feature of the distribution of the beta 5 subunit in the glandular and luminal epithelium is its apical localization, which may suggest an involvement in implantation. However, no evidence was found for regulated expression of epithelial beta 5. In mouse, the beta 5 subunit is found at both the apical and basal surface of epithelial cells and expression is essentially oestrous cycle-independent. Comparisons are made in both species with the distribution of the alpha v and beta 3 subunits which also localize to the apical epithelium.

  14. HIV-1 stimulates nuclear entry of amyloid beta via dynamin dependent EEA1 and TGF-β/Smad signaling

    International Nuclear Information System (INIS)

    András, Ibolya E.; Toborek, Michal

    2014-01-01

    Clinical evidence indicates increased amyloid deposition in HIV-1-infected brains, which contributes to neurocognitive dysfunction in infected patients. Here we show that HIV-1 exposure stimulates amyloid beta (Aβ) nuclear entry in human brain endothelial cells (HBMEC), the main component of the blood–brain barrier (BBB). Treatment with HIV-1 and/or Aβ resulted in concurrent increase in early endosomal antigen-1 (EEA1), Smad, and phosphorylated Smad (pSmad) in nuclear fraction of HBMEC. A series of inhibition and silencing studies indicated that Smad and EEA1 closely interact by influencing their own nuclear entry; the effect that was attenuated by dynasore, a blocker of GTP-ase activity of dynamin. Importantly, inhibition of dynamin, EEA1, or TGF-β/Smad effectively attenuated HIV-1-induced Aβ accumulation in the nuclei of HBMEC. The present study indicates that nuclear uptake of Aβ involves the dynamin-dependent EEA1 and TGF-β/Smad signaling pathways. These results identify potential novel targets to protect against HIV-1-associated dysregulation of amyloid processes at the BBB level. - Highlights: • HIV-1 induces nuclear accumulation of amyloid beta (Aβ) in brain endothelial cells. • EEA-1 and TGF-Β/Smad act in concert to regulate nuclear entry of Aβ. • Dynamin appropriates the EEA-1 and TGF-Β/Smad signaling. • Dynamin serves as a master regulator of HIV-1-induced nuclear accumulation of Aβ

  15. HIV-1 stimulates nuclear entry of amyloid beta via dynamin dependent EEA1 and TGF-β/Smad signaling

    Energy Technology Data Exchange (ETDEWEB)

    András, Ibolya E., E-mail: iandras@med.miami; Toborek, Michal, E-mail: mtoborek@med.miami.edu

    2014-04-15

    Clinical evidence indicates increased amyloid deposition in HIV-1-infected brains, which contributes to neurocognitive dysfunction in infected patients. Here we show that HIV-1 exposure stimulates amyloid beta (Aβ) nuclear entry in human brain endothelial cells (HBMEC), the main component of the blood–brain barrier (BBB). Treatment with HIV-1 and/or Aβ resulted in concurrent increase in early endosomal antigen-1 (EEA1), Smad, and phosphorylated Smad (pSmad) in nuclear fraction of HBMEC. A series of inhibition and silencing studies indicated that Smad and EEA1 closely interact by influencing their own nuclear entry; the effect that was attenuated by dynasore, a blocker of GTP-ase activity of dynamin. Importantly, inhibition of dynamin, EEA1, or TGF-β/Smad effectively attenuated HIV-1-induced Aβ accumulation in the nuclei of HBMEC. The present study indicates that nuclear uptake of Aβ involves the dynamin-dependent EEA1 and TGF-β/Smad signaling pathways. These results identify potential novel targets to protect against HIV-1-associated dysregulation of amyloid processes at the BBB level. - Highlights: • HIV-1 induces nuclear accumulation of amyloid beta (Aβ) in brain endothelial cells. • EEA-1 and TGF-Β/Smad act in concert to regulate nuclear entry of Aβ. • Dynamin appropriates the EEA-1 and TGF-Β/Smad signaling. • Dynamin serves as a master regulator of HIV-1-induced nuclear accumulation of Aβ.

  16. Regulation of glycogen synthase kinase-3{beta} (GSK-3{beta}) after ionizing radiation; Regulation der Glykogen Synthase Kinase-3{beta} (GSK-3{beta}) nach ionisierender Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Boehme, K.A.

    2006-12-15

    Glycogen Synthase Kinase-3{beta} (GSK-3{beta}) phosphorylates the Mdm2 protein in the central domain. This phosphorylation is absolutely required for p53 degradation. Ionizing radiation inactivates GSK-3{beta} by phosphorylation at serine 9 and in consequence prevents Mdm2 mediated p53 degradation. During the work for my PhD I identified Akt/PKB as the kinase that phosphorylates GSK-3{beta} at serine 9 after ionizing radiation. Ionizing radiation leads to phosphorylation of Akt/PKB at threonine 308 and serine 473. The PI3 Kinase inhibitor LY294002 completely abolished Akt/PKB serine 473 phosphorylation and prevented the induction of GSK-3{beta} serine 9 phosphorylation after ionizing radiation. Interestingly, the most significant activation of Akt/PKB after ionizing radiation occurred in the nucleus while cytoplasmic Akt/PKB was only weakly activated after radiation. By using siRNA, I showed that Akt1/PKBa, but not Akt2/PKB{beta}, is required for phosphorylation of GSK- 3{beta} at serine 9 after ionizing radiation. Phosphorylation and activation of Akt/PKB after ionizing radiation depends on the DNA dependent protein kinase (DNA-PK), a member of the PI3 Kinase family, that is activated by free DNA ends. Both, in cells from SCID mice and after knockdown of the catalytic subunit of DNA-PK by siRNA in osteosarcoma cells, phosphorylation of Akt/PKB at serine 473 and of GSK-3{beta} at serine 9 was completely abolished. Consistent with the principle that phosphorylation of GSK-3 at serine 9 contributes to p53 stabilization after radiation, the accumulation of p53 in response to ionizing radiation was largely prevented by downregulation of DNA-PK. From these results I conclude, that ionizing radiation induces a signaling cascade that leads to Akt1/PKBa activation mediated by DNA-PK dependent phosphorylation of serine 473. After activation Akt1/PKBa phosphorylates and inhibits GSK-3{beta} in the nucleus. The resulting hypophosphorylated form of Mdm2 protein is no longer

  17. Two distinct β-sheet structures in Italian-mutant amyloid-beta fibrils : a potential link to different clinical phenotypes

    NARCIS (Netherlands)

    Hubin, Ellen; Deroo, Stéphanie; Schierle, Gabriele Kaminksi; Kaminski, Clemens; Serpell, Louise; Subramaniam, Vinod; van Nuland, Nico; Broersen, Kerensa; Raussens, Vincent; Sarroukh, Rabia

    2015-01-01

    Most Alzheimer's disease (AD) cases are late-onset and characterized by the aggregation and deposition of the amyloid-beta (Aβ) peptide in extracellular plaques in the brain. However, a few rare and hereditary Aβ mutations, such as the Italian Glu22-to-Lys (E22K) mutation, guarantee the development

  18. High beta experiments in CHS

    International Nuclear Information System (INIS)

    Okamura, S.; Matsuoka, K.; Nishimura, K.

    1994-09-01

    High beta experiments were performed in the low-aspect-ratio helical device CHS with the volume-averaged equilibrium beta up to 2.1 %. These values (highest for helical systems) are obtained for high density plasmas in low magnetic field heated with two tangential neutral beams. Confinement improvement given by means of turning off gas puffing helped significantly to make high betas. Magnetic fluctuations increased with increasing beta, but finally stopped to increase in the beta range > 1 %. The coherent modes appearing in the magnetic hill region showed strong dependence on the beta values. The dynamic poloidal field control was applied to suppress the outward plasma movement with the plasma pressure. Such an operation gave fixed boundary operations of high beta plasmas in helical systems. (author)

  19. Obesity in aging exacerbates blood-brain barrier disruption, neuroinflammation, and oxidative stress in the mouse hippocampus: effects on expression of genes involved in beta-amyloid generation and Alzheimer's disease.

    Science.gov (United States)

    Tucsek, Zsuzsanna; Toth, Peter; Sosnowska, Danuta; Gautam, Tripti; Mitschelen, Matthew; Koller, Akos; Szalai, Gabor; Sonntag, William E; Ungvari, Zoltan; Csiszar, Anna

    2014-10-01

    There is growing evidence that obesity has deleterious effects on the brain and cognitive function in the elderly population. However, the specific mechanisms through which aging and obesity interact to promote cognitive decline remain unclear. To test the hypothesis that aging exacerbates obesity-induced cerebromicrovascular damage and neuroinflammation, we compared young (7 months) and aged (24 months) high fat diet-fed obese C57BL/6 mice. Aging exacerbated obesity-induced systemic inflammation and blood-brain barrier disruption, as indicated by the increased circulating levels of proinflammatory cytokines and increased presence of extravasated immunoglobulin G in the hippocampus, respectively. Obesity-induced blood-brain barrier damage was associated with microglia activation, upregulation of activating Fc-gamma receptors and proinflammatory cytokines, and increased oxidative stress. Treatment of cultured primary microglia with sera derived from aged obese mice resulted in significantly more pronounced microglia activation and oxidative stress, as compared with treatment with young sera. Serum-induced activation and oxidative stress were also exacerbated in primary microglia derived from aged animals. Hippocampal expression of genes involved in regulation of the cellular amyloid precursor protein-dependent signaling pathways, beta-amyloid generation, and the pathogenesis of tauopathy were largely unaffected by obesity in aged mice. Collectively, obesity in aging is associated with a heightened state of systemic inflammation, which exacerbates blood-brain barrier disruption. The resulting neuroinflammation and oxidative stress in the mouse hippocampus likely contribute to the significant cognitive decline observed in aged obese animals. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. A study of the application of Brain Atlas with and without +Gz acceleration conditions.

    Science.gov (United States)

    Li, Yifeng; Zhang, Lihui; Zhang, Tao; Li, Baohui

    2017-07-20

    The purposes of this study were to utilize Brain Atlas to investigate the fluctuations in the characteristics of human EEG, with and without +Gz acceleration produced by human centrifuge, and also to examine the G load endurance of human body. The Brain Atlas of the EEG signal with and without +Gz acceleration in a static state were compared in order to reveal the correlation and differences. When compared with those in a static state, it was found that for the EEG readings of the subjects undergoing +Gz acceleration conditions, the energy and gray scale values of the low-frequency component-delta rhythm showed significant increases, while the energy and gray scale values of the high-frequency component-beta rhythm showed significant decreases. Among these, the beta2 rhythm was determined to be significantly inhibited. These fluctuations suggested that the ischemia conditions of brain had been improved. Also, the recoveries in the energy and gray-scale values were determined to be faster, which suggested that the G load endurance of human body had been enhanced. The Brain Atlas was found to show observable changes in color. The experimental results indicated that the Brain Atlas was able to provide assistance during the exploration of the fluctuations in the characteristics of EEG, and provided a criterion to assist in the observations of the function state fluctuations of human brain with +Gz acceleration. It also assisted in the evaluations of the G load endurance of human body.

  1. Conformation, molecular packing and field effect mobility of regioregular beta,beta'-dihexylsexithiophiophene

    DEFF Research Database (Denmark)

    Kiriy, N.; Kiriy, A.; Bocharova, V.

    2004-01-01

    by the pulse-radiolysis time-resolved microwave conductivity (PR-TRMC) technique was found to be Sigmamu(min) = 3.9 x 10(-3) cm(2) V-1 s(-1), which is comparable with the PR-TRMC mobility found for alpha,omega-DH6T. The field-effect mobility (FEM) of beta,beta'-DH6T was found to be on the order of 10(-5) cm(2......) V-1 s(-1), which is considerably less than the FEM of alpha,omega-DH6T. To understand the reason for such poor macroscopic electrical properties, the conformation and the molecular packing of beta,beta'-DH6T were systematically studied by means of UV-vis spectroscopy, scanning electron microscopy...... less dense crystalline packing than alpha,omega-DH6T. In contrast to the almost upright orientation of alpha,omega-DH6T molecules against the substrate (tilt angle about 68), the long axis of beta,beta'-DH6T molecules and the surface plane form an angle of similar to20degrees. Thus, the crystalline...

  2. An integrated taxonomic study of Fusarium langsethiae, Fusarium poae and Fusarium sporotrichioides based on the use of composite datasets

    DEFF Research Database (Denmark)

    Schmidt, H.; Adler, A.; Holst-Jensen, A.

    2004-01-01

    for the construction of a UPGMA dendrogram and a multidimensional scaling, both of which revealed a clear separation of the three taxa. Partial IGS, EF-1alpha and beta-tubulin sequence-as well as chromatography-and AFLP-derived similarities turned out to be comparably consistent, while ITS sequence- and morphology...

  3. Levered and unlevered Beta

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

  4. Beta-haemolytic streptococci in farmed Nile tilapia, Oreochromis niloticus, from Sullana-Piura, Peru

    Directory of Open Access Journals (Sweden)

    Yessica Ortega A

    2017-01-01

    Full Text Available Objective. This investigation aimed to study the presence of Streptococcus spp. in tilapia (Oreochromis niloticus from fish farm located in Sullana-Piura, Peru. Materials and methods. 150 fish with clinical signs of streptococcal disease were sampled, and the bacterium isolation was performed on blood agar, correlated to histopathological lesions description and molecular confirmation by real-time PCR. Results. The necropsy revealed exophthalmia, hyphema, congestion and/or haemorrhagic meninges, ascites, splenomegaly, hepatomegaly and diffuse haemorrhagic zones throughout the body. 102 isolated positives (54 tilapias to Streptococcus spp. were identified in the microbiological analysis (prevalence of 26%, the brain was the organ with the highest percentage of this bacteria (34.31%, and 19 isolates were beta-haemolytic (18.63% with prevalence of 10.12%. Fish beta-haemolytic streptococci presented epicarditis, perisplenitis and chronic meningitis, panophthalmitis, coagulative necrosis of skeletal muscle and granulomas formation. In the confirmatory test by real-time PCR, any positive tilapia to S. iniae was obtained. The results were analysed using a stochastic simulation of beta distribution using @Risk program uncertainty, reporting an average prevalence of 0.66% in sick tilapias. Conclusions. The analysed fishes were positive to bacteria of the genus Streptococcus, which confirms its presence in the fish farm. However, 19 isolates were beta-haemolytic, and the presence of S. iniae was not positive to the limit prevalence of 2.7% in real-time PCR.

  5. Boosted beta regression.

    Directory of Open Access Journals (Sweden)

    Matthias Schmid

    Full Text Available Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1. Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures.

  6. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  7. Effect of early treatment with ivabradine combined with beta-blockers versus beta-blockers alone in patients hospitalised with heart failure and reduced left ventricular ejection fraction (ETHIC-AHF): A randomised study.

    Science.gov (United States)

    Hidalgo, Francisco J; Anguita, Manuel; Castillo, Juan C; Rodríguez, Sara; Pardo, Laura; Durán, Enrique; Sánchez, José J; Ferreiro, Carlos; Pan, Manuel; Mesa, Dolores; Delgado, Mónica; Ruiz, Martín

    2016-08-15

    To analyse the effect of the early coadministration of ivabradine and beta-blockers (intervention group) versus beta-blockers alone (control group) in patients hospitalised with heart failure and reduced left ventricular ejection fraction (HFrEF). A comparative, randomised study was performed to compare the treatment strategies of beta-blockers alone versus ivabradine and beta-blockers starting 24hours after hospital admission, for acute HF in patients with an left ventricular ejection fraction (EF)70bpm. A total of 71 patients were examined, 33 in the intervention group and 38 in the control group. No differences were observed with respect to their baseline characteristics or standard treatment at discharge. HR at 28days (64.3±7.5 vs. 70.3±9.3bpm, p=0.01) and at 4months (60.6±7.5 vs. 67.8±8bpm, p=0.004) after discharge were significantly lower in the intervention group. Significant differences were found with respect to the EF and brain natriuretic peptide levels at 4months. No differences in clinical events (rehospitalisation/death) were reported at 4months. No severe side effects attributable to the early administration of ivabradine were observed. The early coadministration of ivabradine and beta-blockers during hospital admission for acute HFrEF is feasible and safe, and it produces a significant decrease in HR at 28days and at 4months after hospital discharge. It also seemed to improve systolic function and functional and clinical parameters of HF patients at short-term. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Complement activation by the amyloid proteins A beta peptide and beta 2-microglobulin

    DEFF Research Database (Denmark)

    Nybo, Mads; Nielsen, E H; Svehag, S E

    1999-01-01

    component nor heparan sulfate did significantly alter the A beta-induced CA. The results indicate that not only fibrillar A beta but also oligomers of, in particular, beta 2M from patients with dialysis-associated amyloidosis are capable of inducing CA at supra-physiological concentrations....

  9. A method based on Monte Carlo simulations and voxelized anatomical atlases to evaluate and correct uncertainties on radiotracer accumulation quantitation in beta microprobe studies in the rat brain

    Science.gov (United States)

    Pain, F.; Dhenain, M.; Gurden, H.; Routier, A. L.; Lefebvre, F.; Mastrippolito, R.; Lanièce, P.

    2008-10-01

    The β-microprobe is a simple and versatile technique complementary to small animal positron emission tomography (PET). It relies on local measurements of the concentration of positron-labeled molecules. So far, it has been successfully used in anesthetized rats for pharmacokinetics experiments and for the study of brain energetic metabolism. However, the ability of the technique to provide accurate quantitative measurements using 18F, 11C and 15O tracers is likely to suffer from the contribution of 511 keV gamma rays background to the signal and from the contribution of positrons from brain loci surrounding the locus of interest. The aim of the present paper is to provide a method of evaluating several parameters, which are supposed to affect the quantification of recordings performed in vivo with this methodology. We have developed realistic voxelized phantoms of the rat whole body and brain, and used them as input geometries for Monte Carlo simulations of previous β-microprobe reports. In the context of realistic experiments (binding of 11C-Raclopride to D2 dopaminergic receptors in the striatum; local glucose metabolic rate measurement with 18F-FDG and H2O15 blood flow measurements in the somatosensory cortex), we have calculated the detection efficiencies and corresponding contribution of 511 keV gammas from peripheral organs accumulation. We confirmed that the 511 keV gammas background does not impair quantification. To evaluate the contribution of positrons from adjacent structures, we have developed β-Assistant, a program based on a rat brain voxelized atlas and matrices of local detection efficiencies calculated by Monte Carlo simulations for several probe geometries. This program was used to calculate the 'apparent sensitivity' of the probe for each brain structure included in the detection volume. For a given localization of a probe within the brain, this allows us to quantify the different sources of beta signal. Finally, since stereotaxic accuracy is

  10. Improved limits on beta(-) and beta(-) decays of Ca-48

    Czech Academy of Sciences Publication Activity Database

    Bakalyarov, A.; Balysh, A.; Barabash, AS.; Beneš, P.; Briancon, C.; Brudanin, V. B.; Čermák, P.; Egorov, V.; Hubert, F.; Hubert, P.; Korolev, NA.; Kosjakov, VN.; Kovalík, Alojz; Lebedev, NA.; Novgorodov, A. F.; Rukhadze, NI.; Štekl, NI.; Timkin, VV.; Veleshko, IE.; Vylov, T.; Umatov, VI.

    2002-01-01

    Roč. 76, č. 9 (2002), s. 545-547 ISSN 0021-3640 Institutional research plan: CEZ:AV0Z1048901 Keywords : beta decay * double beta decay * Ca-48 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.483, year: 2002

  11. Adrenocorticotropin, beta-endorphin, and beta-lipotropin in normal thyroid and lung: possible implications for ectopic hormone secretion.

    Science.gov (United States)

    Clements, J A; Funder, J W; Tracy, K; Morgan, F J; Campbell, D J; Lewis, P; Hearn, M T

    1982-12-01

    The expression of the proopiomelanocortin (POMC) gene by normal lung and thyroid was examined by measurement of the content of ACTH, beta-lipotropin (beta LPH), and beta-endorphin (beta EP) in porcine lung and thyroid tissue. Acid extracts of normal porcine lung and thyroid tissue each contained appreciable amounts of immunoreactive (ir) ACTH, ir-beta LPH, and ir-beta EP. The content of ir-beta LPH in both tissues exceeded by severalfold, on a molar basis, the content of ir-ACTH and ir-beta EP, suggesting that the common precursor POMC was processed predominantly to peptides other than ir-ACTH and ir-beta EP. A porcine thyroid extract (Calcitare, porcine calcitonin, Armour) showed equivalent levels of beta EP-like immunoreactivity and bioactivity, measured by opiate radioreceptor assay; in contrast, ACTH-like bioactivity, measured by rat zona fasciculata steroidogenesis, was only 4% of ACTH-like immunoreactivity. On reversed phase high performance liquid chromatography, Calcitare showed multiple peaks of ACTH-like immunoreactivity, one of which coeluted with porcine ACTH-(1-39), and two much smaller peaks of beta EP-like immunoreactivity, of which the smaller coeluted with porcine beta EP. These data suggest that both lung and thyroid gland synthesize POMC, which in normal tissue is usually predominantly processed to species other than ACTH and beta EP. Ectopic secretion of ACTH and beta EP by lung and thyroid neoplasms may thus represent the loss of a system(s) normally responsible for processing the precursor beyond ACTH and beta EP.

  12. The effects of beta-endorphin: state change modification.

    Science.gov (United States)

    Veening, Jan G; Barendregt, Henk P

    2015-01-29

    Beta-endorphin (β-END) is an opioid neuropeptide which has an important role in the development of hypotheses concerning the non-synaptic or paracrine communication of brain messages. This kind of communication between neurons has been designated volume transmission (VT) to differentiate it clearly from synaptic communication. VT occurs over short as well as long distances via the extracellular space in the brain, as well as via the cerebrospinal fluid (CSF) flowing through the ventricular spaces inside the brain and the arachnoid space surrounding the central nervous system (CNS). To understand how β-END can have specific behavioral effects, we use the notion behavioral state, inspired by the concept of machine state, coming from Turing (Proc London Math Soc, Series 2,42:230-265, 1937). In section 1.4 the sequential organization of male rat behavior is explained showing that an animal is not free to switch into another state at any given moment. Funneling-constraints restrict the number of possible behavioral transitions in specific phases while at other moments in the sequence the transition to other behavioral states is almost completely open. The effects of β-END on behaviors like food intake and sexual behavior, and the mechanisms involved in reward, meditation and pain control are discussed in detail. The effects on the sequential organization of behavior and on state transitions dominate the description of these effects.

  13. Silencing of beta-carotene hydroxylase increases total carotenoid and beta-carotene levels in potato tubers

    Directory of Open Access Journals (Sweden)

    Pizzichini Daniele

    2007-03-01

    Full Text Available Abstract Background Beta-carotene is the main dietary precursor of vitamin A. Potato tubers contain low levels of carotenoids, composed mainly of the xanthophylls lutein (in the beta-epsilon branch and violaxanthin (in the beta-beta branch. None of these carotenoids have provitamin A activity. We have previously shown that tuber-specific silencing of the first step in the epsilon-beta branch, LCY-e, redirects metabolic flux towards beta-beta carotenoids, increases total carotenoids up to 2.5-fold and beta-carotene up to 14-fold. Results In this work, we silenced the non-heme beta-carotene hydroxylases CHY1 and CHY2 in the tuber. Real Time RT-PCR measurements confirmed the tuber-specific silencing of both genes . CHY silenced tubers showed more dramatic changes in carotenoid content than LCY-e silenced tubers, with beta-carotene increasing up to 38-fold and total carotenoids up to 4.5-fold. These changes were accompanied by a decrease in the immediate product of beta-carotene hydroxylation, zeaxanthin, but not of the downstream xanthophylls, viola- and neoxanthin. Changes in endogenous gene expression were extensive and partially overlapping with those of LCY-e silenced tubers: CrtISO, LCY-b and ZEP were induced in both cases, indicating that they may respond to the balance between individual carotenoid species. Conclusion Together with epsilon-cyclization of lycopene, beta-carotene hydroxylation is another regulatory step in potato tuber carotenogenesis. The data are consistent with a prevalent role of CHY2, which is highly expressed in tubers, in the control of this step. Combination of different engineering strategies holds good promise for the manipulation of tuber carotenoid content.

  14. Frontal brain asymmetry as a marker of depression and effectiveness of TMS therapy

    International Nuclear Information System (INIS)

    Mani, D.; Lithgow, B.

    2010-01-01

    Full text: Resting frontal brain electroencephalography (EEG) asymmetry has been hypothesi sed as a diagnostic marker for depression. A number of studies have shown that depressed individuals are characterised by diminished left sided activation of the prefrontal cortex, which is indicated by greater left than right alpha-band power. Relative left frontal region activity is believed to be associated with positive approach related behaviour and relative right frontal activity is seen to be linked to negative withdrawal related behaviour. In this study, frontal brain EEG was recorded from 17 depressed and 19 control subjects, from which frontal brain asymmetry ratios were calculated. The results confirmed the trend of relative left anterior hypoaclivation for individuals with depression compared to the healthy controls. This study also looked at beta and theta band ratios and found theta for depressed is predominantly negative, while the control group dis played mainly positive values. Beta comparison showed little significant difference between control and depressed groups. In addition, there have been few studies that examined frontal brain asymmetry in depression soon after treatment to gauge its effectiv ness. In a very preliminary study, the effect of Transcranial Magnetic Stimulation (TMS) therapy on the alpha band frontal brain asymmetry ratio for 5 depl'essed subjects before and after treatment found a slight increase in FBA ratio for 4 subjects. Further research and a larger subject group is required to validate these results.

  15. [Regulatory effect of Erbao granules on brain-gut peptide in juvenile animal model of anorexia].

    Science.gov (United States)

    Zhang, Y; Du, Y; Wang, S

    2000-10-01

    To study the regulatory effect of Erbao granules (EBG) on central and peripheral brain-gut peptide in juvenile animal model of anorexia. Juvenile rat model of anorexia was established by imitating the major cause of infantile anorexia and treated with EBG. The cholocystokinin-octapeptide (CCK-8) and beta-endorphin (beta-EP) concentration in hypothalamus, antrum pyloricum and peripheral blood were examined by radioimmunoassay. CCK-8 concentration in hypothalamus and plasma in the model rats increased (P anorexia model.

  16. Brain insulin signaling and Alzheimer's disease: current evidence and future directions.

    Science.gov (United States)

    Schiöth, Helgi B; Craft, Suzanne; Brooks, Samantha J; Frey, William H; Benedict, Christian

    2012-08-01

    Insulin receptors in the brain are found in high densities in the hippocampus, a region that is fundamentally involved in the acquisition, consolidation, and recollection of new information. Using the intranasal method, which effectively bypasses the blood-brain barrier to deliver and target insulin directly from the nose to the brain, a series of experiments involving healthy humans has shown that increased central nervous system (CNS) insulin action enhances learning and memory processes associated with the hippocampus. Since Alzheimer's disease (AD) is linked to CNS insulin resistance, decreased expression of insulin and insulin receptor genes and attenuated permeation of blood-borne insulin across the blood-brain barrier, impaired brain insulin signaling could partially account for the cognitive deficits associated with this disease. Considering that insulin mitigates hippocampal synapse vulnerability to amyloid beta and inhibits the phosphorylation of tau, pharmacological strategies bolstering brain insulin signaling, such as intranasal insulin, could have significant therapeutic potential to deter AD pathogenesis.

  17. Determinants of RNA polymerase alpha subunit for interaction with beta, beta', and sigma subunits: hydroxyl-radical protein footprinting.

    OpenAIRE

    Heyduk, T; Heyduk, E; Severinov, K; Tang, H; Ebright, R H

    1996-01-01

    Escherichia coli RNA polymerase (RNAP) alpha subunit serves as the initiator for RNAP assembly, which proceeds according to the pathway 2 alpha-->alpha 2-->alpha 2 beta-->alpha 2 beta beta'-->alpha 2 beta beta' sigma. In this work, we have used hydroxyl-radical protein footprinting to define determinants of alpha for interaction with beta, beta', and sigma. Our results indicate that amino acids 30-75 of alpha are protected from hydroxyl-radical-mediated proteolysis upon interaction with beta ...

  18. Brain Oscillations, Hypnosis, and Hypnotizability.

    Science.gov (United States)

    Jensen, Mark P; Adachi, Tomonori; Hakimian, Shahin

    2015-01-01

    This article summarizes the state-of-science knowledge regarding the associations between hypnosis and brain oscillations. Brain oscillations represent the combined electrical activity of neuronal assemblies, usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) oscillations. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These oscillations are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. The authors propose that this role may be the mechanistic link between theta (and perhaps gamma) oscillations and hypnosis, specifically, that the increases in theta oscillations and changes in gamma activity observed with hypnosis may underlie some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis and for enhancing response to hypnotic treatments.

  19. Mobile Phone Chips Reduce Increases in EEG Brain Activity Induced by Mobile Phone-Emitted Electromagnetic Fields

    Science.gov (United States)

    Henz, Diana; Schöllhorn, Wolfgang I.; Poeggeler, Burkhard

    2018-01-01

    Recent neurophysiological studies indicate that exposure to electromagnetic fields (EMFs) generated by mobile phone radiation can exert effects on brain activity. One technical solution to reduce effects of EMFs in mobile phone use is provided in mobile phone chips that are applied to mobile phones or attached to their surfaces. To date, there are no systematical studies on the effects of mobile phone chip application on brain activity and the underlying neural mechanisms. The present study investigated whether mobile phone chips that are applied to mobile phones reduce effects of EMFs emitted by mobile phone radiation on electroencephalographic (EEG) brain activity in a laboratory study. Thirty participants volunteered in the present study. Experimental conditions (mobile phone chip, placebo chip, no chip) were set up in a randomized within-subjects design. Spontaneous EEG was recorded before and after mobile phone exposure for two 2-min sequences at resting conditions. During mobile phone exposure, spontaneous EEG was recorded for 30 min during resting conditions, and 5 min during performance of an attention test (d2-R). Results showed increased activity in the theta, alpha, beta and gamma bands during EMF exposure in the placebo and no chip conditions. Application of the mobile phone chip reduced effects of EMFs on EEG brain activity and attentional performance significantly. Attentional performance level was maintained regarding number of edited characters. Further, a dipole analysis revealed different underlying activation patterns in the chip condition compared to the placebo chip and no chip conditions. Finally, a correlational analysis for the EEG frequency bands and electromagnetic high-frequency (HF) emission showed significant correlations in the placebo chip and no chip condition for the theta, alpha, beta, and gamma bands. In the chip condition, a significant correlation of HF with the theta and alpha bands, but not with the beta and gamma bands was

  20. Mobile Phone Chips Reduce Increases in EEG Brain Activity Induced by Mobile Phone-Emitted Electromagnetic Fields.

    Science.gov (United States)

    Henz, Diana; Schöllhorn, Wolfgang I; Poeggeler, Burkhard

    2018-01-01

    Recent neurophysiological studies indicate that exposure to electromagnetic fields (EMFs) generated by mobile phone radiation can exert effects on brain activity. One technical solution to reduce effects of EMFs in mobile phone use is provided in mobile phone chips that are applied to mobile phones or attached to their surfaces. To date, there are no systematical studies on the effects of mobile phone chip application on brain activity and the underlying neural mechanisms. The present study investigated whether mobile phone chips that are applied to mobile phones reduce effects of EMFs emitted by mobile phone radiation on electroencephalographic (EEG) brain activity in a laboratory study. Thirty participants volunteered in the present study. Experimental conditions (mobile phone chip, placebo chip, no chip) were set up in a randomized within-subjects design. Spontaneous EEG was recorded before and after mobile phone exposure for two 2-min sequences at resting conditions. During mobile phone exposure, spontaneous EEG was recorded for 30 min during resting conditions, and 5 min during performance of an attention test (d2-R). Results showed increased activity in the theta, alpha, beta and gamma bands during EMF exposure in the placebo and no chip conditions. Application of the mobile phone chip reduced effects of EMFs on EEG brain activity and attentional performance significantly. Attentional performance level was maintained regarding number of edited characters. Further, a dipole analysis revealed different underlying activation patterns in the chip condition compared to the placebo chip and no chip conditions. Finally, a correlational analysis for the EEG frequency bands and electromagnetic high-frequency (HF) emission showed significant correlations in the placebo chip and no chip condition for the theta, alpha, beta, and gamma bands. In the chip condition, a significant correlation of HF with the theta and alpha bands, but not with the beta and gamma bands was