WorldWideScience

Sample records for brain beta tubulin

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

    Science.gov (United States)

    Libusová, L; Sulimenko, T; Sulimenko, V; Janisch, R; Hozák, P; Dráber, P

    2005-10-01

    Many of the highly organized microtubular arrangements in ciliates are located in the cortical area containing membrane vesicles and vacuoles. In Tetrahymena thermophila and Paramecium caudatum, immunofluorescence microscopy with the monoclonal antibody TU-06, directed against beta-tubulin, revealed distinct staining of this cortical region alone, while the cilia and other microtubular structures were unstained. The specificity of the antibody was confirmed by immunoblotting and by preabsorption of the antibody with purified tubulin. Double-label immunofluorescence with antibodies against gamma-tubulin, detyrosinated alpha-tubulin, and centrin showed that the TU-06 epitope is localized outside the basal body region. This was also confirmed by immunogold electron microscopy of thin sections. Proteolytic digestion of porcine brain beta-tubulin combined with a peptide scan of immobilized, overlapping peptides disclosed that the epitope was in the beta-tubulin region beta81-95, a region which is phylogenetically highly conserved. As known posttranslational modifications of beta-tubulin are located outside this area, the observed staining pattern cannot be interpreted as evidence of subcellular sequestration of modified tubulin. The limited distribution of the epitope could rather reflect the dependence of TU-06 epitope exposition on conformations of tubulin molecules in microtubule arrangements or on differential masking by interacting proteins.

  2. Interaction of ethacrynic acid with bovine brain tubulin.

    Science.gov (United States)

    Ludueña, R F; Roach, M C; Epstein, D L

    1994-04-29

    Ethacrynic acid is a diuretic agent that reacts with sulfhydryl groups in proteins, and which shows promise of effectiveness in the treatment of glaucoma. Ethacrynic acid is a known inhibitor of microtubule assembly in vitro (Xu et al., Arch Biochem Biophys 296: 462-67, 1992). We have used N,N'-ethylenebis (iodoacetamide) (EBI) as a probe to examine the sulfhydryl groups of tubulin; EBI can form two intra-chain cross-links in beta-tubulin. One of these, beta*, connects Cys239 with Cys354; the other, beta s, joins Cys12 with either Cys201 or Cys211 (Little and Ludueña, EMBO J 4: 51-56, 1985; Biochim Biophys Acta 912: 28-33, 1987). Formation of beta * inhibits microtubule assembly in vitro, consistent with the hypothesis that Cys239 has an assembly-critical sulfhydryl (Bai et al., Biochemistry 28: 5606-5612, 1989). We have examined the interaction of ethacrynic acid with the sulfhydryl groups of bovine brain tubulin. We found that 130 microM ethacrynic acid gave half-maximal inhibition of assembly, but had no effect on the formation of the beta * cross-link by EBI. Ethacrynic acid, however, did inhibit substantially formation of the beta s cross-link at this concentration and half-maximally inhibited it at approximately 185 microM. Half-maximal inhibition of the alkylation of tubulin sulfhydryls by iodo [14C]acetamide was obtained at an ethacrynic acid concentration in the range of 190-325 microM. These results indicate that ethacrynic acid can inhibit microtubule assembly by reacting with sulfhydryl groups other than those of Cys239 and Cys354 and suggest that other sulfhydryl groups in tubulin could be assembly-critical. These results also raise the possibility that these other assembly-critical sulfhydryls may be those of Cys12, Cys201 or Cys211.

  3. GTP binding to the. beta. -subunit of tubulin is greatly reduced in Alzheimers disease

    Energy Technology Data Exchange (ETDEWEB)

    Khatoon, S.; Slevin, J.T.; Haley, B.E.

    1987-05-01

    A decrease occurs (80-100%) in the (/sup 32/P)8N/sub 3/GTP photoinsertion into a cytosolic protein (55K M/sub r/) of Alzheimer's (AD) brain, tentatively identified as the ..beta..-subunit of tubulin (co-migration with purified tubulin, concentration dependence of interaction with GTP, ATP and their 8-azido photoprobes, and similar effects of Ca/sup 2 +/ and EDTA on photoinsertion). This agrees with prior observations of (/sup 32/P)8N/sub 3/GTP interactions with brain tubulin and a recent report on faulty microtubular assembly in AD brain. The decrease in (/sup 32/P)8N/sub 3/GTP photoinsertion into the 55K M/sub r/ protein of AD brain was in contrast with other photolabeled proteins, which remained at equal levels in AD and age-matched normal brain tissues. The 55K and 45K M/sub r/ were the two major (/sup 32/P)8N/sub 3/GTP photoinsertion species in non-AD brain. Of 5 AD brains, the photoinsertion of (/sup 32/P)8N/sub 3/GTP into the 55K M/sub r/ region was low or absent in 4 (55K/45K=0.1); one was 75% below normals (55K/45K=0.24). Total protein migrating at 55K M/sub r/ was similar in AD and controls. AD brain tubulin, while present, has its exchangeable GTP binding site on ..beta..-tubulin blocked/modified such that (/sup 32/P)8N/sub 3/GTP cannot interact normally with this site.

  4. Characterization of the carrot beta-tubulin gene coding a divergent isotype, beta-2.

    Science.gov (United States)

    Okamura, S; Naito, K; Sonehara, S; Ohkawa, H; Kuramori, S; Tatsuta, M; Minamizono, M; Kataoka, T

    1997-04-01

    Four different beta-tubulin clones were isolated from carrot genomic and cDNA libraries. Their nucleotide sequences were determined 1 and their predicted amino acids were compared with each other. The predicted amino acid composition of the C-terminal region of three of them (beta-1, 3, 4) resembled one another, but that of one isotype (beta-2) was divergent. The beta-2 tubulin included two hydroxyl amino acids, serine and threonine, and consisted of a lower number of negatively charged amino acids than the others in the C-terminal region. The predicted hydrophobicity profile of the beta-2 tubulin around the residue 200 is less hydrophobic than beta-1, but it is still more hydrophobic than those of animal and fungal beta-tubulins. The beta-2 gene was transcribed in cultured cells and flowers, while the beta-1 gene was ubiquitously transcribed in cultured cells, roots, shoots and flowers. When the predicted amino acids of plant tubulin were compared with those of other organisms, substitutions from non-polar amino acids to those with hydroxyl group were conspicuous in the region corresponding to the third exon in the plant genes.

  5. De Novo Mutations in the Beta-Tubulin Gene TUBB2A Cause Simplified Gyral Patterning and Infantile-Onset Epilepsy

    Science.gov (United States)

    Cushion, Thomas D.; Paciorkowski, Alex R.; Pilz, Daniela T.; Mullins, Jonathan G.L.; Seltzer, Laurie E.; Marion, Robert W.; Tuttle, Emily; Ghoneim, Dalia; Christian, Susan L.; Chung, Seo-Kyung; Rees, Mark I.; Dobyns, William B.

    2014-01-01

    Tubulins, and microtubule polymers into which they incorporate, play critical mechanical roles in neuronal function during cell proliferation, neuronal migration, and postmigrational development: the three major overlapping events of mammalian cerebral cortex development. A number of neuronally expressed tubulin genes are associated with a spectrum of disorders affecting cerebral cortex formation. Such “tubulinopathies” include lissencephaly/pachygyria, polymicrogyria-like malformations, and simplified gyral patterns, in addition to characteristic extracortical features, such as corpus callosal, basal ganglia, and cerebellar abnormalities. Epilepsy is a common finding in these related disorders. Here we describe two unrelated individuals with infantile-onset epilepsy and abnormalities of brain morphology, harboring de novo variants that affect adjacent amino acids in a beta-tubulin gene TUBB2A. Located in a highly conserved loop, we demonstrate impaired tubulin and microtubule function resulting from each variant in vitro and by using in silico predictive modeling. We propose that the affected functional loop directly associates with the alpha-tubulin-bound guanosine triphosphate (GTP) molecule, impairing the intradimer interface and correct formation of the alpha/beta-tubulin heterodimer. This study associates mutations in TUBB2A with the spectrum of “tubulinopathy” phenotypes. As a consequence, genetic variations affecting all beta-tubulin genes expressed at high levels in the brain (TUBB2B, TUBB3, TUBB, TUBB4A, and TUBB2A) have been linked with malformations of cortical development. PMID:24702957

  6. Molecular characterization of beta-tubulin gene from Pleurotus sajor-caju.

    Science.gov (United States)

    Kim, B G; Yoo, Y B; Kwon, S T; Magae, Y

    2001-10-01

    A beta-tubulin gene (TUB1) from the basidiomycete Pleurotus sajor-caju was sequenced. TUB1 encodes a 446-amino-acid protein. The coding region is interrupted by 9 introns, all of which had a 5'-GTRNGT... YAG-3' sequence at the boundaries. Locations of the introns in TUB1 were common between the beta-tubulin genes of other basidiomycetes, but not with animals, ascomycetes, or plants. This suggests that the introns were inserted independently into the beta-tubulin gene after these divisions had diverged.

  7. Evidence from beta-tubulin phylogeny that microsporidia evolved from within the fungi.

    Science.gov (United States)

    Keeling, P J; Luker, M A; Palmer, J D

    2000-01-01

    Microsporidia are obligate intracellular parasites that were thought to be an ancient eukaryotic lineage based on molecular phylogenies using ribosomal RNA and translation elongation factors. However, this ancient origin of microsporidia has been contested recently, as several other molecular phylogenies suggest that microsporidia are closely related to fungi. Most of the protein trees that place microsporidia with fungi are not well sampled, however, and it is impossible to resolve whether microsporidia evolved from a fungus or from a protistan relative of fungi. We have sequenced beta-tubulins from 3 microsporidia, 4 chytrid fungi, and 12 zygomycete fungi, expanding the representation of beta-tubulin to include all four fungal divisions and a wide diversity of microsporidia. In phylogenetic trees including these new sequences, the overall topology of the fungal beta-tubulins generally matched the expected relationships among the four fungal divisions, although the zygomycetes were polyphyletic in some analyses. The microsporidia consistently fell within this fungal diversification, and not as a sister group to fungi. Overall, beta-tubulin phylogeny suggests that microsporidia evolved from a fungus sometime after the divergence of chytrids. We also found that chytrid alpha- and beta-tubulins are much less divergent than are tubulins from other fungi or microsporidia. In trees in which the only fungal representatives were the chytrids, microsporidia still branched with fungi (i.e., with chytrids), suggesting that the affiliation between microsporidian and fungal tubulins is not an artifact of long-branch attraction.

  8. 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

    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...... study found that hippocampal volume and beta-tubulin isotype III intensity in the prenatal guinea pig were influenced by gestational day but not by maternal vitC intake...

  9. Interaction of ustiloxin A with bovine brain tubulin.

    Science.gov (United States)

    Ludueńa, R F; Roach, M C; Prasad, V; Banerjee, M; Koiso, Y; Li, Y; Iwasaki, S

    1994-04-29

    Ustiloxin A is a modified peptide derived from false smut balls on rice panicles, caused by the fungus Ustilaginoidea virens; structurally, it resembles phomopsin A. Ustiloxin A is cytotoxic and is an inhibitor of microtubule assembly in vitro. Because of its resemblance to phomopsin A, we examined its interaction with tubulin and compared the results with those obtained with phomopsin A and dolastatin 10, both of which were found previously to have very similar effects. We determined that ustiloxin A inhibited the formation of a particular intra-chain cross-link in beta-tubulin, as do vinblastine, maytansine, rhizoxin, phomopsin A, dolastatin 10, halichondrin B and homohalichondrin B; this is in contrast to colchicine and podophyllotoxin which do not inhibit formation of this cross-link. Ustiloxin A also inhibited the alkylation of tubulin by iodo[14C]acetamide, as do phomopsin A and dolastatin 10; vinblastine was almost as potent as inhibitor of alkylation as ustiloxin A, whereas maytansine, halichondrin B and homohalichondrin B have little or no effect. In addition, ustiloxin A inhibited exposure of hydrophobic areas on the surface of the tubulin molecule. In this respect, ustiloxin A was indistinguishable from phomopsin A but slightly more effective than dolastatin 10 and considerably more effective than vinblastine; this provides a strong contrast to maytansine, rhizoxin, and homohalichondrin B which have no effect on exposure of hydrophobic areas and to halichondrin B which enhances exposure. Lastly, ustiloxin A strongly stabilized the binding of [3H]colchicine to tubulin. The combination of ustiloxin A with cholchicine stabilized tubulin with a half-life of over 8 days, comparable with results obtained with phomopsin A and colchicine. A comparison of the structures of ustiloxin A, phomopsin A and dolastatin 10 raised the possibility that the strong stabilization of the tubulin structure may require a short segment of hydrophobic amino acids such as the

  10. Ivermectin selection on beta-tubulin: evidence in Onchocerca volvulus and Haemonchus contortus.

    Science.gov (United States)

    Eng, J K L; Blackhall, W J; Osei-Atweneboana, M Y; Bourguinat, C; Galazzo, D; Beech, R N; Unnasch, T R; Awadzi, K; Lubega, G W; Prichard, R K

    2006-12-01

    Ivermectin resistance is common in trichostrongylid nematodes of livestock, such as Haemonchus contortus. This anthelmintic is the only drug approved for mass administration to control onchocerciasis caused by the nematode parasite, Onchocerca volvulus. In parts of West Africa up to 18 rounds of ivermectin treatment have been administered to communities and there are reports of poor parasitological responses to treatment. Understanding ivermectin resistance and ivermectin selection is an important step to reduce selection pressure for resistance, and to develop molecular markers which can be used to monitor the development of resistance and its spread. Here we report evidence that ivermectin selection changes the frequency of beta-tubulin alleles in both the sheep parasite, H. contortus, and the human parasite, O. volvulus. In O. volvulus we have been able to look at the frequency of beta-tubulin alleles in O. volvulus obtained before any ivermectin was used in humans in Africa, and following its widespread use. In H. contortus, we have been able to look at the frequency of beta-tubulin alleles in a strain which has not seen any anthelmintic selection and in an ivermectin selected strain derived from the unselected strain. We have found ivermectin selects on beta-tubulin in both of these nematode species. In the case of O. volvulus, we had previously reported that ivermectin selects for specific single nucleotide polymorphisms in the O. volvulus beta-tubulin gene. This polymorphism results in three amino acid changes in the H3 helix of beta-tubulin, as well as deletions in an associated intron. We report a simple PCR assay to detect the amplicon length polymorphism, resulting from these intronic deletions, which can be used to monitor the frequency of the beta-tubulin allele selected for by ivermectin in O. volvulus.

  11. 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)

  12. 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.

  13. Photomorphogenesis in Physarum polycephalum. Temporal expression pattern of actin, alpha- and beta-tubulin.

    Science.gov (United States)

    Poetsch, B; Schreckenbach, T; Werenskiold, A K

    1989-01-15

    Photo-induced fruiting-body formation of the slime mold Physarum polycephalum can be divided into two stages. The first stage (I) starts with the beginning of illumination (0 h) and ends with the formation of nodules (12 h). The second stage (II) is characterized by culmination, sporangiophore formation and melanization of sporangiophore heads (13-17 h). We investigated the expression of actin, alpha- and beta-tubulin during this differentiation process using Northern blot analysis and run-off transcription in isolated nuclei. Whereas actin mRNA is irreversibly lost during stage I, we observed two peaks in mRNA concentration for alpha-tubulin and one peak for that of beta-tubulin during stage I and a coordinated alpha/beta-tubulin mRNA induction during stage II. Stage II induction appears to be related to a presporangial mitosis. Transcriptional activity of the three genes studied shows two maxima, namely one in the middle of stage I and the other at the end of stage II. Our data suggest that the expression of the three cytoskeletal proteins investigated follows a distinct temporal pattern comprising changes in both mRNA synthesis and decay. We also propose a novel function of tubulin in Physarum which is not related to mitosis.

  14. Nucleotide sequence analysis of beta tubulin gene in a wide range of dermatophytes

    NARCIS (Netherlands)

    Rezaei-Matehkolaei, Ali; Mirhendi, Hossein; Makimura, Koichi; de Hoog, G Sybren; Satoh, Kazuo; Najafzadeh, Mohammad Javad; Shidfar, Mohammad Reza

    2014-01-01

    We investigated the resolving power of the beta tubulin protein-coding gene (BT2) for systematic study of dermatophyte fungi. Initially, 144 standard and clinical strains belonging to 26 species in the genera Trichophyton, Microsporum, and Epidermophyton were identified by internal transcribe spacer

  15. Anti-beta-tubulin antibodies have no diagnostic value in patients with chronic inflammatory demyelinating polyneuropathy

    NARCIS (Netherlands)

    van Schaik, I. N.; Vermeulen, M.; van Doorn, P. A.; Brand, A.

    1995-01-01

    High-titre anti-beta-tubulin antibodies were recently reported to occur in over 50% of sera from patients with chronic inflammatory demyelinating polyneuropathy (CIDP). It was concluded that these antibodies may help to distinguish CIDP from other neuropathies and that they are diagnostically

  16. Specific alpha- and beta-tubulin isotypes optimize the functions of sensory Cilia in Caenorhabditis elegans.

    Science.gov (United States)

    Hurd, Daryl D; Miller, Renee M; Núñez, Lizbeth; Portman, Douglas S

    2010-07-01

    Primary cilia have essential roles in transducing signals in eukaryotes. At their core is the ciliary axoneme, a microtubule-based structure that defines cilium morphology and provides a substrate for intraflagellar transport. However, the extent to which axonemal microtubules are specialized for sensory cilium function is unknown. In the nematode Caenorhabditis elegans, primary cilia are present at the dendritic ends of most sensory neurons, where they provide a specialized environment for the transduction of particular stimuli. Here, we find that three tubulin isotypes--the alpha-tubulins TBA-6 and TBA-9 and the beta-tubulin TBB-4--are specifically expressed in overlapping sets of C. elegans sensory neurons and localize to the sensory cilia of these cells. Although cilia still form in mutants lacking tba-6, tba-9, and tbb-4, ciliary function is often compromised: these mutants exhibit a variety of sensory deficits as well as the mislocalization of signaling components. In at least one case, that of the CEM cephalic sensory neurons, cilium architecture is disrupted in mutants lacking specific ciliary tubulins. While there is likely to be some functional redundancy among C. elegans tubulin genes, our results indicate that specific tubulins optimize the functional properties of C. elegans sensory cilia.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  18. Prognostic Value of Beta-Tubulin-3 and c-Myc in Muscle Invasive Urothelial Carcinoma of the Bladder

    Science.gov (United States)

    Massari, Francesco; Bria, Emilio; Ciccarese, Chiara; Munari, Enrico; Modena, Alessandra; Zambonin, Valentina; Sperduti, Isabella; Artibani, Walter; Cheng, Liang; Martignoni, Guido; Tortora, Giampaolo; Brunelli, Matteo

    2015-01-01

    Background To date, putative prognostic biomarkers have shown limited utility from the clinical perspective for bladder urothelial carcinoma. Herein, the expression of beta-tubulin-3 and c-Myc was evaluated to determine their prognostic potential. Methods In formalin fixed-paraffin embedded blocks, immunohistochemical expression of c-Myc and beta-tubulin-3 was evaluated. H score ranging from 0 to 300 was obtained by multiplying the percentage of positive cells by intensity (0–3); c-Myc and beta-tubulin-3 expression was defined: 0: negative, 1: weakly positive, 2: strongly positive. Results beta-tubulin-3 and c-Myc immunoexpression was available for 46 cases. At the univariate analysis, node-involvement, beta-tubulin-3 and c-Myc overexpression discriminate shorter DFS (HR 2.19, p = 0.043; HR 3.10, p = 0.24 and HR 3.05, p = 0.011, respectively); 2-yrs DFS log-rank analysis according to low versus high level of immunoexpression were statistically significant; beta-tubulin-3, 53% low vs 12.7% high (p = value 0.02) and c-Myc 28 low vs 8 high (p-value 0.007). Patients displaying negative beta-tubulin-3/c-Myc had statistically significant better 2-yrs DFS than those with mixed expression or double positivity (54.5% versus 18.7% versus 0%, log-rank p = 0.006). Conclusions c-Myc and beta-tubulin-3 show improvement for prognostic risk stratification in patients with muscle invasive bladder urothelial carcinoma. These molecular pathways may also be candidate to improve predictiveness to targeted therapies. PMID:26046361

  19. Prognostic Value of Beta-Tubulin-3 and c-Myc in Muscle Invasive Urothelial Carcinoma of the Bladder.

    Directory of Open Access Journals (Sweden)

    Francesco Massari

    Full Text Available To date, putative prognostic biomarkers have shown limited utility from the clinical perspective for bladder urothelial carcinoma. Herein, the expression of beta-tubulin-3 and c-Myc was evaluated to determine their prognostic potential.In formalin fixed-paraffin embedded blocks, immunohistochemical expression of c-Myc and beta-tubulin-3 was evaluated. H score ranging from 0 to 300 was obtained by multiplying the percentage of positive cells by intensity (0-3; c-Myc and beta-tubulin-3 expression was defined: 0: negative, 1: weakly positive, 2: strongly positive.beta-tubulin-3 and c-Myc immunoexpression was available for 46 cases. At the univariate analysis, node-involvement, beta-tubulin-3 and c-Myc overexpression discriminate shorter DFS (HR 2.19, p = 0.043; HR 3.10, p = 0.24 and HR 3.05, p = 0.011, respectively; 2-yrs DFS log-rank analysis according to low versus high level of immunoexpression were statistically significant; beta-tubulin-3, 53% low vs 12.7% high (p = value 0.02 and c-Myc 28 low vs 8 high (p-value 0.007. Patients displaying negative beta-tubulin-3/c-Myc had statistically significant better 2-yrs DFS than those with mixed expression or double positivity (54.5% versus 18.7% versus 0%, log-rank p = 0.006.c-Myc and beta-tubulin-3 show improvement for prognostic risk stratification in patients with muscle invasive bladder urothelial carcinoma. These molecular pathways may also be candidate to improve predictiveness to targeted therapies.

  20. Identification of cysteine 354 of beta-tubulin as part of the binding site for the A ring of colchicine.

    Science.gov (United States)

    Bai, R; Pei, X F; Boyé, O; Getahun, Z; Grover, S; Bekisz, J; Nguyen, N Y; Brossi, A; Hamel, E

    1996-05-24

    The colchicine analog 3-chloroacetyl-3-demthylthio-colchicine (3CTC) is a competitive inhibitor of colchicine binding to tubulin, binds to tubulin at 37 degrees C, but not at 0 degree C, and covalently reacts with beta-tubulin at 37 degree C, but not at 0 degree C, in a reaction inhibited by colchicine site drugs. The approximate intramolecular distance between the oxygen at position C-3 in 3CTC and the chlorine atom of the 3-chloroacetyl group is 3 A. using decylagarose chromatography, we purified beta-tubulin that had reacted with 3-(chloromethyl-[14C] Carbonyl)-3- demethylthiocolchicine ([14C]3CTC). This beta-tubulin that had reacted with 3-(chloromethyl-[14C]carbonyl)- 3-demethythiocolchicine ([14C]3CTC). This beta-tubulin was digested with formic acid, cyanogen bromide, endoproteinase Glu-C, or endoproteinase Lys-C, and the radio-labeled peptide(s) were isolated. The sequences of these peptides indicated that as much as 90% of the covalent reaction between the [14C]3CTC and beta-tubulin occurred at cysteine 354. This finding indicates that the C-3 oxygen atom of colchicinoids is within 3 A of the sulfur atom of the Cys-354 residue, suggests that the colchicine A ring lies between Cys-354 and Cys-239, based on the known 9 A distance between these residues, and may indicate that the tropolone C ring lies between the peptide region containing Cys-239 and the amino-terminal beta-tubulin sequence, based on the labeling pattern observed following direct photoactivation of tubulin-bound colchicine.

  1. Immunization with recombinant beta-tubulin from Trypanosoma evansi induced protection against T. evansi, T. equiperdum and T. b. brucei infection in mice.

    Science.gov (United States)

    Li, S-Q; Fung, M-C; Reid, S A; Inoue, N; Lun, Z-R

    2007-04-01

    The beta-tubulin gene of Trypanosoma evansi (STIB 806) was cloned and expressed in Escherichia coli. The predicted amino acid sequence of T. evansi beta-tubulin shows 100%, 99.8%, 99.1%, and 98.6% homology with T. equiperdum, T. b. brucei, T. cruzi and T. danilewskyi, respectively, but is diverse from that of T. cyclops, showing only 51.6% of homology. Recombinant beta-tubulin was expressed as inclusion bodies in E. coli. It was purified and renatured for immunological studies. Mice immunized with the renatured recombinant beta-tubulin were protected from lethal challenge with T. evansi STIB 806, T. equiperdum STIB 818 and T. b. brucei STIB 940, showing 83.3%, 70% and 76.7% protection, respectively. Serum collected from the rabbit immunized with recombinant beta-tubulin inhibited the growth of T. evansi, T. equiperdum and T. b. brucei in vitro. Serum from mice and rabbits immunized with recombinant beta-tubulin recognized only T. evansi beta-tubulin and not mouse beta-tubulin. The results of this study demonstrated that the recombinant T. evansi beta-tubulin is a potential candidate for the development of a vaccine to prevent animal trypanosomiasis caused by these three trypanosome species.

  2. Genetic variations in the beta-tubulin gene and the internal transcribed spacer 2 region of Trichuris species from man and baboons

    DEFF Research Database (Denmark)

    Hansen, Tina Vicky Alstrup; Thamsborg, Stig Milan; Olsen, Annette

    2013-01-01

    of this study was to investigate whether these SNPs were present in the beta-tubulin gene of Trichuris spp. from humans and baboons. As a secondary objective, the degree of identity between T. trichiura from humans and Trichuris spp. from baboons was evaluated based on the beta-tubulin gene and the internal...

  3. Plastic changes in the astrocyte GLUT1 glucose transporter and beta-tubulin microtubule protein following voluntary exercise in mice.

    Science.gov (United States)

    Allen, Angela; Messier, Claude

    2013-03-01

    Glucose, the predominant energy substrate of the central and peripheral nervous system, is delivered to neurons via a family of facilitative glucose transporters (GLUT). The majority of glucose is transported to the brain via glucose transporter 1 (GLUT1) located on epithelial cells of capillaries and on the astrocytes that wrap around them. Changes in neuronal activity are linked to increases in glucose demand and local cerebral glucose utilization. Current research has indicated a corresponding change in GLUT1 expression in response to increased metabolic demand in operant tasks. The purpose of this study was to examine, in the mouse brain, the effects of neuronal activation induced by voluntary running on the plastic expression of vascular GLUT1 and neuronal plasticity as measured by the microtubule protein beta-tubulin III (Tuj). The results showed that access to a running wheel for 48h induced plastic changes in the expression of GLUT1, Tuj and GLUT1-associated estimate of astrocyte vascular endfeet in motor regions. The results tend to support the plastic association between mechanisms of energy supply and plastic reorganization of neurons following a new training experience. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. The α-Tubulin gene TUBA1A in Brain Development: A Key Ingredient in the Neuronal Isotype Blend

    Directory of Open Access Journals (Sweden)

    Jayne Aiken

    2017-09-01

    Full Text Available Microtubules are dynamic cytoskeletal polymers that mediate numerous, essential functions such as axon and dendrite growth and neuron migration throughout brain development. In recent years, sequencing has revealed dominant mutations that disrupt the tubulin protein building blocks of microtubules. These tubulin mutations lead to a spectrum of devastating brain malformations, complex neurological and physical phenotypes, and even fatality. The most common tubulin gene mutated is the α-tubulin gene TUBA1A, which is the most prevalent α-tubulin gene expressed in post-mitotic neurons. The normal role of TUBA1A during neuronal maturation, and how mutations alter its function to produce the phenotypes observed in patients, remains unclear. This review synthesizes current knowledge of TUBA1A function and expression during brain development, and the brain malformations caused by mutations in TUBA1A.

  5. The α-Tubulin gene TUBA1A in Brain Development: A Key Ingredient in the Neuronal Isotype Blend.

    Science.gov (United States)

    Aiken, Jayne; Buscaglia, Georgia; Bates, Emily A; Moore, Jeffrey K

    2017-09-01

    Microtubules are dynamic cytoskeletal polymers that mediate numerous, essential functions such as axon and dendrite growth and neuron migration throughout brain development. In recent years, sequencing has revealed dominant mutations that disrupt the tubulin protein building blocks of microtubules. These tubulin mutations lead to a spectrum of devastating brain malformations, complex neurological and physical phenotypes, and even fatality. The most common tubulin gene mutated is the α-tubulin gene TUBA1A, which is the most prevalent α-tubulin gene expressed in post-mitotic neurons. The normal role of TUBA1A during neuronal maturation, and how mutations alter its function to produce the phenotypes observed in patients, remains unclear. This review synthesizes current knowledge of TUBA1A function and expression during brain development, and the brain malformations caused by mutations in TUBA1A.

  6. Interactions of tubulin with guanine nucleotides that have paclitaxel-like effects on tubulin assembly: 2',3'-dideoxyguanosine 5'-[alpha,beta-methylene]triphosphate, guanosine 5'-[alpha,beta-methylene]triphosphate, and 2',3'-dideoxyguanosine 5'-triphosphate.

    Science.gov (United States)

    Hamel, E; Vaughns, J; Getahun, Z; Johnson, R; Lin, C M

    1995-10-01

    Despite reduced affinity for the exchangeable nucleotide binding site of tubulin relative to GTP, 2',3'-dideoxyguanosine 5'-triphosphate (ddGTP) and guanosine 5'-[alpha, beta-methylene]triphosphate [pp(CH2)pG] are highly active in promoting tubulin assembly. Like the antimitotic drug paclitaxel, which interacts with the same part of the beta-tubulin molecule as exchangeable-site GTP, both analogs enhance nucleation reactions and promote formation hyperstable polymers. These observations led us to synthesize the doubly modified analog 2',3'-dideoxyguanosine 5'-[alpha, beta-methylene]triphosphate [pp(CH2)pddG]. We compared the effects of pp(CH2)pddG to those of ddGTP, pp(CH2)pG, and the three-cognate diphosphates in their interactions with tubulin. We found that pp(CH2)pddG was as active as ddGTP and pp(CH2)pG in supporting formation of polymer of increased stability, but that its affinity for the exchangeable site was lower than that of both singly modified analogs [relative affinities for the exchangeable site for pp(CH2)pddG:ddGTP:pp(CH2)-pG:GTP were 1:2.8:10:273]. There were significant differences in interactions of each of the three analogs with tubulin, and the behavior of pp(CH2)pddG was intermediate between that of ddGTP and that of pp(CH2)pG. Most importantly, under the reaction conditions studied, with heat-treated microtubule-associated proteins (MAPs) ddGTP-induced polymer consisted of short microtubules, while polymer formed with both pp(CH2)pddG and pp(CH2)pG consisted of short sheets. On the other hand, assembly without MAPs had a fivefold lower critical concentration for tubulin with ddGTP and pp(CH2)pddG (0.5 mg/ml) than with pp(CH2)pG (2.5 mg/ml). De novo assembly, which occurs readily with 2',3'-dideoxyguanosine 5'-diphosphate, was not observed with either alpha, beta-methylenediphosphate GDP analog.

  7. βIII-Tubulin Regulates Breast Cancer Metastases to the Brain.

    Science.gov (United States)

    Kanojia, Deepak; Morshed, Ramin A; Zhang, Lingjiao; Miska, Jason M; Qiao, Jian; Kim, Julius W; Pytel, Peter; Balyasnikova, Irina V; Lesniak, Maciej S; Ahmed, Atique U

    2015-05-01

    Brain metastases occur in about 10% to 30% of breast cancer patients, which culminates in a poor prognosis. It is, therefore, critical to understand the molecular mechanisms underlying brain metastatic processes to identify relevant targets. We hypothesized that breast cancer cells must express brain-associated markers that would enable their invasion and survival in the brain microenvironment. We assessed a panel of brain-predominant markers and found an elevation of several neuronal markers (βIII-tubulin, Nestin, and AchE) in brain metastatic breast cancer cells. Among these neuronal predominant markers, in silico analysis revealed overexpression of βIII-tubulin (TUBB3) in breast cancer brain metastases (BCBM) and its expression was significantly associated with distant metastases. TUBB3 knockdown studies were conducted in breast cancer models (MDA-Br, GLIM2, and MDA-MB-468), which revealed significant reduction in their invasive capabilities. MDA-Br cells with suppressed TUBB3 also demonstrated loss of key signaling molecules such as β3 integrin, pFAK, and pSrc in vitro. Furthermore, TUBB3 knockdown in a brain metastatic breast cancer cell line compromised its metastatic ability in vivo, and significantly improved survival in a brain metastasis model. These results implicate a critical role of TUBB3 in conferring brain metastatic potential to breast cancer cells. ©2015 American Association for Cancer Research.

  8. Expression of class III {beta}-tubulin is predictive of patient outcome in patients with non-small cell lung cancer receiving vinorelbine-based chemotherapy.

    Science.gov (United States)

    Sève, Pascal; Isaac, Sylvie; Trédan, Olivier; Souquet, Pierre-Jean; Pachéco, Yves; Pérol, Maurice; Lafanéchère, Laurence; Penet, Aurélie; Peiller, Eva-Laure; Dumontet, Charles

    2005-08-01

    To determine the prevalence and the prognostic value of microtubule component expression in tumors of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC). Expression of microtubular components was immunohistochemically examined in 93 tumor samples from untreated patients with stage III and IV NSCLC. All patients received vinorelbine-based chemotherapy. Response to chemotherapy, progression-free survival, and overall survival were correlated with the expression of microtubule proteins. The response rate was 27.3% (21 partial responses among 77 valuable patients). Although expression of microtubule components was not associated with the response rate, high class III beta-tubulin expression was correlated with resistance to vinorelbine, defined as disease progression under treatment. Patients whose tumors expressed high levels of class III beta-tubulin isotype had shorter progression-free survival and overall survival (P = 0.002 and 0.001, respectively). High Delta2 alpha-tubulin expression was associated with a shorter overall survival (P = 0.018). Tubulin II levels were not found to be correlated with patient outcome. A multivariate analysis, taking into account sex, age, histology, stage, weight loss, and class II beta-tubulin, class III beta-tubulin, and Delta2 alpha-tubulin levels, confirmed that class III beta-tubulin expression was independently correlated with progression-free survival (P = 0.04) and overall survival (P = 0.012). These findings suggest that a high level of expression of class III beta-tubulin in tumor cells is associated with resistance to vinorelbine and a poor prognosis in patients with NSCLC receiving vinorelbine-based chemotherapy.

  9. 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.

  10. ncd and kinesin motor domains interact with both alpha- and beta-tubulin.

    OpenAIRE

    Walker, R. A.

    1995-01-01

    Motor domains of the Drosophila minus-end-directed microtubule (MT) motor protein ncd, were found to saturate microtubule binding sites at a stoichiometry of approximately one motor domain per tubulin dimer. To determine the tubulin subunit(s) involved in binding to ncd, mixtures of ncd motor domain and MTs were treated with the zero-length cross-linker 1-ethyl-3-(3-dimethylaminopropyl-carbodiimide) (EDC). EDC treatment generated covalently cross-linked products of ncd and alpha-tubulin and o...

  11. The P-glycoprotein (ABCB1) linker domain encodes high-affinity binding sequences to alpha- and beta-tubulins.

    Science.gov (United States)

    Georges, Elias

    2007-06-26

    P-Glycoprotein (or ABCB1) has been shown to cause multidrug resistance in tumor cell lines selected with lipophilic anticancer drugs. ABCB1 encodes a duplicated molecule with two hydrophobic and hydrophilic domains linked by a highly charged region of approximately 90 amino acids, the "linker domain" with as yet unknown function(s). In this report, we demonstrate a role for this domain in binding to other cellular proteins. Using overlapping hexapeptides that encode the entire amino acid sequence of the linker domain of human ABCB1, we show a direct and specific binding between sequences in the linker domain and several intracellular proteins. Three different polypeptide sequences [617EKGIYFKLVTM627 (LDS617-627), 657SRSSLIRKRSTRRSVRGSQA676 (LDS657-676), and 693PVSFWRIMKLNLT705 (LDS693-705)] in the linker domain interacted tightly with several proteins with apparent molecular masses of approximately 80, 57, and 30 kDa. Interestingly, only the 57 kDa protein (or P57) interacted with all three different sequences of the linker domain. Purification and partial N-terminal amino acid sequencing of P57 showed that it encodes the N-terminal amino acids of alpha- and beta-tubulins. The identity of the P57 interacting protein as tubulins was further confirmed by Western blotting using monoclonal antibodies to alpha- and beta-tubulin. Taken together, the results of this study provide the first evidence for ABCB1 protein interaction mediated by sequences in the linker domain. These findings are likely to provide further insight into the functions of ABCB1 in normal and drug resistant tumor cells.

  12. Molecular karyotype and chromosomal localization of genes encoding beta-tubulin, cysteine proteinase, hsp 70 and actin in Trypanosoma rangeli.

    Science.gov (United States)

    Toaldo, C B; Steindel, M; Sousa, M A; Tavares, C C

    2001-01-01

    The molecular karyotype of nine Trypanosoma rangeli strains was analyzed by contour-clamped homogeneous electric field electrophoresis, followed by the chromosomal localization of beta-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 beta-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.

  13. 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.

  14. In trangenic rice, alpha- and beta-tubulin regulatory sequences control GUS amount and distribution through intron mediated enhancement and intron dependent spatial expression.

    Science.gov (United States)

    Gianì, Silvia; Altana, Andrea; Campanoni, Prisca; Morello, Laura; Breviario, Diego

    2009-04-01

    The genomic upstream sequence of the rice tubulin gene OsTub6 has been cloned, sequenced and characterized. The 5'UTR sequence is interrupted by a 446 bp long leader intron. This feature is shared with two other rice beta-tubulin genes (OsTub4 and OsTub1) that, together with OsTub6, group in the same clade in the evolutionary phylogenetic tree of plant beta-tubulins. Similarly to OsTub4, the leader intron of OsTub6 is capable of sustaining intron mediated enhancement (IME) of gene expression, in transient expression assays. A general picture is drawn for three rice alpha-tubulin and two rice beta-tubulin genes in which the first intron of the coding sequence for the formers and the intron present in the 5'UTR for the latters, are important elements for controlling gene expression. We used OsTua2:GUS, OsTua3:GUS, OsTub4:GUS and OsTub6:GUS chimeric constructs to investigate the in vivo pattern of beta-glucuronidase (GUS) expression in transgenic rice plants. The influence of the regulatory introns on expression patterns was evaluated for two of them, OsTua2 and OsTub4. We have thus characterized distinct patterns of expression attributable to each tubulin isotype and we have shown that the presence of the regulatory intron can greatly influence both the amount and the actual site of expression. We propose the term Intron Dependent Spatial Expression (IDSE) to highlight this latter effect.

  15. Cloning two full-length beta-tubulin isotype cDNAs from Cooperia oncophora, and screening for benzimidazole resistance-associated mutations in two isolates.

    Science.gov (United States)

    Njue, A I; Prichard, R K

    2003-12-01

    Two full-length beta-tubulin cDNAs, representing isotypes 1 and 2, were cloned from the cattle nematode Cooperia oncophora. The predicted protein sequences span 448 amino acids, and show a high degree of identity to beta-tubulins from other nematodes. While C. oncophora isotype 1 sequence had the highest identity to Haemonchus contortus isotype 1 and Teladorsagia circumcincta sequences (95% identity), the C. oncophora isotype 2 sequence was most similar to H. contortus isotype 2 and Trichostrongylus colubriformis (92% identity). Alignment of the two C. oncophora sequences with other trichostrongylid beta-tubulins deposited in GenBank showed a clear distinction between isotype 1 and 2 beta-tubulin classes. The two classes differed at 19 amino acid positions, most notably at the carboxy terminus. These isotype-defining residues were conserved among different trichostrongylid species within a class. Analysis of fragments of both genes revealed a high degree of genetic variability in coding and non-coding regions. However, all nucleotide differences detected in the coding region were silent, as they did not result in any amino acid substitution. Analysis of 2 groups of worms for the codon 200 polymorphism associated with benzimidazole resistance revealed a proportion of worms in 1 of the groups bearing a tyrosine at this position.

  16. Thiabendazole resistance and mutations in the beta-tubulin gene of Penicillium expansum strains isolated from apples and pears with blue mold decay.

    Science.gov (United States)

    Cabañas, Romualdo; Castellá, Gemma; Abarca, M Lourdes; Bragulat, M Rosa; Cabañes, F Javier

    2009-08-01

    Penicillium expansum is the causal agent of blue mold rot, a postharvest decay of stored fruits. This fungus also produces the mycotoxins patulin and citrinin. Control of P. expansum still relies mainly on the use of fungicides such as thiabendazole. Since its introduction, resistant strains have been reported. The aim of this work was to investigate the thiabendazole resistance and mutations in the beta-tubulin gene of P. expansum strains isolated from apples and pears with blue mold decay from Spain. A total of 71 strains of P. expansum were scored for resistance to thiabendazole and the beta-tubulin gene was sequenced. Out of 71 strains, 37 were sensitive and 34 were resistant to thiabendazole. Regarding the beta-tubulin gene sequence, 10 different genetic types were determined, with a 99.7-100% similarity. When the amino acid sequence was deduced, five different amino acid sequences were found. All except one of the sensitive strains lacked mutations in the region sequenced. Of the 34 resistant strains, only eight had mutations that involved the residues 198 and 240. All the strains with mutations at position 198 always corresponded to resistant isolates. However, a high percentage of resistant strains had no mutations in the region of the beta-tubulin gene sequenced, and so other mechanisms may be involved in thiabendazole resistance.

  17. Detection of disulfide bonds in bovine brain tubulin and their role in protein folding and microtubule assembly in vitro: a novel disulfide detection approach.

    Science.gov (United States)

    Chaudhuri, A R; Khan, I A; Ludueña, R F

    2001-07-31

    Cysteine residues in tubulin are actively involved in regulating ligand interactions and microtubule formation both in vivo and in vitro. These cysteine residues are sensitive reporters in determining the conformation of tubulin. Although some of the cysteines are critical in modulating drug binding and microtubule assembly, it is not clear how many of these normally exist as disulfides. The controversy regarding the disulfide bonds led us to develop a disulfide detection assay to reexamine the presence of the disulfide linkages in purified alphabeta tubulin and explore their possible biological functions in vitro. The accessible cysteine residues in alphabeta tubulin were alkylated with an excess of iodoacetamide to prevent artifactual generation of disulfide linkages in tubulin. After removal of excess iodoacetamide, tubulin was unfolded in 8 M urea. Half of the unfolded tubulin was treated with dithiothreitol to reduce any disulfide bonds present. The aliquots were then treated with iodo[(14)C]acetamide and the incorporation of radioactivity was measured. We also used the same approach to detect the disulfide linkages in the tubulin in a whole-cell extract. We found in both cases that the samples which were not treated with dithiothreitol had little or no incorporation of iodo[(14)C]acetamide, while the others that were treated with dithiothreitol had significant amounts of (14)C incorporation into tubulin. Moreover, the reduction of the disulfide linkages in tubulin resulted in inhibition of microtubule assembly (29-54%) and markedly affected refolding of the tubulin from both an intermediate and a completely unfolded state. All these data therefore suggest that tubulin has intrachain disulfide bonds in the alpha- and beta-subunits and that these disulfides assist in correct refolding of tubulin from the intermediate unfolded state or help to recover the hydrophobic domains from the completely unfolded state. These disulfides also regulate microtubule assembly

  18. 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

    and used to amplify a ~476 bp fragment of the beta-tubulin gene. The PCR products were sequenced, analysed and evaluated. We did not identify SNPs in codons 167, 198 or 200 that led to amino acid substitutions in any of the studied Trichuris spp., but genetic variation expected to be related to species......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...... to investigate the presence of these SNPs in the beta-tubulin gene of Trichuris spp. obtained from a range of animals. DNA was extracted from a total of 121 Trichuris spp. adult whipworm specimens obtained from 6 different host species. The number of worms from each host was pig: 31, deer: 21, sheep: 18, mouse...

  19. Separation of assembly-competent tubulin from brain microtubule protein preparations using a fast-performance liquid chromatography procedure.

    Science.gov (United States)

    Roychowdhury, S; Gaskin, F

    1986-05-01

    Fast-performance liquid chromatography was used to purify assembly-competent tubulin from porcine brain microtubule protein prepared by two cycles of assembly-disassembly. Microtubule protein (1-100 mg at 1.5-2.5 mg/ml) in buffer consisting of 0.1 M 2-(N-morpholino)ethanesulfonic acid, 0.5 mM MgCl2, 1 mM EGTA, 0.3 M KCl, and 0.02 mM GTP (pH 6.6) was applied to the Mono Q column (anion exchanger). The microtubule-associated proteins, GTP and GDP, eluted in the void volume. The tubulin fraction eluted at 0.45-0.50 M KCl with 65-80% recovery. The tubulin fraction contained trace enzymatic activities when compared with the starting microtubule protein, i.e., less than 1 versus 60 mU/mg/min of nucleoside diphosphate kinase, 0.2 versus 7.0 nmol/mg/min of Mg-ATPase at pH 6.6, and 0.2 versus 88 mU/mg/min of adenylate kinase. Both the Mono Q-purified tubulin and the pelleted microtubules that were assembled in 0.5 mM [3H]GTP contained 0.77 mol of labeled nucleotide/tubulin dimer. The Mono Q-purified tubulin fraction was competent to assemble, i.e., the critical concentration was 0.1 mg/ml in the presence of 0.03 mM taxol and 1 mM GTP at 37 degrees C. The Mono Q-purified tubulin fraction showed trace high-molecular-weight components, which were removed on Mono S (cation exchanger) columns. Alternatively, microtubule protein in buffer was applied to the Mono S column. Tubulin, trace nontubulin proteins, and several enzymatic activities came off in the void volume. A combination of Mono Q-Mono S or Mono S-Mono Q chromatography resulted in highly purified protein.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Benzimidazole-resistant beta-tubulin alleles in a population of parasitic nematodes (Cooperia oncophora) of cattle.

    Science.gov (United States)

    Winterrowd, C A; Pomroy, W E; Sangster, N C; Johnson, S S; Geary, T G

    2003-11-14

    Three anthelmintic classes with distinct mechanisms of action are commercially available. Selection of nematode populations resistant to all these drugs has occurred, particularly in trichostrongyloid parasites of sheep. Anthelmintic resistance in cattle parasites has only recently been recognized and appears to be less pronounced, even though very similar species infect both hosts. To understand the bases for differences in the rate of resistance development in sheep versus cattle parasites, it is important to first demonstrate that the same kinds of resistance alleles exist in both. The benzimidazoles (BZ), which have been used for more than 40 years, were chosen as an example. BZ-sensitive (BZ(S)) and BZ-resistant (BZ(R)) nematodes that parasitize sheep have been distinguished at the molecular level by a single nucleotide change in the codon for amino acid 200 of a beta-tubulin gene, a switch from TTC (phenylalanine) to TAC (tyrosine). PCR primers were designed to completely conserved regions of trichostrongyloid beta-tubulin genes and were used to amplify DNA fragments from Haemonchus contortus (cDNA from a BZ(S) and a BZ(R) library) as positive controls. The technique was then extended to the cattle parasites, Cooperia oncophora and Ostertagia ostertagi (from genomic DNA). Sequence analysis proved the presence of amplified BZ(S) alleles in all three species and BZ(R) alleles in the BZ(R) population of H. contortus. Based on these data, nested PCR primers using the diagnostic T or A as the most 3' nucleotide were designed for each species. Conditions for selective PCR were determined. To demonstrate feasibility, genomic DNA was recovered from individual H. contortus L(3) larvae from both BZ(S) and BZ(R) populations. Genomic DNA was also isolated from >70 individual adult male C. oncophora collected from a cattle farm in New Zealand with reported BZ resistance. Allele-specific PCR discriminated among heterozygotes and homozygotes in both species. This method

  1. Purification, characterization, and assembly properties of tubulin from unfertilized eggs of the sea urchin Strongylocentrotus purpuratus.

    Science.gov (United States)

    Detrich, H W; Wilson, L

    1983-05-10

    Tubulin was purified from unfertilized eggs of the sea urchin Strongylocentrotus purpuratus by chromatography of an egg supernatant fraction on DEAE-Sephacel or DEAE-cellulose followed by cycles of temperature-dependent microtubule assembly and disassembly in vitro. After two assembly cycles, the microtubule protein consisted of the alpha- and beta-tubulins (greater than 98% of the protein) and trace quantities of seven proteins with molecular weights less than 55 000; no associated proteins with molecular weights greater than tubulin were observed. When analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis on urea-polyacrylamide gradient gels, the alpha- and beta-tubulins did not precisely comigrate with their counterparts from bovine brain. Two-dimensional electrophoresis revealed that urchin egg tubulin contained two major alpha-tubulins and a single major beta species. No oligomeric structures were observed in tubulin preparations maintained at 0 degrees C. Purified egg tubulin assembled efficiently into microtubules when warmed to 37 degrees C in a glycerol-free polymerization buffer containing guanosine 5'-triphosphate. The critical concentration for assembly of once- or twice-cycled egg tubulin was 0.12-0.15 mg/mL. Morphologically normal microtubules were observed by electron microscopy, and these microtubules were depolymerized by exposure to low temperature or to podophyllotoxin. Chromatography of a twice-cycled egg tubulin preparation on phosphocellulose did not alter its protein composition and did not affect its subsequent assembly into microtubules. At concentrations above 0.5-0.6 mg/mL, a concentration-dependent "overshoot" in turbidity was observed during the assembly reaction. These results suggest that egg tubulin assembles into microtubules in the absence of the ring-shaped oligomers and microtubule-associated proteins that characterize microtubule protein from vertebrate brain.

  2. Giant cell glioblastoma and pleomorphic xanthoastrocytoma show different immunohistochemical profiles for neuronal antigens and p53 but share reactivity for class III beta-tubulin.

    Science.gov (United States)

    Martinez-Diaz, Hilda; Kleinschmidt-DeMasters, B K; Powell, Suzanne Z; Yachnis, Anthony T

    2003-09-01

    Giant cell glioblastoma multiforme (GCGBM) and pleomorphic xanthoastrocytoma (PXA) are clinically, radiographically, and histologically distinct tumors of the central nervous system. However, they share features of gross circumscription, reticulin deposition, lymphocytic infiltrates, and prominent populations of tumor giant cells. Neuronal antigens have been detected in the neoplastic cells of PXAs, but to our knowledge have not been studied previously in GCGBMs. While TP53 is mutated in most GCGBMs, a feature usually paralleled by strong immunostaining of the protein, the expression pattern of PXAs has not been extensively studied. To compare the immunoprofiles of GCGBM and PXA with regard to neuronal antigens and p53 and to evaluate the potential diagnostic utility of such a panel. Archival paraffin sections of 9 GCGBMs and 9 PXAs were immunostained for class III beta-tubulin, neuronal nuclear antigen, neurofilament protein, synaptophysin, glial fibrillary acidic protein, and p53. Giant cell glioblastomas were strongly immunoreactive for class III beta-tubulin and glial fibrillary acidic protein, but showed only rare staining for the other neuronal polypeptides. In contrast, PXAs usually showed at least focal staining of individual tumor cells for most of the neuronal antigens tested. Tubulin was strongly positive in tumor giant cells and in smaller neoplastic cells of both tumor types. Double-immunolabeling revealed distinct populations of tumor cells that expressed either glial fibrillary acidic protein or tubulin and dual-labeling of individual cells in GCGBM and PXA. Strong p53 staining was observed in many tumor cells in 5 of 8 GCGBMs tested, while staining for this antigen was negative or focally positive in 6 of 8 PXAs examined. Giant cell glioblastoma multiforme and PXA show distinct patterns of immunoreactivity for neuronal antigens and p53 that may be useful diagnostically in difficult cases or in limited samples. These results provide further evidence

  3. 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.

  4. 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.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Altered Wnt signalling in the teenage suicide brain: focus on glycogen synthase kinase-3[beta] and [beta]-catenin

    National Research Council Canada - National Science Library

    Xinguo Ren; Hooriyah S Rizavi; Mansoor A Khan; Yogesh Dwivedi; Ghanshyam N Pandey

    2013-01-01

      Abstract Glycogen synthase kinase (GSK)-3[beta] and [beta]-catenin are important components of the Wnt signalling pathway, which is involved in numerous physiological functions such as cognition, brain development and cell survival...

  9. Recognizable cerebellar dysplasia associated with mutations in multiple tubulin genes

    NARCIS (Netherlands)

    R. Oegema (Renske); T.D. Cushion (Thomas); I.G. Phelps (Ian G.); S.-K. Chung (Seo-Kyung); J.C. Dempsey (Jennifer C.); S. Collins (Sarah); J.G.L. Mullins (Jonathan G.L.); T. Dudding (Tracy); H. Gill (Harinder); A.J. Green (Andrew J.); W.B. Dobyns (William); G.E. Ishak (Gisele E.); M.I. Rees (Mark); D. Doherty (Dan)

    2015-01-01

    textabstractMutations in alpha- and beta-tubulins are increasingly recognized as a major cause of malformations of cortical development (MCD), typically lissencephaly, pachygyria and polymicrogyria; however, sequencing tubulin genes in large cohorts of MCD patients has detected tubulin mutations in

  10. TGF-beta signaling specifies axons during brain development.

    Science.gov (United States)

    Yi, Jason J; Barnes, Anthony P; Hand, Randal; Polleux, Franck; Ehlers, Michael D

    2010-07-09

    In the mammalian brain, the specification of a single axon and multiple dendrites occurs early in the differentiation of most neuron types. Numerous intracellular signaling events for axon specification have been described in detail. However, the identity of the extracellular factor(s) that initiate neuronal polarity in vivo is unknown. Here, we report that transforming growth factor beta (TGF-beta) initiates signaling pathways both in vivo and in vitro to fate naive neurites into axons. Neocortical neurons lacking the type II TGF-beta receptor (TbetaR2) fail to initiate axons during development. Exogenous TGF-beta is sufficient to direct the rapid growth and differentiation of an axon, and genetic enhancement of receptor activity promotes the formation of multiple axons. Finally, we show that the bulk of these TGF-beta-dependent events are mediated by site-specific phosphorylation of Par6. These results define an extrinsic cue for neuronal polarity in vivo that patterns neural circuits in the developing brain. Copyright 2010 Elsevier Inc. All rights reserved.

  11. Isolation, characterization, and expression of a second {beta}-tubulin-encoding gene from Colletotrichum gloeosporioides f. sp. aeschynomene

    Energy Technology Data Exchange (ETDEWEB)

    Buhr, T.L.; Dickman, M.B. [Univ. of Nebraska, Lincoln, NE (United States)

    1994-11-01

    Colletotrichum gloeosporioides (Penz.) Sacc. F. sp. aeschynomene incites anthracnose on Aeschynomene virgininica (northern jointvetch). Northern jointvetch is a leguminous weed in rice and soybean fields. Contaminating northern jointvetch seeds greatly reduce the market value of rice. C. gloeosporioides (Penz.) Sacc. F. sp. aeschynomene has been commercially marketed as a mycoherbicide to decrease populations of northern jointvetch. Development of a transformation system would be extremely useful for investigating the molecular biology of C. gloeosporioides (Penz.) Sacc. F. sp. aeschynomen. This paper reports the nucleotide sequence of a second gene for {beta} Tub (TUB2) in C. gloeosporioides (Penz.) Sacc. F. sp. aeschynomene and identifies a molecular lesion which likely confers BEN (systemic fungicide) resistance.

  12. 3D QSAR studies for the beta-tubulin binding site of microtubule-stabilizing anticancer agents (MSAAs): a pseudoreceptor model for taxanes based on the experimental structure of tubulin.

    Science.gov (United States)

    Maccari, Laura; Manetti, Fabrizio; Corelli, Federico; Botta, Maurizio

    2003-09-01

    The antimitotic agent paclitaxel continues to play an important role in the cancer chemotherapy. However, its inefficacy on certain resistant cells and toxic side effects have led to the search of new taxanes with improved biological activity. By means of a pseudoreceptor modeling approach, we have developed a binding site model for a series of taxanes. It is the first 3D QSAR model derived from the experimentally determined tubulin structure obtained by electron crystallography studies. The model is able to correlate quantitatively the structural properties of the studied compounds with their biological data.

  13. Changes of protein oxidation, calpain and cytoskeletal proteins (alpha tubulin and pNF-H) levels in rat brain after nerve agent poisoning.

    Science.gov (United States)

    RamaRao, Golime; Acharya, J N; Bhattacharya, B K

    2011-06-24

    Highly toxic organophosphorus (OP) nerve agents, sarin and soman act by inhibiting acetylcholinesterase (AChE) function at neuronal synapses and cause many toxic effects including death within minutes. The effect of nerve agents on protein oxidation, calpain, and cytoskeletal protein levels was not well known. In the present study we investigated these parameters after subcutaneous injection of sarin (120 μg/kg) and soman (80 μg/kg) in the rat brain. Results indicate that several rat brain proteins were intensely oxidized after nerve agent poisoning. Immunoreactivity levels of μ-calpain were significantly elevated in cerebral cortex and cerebellum regions of rat brain from 2.5 h to 30 days. Alpha tubulin levels reduced from 1 to 7 days in the supernatant and 1 to 3 days in the pellet fractions of cerebellum and cerebral cortex, where as phosphorylation of high molecular weight neurofilament (pNF-H) was increased significantly in nerve agent intoxicated rat brains as compared to control rats. AChE activity was inhibited up to 3 days after nerve agent exposure in plasma and brain. Results suggest that altered protein oxidation, calpain and cytoskeletal protein levels are due to multiple mechanisms of nerve agents actions and these changes might be involved in nerve agent induced complex neurotoxicity. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. The katablepharids are a distant sister group of the Cryptophyta: A proposal for Katablepharidophyta divisio nova/ Kathablepharida phylum novum based on SSU rDNA and beta-tubulin phylogeny.

    Science.gov (United States)

    Okamoto, Noriko; Inouye, Isao

    2005-08-01

    The katablepharids are a morphologically well-defined group of heterotrophic flagellates. Since their original description in 1939, they have been classified in the Cryptophyceae (Cryptophyta) based on their similar cell shape, flagellar orientation, and the presence of ejectisomes visible by light microscopy. However, electron microscopy suggests that the katablepharids are distinct from cryptomonads. A possible affinity with the Alveolata has been proposed which is mainly based on the resemblance of their feeding apparatus to the apical complex of the Apicomplexa or to the tentacles of the Ciliophora. In this study, we provide the first SSU rDNA and beta-tubulin molecular sequence data for two katablepharids: Katablepharis japonica sp. nov. and Leucocryptos marina. We reveal that the katablepharids are not closely related to the Alveolata; rather, phylogenetic reconstruction analyses of SSU rDNA and beta-tubulin suggest that the katablepharids are a distant sister group of the Cryptophyta. We therefore conclude that the katablepharids should be a group equivalent to the Cryptophyta and propose Katablepharidophyta divisio nova (ICBN)/Kathablepharida phylum novum (ICZN).

  15. [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

  16. Urinary and brain beta-carboline-3-carboxylates as potent inhibitors of brain benzodiazepine receptors.

    OpenAIRE

    Braestrup, C; Nielsen, M; Olsen, C E

    1980-01-01

    Benzodiazepines probably exert their anxiolytic, hypnotic, and anticonvulsant effects by interacting with brain-specific high-affinity benzodiazepine receptors. In searching for possible endogenous ligands for these receptors we have purified a compound 10(7)-fold from human urine by extractions, treatment with hot ethanol, and column chromatography. The compound was identified as beta-carboline-3-carboxylic acid ethyl ester (IIc) by mass spectrometry, NMR spectrometry, and synthesis; IIc was...

  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. A Simulation Model of Periarterial Clearance of Amyloid-beta from the Brain

    Directory of Open Access Journals (Sweden)

    Alexandra Katharina Diem

    2016-02-01

    Full Text Available The accumulation of soluble and insoluble amyloid-beta (A-beta in the brain indicates failure of elimination of A-beta from the brain with age and Alzheimer's disease. There is a variety of mechanisms for elimination of A-beta from the brain. They include the action of microglia and enzymes together with receptor-mediated absorption of A-beta into the blood and periarterial lymphatic drainage of A-beta. Although the brain possesses no conventional lymphatics, experimental studies have shown that fluid and solutes, such as A-beta, are eliminated from the brain along 100 nm wide basement membranes in the walls of cerebral capillaries and arteries. This lymphatic drainage pathway is reflected in the deposition of A-beta in the walls of human arteries with age and Alzheimer's disease as cerebral amyloid angiopathy (CAA. Initially, A-beta diffuses through the extracellular spaces of grey matter in the brain and then enters basement membranes in capillaries and arteries to flow out of the brain. Although diffusion through the extracellular spaces of the brain has been well characterised, the exact mechanism whereby perivascular elimination of A-beta occurs has not been resolved. Here we use a computational model to describe the process of periarterial drainage in the context of diffusion in the brain, demonstrating that periarterial drainage along basement membranes is very rapid compared with diffusion. Our results are a validation of experimental data and are significant in the context of failure of periarterial drainage as a mechanism underlying the pathogenesis of AD as well as complications associated with its immunotherapy.

  19. 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

  20. 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

    2017-01-01

    Abstract 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

  1. Effect of Accent Familiarity on Language Processing via Alpha and Beta Brain Wave Activity

    National Research Council Canada - National Science Library

    Rachel Elizabeth Capps; Erick Van Buren; Brian Kluge; Sara Thompson; David F Nichols

    2016-01-01

    .... The current study was designed to test the effects of familiarity of geographically diverse accents on the amplitudes of relaxed, i.e., alpha (~10 Hz), and alert, i.e., beta (~20 Hz), brain waves...

  2. Analysis of Post-Traumatic Brain Injury Gene Expression Signature Reveals Tubulins, Nfe2l2, Nfkb, Cd44, and S100a4 as Treatment Targets.

    Science.gov (United States)

    Lipponen, Anssi; Paananen, Jussi; Puhakka, Noora; Pitkänen, Asla

    2016-08-17

    We aimed to define the chronically altered gene expression signature of traumatic brain injury (TBI-sig) to discover novel treatments to reverse pathologic gene expression or reinforce the expression of recovery-related genes. Genome-wide RNA-sequencing was performed at 3 months post-TBI induced by lateral fluid-percussion injury in rats. We found 4964 regulated genes in the perilesional cortex and 1966 in the thalamus (FDR sig was used for a LINCS analysis which identified 11 compounds that showed a strong connectivity with the TBI-sig in neuronal cell lines. Of these, celecoxib and sirolimus were recently reported to have a disease-modifying effect in in vivo animal models of epilepsy. Other compounds revealed by the analysis were BRD-K91844626, BRD-A11009626, NO-ASA, BRD-K55260239, SDZ-NKT-343, STK-661558, BRD-K75971499, ionomycin, and desmethylclomipramine. Network analysis of overlapping genes revealed the effects on tubulins (Tubb2a, Tubb3, Tubb4b), Nfe2l2, S100a4, Cd44, and Nfkb2, all of which are linked to TBI-relevant outcomes, including epileptogenesis and tissue repair. Desmethylclomipramine modulated most of the gene targets considered favorable for TBI outcome. Our data demonstrate long-lasting transcriptomics changes after TBI. LINCS analysis predicted that these changes could be modulated by various compounds, some of which are already in clinical use but never tested in TBI.

  3. Gene expression of the TGF-beta family in rat brain infected with Borna disease virus.

    Science.gov (United States)

    Nishino, Yoshii; Ooishi, Ryo; Kurokawa, Sachiko; Fujino, Kan; Murakami, Masaru; Madarame, Hiroo; Hashimoto, Osamu; Sugiyama, Kazutoshi; Funaba, Masayuki

    2009-01-01

    CRNP5, a variant of Borna disease virus (BDV), has stronger pathogenesis in rats than the related variant CRP3, although only 4 amino acids in the whole genome are different. As a first step to clarify the differential pathogenesis between the variants, the present study focused on examining the expression of the transforming growth factor (TGF)-beta family in the brain of rats infected with BDV. The main results were as follows. (1) BDV infection, irrespective of the variant, up-regulates TGF-beta1 expression in the brain, (2) the expressions of signal receptors for TGF-beta1 are also increased, (3) the expression of brain inhibin/activin betaE is up-regulated by BDV infection, and (4) the expression of brain inhibin/activin betaC tends to be higher in rats exhibiting severe Borna disease. These results indicate that members of the TGF-beta family are involved in neuronal disorders induced by BDV infection in a ligand-dependent manner. In particular, up-regulation of inhibin/activin betaC may be a key event responsible for induction of the stronger pathogenesis of the CRNP5 variant of BDV.

  4. 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.

  5. A radioimmunoassay for ependymins beta and gamma: two goldfish brain proteins involved in behavioral plasticity.

    Science.gov (United States)

    Schmidt, R; Shashoua, V E

    1981-04-01

    A radioimmunoassay (RIA) using 125I-labeled antigen was developed for the quantitative determination of two goldfish brain proteins (ependymins beta and gamma). The proteins were isolated from the cerebrospinal fluid (CSF) and cells of the ependymal zone surrounding goldfish brain ventricles. The turnover rates of beta and gamma were previously shown to be specifically enhanced after the animals successfully acquired a new pattern of swimming behavior. Femtomole quantities of ependymin beta were measurable by the RIA. In applications of the assay, beta and gamma ependymins were found to have common immunological properties, since 125I-beta-antigen bound to antibody could be displaced by unlabeled ependymin gamma as well as ependymin beta but not by a variety of other proteins including several purified glycoproteins isolated from goldfish brain. The ependymins were shown to constitute 14% of the total protein content of the brain extracellular fluid and also to be present as a minor component of the serum proteins (0.3%). Ependymins beta and gamma have an immunological reactivity in these fractions that can be increased by a factor of 30 on heating. The data suggest that the antigenicity of the molecules is highly masked, and that it may require some unraveling of the quaternary structure of the proteins before maximal interaction with the antisera becomes possible.

  6. 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.

  7. Selection of a nucleation-promoting element following chemical modification of tubulin.

    Science.gov (United States)

    Sioussat, T M; Boekelheide, K

    1989-05-16

    Following a 16-h incubation with a large excess of 2,5-hexanedione (2,5-HD) while in the assembled state, bovine brain tubulin contained a powerful nucleating component, the presence of which lowered the dissociation rate from 83 s-1 for untreated tubulin to 13 s-1 for 2,5-HD-treated tubulin. This nucleating component could be selectively concentrated by sequential stringent (conditions of low temperature and low tubulin concentration) cycles of assembly and disassembly. In 2-(N-morpholino)ethanesulfonic acid buffer without glycerol, the critical concentration of assembly of untreated tubulin (2.4 mg/mL) was 19 times higher than that of 2,5-HD-treated tubulin subjected to three sequential stringent cycles of assembly and disassembly (0.13 mg/mL). This highly nucleating 2,5-HD-treated tubulin preparation could both copolymerize with untreated tubulin and seed subcritical concentration assembly of untreated tubulin. Experiments to define the assembly-altering component have identified structural alterations to the alpha-tubulin monomer. While the alpha-tubulin subunit of native untreated tubulin dimer contained no chymotryptic cleavage sites, the native 2,5-HD-treated alpha-tubulin subunit was cleaved by chymotrypsin to yield a 37-kDa C-terminal fragment.

  8. Effects of beta-hydroxybutyrate on brain vascular permeability in rats with traumatic brain injury.

    Science.gov (United States)

    Orhan, Nurcan; Ugur Yilmaz, Canan; Ekizoglu, Oguzhan; Ahishali, Bulent; Kucuk, Mutlu; Arican, Nadir; Elmas, Imdat; Gürses, Candan; Kaya, Mehmet

    2016-01-15

    This study investigates the effect of beta-hydroxybutyrate (BHB) on blood-brain barrier (BBB) integrity during traumatic brain injury (TBI) in rats. Evans blue (EB) and horseradish peroxidase (HRP) were used as determinants of BBB permeability. Glutathione (GSH) and malondialdehyde (MDA) levels were estimated in the right (injury side) cerebral cortex of animals. The gene expression levels for occludin, glucose transporter (Glut)-1, aquaporin4 (AQP4) and nuclear factor-kappaB (NF-κB) were performed, and Glut-1 and NF-κB activities were analyzed. BHB treatment decreased GSH and MDA levels in intact animals and in those exposed to TBI (P<0.05). Glut-1 protein levels decreased in sham, BHB and TBI plus BHB groups (P<0.05). NF-κB protein levels increased in animals treated with BHB and/or exposed to TBI (P<0.05). The expression levels of occludin and AQP4 did not significantly change among experimental groups. Glut-1 expression levels increased in BHB treated and untreated animals exposed to TBI (P<0.05). While NF-κB expression levels increased in animals in TBI (P<0.01), a decrease was noticed in these animals upon BHB treatment (P<0.01). In animals exposed to TBI, EB extravasation was observed in the ipsilateral cortex regardless of BHB treatment. Ultrastructurally, BHB attenuated but did not prevent the presence of HRP in brain capillary endothelial cells of animals with TBI; moreover, the drug also led to the observation of the tracer when used in intact rats (P<0.01). Altogether, these results showed that BHB not only failed to provide overall protective effects on BBB in TBI but also led to BBB disruption in healthy animals. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The benzodiazepine receptor in rat brain and its interaction with ethyl beta-carboline-3-carboxylate

    Energy Technology Data Exchange (ETDEWEB)

    Martin, I.L.; Doble, A.

    1983-06-01

    (3H)Ethyl beta-carboline-3-carboxylate ((3H) beta-CCE) binds to a homogeneous population of recognition sites in rat whole brain membranes with high affinity. The (3H)beta-CCE binding is completely displaceable by low concentrations of a number of benzodiazepines with similar potencies found when using a 3H-benzodiazepine as the ligand. This suggests that the recognition sites for beta-CCE and the benzodiazepines are identical or that they are involved in a close interaction. The binding of (3H)beta-CCE does not obey simple mass-action kinetics. (3H)Flunitrazepam dissociation from its receptor population is biphasic, and different methods of initiation of this dissociation indicate that cooperative interactions take place within the receptor population. We conclude that the benzodiazepine receptor is a single entity that can exist in two conformations, the equilibrium between which may be controlled by some as yet unidentified factor.

  10. Effect of prolonged 5-hydroxytryptamine uptake inhibition by paroxetine on cortical. beta. sub 1 and. beta. sub 2 -adrenoceptors in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, D.R.; Palmer, K.J.; Johnson, A.M. (SmithKline Beecham Pharmaceuticals, Essex (England))

    1990-01-01

    The effects of prolonged oral administration of the antidepressants paroxetine and amitriptyline on rat brain cortical {beta}{sub 1}- and {beta}{sub 2}-adrenoceptor numbers and affinities were investigated using ({sup 3}H)-CGP 12177. Although amitriptyline, 27 mg/kg, caused a significant 20% reduction in the number of {beta}{sub 1}-adrenoceptors, paroxetine, at does up to 8.9 mg/kg p.o., did not influence binding of ({sup 3}H)-CGP 12177 to cortical {beta}{sub 1}- or {beta}{sub 2}-adrenoceptors. This study with paroxetine provides further evidence that the down-regulation of central {beta}{sub 1}-adrenoceptors in rat brain after repeated administration is not a property of all antidepressant drugs.

  11. Cloning and sequence analysis of the human brain beta-adrenergic receptor. Evolutionary relationship to rodent and avian beta-receptors and porcine muscarinic receptors.

    Science.gov (United States)

    Chung, F Z; Lentes, K U; Gocayne, J; Fitzgerald, M; Robinson, D; Kerlavage, A R; Fraser, C M; Venter, J C

    1987-01-26

    Two cDNA clones, lambda-CLFV-108 and lambda-CLFV-119, encoding for the beta-adrenergic receptor, have been isolated from a human brain stem cDNA library. One human genomic clone, LCV-517 (20 kb), was characterized by restriction mapping and partial sequencing. The human brain beta-receptor consists of 413 amino acids with a calculated Mr of 46480. The gene contains three potential glucocorticoid receptor-binding sites. The beta-receptor expressed in human brain was homology with rodent (88%) and avian (52%) beta-receptors and with porcine muscarinic cholinergic receptors (31%), supporting our proposal [(1984) Proc. Natl. Acad. Sci. USA 81, 272 276] that adrenergic and muscarinic cholinergic receptors are structurally related. This represents the first cloning of a neurotransmitter receptor gene from human brain.

  12. TUBA1A mutations cause wide spectrum lissencephaly (smooth brain) and suggest that multiple neuronal migration pathways converge on alpha tubulins

    NARCIS (Netherlands)

    R.A. Kumar (Ravinesh); D.T. Pilz (Daniela); T.D. Babatz (Timothy); T.D. Cushion (Thomas); K. Harvey (Kirsten); M. Topf (Maya); L. Yates (Laura); S. Robb (Stephanie); G. Uyanik (Gökhan); G.M.S. Mancini (Grazia); M.I. Rees (Mark); R.J. Harvey (Robert); W.B. Dobyns (William)

    2010-01-01

    textabstracte previously showed that mutations in LIS1 and DCX account for ~85% of patients with the classic form of lissencephaly (LIS). Some rare forms of LIS are associated with a disproportionately small cerebellum, referred to as lissencephaly with cerebellar hypoplasia (LCH). Tubulin alpha1A

  13. Brain protein metabolism and the acquisition of new behaviors. II. Immunological studies of the alpha, beta and gamma proteins of goldfish brain.

    Science.gov (United States)

    Shashoua, V E

    1977-02-11

    In a previous study, the labeling pattern of three proteins (alpha, beta and gamma) in goldfish brain was found to change after the animals successfully acquired a new pattern of behavior. In the present study, these proteins were isolated from the brain cytoplasmic fraction, purified by successive gel electrophoresis and used as antigent to immunize rabbits. Antisera containing antibodies to two of the proteins (beta and gamma) were obtained. These gave single precipitin bands when plated against the antigens and a mixture of the total cytoplasmic proteins. The distribution of beta and gamma in brain subcellular fractions and in a variety of goldfish tissues was determined by immunodiffusion methods. gamma was specific to brain. The beta protein cross-reacted but was not identical to a widely distributed substance in plasma, liver and kidney. Both beta and gamma appear to be species specific in that no cross-reactivity was obtained with mouse, chick or rat brain proteins. Immunological methods, in combination with double labeling experiments were used to establish that the beta and gamma antigens were proteins which were normally present in goldfish brain. Both the beta and gamma antisera were equally capable of specifically precipitating the proteins which were differentially labeled after training as well as purified proteins of the same molecular weight present in the brains of control animals. These results suggest that the acquisition of a new pattern of behavior can increase the demand for the synthesis of specific proteins (beta and gamma) normally present in goldfish brain.

  14. Identification of tubulin drug binding sites and prediction of relative differences in binding affinities to tubulin isotypes using digital signal processing.

    Science.gov (United States)

    Chen, Ke; Huzil, J Torin; Freedman, Holly; Ramachandran, Parameswaran; Antoniou, Andreas; Tuszynski, Jack A; Kurgan, Lukasz

    2008-11-01

    Microtubules are involved in numerous cellular processes including chromosome segregation during mitosis and, as a result, their constituent protein, tubulin, has become a successful target of several chemotherapeutic drugs. In general, these drugs bind indiscriminately to tubulin within both cancerous and healthy cells, resulting in unwanted side effects. However, differences between beta-tubulin isotypes expressed in a wide range of cell types may aid in the development of anti-tubulin drugs having increased specificity for only certain types of cells. Here, we describe a digital signal processing (DSP) method that is capable of predicting hot spots for the tubulin family of proteins as well as determining relative differences in binding affinities to these hot spots based only on the primary sequence of 10 human tubulin isotypes. Due to the fact that several drug binding sites have already been characterized within beta-tubulin, we are able to correlate hot spots with the binding sites for known chemotherapy drugs. We have also verified the accuracy of this method using the correlation between the binding affinities of characterized drugs and the tubulin isotypes. Additionally, the DSP method enables the rapid estimation of relative differences in binding affinities within the binding sites of tubulin isotypes that are yet to be experimentally determined.

  15. Cold-adapted tubulins in the glacier ice worm, Mesenchytraeus solifugus.

    Science.gov (United States)

    Tartaglia, Lawrence J; Shain, Daniel H

    2008-11-01

    Glacier ice worms, Mesenchytraeus solifugus and related species, are the only known annelids that survive obligately in glacier ice and snow. One fundamental component of cold temperature adaptation is the ability to polymerize tubulin, which typically depolymerizes at low physiological temperatures (e.g., <10 degrees C) in most temperate species. In this study, we isolated two alpha-tubulin (Msalpha1, Msalpha2) and two beta-tubulin (Msbeta1, Msbeta2) subunits from an ice worm cDNA library, and compared their predicted amino acid sequences with homologues from other cold-adapted organisms (e.g., Antarctic fish, ciliate) in an effort to identify species-specific amino acid substitutions that contribute to cold temperature-dependent tubulin polymerization. Our comparisons and predicted protein structures suggest that ice worm-specific amino acid substitutions stabilize lateral contact associations, particularly between beta-tubulin protofilaments, but these substitutions occur at different positions in comparison with other cold-adapted tubulins. The ice worm tubulin gene family appears relatively small, comprising one primary alpha- and one primary beta-tubulin monomers, though minor isoforms and pseudogenes were identified. Our analyses suggest that variation occurs in the strategies (i.e., species-specific amino acid substitutions, gene number) by which cold-adapted taxa have evolved the ability to polymerize tubulin at low physiological temperatures.

  16. Tubulin dimers oligomerize before their incorporation into microtubules.

    Directory of Open Access Journals (Sweden)

    Julien Mozziconacci

    Full Text Available In the presence of GTP, purified dimers of alpha- and beta-tubulin will interact longitudinally and laterally to self-assemble into microtubules (MTs. This property provides a powerful in vitro experimental system to describe MT dynamic behavior at the micrometer scale and to study effects and functioning of a large variety of microtubule associated proteins (MAPs. Despite the plethora of such data produced, the molecular mechanisms of MT assembly remain disputed. Electron microscopy (EM studies suggested that tubulin dimers interact longitudinally to form short oligomers which form a tube by lateral interaction and which contribute to MT elongation. This idea is however challenged: Based on estimated association constants it was proposed that single dimers represent the major fraction of free tubulin. This view was recently supported by measurements suggesting that MTs elongate by addition of single tubulin dimers. To solve this discrepancy, we performed a direct measurement of the longitudinal interaction energy for tubulin dimers. We quantified the size distribution of tubulin oligomers using EM and fluorescence correlation spectroscopy (FCS. From the distribution we derived the longitudinal interaction energy in the presence of GDP and the non-hydrolysable GTP analog GMPCPP. Our data suggest that MT elongation and nucleation involves interactions of short tubulin oligomers rather than dimers. Our approach provides a solid experimental framework to better understand the role of MAPs in MT nucleation and growth.

  17. 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

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

    Directory of Open Access Journals (Sweden)

    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. Activation of tubulin assembly into microtubules upon a series of repeated femtosecond laser impulses

    NARCIS (Netherlands)

    Tulub, AA; Stefanov, VE

    2004-01-01

    Tubulin, a globular protein, mostly distributed in nature in the dimeric alpha, beta form, can polymerize in vivo and in vitro into microtubules-longitudinal dynamic assemblies, involved in numerous cellular functions, including cell division and signaling. Tubulin polymerization starts upon binding

  20. Effect of repeated benzimidazole treatments with increasing dosages on the phenotype of resistance and the beta-tubulin codon 200 genotype distribution in a benzimidazole-resistant cyathostomin population.

    Science.gov (United States)

    Drogemuller, Michaela; Failing, Klaus; Schnieder, Thomas; von Samson-Himmelstjerna, Georg

    2004-09-02

    This study was designed to investigate the effect of repeated treatments with increasingly high fenbendazole (FBZ) dosages on the phenotype and genotype of a benzimidazole (BZ)-resistant cyathostomin population. An experimentally infected horse was treated repeatedly with FBZ dose rates between 7.5 and 30.0 mg/kg body weight (bw) over approximately 2 years. Faecal egg counts (FECs) and larval cultures were performed weekly. A total of 45 faecal egg count reduction tests (FECRTs) were analysed, revealing a high variability during the course of experiment with a mean value in faecal egg count reduction (FECR) of -17% (S.D. +/- 78). The FECR was always 0.36 microg/ml TBZ, confirming the phenotype of resistance. The LD(99) varied between 0.40 and 0.63 microg/ml TBZ. Despite consecutive treatments, no noticeable increase of the LD(50), LD(96) and LD(99) values was detected for the duration of the experiment. The molecular analysis of the codon 200 of 106 third stage larvae (L3) was carried out following repeated treatments with 30 mg FBZ/kg bw. Out of these larvae 32% were homozygous TTC/TTC, 60% showed the heterozygous TTC/TAC genotype, and 8% were homozygous TAC/TAC. The resulting allele frequencies were 62% for TTC and 38% for TAC. These findings suggest that repeated BZ treatments with increasing dosages do not alter significantly the FECRT and EHT characteristics of a BZ-resistant cyathostomin population. Furthermore, it may also be concluded that, in contrast to sheep trichostrongyles, such a selection regime does not result in beta-tubulin codon 200 TAC allele autocracy.

  1. 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.

  2. βIII-tubulin enhances efficacy of cabazitaxel as compared with docetaxel.

    Science.gov (United States)

    Smiyun, Gregoriy; Azarenko, Olga; Miller, Herbert; Rifkind, Alexander; LaPointe, Nichole E; Wilson, Leslie; Jordan, Mary Ann

    2017-07-01

    Cabazitaxel is a novel taxane approved for treatment of metastatic hormone-refractory prostate cancer in patients pretreated with docetaxel. Cabazitaxel, docetaxel, and paclitaxel bind specifically to tubulin in microtubules, disrupting functions essential to tumor growth. High levels of βIII-tubulin isotype expression are associated with tumor aggressivity and drug resistance. To understand cabazitaxel's increased efficacy, we examined binding of radio-labeled cabazitaxel and docetaxel to microtubules and the drugs' suppression of microtubule dynamic instability in vitro in microtubules assembled from purified bovine brain tubulin containing or devoid of βIII-tubulin. We found that cabazitaxel suppresses microtubule dynamic instability significantly more potently in the presence of βIII-tubulin than in its absence. In contrast, docetaxel showed no βIII-tubulin-enhanced microtubule stabilization. We also asked if the selective potency of cabazitaxel on βIII-tubulin-containing purified microtubules in vitro extends to cabazitaxel's effects in human tumor cells. Using MCF7 human breast adenocarcinoma cells, we found that cabazitaxel also suppressed microtubule shortening rates, shortening lengths, and dynamicity significantly more strongly in cells with normal levels of βIII-tubulin than after 50% reduction of βIII-tubulin expression by siRNA knockdown. Cabazitaxel also more strongly induced mitotic arrest in MCF7 cells with normal βIII-tubulin levels than after βIII-tubulin reduction. In contrast, docetaxel had little or no βIII-tubulin-dependent selective effect on microtubule dynamics or mitotic arrest. The selective potency of cabazitaxel on purified βIII-tubulin-containing microtubules and in cells expressing βIII-tubulin suggests that cabazitaxel may be unusual among microtubule-targeted drugs in its superior anti-tumor efficacy in tumors overexpressing βIII-tubulin.

  3. 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...

  4. The role of an endogenous amnesic mechanism mediated by brain beta-endorphin in memory modulation.

    Science.gov (United States)

    Izquierdo, I

    1982-07-01

    1. Post-training administration of the opiate receptor antagonist naloxone facilitates the memory consolidation of a wide variety of tasks by rats. 2. Post-training administration of subanalgesic doses of beta-endorphin causes retrograde amnesia. This effect is shared by other opiates and opioids and is competitively antagonized by naloxone. These other opiates and opioids probably act by the release of endogenous beta-endorphin. 3. During various forms of aversive and non-aversive training beta-endorphin (but not Met-enkephalin) is released in the rat brain in amounts compatible with amnestic doses of this substance. 4. A number of treatments that cause naloxone-reversible retrograde amnesia, i.e. high doses of ACTH or adrenaline, low doses of morphine or of opioids, electroconvulsive shock, release massive amounts of beta-endorphin and Met-enkephalin in the rat brain. 5. These findings point to the existence of a physiological amnesic mechanism mediated by beta-endorphin, and perhaps other opioids as well, that normally prevents memory from being as good as it could be, and when operating at an exaggerated level may cause complete amnesia. 6. This mechanism interacts with other systems that influence memory consolidation (central dopaminergic and noradrenergic pathways, ACTH, peripheral adrenaline) and is a powerful modulator of their activity. 7. One possible role of the amnesic mechanism during training is to cause the rapid forgetting of adventitious learning that may interfere with acquisition of the main tasks for which animals are being trained. 8. Either through this action, or by some direct effect, beta-endorphin facilitates retrieval of a variety of behaviors in the rat when given before a test session.

  5. 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

  6. Protective Effects of Beta Glucan and Gliclazide on Brain Tissue and Sciatic Nerve of Diabetic Rats Induced by Streptozosin

    Directory of Open Access Journals (Sweden)

    Harun Alp

    2012-01-01

    Full Text Available There have not been yet enough studies about effects of beta glucan and gliclazide on oxidative stress created by streptozotocin in the brain and sciatic nerve of diabetic rats. The aim of this paper was to investigate the antioxidant effects of gliclazide and beta glucan on oxidative stress and lipid peroxidation created by streptozotosin in brain and sciatic nerve. Total of 42 rats were divided into 6 groups including control, diabetic untreated (DM (only STZ, diabetic, STZ (DM + beta glucan, STZ (DM + gliclazide, only beta glucan treated (no diabetic, and only gliclazide treated (no diabetic. The brain and sciatic nerve tissue samples were analyzed for malondialdehyde (MDA, total oxidant status (TOS, total antioxidant status (TAS, oxidative stress index (OSI, and paraoxonase (PON-1 levels. We found a significant increase in MDA, TOS, and OSI along with a reduction in TAS level, catalase, and PON-1 activities in brain and sciatic nerve of streptozotocin-induced diabetic rats. Also, this study shows that in terms of these parameters both gliclazide and beta glucan have a neuroprotective effect on the brain and sciatic nerve of the streptozotocin-induced diabetic rat. Our conclusion was that gliclazide and beta glucan have antioxidant effects on the brain and sciatic nerve of the streptozotocin-induced diabetic rat.

  7. Recovery of running performance following muscle-damaging exercise: relationship to brain IL-1beta.

    Science.gov (United States)

    Carmichael, Martin D; Davis, J Mark; Murphy, E Angela; Brown, Adrienne S; Carson, James A; Mayer, Eugene; Ghaffar, Abdul

    2005-09-01

    Recovery following muscle-damaging downhill running is associated with increased muscle inflammatory cytokines. Various inflammatory challenges can also increase cytokines in the brain, which have been linked to sickness behaviors, including fatigue, but little is known about the brain cytokine response to stressful exercise. We used a downhill running model to determine the relationship between brain IL-1beta and recovery of running performance. Male C57BL/6 mice were assigned to: downhill (DH), uphill (UH), or non-running control (Con) groups and run on a treadmill at 22 m/min and -14% or 14% grade, for 150 min. Following the run, a subset of DH and UH was placed into activity wheel cages where voluntary running activity was measured for 7 days. A second subset was run to fatigue on a motorized treadmill at 36 m/min, 8% grade at 24, 48, and 96 h post-up/downhill run. A third subset of DH, UH, and Con mice had brains dissected and assayed for IL-1beta at 24 and 48 h. DH resulted in delayed recovery of both voluntary wheel-running and treadmill running to fatigue as compared to UH (p coordination, motivation, perception of effort, and pain.

  8. F-18 Polyethyleneglycol stilbenes as PET imaging agents targeting A{beta} aggregates in the brain

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wei [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Oya, Shunichi [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kung Meiping [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Hou, Catherine [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Maier, Donna L. [Department of Neuroscience, AstraZeneca, Wilmington, DE 19850 (United States); Kung, Hank F. [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States) and Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States)]. E-mail: kunghf@sunmac.spect.upenn.edu

    2005-11-01

    This paper describes a novel series of {sup 18}F-labeled polyethyleneglycol (PEG)-stilbene derivatives as potential {beta}-amyloid (A{beta}) plaque-specific imaging agents for positron emission tomography (PET). In these series of compounds, {sup 18}F is linked to the stilbene through a PEG chain, of which the number of ethoxy groups ranges from 2 to 5. The purpose of adding PEG groups is to lower the lipophilicity and improve bioavailability. The syntheses of the 'cold' compounds and the {sup 18}F-labeled PEG stilbene derivatives are successfully achieved. All of the fluorinated stilbenes displayed high binding affinities in an assay using postmortem AD brain homogenates (K {sub i}=2.9-6.7 nM). Labeling was successfully performed by a substitution of the mesylate group of 10a-d by [{sup 18}F]fluoride giving the target compounds [{sup 18}F]12a-d (EOS, specific activity, 900-1500 Ci/mmol; radiochemical purity >99%). In vivo biodistribution of these novel {sup 18}F ligands in normal mice exhibited excellent brain penetrations and rapid washouts after an intravenous injection (6.6-8.1 and 1.2-2.6% dose/g at 2 and 60 min, respectively). Autoradiography of postmortem AD brain sections of [{sup 18}F]12a-d confirmed the specific binding related to the presence of A{beta} plaques. In addition, in vivo plaque labeling can be clearly demonstrated with these {sup 18}F-labeled agents in transgenic mice (Tg2576), a useful animal model for Alzheimer's disease. In conclusion, the preliminary results strongly suggest these fluorinated PEG stilbene derivatives are suitable candidates as A{beta} plaque imaging agents for studying patients with Alzheimer's disease.

  9. Growth and development of maize that contains mutant tubulin genes

    Energy Technology Data Exchange (ETDEWEB)

    Susan M. Wick

    2004-07-23

    Mutant maize plants containing a Mu transposon disrupting one of the five beta tubulin genes of interest were followed for several generations and hybridized with each other to produce plants containing disruptions in both copies of a single gene or disruption of more than one tubulin gene. Seedlings of some of these plants were grown under chilling conditions for a few weeks. After DOE funding ended, plants have been assessed to see whether mutant are more or less tolerant to chilling. Other mutant plants will be assessed for their male and female fertility relative to non-mutant siblings or other close relatives.

  10. 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.

  11. 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.)

  12. The effect of beta-turn structure on the permeation of peptides across monolayers of bovine brain microvessel endothelial cells

    DEFF Research Database (Denmark)

    Sorensen, M; Steenberg, B; Knipp, G T

    1997-01-01

    PURPOSE: To investigate the effects of the beta-turn structure of a peptide on its permeation via the paracellular and transcellular routes across cultured bovine brain microvessel endothelial cell (BBMEC) monolayers, an in vitro model of the blood-brain barrier (BBB). METHODS: The effective...

  13. [Changes of MDA, SOD, TNF-alpha, and IL-1beta in rat brain tissue after concussion].

    Science.gov (United States)

    Gao, Feng; Zhao, Li; Gu, Zhen-Yong; Cong, Bin

    2014-02-01

    To observe the changes of malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) in rat brain tissue and to explore the mechanism of secondary cerebral injury after brain concussion. The brain concussion model was established with the pathological changes of rat brain tissue by Weil stain. The expressions of MDA and SOD in brain tissue were examined by photochemical method. The expressions of TNF-alpha and IL-1beta in cerebral cortex and hippocampus were examined by immunochemistry. Nerve myelin sheath showed disorder, disruption, gryposis and swelling by Weil stain. Above changes were more severe at 12h. The quantity of MDA in rat brain tissue after concussion was significantly higher than that in the control group. The activity of SOD was significantly lower than that in the control group. The expressions of TNF-alpha and IL-1beta increased more significantly in cerebral cortex and hippocampus in rat brain tissue after concussion than that in the control group. Oxidative stress and inflammatory injury in the rat brain tissue, which may play an important role in secondary cerebral injury after concussion.

  14. Passage of amyloid beta protein antibody across the blood-brain barrier in a mouse model of Alzheimer's disease.

    Science.gov (United States)

    Banks, William A; Terrell, Brie; Farr, Susan A; Robinson, Sandra M; Nonaka, Naoko; Morley, John E

    2002-12-01

    Vaccinations against amyloid beta protein (A beta P) reduce amyloid deposition and reverse learning and memory deficits in mouse models of Alzheimer's disease. This has raised the question of whether circulating antibodies, normally restricted by the blood-brain barrier (BBB), can enter the brain [Nat. Med. 7 (2001) 369-372]. Here, we show that antibody directed against A beta P does cross the BBB at a very low rate. Entry is by way of the extracellular pathways with about 0.11% of an intravenous (i.v.) dose entering the brain by 1h. Clearance of antibody from brain increasingly dominates over time, but antibody is still detectable in brain 72 h after i.v. injection. Uptake and clearance is not altered in mice overexpressing A beta P. This ability to enter and exit the brain even in the presence of increased brain ligand supports the use of antibody in the treatment of Alzheimer's and other diseases of the brain.

  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. Tau, Amyloid Beta and Deep Brain Stimulation: Aiming to Restore Cognitive Deficit in Alzheimer's Disease.

    Science.gov (United States)

    Mondragón-Rodríguez, Siddhartha; Perry, George; Pena-Ortega, Fernando; Williams, Sylvain

    2017-01-01

    The last two decades have seen a great advance in the data that supports the two current hypotheses in Alzheimer`s disease field, the amyloid beta hypothesis and the tau hypothesis. Not surprisingly, Aβ and tau proteins are currently the major therapeutic research targets for AD treatment. Unfortunately, nothing but moderate success has emerged from such therapeutic approaches. With this in mind, we will discuss deep brain stimulation as a promising therapeutic strategy that aims to restore brain activity. Lastly, in the scope of cognitive deficit restoration, we will discuss the relevance of the limbic formation as a promising neuroanatomical target for deep brain stimulation. Immunohistochemistry for modified tau (phosphorylated at Ser199-202-Thr205 labelled by the antibody AT8) was performed on paraffin-embedded human brain sections providing a detailed characterization of NFT pathology. Abnormally phosphorylated tau protein is the key common marker in several brain diseases such as Alzheimer's disease, Parkinson`s disease, Pick Disease, Down syndrome and frontotemporal dementia and is capable of affecting synaptic events that are critical for memory formation. With this in mind, therapeutic strategies aiming to restore synaptic events could offer better outcomes. The humble success of current therapeutic strategies along with the lack of basic knowledge of the brain disease mechanisms calls for alternatives that benefit patients in the present moment. One of particular interest is the neurostimulation strategy that is already a well-established treatment for several movement disorders and when compared to current Alzheimer`s therapeutic strategies, deep brain stimulation does not directly interfere with the normal protein function, therefore increasing the probability of success.

  17. Soluble Amyloid-beta Aggregates from Human Alzheimer’s Disease Brains

    Science.gov (United States)

    Esparza, Thomas J.; Wildburger, Norelle C.; Jiang, Hao; Gangolli, Mihika; Cairns, Nigel J.; Bateman, Randall J.; Brody, David L.

    2016-01-01

    Soluble amyloid-beta (Aβ) aggregates likely contribute substantially to the dementia that characterizes Alzheimer’s disease. However, despite intensive study of in vitro preparations and animal models, little is known about the characteristics of soluble Aβ aggregates in the human Alzheimer’s disease brain. Here we present a new method for extracting soluble Aβ aggregates from human brains, separating them from insoluble aggregates and Aβ monomers using differential ultracentrifugation, and purifying them >6000 fold by dual antibody immunoprecipitation. The method resulted in soluble aggregate sizes. By immunoelectron microscopy, soluble Aβ aggregates typically appear as clusters of 10–20 nanometer diameter ovoid structures with 2-3 amino-terminal Aβ antibody binding sites, distinct from previously characterized structures. This approach may facilitate investigation into the characteristics of native soluble Aβ aggregates, and deepen our understanding of Alzheimer’s dementia. PMID:27917876

  18. The small genome of Arabidopsis contains at least six expressed alpha-tubulin genes.

    Science.gov (United States)

    Kopczak, S D; Haas, N A; Hussey, P J; Silflow, C D; Snustad, D P

    1992-05-01

    The goal of our investigations is to define the genetic control of microtubule-based processes in a higher plant. The available evidence suggests that we have achieved our first objective: the characterization of the complete alpha-tubulin and beta-tubulin gene families of Arabidopsis. Four additional alpha-tubulin genes (TUA2, TUA4, TUA5, and TUA6) of Arabidopsis have been cloned and sequenced to complete the analysis of the gene structure for all six alpha-tubulin genes detectable on DNA gel blots of Arabidopsis genomic DNA hybridized with alpha-tubulin coding sequences. TUA1 and TUA3 were characterized earlier in our laboratory. Noncoding gene-specific hybridization probes have been constructed for all six alpha-tubulin genes and used in RNA gel blot analyses to demonstrate that all six genes are transcribed. The six genes encode four different alpha-tubulin isoforms; TUA2 and TUA4 encode a single isoform, as do TUA3 and TUA5. Two-dimensional protein gel immunoblot analyses have resolved at least four alpha-tubulin isoforms from plant tissues, suggesting that all of the predicted TUA gene products are synthesized in vivo.

  19. Group B streptococcal beta-hemolysin/cytolysin activates neutrophil signaling pathways in brain endothelium and contributes to development of meningitis.

    Science.gov (United States)

    Doran, Kelly S; Liu, George Y; Nizet, Victor

    2003-09-01

    Meningitis occurs when blood-borne pathogens cross the blood-brain barrier (BBB) in a complex interplay between endothelial cells and microbial gene products. We sought to understand the initial response of the BBB to the human meningeal pathogen group B Streptococcus (GBS) and the organism's major virulence factors, the exopolysaccharide capsule and the beta-hemolysin/cytolysin toxin (beta-h/c). Using oligonucleotide microarrays, we found that GBS infection of human brain microvascular endothelial cells (HBMEC) induced a highly specific and coordinate set of genes including IL-8, Groalpha, Grobeta, IL-6, GM-CSF, myeloid cell leukemia sequence-1 (Mcl-1), and ICAM-1, which act to orchestrate neutrophil recruitment, activation, and enhanced survival. Most strikingly, infection with a GBS strain lacking beta-h/c resulted in a marked reduction in expression of genes involved in the immune response, while the unencapsulated strain generally induced similar or greater expression levels for the same subset of genes. Cell-free bacterial supernatants containing beta-h/c activity induced IL-8 release, identifying this toxin as a principal provocative factor for BBB activation. These findings were further substantiated in vitro and in vivo. Neutrophil migration across polar HBMEC monolayers was stimulated by GBS and its beta-h/c through a process involving IL-8 and ICAM-1. In a murine model of hematogenous meningitis, mice infected with beta-h/c mutants exhibited lower mortality and decreased brain bacterial counts compared with mice infected with the corresponding WT GBS strains.

  20. IRC-083927 is a new tubulin binder that inhibits growth of human tumor cells resistant to standard tubulin-binding agents.

    Science.gov (United States)

    Liberatore, Anne-Marie; Coulomb, Hélène; Pons, Dominique; Dutruel, Olivier; Kasprzyk, Philip G; Carlson, Mark; Nelson, Ann Savola; Newman, Simon P; Stengel, Chloe; Auvray, Pierrïck; Hesry, Vincent; Foll, Béatrice; Narboux, Nadine; Morlais, Delphine; Le Moing, Mélissa; Bernetiere, Sonia; Dellile, Raphael; Camara, Jose; Ferrandis, Eric; Bigg, Dennis C; Prévost, Grégoire P

    2008-08-01

    Tubulin is a validated target for antitumor drugs. However, the effectiveness of these microtubule-interacting agents is limited by the fact that they are substrates for drug efflux pumps (P-glycoprotein) and/or by the acquisition of point mutations in tubulin residues important for drug-tubulin binding. To bypass these resistance systems, we have identified and characterized a novel synthetic imidazole derivative IRC-083927, which inhibits the tubulin polymerization by a binding to the colchicine site. IRC-083927 inhibits in vitro cell growth of human cancer cell lines in the low nanomolar range. More interesting, it remains highly active against cell lines resistant to microtubule-interacting agents (taxanes, Vinca alkaloids, or epothilones). Such resistances are due to the presence of efflux pumps (NCI-H69/LX4 resistant to navelbine and paclitaxel) and/or the presence of mutations on beta-tubulin and on alpha-tubulin and beta-tubulin (A549.EpoB40/A549.EpoB480 resistant to epothilone B or paclitaxel). IRC-083927 displayed cell cycle arrest in G(2)-M phase in tumor cells, including in the drug-resistant cells. In addition, IRC-083927 inhibited endothelial cell proliferation in vitro and vessel formation in the low nanomolar range supporting an antiangiogenic behavior. Finally, chronic oral treatment with IRC-083927 (5 mg/kg) inhibits the growth of two human tumor xenografts in nude mice (C33-A, human cervical cancer and MDA-MB-231, human hormone-independent breast cancer). Together, the antitumor effects induced by IRC-083927 on tumor models resistant to tubulin agents support further investigations to fully evaluate its potential for the treatment of advanced cancers, particularly those resistant to current clinically available drugs.

  1. Effect of antisera to beta and gamma goldfish brain proteins on the retention of a newly acquired behavior.

    Science.gov (United States)

    Shashoua, V E; Moore, M E

    1978-06-16

    The metabolism of 3 brain cytoplasmic proteins (alpha, beta, and gamma) increases markedly when goldfish acquire a new pattern of behavior. Antisera specific to beta and beta + gamma proteins were prepared and injected into the fourth ventricle of the brains of trained animals at 8 and 24 h after the initiation of training. When tested 3 days later, such goldfish (N = 98) could not recall the training; whereas trained goldfish (N = 97) receiving non-immunized rabbit serum had complete recall of the behavior. Also no amnesia was obtained in control experiments in which trained goldfish were injected with an antiserum to a neural surface membrane protein NS-6. The fact that antisera to beta + gamma had no toxic effects was demonstrated by injecting them prior to training; no effects on the rate of acquisition and recall of the behavior was found. The antisera to beta + gamma were effective in inhibiting recall of the training when they were injected any time between 3 h up to 48 h after training; no effect was obtained at 72 h post training. These results are consistent with the hypothesis that beta and gamma might have some functional role in the plasticity of the CNS.

  2. Differential effects of central and peripheral injection of interleukin-1 beta on brain c-fos expression and neuroendocrine functions.

    Science.gov (United States)

    Rivest, S; Torres, G; Rivier, C

    1992-07-31

    Cytokines such as interleukin-1 beta (IL-1 beta) alter the activity of the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes in the rat. However, the brain sites at which IL-1 beta exerts these effects have not been well identified. The present study sought to identify some of these sites, using c-fos protein expression as an index of cellular activation. We also attempted to determine possible differences between the effects of peripheral and central injection of IL-1 beta on the activation of specific brain areas. Castrated male rats received intravenous (i.v.) or intracerebroventricular (i.c.v.) injections of IL-1 beta through a jugular catheter or a permanent cannula implanted in the right lateral ventricle, respectively. Blood samples were taken before, as well as 30 and 120 min after i.v. or i.c.v. IL-1 beta infusion in order to measure plasma ACTH and LH levels. Immediately thereafter, the rats were anesthetized with pentobarbital, then perfused. Their brains were removed and postfixed for one hour. Thirty-microns frozen sections were cut and approximately every fourth tissue section was processed for c-fos expression by an avidin-biotin-peroxidase method. Both i.v. (1 microgram) and i.c.v. (100 ng) injection of IL-1 beta significantly increased plasma ACTH levels, but only i.c.v. treatment measurably inhibited LH secretion. I.c.v. infusion of the cytokine markedly augmented c-fos expression in the paraventricular nucleus (PVN) and the arcuate nucleus (ARC) of the hypothalamus. A large amount of CRF cells in the PVN contained labelled c-fos protein (as measured by a double labelling technique), which indicates that CRF perikarya in this hypothalamic region are activated by the central administration of IL-1 beta. In contrast, i.v. injection of IL-1 beta did not significantly alter c-fos expression in the PVN or the ARC of the hypothalamus. These results suggest that the increased HPA axis activity which follows the peripheral

  3. TGF-beta1 regulates human brain pericyte inflammatory processes involved in neurovasculature function.

    Science.gov (United States)

    Rustenhoven, Justin; Aalderink, Miranda; Scotter, Emma L; Oldfield, Robyn L; Bergin, Peter S; Mee, Edward W; Graham, E Scott; Faull, Richard L M; Curtis, Maurice A; Park, Thomas I-H; Dragunow, Mike

    2016-02-11

    Transforming growth factor beta 1 (TGFβ1) is strongly induced following brain injury and polarises microglia to an anti-inflammatory phenotype. Augmentation of TGFβ1 responses may therefore be beneficial in preventing inflammation in neurological disorders including stroke and neurodegenerative diseases. However, several other cell types display immunogenic potential and identifying the effect of TGFβ1 on these cells is required to more fully understand its effects on brain inflammation. Pericytes are multifunctional cells which ensheath the brain vasculature and have garnered recent attention with respect to their immunomodulatory potential. Here, we sought to investigate the inflammatory phenotype adopted by TGFβ1-stimulated human brain pericytes. Microarray analysis was performed to examine transcriptome-wide changes in TGFβ1-stimulated pericytes, and results were validated by qRT-PCR and cytometric bead arrays. Flow cytometry, immunocytochemistry and LDH/Alamar Blue® viability assays were utilised to examine phagocytic capacity of human brain pericytes, transcription factor modulation and pericyte health. TGFβ1 treatment of primary human brain pericytes induced the expression of several inflammatory-related genes (NOX4, COX2, IL6 and MMP2) and attenuated others (IL8, CX3CL1, MCP1 and VCAM1). A synergistic induction of IL-6 was seen with IL-1β/TGFβ1 treatment whilst TGFβ1 attenuated the IL-1β-induced expression of CX3CL1, MCP-1 and sVCAM-1. TGFβ1 was found to signal through SMAD2/3 transcription factors but did not modify nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) translocation. Furthermore, TGFβ1 attenuated the phagocytic ability of pericytes, possibly through downregulation of the scavenger receptors CD36, CD47 and CD68. Whilst TGFβ did decrease pericyte number, this was due to a reduction in proliferation, not apoptotic death or compromised cell viability. TGFβ1 attenuated pericyte expression of key chemokines and

  4. Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study.

    Directory of Open Access Journals (Sweden)

    Marina Yazigi Solis

    Full Text Available Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d(-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1 and on cognitive function before and after exercise in trained cyclists (Study 2.In Study 1, seven healthy vegetarians (3 women and 4 men and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation, with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task being performed before and after exercise on each occasion.In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99 or omnivores (p = 0.27; nor was there any effect when data from both groups were pooled (p = 0.19. Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27. In study 2, exercise improved cognitive function across all tests (P 0.05 of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise.28 d of beta-alanine supplementation at 6.4 g d(-1 appeared not to influence brain homocarnosine/carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists.

  5. Inhibition of amyloid-beta-induced cell death in human brain pericytes in vitro.

    NARCIS (Netherlands)

    Rensink, A.A.M.; Verbeek, M.M.; Otte-Holler, I.; Donkelaar, H.J. ten; Waal, R.M.W. de; Kremer, H.P.H.

    2002-01-01

    Amyloid-beta protein (A beta) deposition in the cerebral vascular walls is one of the key features of Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D). A beta(1-40) carrying the 'Dutch' mutation (HCHWA-D A beta(1-40)) induces pronounced degeneration of

  6. A previously uncharacterized role for estrogen receptor beta: defeminization of male brain and behavior.

    Science.gov (United States)

    Kudwa, Andrea E; Bodo, Cristian; Gustafsson, Jan-Ake; Rissman, Emilie F

    2005-03-22

    Sex differences in brain and behavior are ubiquitous in sexually reproducing species. One cause of sexual dimorphisms is developmental differences in circulating concentrations of gonadal steroids. Neonatal testes produce androgens; thus, males are exposed to both testosterone and estradiol, whereas females are not exposed to high concentrations of either hormone until puberty. Classically, the development of neural sex differences is initiated by estradiol, which activates two processes in male neonates; masculinization, the development of male-type behaviors, and defeminization, the loss of the ability to display female-type behaviors. Here, we test the hypothesis that defeminization is regulated by estrogen receptor beta (ERbeta). Adult male ERbeta knockout and WT mice were gonadectomized, treated with female priming hormones, and tested for receptive behavior. Indicative of incomplete defeminization, male ERbeta knockout mice showed significantly higher levels of female receptivity as compared with WT littermates. Testes-intact males did not differ in any aspects of their male sexual behavior, regardless of genotype. In olfactory preference tests, males of both genotypes showed equivalent preferences for female-soiled bedding. Based on these results, we hypothesize that ERbeta is involved in defeminization of brain and behavior. This aspect of ERbeta function may lead to developments in our understanding of neural-based sexually dimorphic human behaviors.

  7. The functions of estrogen receptor beta in the female brain: A systematic review.

    Science.gov (United States)

    Vargas, Kris G; Milic, Jelena; Zaciragic, Asija; Wen, Ke-Xin; Jaspers, Loes; Nano, Jana; Dhana, Klodian; Bramer, Wichor M; Kraja, Bledar; van Beeck, Ed; Ikram, M Arfan; Muka, Taulant; Franco, Oscar H

    2016-11-01

    Females have unique and additional risk factors for neurological disorders. Among classical estrogen receptors, estrogen receptor beta (ERβ) has been suggested as a therapeutic target. However, little is known about the role of ERβ in the female brain. Six electronic databases were searched for articles evaluating the role of ERβ in the female brain and the influence of age and menopause on ERβ function. After screening 3186 titles and abstracts, 49 articles were included in the review, all of which were animal studies. Of these, 19 focused on cellular signaling, 7 on neuroendocrine pathways, 8 on neurological disorders, 4 on neuroprotection and 19 on psychological and psychiatric outcomes (6 studies evaluated two or more outcomes). Our findings showed that ERβ phosphorylated and activated intracellular second messenger proteins and regulated protein expression of genes involved in neurological functions. It also promoted neurogenesis, modulated the neuroendocrine regulation of stress response, conferred neuroprotection against ischemia and inflammation, and reduced anxiety- and depression-like behaviors. Targeting ERβ may constitute a novel treatment for menopausal symptoms, including anxiety, depression, and neurological diseases. However, to establish potential therapeutic and preventive strategies targeting ERβ, future studies should be conducted in humans to further our understanding of the importance of ERβ in women's mental and cognitive health. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  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. PET imaging of beta-adrenoceptors in human brain: A realistic goal or a mirage?

    NARCIS (Netherlands)

    van Waarde, Aaren; Vaalburg, W.; Doze, Petra; Bosker, Fokko; Elsinga, P.H

    2004-01-01

    Beta-adrenoceptors are predominantly located in the cerebral cortex, nucleus accumbens and striatum. At lower densities, they are also present in amygdala, hippocampus and cerebellum. Beta-2 sites regulate glial proliferation during ontogenic development, after trauma and in neurodegenerative

  10. Imaging beta-adrenoceptors in the human brain with (S)-1'-[F-18]fluorocarazolol

    NARCIS (Netherlands)

    vanWaarde, A; Elsinga, PH; deJong, BM; vanderMark, TW; Kraan, J; Ensing, K; Pruim, J; Willemsen, ATM; Brodde, OE; Paans, AMJ; Vaalburg, W; Visser, Thomas; Visser, Gerben

    We evaluated the suitability of fluorocarazolol for in vivo studies of cerebral beta-adrenoceptors because (S)-1'-[F-18]fluorocarazolol has a higher affinity to beta-adrenoceptors than to serotonergic receptors (pK(i) beta(1) 9.4, beta(2) 10.0, 5HT(1A) 7.4, 5HT(1B) 8.1) and rapidly crosses the

  11. Fourteen. beta. -(bromoacetamido)morphine irreversibly labels. mu. opioid receptors in rat brain membranes

    Energy Technology Data Exchange (ETDEWEB)

    Bidlack, J.M.; Frey, D.K.; Seyed-Mozaffari, A.; Archer, S. (Univ. of Rochester School of Medicine and Dentistry, NY (USA))

    1989-05-16

    The binding properties of 14{beta}-(bromoacetamido)morphine (BAM) and the ability of BAM to irreversibly inhibit opioid binding to rat brain membranes were examined to characterize the affinity and selectivity of BAM as an irreversible affinity ligand for opioid receptors. BAM had the same receptor selectivity as morphine, with a 3-5-fold decrease in affinity for the different types of opioid receptors. When brain membranes were incubated with BAM, followed by extensive washing, opioid binding was restored to control levels. However, when membranes were incubated with dithiothreitol (DTT), followed by BAM, and subsequently washed, 90% of the 0.25 nM ({sup 3}H)(D-Ala{sup 2},(Me)Phe{sup 4},Gly(ol){sup 5})enkephalin (DAGO) binding was irreversibly inhibited as a result of the specific alkylation of a sulfhydryl group at the {mu} binding site. This inhibition was dependent on the concentrations of both DTT and BAM. The {mu} receptor specificity of BAM alkylation was demonstrated by the ability of BAM alkylated membranes to still bind the {delta}-selective peptide ({sup 3}H)(D-penicillamine{sup 2},D-penicillamine{sup 5})enkephalin (DPDPE) and (-)-({sup 3}H)bremazocine in the presence of {mu} and {delta} blockers, selective for {kappa} binding sites. Morphine and naloxone partially protected the binding site from alkylation with BAM, while ligands that did not bind to the {mu}s site did not afford protection. These studies have demonstrated that when a disulfide bond at or near {mu} opioid binding sites was reduced, BAM could then alkylate this site, resulting in the specific irreversible labeling of {mu} opioid receptors.

  12. Alzheimer's disease and amyloid beta-peptide deposition in the brain: a matter of 'aging'?

    Science.gov (United States)

    Moro, Maria Luisa; Collins, Matthew J; Cappellini, Enrico

    2010-04-01

    Biomolecules can experience aging processes that limit their long-term functionality in organisms. Typical markers of protein aging are spontaneous chemical modifications, such as AAR (amino acid racemization) and AAI (amino acid isomerization), mainly involving aspartate and asparagine residues. Since these modifications may affect folding and turnover, they reduce protein functionality over time and may be linked to pathological conditions. The present mini-review describes evidence of AAR and AAI involvement in the misfolding and brain accumulation of Abeta (amyloid beta-peptide), a central event in AD (Alzheimer's disease) synaptic dysfunctions. Structural alterations introduced by site-specific modifications linked to protein aging may affect Abeta production, polymerization and clearance, and therefore play a pivotal role in the pathogenesis of sporadic and genetic forms of AD. Early changes associated with molecular aging also have significant long-term consequences for Abeta folding and turnover. New fast, reproducible and accurate methods for the screening of protein aging markers in biological samples may contribute to improve diagnostic and therapeutic approaches in AD.

  13. Amyloid-beta and tau pathology following repetitive mild traumatic brain injury.

    Science.gov (United States)

    Edwards, George; Moreno-Gonzalez, Ines; Soto, Claudio

    2017-02-19

    Neurodegenerative diseases are characterized by distinctive neuropathological alterations, including the cerebral accumulation of misfolded protein aggregates, neuroinflammation, synaptic dysfunction, and neuronal loss, along with behavioral impairments. Traumatic brain injury (TBI) is believed to be an important risk factor for certain neurodegenerative diseases, such as Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). TBI represents a ubiquitous problem in the world and could play a major role in the pathogenesis and etiology of AD or CTE later in life. TBI events appear to trigger and exacerbate some of the pathological processes in these diseases, in particular, the formation and accumulation of misfolded protein aggregates composed of amyloid-beta (Aβ) and tau. Here, we describe the relationship between repetitive mild TBI and the development of Aβ and tau pathology in patients affected by AD or CTE on the basis of epidemiological and pathological studies in human cases, and a thorough overview of data obtained in experimental animal models. We also discuss the possibility that TBI may contribute to initiate the formation of misfolded oligomeric species that may subsequently spread the pathology through a prion-like process of seeding of protein misfolding. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Demonstration of in vivo synthesis of pro-opiomelanocortin-, beta- endorphin-, and alpha-melanotropin-like species in the adult rat brain

    National Research Council Canada - National Science Library

    Liotta, AS; Advis, JP; Krause, JE; McKelvy, JF; Krieger, DT

    1984-01-01

    ...)-, beta-endorphin- and alpha- melanotropin (MSH)-like molecular species in rat brain. Unrestrained adult female rats were bilaterally cannulated in the hypothalamic arcuate nuclear region; [35S...

  15. Cysteine protease inhibitors effectively reduce in vivo levels of brain beta-amyloid related to Alzheimer's disease.

    Science.gov (United States)

    Hook, Vivian; Kindy, Mark; Hook, Gregory

    2007-02-01

    Abnormal accumulation of neurotoxic beta-amyloid peptides (Abeta) in brain represents a key factor in the progression of Alzheimer's disease (AD). Identification of small molecules that effectively reduce brain levels of Abeta is important for development of Abeta-lowering agents for AD. In this study, we demonstrate that in vivo Abeta levels in brain are significantly reduced by the cysteine protease inhibitor E64d and the related CA074Me inhibitor, which inhibits cathepsin B. Direct infusion of these inhibitors into brains of guinea pigs resulted in reduced levels of Abeta by 50-70% after 30 days of treatment. Substantial decreases in Abeta also occurred after only 7 days of inhibitor infusion, with a reduction in both Abeta40 and Abeta42 peptide forms. A prominent decrease in Abeta peptides was observed in brain synaptosomal nerve terminal preparations after CA074Me treatment. Analyses of APP-derived proteolytic fragments showed that CA074Me reduced brain levels of the CTFbeta fragment, and increased amounts of the sAPPalpha fragment. These results suggest that CA074Me inhibits Abeta production by modulating APP processing. Animals appeared healthy after treatment with these inhibitors. These results, showing highly effective in vivo decreases in brain Abeta levels by these cysteine protease inhibitors, indicate the feasibility of using related compounds for lowering Abeta in AD.

  16. Protein kinase CK2: evidence for a protein kinase CK2beta subunit fraction, devoid of the catalytic CK2alpha subunit, in mouse brain and testicles

    DEFF Research Database (Denmark)

    Guerra, B; Siemer, S; Boldyreff, B

    1999-01-01

    The highest CK2 activity was found in mouse testicles and brain, followed by spleen, liver, lung, kidney and heart. The activity values were directly correlated with the protein expression level of the CK2 subunits alpha (catalytic) and beta (regulatory). The alpha' subunit was only detected...... signals were observed for lung, liver and testicles. In the case of CK2beta mRNA the highest signals were found for testicles, kidney, brain and liver. The amount of CK2beta mRNA in testicles was estimated to be about 6-fold higher than in brain. The strongest CK2beta signals in the Western blot were...... found for testicles and brain. The amount of CK2beta protein in brain in comparison to the other organs (except testicles) was estimated to be ca. 2-3-fold higher whereas the ratio of CK2beta between testicles and brain was estimated to be 3-4-fold. Results from the immunoprecipitation experiments...

  17. 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.

  18. 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

  19. The binding mode of side chain- and C3-modified epothilones to tubulin.

    Science.gov (United States)

    Erdélyi, Máté; Navarro-Vázquez, Armando; Pfeiffer, Bernhard; Kuzniewski, Christian N; Felser, Andrea; Widmer, Toni; Gertsch, Jürg; Pera, Benet; Díaz, José Fernando; Altmann, Karl-Heinz; Carlomagno, Teresa

    2010-06-07

    The tubulin-binding mode of C3- and C15-modified analogues of epothilone A (Epo A) was determined by NMR spectroscopy and computational methods and compared with the existing structural models of tubulin-bound natural Epo A. Only minor differences were observed in the conformation of the macrocycle between Epo A and the C3-modified analogues investigated. In particular, 3-deoxy- (compound 2) and 3-deoxy-2,3-didehydro-Epo A (3) were found to adopt similar conformations in the tubulin-binding cleft as Epo A, thus indicating that the 3-OH group is not essential for epothilones to assume their bioactive conformation. None of the available models of the tubulin-epothilone complex is able to fully recapitulate the differences in tubulin-polymerizing activity and microtubule-binding affinity between C20-modified epothilones 6 (C20-propyl), 7 (C20-butyl), and 8 (C20-hydroxypropyl). Based on the results of transferred NOE experiments in the presence of tubulin, the isomeric C15 quinoline-based Epo B analogues 4 and 5 show very similar orientations of the side chain, irrespective of the position of the nitrogen atom in the quinoline ring. The quinoline side chain stacks on the imidazole moiety of beta-His227 with equal efficiency in both cases, thus suggesting that the aromatic side chain moiety in epothilones contributes to tubulin binding through strong van der Waals interactions with the protein rather than hydrogen bonding involving the heteroaromatic nitrogen atom. These conclusions are in line with existing tubulin polymerization and microtubule-binding data for 4, 5, and Epo B.

  20. [C-11]{beta}CNT: A new monoamine uptake ligand for studying serotonin and dopamine transporter sites in the living brain with PET

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, G.K.; Zheng, Q.H.; Zhou, F.C. [Indiana Univ. Medical Center, Indianapolis, IN (United States)] [and others

    1996-05-01

    There is considerable interest in measuring serotonin (5HT) and dopamine (DA) function in the human brain. Altered levels of 5HT and DA are recognized in drug abuse, neurotoxicities, psychiatric disorders, and neurodegenerative conditions including Alzheimer`s and Parkinson`s disease. Several phenyltropane analogs of cocaine bind tightly to both DA and 5HT uptake proteins. We have made a new agent from this class called {beta}CNT, 2{beta}-carboxymethyl-3{beta}-(2-naphthyl)-tropane, the isosteric O-for-CH{sub 2} analog of a compound reported to have among the highest measured affinities for DA and 5HT transporters and studied its in vivo brain distributions in animals for the first time. Optically pure {beta}CNT was made from cocaine, and labeled at the O-methyl position by esterification of {beta}CNT-acid with [C-11]CH{sub 3}OTfl under conditions similar to Wilson`s. HPLC-purified (99+%) final products (15-50% eob yield from CO{sub 2}, 40 min synth) had specific activities 0.1-1.2 Ci/{mu}mol at the time of injection. Preliminary [C-11]{beta}{beta}CNT rodent distribution showed very high brain uptake (3% ID at 60 min) and localization (striat: fr cort: hypo: cer: blood, 11: 5: 4: 1: 06). {beta}CNT-PET studies in juvenile pigs (5-20 mCi, 20-35 kg) found rapid brain uptake, and prominent retention (85 min) in midbrain, anterior brainstem and striatum, followed by cortex and olfactory bulb. Paroxetine pretreatment (5HT uptake blocker, 2mg/kg), diminished retention in most brain areas; nomifensine (DA/NE uptake blocker, 6 mg/kg) reduced striatum selectively. Direct comparisons of [C-11]{beta}CNT with other PET transporter radioligands {beta}CFT, {beta}CIT, and {beta}CTT (RTI-32) in the same pig found {beta}CNT had highest overall brain uptake among the agents. These initial results suggest {beta}CNT has favorable properties for imaging both 5HT and DA transporters in vivo, and further evaluation of its potential as a human PET agent is warranted.

  1. Frequency Matters: Beta Band Subthalamic Nucleus Deep Brain Stimulation Induces Parkinsonian-like Blink Abnormalities in Normal Rats

    Science.gov (United States)

    Kaminer, Jaime; Thakur, Pratibha; Evinger, Craig

    2014-01-01

    The synchronized beta band oscillations in the basal ganglia-cortical networks in Parkinson's disease (PD) may be responsible for PD motor symptoms or an epiphenomenon of dopamine loss. We investigated the causal role of beta band activity in PD motor symptoms by testing the effects of beta frequency subthalamic nucleus deep brain stimulation (STN DBS) on blink reflex excitability, amplitude, and plasticity in normal rats. Delivering 16 Hz STN DBS produced the same increase in blink reflex excitability and impairment in blink reflex plasticity in normal rats as occurs in rats with 6-OHDA lesions and PD patients. These deficits were not an artifact of STN DBS because when these normal rats received 130 Hz STN DBS, their blink characteristics were the same as without STN DBS. To demonstrate the blink reflex disturbances with 16 Hz STN DBS were frequency specific, we tested the same rats with 7 Hz STN DBS, a theta band frequency typical of dystonia. In contrast to beta stimulation, 7 Hz DBS exaggerated blink reflex plasticity as occurs in focal dystonia. Thus, without destroying dopamine neurons or blocking dopamine receptors, frequency specific STN DBS can be used to create PD- or dystonic-like symptoms in a normal rat. PMID:25146113

  2. Frequency matters: beta-band subthalamic nucleus deep-brain stimulation induces Parkinsonian-like blink abnormalities in normal rats.

    Science.gov (United States)

    Kaminer, Jaime; Thakur, Pratibha; Evinger, Craig

    2014-10-01

    The synchronized beta-band oscillations in the basal ganglia-cortical networks in Parkinson's disease (PD) may be responsible for PD motor symptoms or an epiphenomenon of dopamine loss. We investigated the causal role of beta-band activity in PD motor symptoms by testing the effects of beta-frequency subthalamic nucleus deep-brain stimulation (STN DBS) on the blink reflex excitability, amplitude, and plasticity in normal rats. Delivering 16 Hz STN DBS produced the same increase in blink reflex excitability and impairment in blink reflex plasticity in normal rats as occurs in rats with 6-hydroxydopamine lesions and patients with PD. These deficits were not an artifact of STN DBS because, when these normal rats received 130 Hz STN DBS, their blink characteristics were the same as without STN DBS. To demonstrate that the blink reflex disturbances with 16 Hz STN DBS were frequency specific, we tested the same rats with 7 Hz STN DBS, a theta-band frequency typical of dystonia. In contrast to beta stimulation, 7 Hz STN DBS exaggerated the blink reflex plasticity as occurs in focal dystonia. Thus, without destroying dopamine neurons or blocking dopamine receptors, frequency-specific STN DBS can be used to create PD-like or dystonic-like symptoms in a normal rat. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  3. Deficiency of Calcium-Independent Phospholipase A2 Beta Induces Brain Iron Accumulation through Upregulation of Divalent Metal Transporter 1.

    Directory of Open Access Journals (Sweden)

    Goichi Beck

    Full Text Available Mutations in PLA2G6 have been proposed to be the cause of neurodegeneration with brain iron accumulation type 2. The present study aimed to clarify the mechanism underlying brain iron accumulation during the deficiency of calcium-independent phospholipase A2 beta (iPLA2β, which is encoded by the PLA2G6 gene. Perl's staining with diaminobenzidine enhancement was used to visualize brain iron accumulation. Western blotting was used to investigate the expression of molecules involved in iron homeostasis, including divalent metal transporter 1 (DMT1 and iron regulatory proteins (IRP1 and 2, in the brains of iPLA2β-knockout (KO mice as well as in PLA2G6-knockdown (KD SH-SY5Y human neuroblastoma cells. Furthermore, mitochondrial functions such as ATP production were examined. We have discovered for the first time that marked iron deposition was observed in the brains of iPLA2β-KO mice since the early clinical stages. DMT1 and IRP2 were markedly upregulated in all examined brain regions of aged iPLA2β-KO mice compared to age-matched wild-type control mice. Moreover, peroxidized lipids were increased in the brains of iPLA2β-KO mice. DMT1 and IRPs were significantly upregulated in PLA2G6-KD cells compared with cells treated with negative control siRNA. Degeneration of the mitochondrial inner membrane and decrease of ATP production were observed in PLA2G6-KD cells. These results suggest that the genetic ablation of iPLA2β increased iron uptake in the brain through the activation of IRP2 and upregulation of DMT1, which may be associated with mitochondrial dysfunction.

  4. Lipopolysaccharide impairs amyloid beta efflux from brain: altered vascular sequestration, cerebrospinal fluid reabsorption, peripheral clearance and transporter function at the blood–brain barrier

    Directory of Open Access Journals (Sweden)

    Erickson Michelle A

    2012-06-01

    Full Text Available Abstract Background Defects in the low density lipoprotein receptor-related protein-1 (LRP-1 and p-glycoprotein (Pgp clearance of amyloid beta (Aβ from brain are thought to contribute to Alzheimer’s disease (AD. We have recently shown that induction of systemic inflammation by lipopolysaccharide (LPS results in impaired efflux of Aβ from the brain. The same treatment also impairs Pgp function. Here, our aim is to determine which physiological routes of Aβ clearance are affected following systemic inflammation, including those relying on LRP-1 and Pgp function at the blood–brain barrier. Methods CD-1 mice aged between 6 and 8 weeks were treated with 3 intraperitoneal injections of 3 mg/kg LPS at 0, 6, and 24 hours and studied at 28 hours. 125I-Aβ1-42 or 125I-alpha-2-macroglobulin injected into the lateral ventricle of the brain (intracerebroventricular (ICV or into the jugular vein (intravenous (IV was used to quantify LRP-1-dependent partitioning between the brain vasculature and parenchyma and peripheral clearance, respectively. Disappearance of ICV-injected 14 C-inulin from brain was measured to quantify bulk flow of cerebrospinal fluid (CSF. Brain microvascular protein expression of LRP-1 and Pgp was measured by immunoblotting. Endothelial cell localization of LRP-1 was measured by immunofluorescence microscopy. Oxidative modifications to LRP-1 at the brain microvasculature were measured by immunoprecipitation of LRP-1 followed by immunoblotting for 4-hydroxynonenal and 3-nitrotyrosine. Results We found that LPS: caused an LRP-1-dependent redistribution of ICV-injected Aβ from brain parenchyma to brain vasculature and decreased entry into blood; impaired peripheral clearance of IV-injected Aβ; inhibited reabsorption of CSF; did not significantly alter brain microvascular protein levels of LRP-1 or Pgp, or oxidative modifications to LRP-1; and downregulated LRP-1 protein levels and caused LRP-1 mislocalization in cultured brain

  5. Amyloid beta 1-42 and phoshorylated tau threonin 231 in brains of aged cynomolgus monkeys (Macaca fascicularis

    Directory of Open Access Journals (Sweden)

    Huda Shalahudin Darusman

    2014-11-01

    Full Text Available Pathological hallmarks indicative of Alzheimer’s disease, which are the plaques of Amyloid Beta 1-42 and neurofibrillary tangles, were found in brain of aged cynomolgus monkey. The aim of the study was to investigate if aged monkeys exhibiting spatial memory impairment and levels of biomarkers indicative of Alzheimer’s disease, had brain lesions similar to human patients suffering from senile dementia. Generating immunohistochemistry technique to biomarkers of Amyloid beta 1-42 and the phosphorylated tau 231, our study assessed the amyloidopathy, such as indicative to the senile plaques and cerebral amyloid angiopathy, and the tauopathy, to possible neurofibrillary tangles. Six aged monkeys were selected based on their spatial memory performance and profile of biomarkers of Alzheimer’s disease, divided equally to affected aged subject - with Memory-affected and low amyloid level, and aged with higher performance in memory and amyloid, as the age-matched subjects. Using immunohistochemistry, plaques of Amyloid Beta 1-42 were observed in two out of three brains of aged subjects with memory impairment and biomarkers indicative of Alzheimer’s disease. The cerebral amyloid angiopathy was observed in both aged monkey groups, and unlike in the human, the amyloids were found to deposit in the small veins and capillaries. In one of the affected individuals, phosphorylated tau was positively stained intracellularly of the neurons, indicating a possibility of an early stage of the formation of tangles. These findings add to the body of evidence of the utility of the aged cynomolgus monkeys as a spontaneous model for Alzheimer-related disease.

  6. An Analysis of Beta-Blocker Administration Pre-and Post-Traumatic Brain Injury with Subanalyses for Head Injury Severity and Myocardial Injury.

    Science.gov (United States)

    Edavettal, Mathew; Gross, Brian W; Rittenhouse, Katelyn; Alzate, James; Rogers, Amelia; Estrella, Lisa; Miller, Jo Ann; Rogers, Frederick B

    2016-12-01

    A growing body of literature indicates that beta-blocker administration after traumatic brain injury (TBI) is cerebroprotective, limiting secondary injury; however, the effects of preinjury beta blocker status remain poorly understood. We sought to characterize the effects of pre- and postinjury beta-blocker administration on mortality with subanalyses accounting for head injury severity and myocardial injury. In a Level II trauma center, all admissions of patients ≥18 years with a head Abbreviated Injury Scale Score ≥2, Glasgow Coma Scale ≤13 from May 2011 to May 2013 were queried. Demographic, injury-specific, and outcome variables were analyzed using univariate analyses. Subsequent multivariate analyses were conducted to determine adjusted odds of mortality for beta-blocker usage controlling for age, Injury Severity Score, head Abbreviated Injury Scale, arrival Glasgow Coma Scale, ventilator use, and intensive care unit stay. A total of 214 trauma admissions met inclusion criteria: 112 patients had neither pre- nor postinjury beta-blocker usage, 46 patients had preinjury beta-blocker usage, and 94 patients had postinjury beta-blocker usage. Both unadjusted and adjusted odds ratios of preinjury beta-blocker were insignificant with respect to mortality. However, postinjury in-hospital administration of beta blockers was found to significantly in the decrease of mortality in both univariate (P = 0.002) and multivariate analyses (P = 0.001). Our data indicate that beta-blocker administration post-TBI in hospital reduces odds of mortality; however, preinjury beta-blocker usage does not. Additionally, myocardial injury is a useful indicator for beta-blocker administration post-TBI. Further research into which beta blockers confer the best benefits as well as the optimal period of beta-blocker administration post-TBI is recommended.

  7. Tau and Beta-Amyloid Deposition, Microhemorrhage and Brain Function after Traumatic Brain Injury in War Veterans

    Science.gov (United States)

    2015-10-01

    NOTES 14. ABSTRACT Background: Studies suggest an increased risk of Alzheimer’s disease (AD) and chronic traumatic encephalopathy (CTE) after traumatic...traumatic encephalopathy (CTE) as a result of traumatic brain injury (TBI) sustained during military service. Greater understanding of the chronic ...brain injury (TBI). Greater understanding of the chronic effects of TBI may lead to new therapies. This proposal will add a TBI cohort, tau PET

  8. Prognostic value of interleukin-1 beta levels after acute brain injury.

    Science.gov (United States)

    Taşçi, Alptekin; Okay, Onder; Gezici, Ali Riza; Ergün, Rüçhan; Ergüngör, Fikret

    2003-12-01

    Traumatic injury to central nervous system results in the production of inflammatory cytokines via intrinsic mechanisms by neurons, astrocytes and microglia, and extrinsic mechanisms by infiltrating macrophages, lymphocytes and other leukocytes. Interleukin-1 beta is the key mediator of the acute inflammatory host response. While this response is necessary for resolution of the pathologic event, the toxic nature of many of its products can cause significant tissue damage. We analyzed serum interleukin-1 beta levels by enzyme-linked immunosorbent assay in 48 patients with solitary head injury who were transported to our clinic immediately after trauma. We categorized the patients according to their initial Glasgow coma scores in three groups, and compared their serum interleukin-1 beta values both with their Glasgow coma initial and outcome scores. This study helped to provide quantitative data to estimate clinical impressions and prognosis after head injury.

  9. The ADNP derived peptide, NAP modulates the tubulin pool: implication for neurotrophic and neuroprotective activities.

    Directory of Open Access Journals (Sweden)

    Saar Oz

    Full Text Available Microtubules (MTs, key cytoskeletal elements in living cells, are critical for axonal transport, synaptic transmission, and maintenance of neuronal morphology. NAP (NAPVSIPQ is a neuroprotective peptide derived from the essential activity-dependent neuroprotective protein (ADNP. In Alzheimer's disease models, NAP protects against tauopathy and cognitive decline. Here, we show that NAP treatment significantly affected the alpha tubulin tyrosination cycle in the neuronal differentiation model, rat pheochromocytoma (PC12 and in rat cortical astrocytes. The effect on tubulin tyrosination/detyrosination was coupled to increased MT network area (measured in PC12 cells, which is directly related to neurite outgrowth. Tubulin beta3, a marker for neurite outgrowth/neuronal differentiation significantly increased after NAP treatment. In rat cortical neurons, NAP doubled the area of dynamic MT invasion (Tyr-tubulin into the neuronal growth cone periphery. NAP was previously shown to protect against zinc-induced MT/neurite destruction and neuronal death, here, in PC12 cells, NAP treatment reversed zinc-decreased tau-tubulin-MT interaction and protected against death. NAP effects on the MT pool, coupled with increased tau engagement on compromised MTs imply an important role in neuronal plasticity, protecting against free tau accumulation leading to tauopathy. With tauopathy representing a major pathological hallmark in Alzheimer's disease and related disorders, the current findings provide a mechanistic basis for further development. NAP (davunetide is in phase 2/3 clinical trial in progressive supranuclear palsy, a disease presenting MT deficiency and tau pathology.

  10. 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)

  11. A high performance sensorimotor beta rhythm-based brain computer interface associated with human natural motor behavior

    Science.gov (United States)

    Bai, Ou; Lin, Peter; Vorbach, Sherry; Floeter, Mary Kay; Hattori, Noriaki; Hallett, Mark

    2008-03-01

    To explore the reliability of a high performance brain-computer interface (BCI) using non-invasive EEG signals associated with human natural motor behavior does not require extensive training. We propose a new BCI method, where users perform either sustaining or stopping a motor task with time locking to a predefined time window. Nine healthy volunteers, one stroke survivor with right-sided hemiparesis and one patient with amyotrophic lateral sclerosis (ALS) participated in this study. Subjects did not receive BCI training before participating in this study. We investigated tasks of both physical movement and motor imagery. The surface Laplacian derivation was used for enhancing EEG spatial resolution. A model-free threshold setting method was used for the classification of motor intentions. The performance of the proposed BCI was validated by an online sequential binary-cursor-control game for two-dimensional cursor movement. Event-related desynchronization and synchronization were observed when subjects sustained or stopped either motor execution or motor imagery. Feature analysis showed that EEG beta band activity over sensorimotor area provided the largest discrimination. With simple model-free classification of beta band EEG activity from a single electrode (with surface Laplacian derivation), the online classifications of the EEG activity with motor execution/motor imagery were: >90%/~80% for six healthy volunteers, >80%/~80% for the stroke patient and ~90%/~80% for the ALS patient. The EEG activities of the other three healthy volunteers were not classifiable. The sensorimotor beta rhythm of EEG associated with human natural motor behavior can be used for a reliable and high performance BCI for both healthy subjects and patients with neurological disorders. Significance: The proposed new non-invasive BCI method highlights a practical BCI for clinical applications, where the user does not require extensive training.

  12. Chronic sleep restriction elevates brain interleukin-1 beta and tumor necrosis factor-alpha and attenuates brain-derived neurotrophic factor expression.

    Science.gov (United States)

    Zielinski, Mark R; Kim, Youngsoo; Karpova, Svetlana A; McCarley, Robert W; Strecker, Robert E; Gerashchenko, Dmitry

    2014-09-19

    Acute sleep loss increases pro-inflammatory and synaptic plasticity-related molecules in the brain, including interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and brain-derived neurotrophic factor (BDNF). These molecules enhance non-rapid eye movement sleep slow wave activity (SWA), also known as electroencephalogram delta power, and modulate neurocognitive performance. Evidence suggests that chronic sleep restriction (CSR), a condition prevalent in today's society, does not elicit the enhanced SWA that is seen after acute sleep loss, although it cumulatively impairs neurocognitive functioning. Rats were continuously sleep deprived for 18h per day and allowed 6h of ad libitum sleep opportunity for 1 (SR1), 3 (SR3), or 5 (SR5) successive days (i.e., CSR). IL-1β, TNF-α, and BDNF mRNA levels were determined in the somatosensory cortex, frontal cortex, hippocampus, and basal forebrain. Largely, brain IL-1β and TNF-α expression were significantly enhanced throughout CSR. In contrast, BDNF mRNA levels were similar to baseline values in the cortex after 1 day of SR and significantly lower than baseline values in the hippocampus after 5 days of SR. In the basal forebrain, BDNF expression remained elevated throughout the 5 days of CSR, although IL-1β expression was significantly reduced. The chronic elevations of IL-1β and TNF-α and inhibition of BDNF might contribute to the reported lack of SWA responses reported after CSR. Further, the CSR-induced enhancements in brain inflammatory molecules and attenuations in hippocampal BDNF might contribute to neurocognitive and vigilance detriments that occur from CSR. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. 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.

  14. The Effect of Six Weeks-Voluntary Wheel Running on Brain Amyloid Beta (1-42 Levels of Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Ziya Fallah-Mohammadi

    2013-05-01

    Full Text Available Background: Amyloid Beta (1-42 is derived from amyloid precursor protein and plays a critical role in AD pathogenesis. The purpose of this study was to investigate the effect of 6 weeks of voluntary wheel running on brain Amyloid beta (1-42 in the diabetic rats induced with alloxan. Materials and Methods: 28 male rats weight 185±1 were assigned randomly to 4 groups (N=7: normal control (C, training (T, control-diabetic (CD and diabetic-training (DT. Diabetes was induced with injecting Alloxan (120 mg/kg dissolved in saline intraperitoneal. Results: 6 weeks of voluntary wheel running decreased the cortex Aβ1-42 in T and DT groups. Aβ1-42 levels significantly decreased in the T and DT in compare with C and CD (p<0.001, respectively. Also Aβ1-42 levels significantly increased in the CD in compare with C (p<0.001.Conclusion: voluntary exercise had positive effects on decreasing of Aβ1-42 levels during 6 weeks. Therefore it can be recommended as therapeutic strategy for diabetes.

  15. Aggressiveness and brain amine concentration in dominant and subordinate finishing pigs fed the beta-adrenoreceptor agonist ractopamine.

    Science.gov (United States)

    Poletto, R; Cheng, H W; Meisel, R L; Garner, J P; Richert, B T; Marchant-Forde, J N

    2010-09-01

    Under farm conditions, aggression related to the formation of social hierarchy and competition for resources can be a major problem because of associated injuries, social stress, and carcass losses. Any factor that may affect the regulation and amount of aggression within a farmed system, for instance, feeding the beta-adrenoreceptor agonist ractopamine (RAC), is therefore worthy of investigation. The objectives of this study were to assess the effects of the widely used swine feed additive RAC, considering also the effects of sex and social rank on aggressiveness and concentrations of brain amines, neurotransmitters essential for controlling aggression, in finishing pigs. Thirty-two barrows and 32 gilts (4 pigs/pen by sex) were fed either a control diet or a diet with RAC (Paylean, Elanco Animal Health, Greenfield, IN) added (5 mg/kg for 2 wk, followed by 10 mg/kg for 2 wk). The top dominant and bottom subordinate pigs (16 pigs/sex) in each pen were determined after mixing by a 36-h period of continuous behavioral observation. These pigs were then subjected to resident-intruder tests (maximum 300 s) during the feeding trial to measure aggressiveness. At the end of wk 4, the amygdala, frontal cortex, hypothalamus, and raphe nuclei were dissected and analyzed for concentrations of dopamine (DA); serotonin (5-HT); their metabolites 3,4-dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid, and 5-hydroxyindoleacetic acid (5-HIAA), respectively; norepinephrine; and epinephrine using HPLC. Ractopamine-fed gilts performed more attacks during the first 30 s of testing than pigs in all other subgroups (P dominant control gilts and barrows, and both dominant and subordinate RAC-fed gilts performed the greatest percentage of attacks (P brain 5-HT synthesis) of dominant gilts (P brain monoamine profiling of a deficient serotonergic system in the raphe nuclei, amygdala, and frontal cortex, and enhanced DA metabolism in the amygdala, brain areas vital for aggression

  16. Amyloid beta1–42 and the phoshorylated tau threonine 231 in brains of aged cynomolgus monkeys (Macaca fascicularis)

    DEFF Research Database (Denmark)

    Darusman, Huda Shalahudin; Gjedde, Albert; Sajuthi, Dondin

    2014-01-01

    Pathological hallmarks indicative of Alzheimer's disease (AD), which are the plaques of amyloid beta1-42 and neurofibrillary tangles, were found in brain of aged cynomolgus monkey. The aim of this study was to investigate if aged monkeys exhibiting spatial memory impairment and levels of biomarke...

  17. Spatial patterns of brain amyloid-beta burden and atrophy rate associations in mild cognitive impairment

    NARCIS (Netherlands)

    Tosun, Duygu; Schuff, Norbert; Mathis, Chester A.; Jagust, William; Weiner, Michael W.; Saradha, A.; Abdi, Herve; Abdulkadir, Ahmed; Abeliovich, Asa; Abellan van Kan, Gabor; Abner, Erin; Acharya, Deepa; Agrusti, Antonella; Agyemang, Alex; Ahdidan, Jamila; Ahmed, Shiek; Ahn, Jae Eun; Aisen, Paul; Aksu, Yaman; Al-Akhras, Mousa; Alarcon, Marcelo; Alberca, Roman; Alexander, Gene; Alexander, Daniel; Alin, Aylin; Almeida, Fabio; Amlien, Inge; Anand, Shyam; Anderson, Dallas; Andrew, Marilee; Angersbach, Steve; Anjum, Ayesha; Aoyama, Eiji; Arfanakis, Konstantinos; Armor, Tom; Arnold, Steven; Arunagiri, Vidhya; Asatryan, Albert; Ashe-McNalley, Cody; Ashiga, Hirokazu; Assareh, Arezoo; Le Page, Aurelie; Avants, Brian; Avinash, Gopal; Aviv, Richard; Awasthi, Sukrati; Ayan-Oshodi, Mosun; Babic, Tomislav; Baek, Young; Bagci, Ulas; Bai, Shuyang; Baird, Geoffrey; Baker, John; Banks, Sarah; Bard, Jonathan; Barnes, Josephine; Bartlett, Jonathan; Bartzokis, George; Barua, Neil; Bauer, Corinna; Bayley, Peter; Beck, Irene; Becker, James; Becker, J. Alex; Beckett, Laurel; Bednar, Martin; Beg, Mirza Faisal; Bek, Stephan; Belaroussi, Boubakeur; Belmokhtar, Nabil; Bernard, Charlotte; Bertram, Lars; Bhaskar, Uday; Biffi, Alessandro; Bigler, Erin; Bilgic, Basar; Bishop, Courtney; Bittner, Daniel; Black, Ronald; Bogorodzki, Piotr; Bokde, Arun; Bonner-Jackson, Aaron; Boppana, Madhu; Bourgeat, Pierrick; Bowes, Mike; Bowman, DuBois; Bowman, Gene; Braskie, Meredith; Braunewell, Karl; Breitner, Joihn; Bresell, Anders; Brewer, James; Brickman, Adam; Britschgi, Markus; Broadbent, Steve; Brogren, Jacob; Brooks, David; Browndyke, Jeffrey; Brunton, Simon; Buchert, Ralph; Buchsbaum, Monte; Buckley, Chris; Buerger, Katharina; Burger, Cyrill; Burnham, Samantha; Burns, Jeffrey; Burton, David; Butman, John; Cabeza, Rafael; Cairns, Nigel; Callhoff, Johanna; Calvini, Piero; Cantillon, Marc; Capella, Heraldo; Carbotti, Angela; Cardona-Sanclemente, Luis Eduardo; Carle, Adam; Carmasin, Jeremy; Carranza-Ath, Fredy; Casabianca, Jodi; Casanova, Ramon; Cash, David; Cedarbaum, Jesse; Cella, Massimo; Celsis, Pierre; Chanu, Pascal; Chao, Linda; Charil, Arnaud; Chemali, Zeina; Chen, Rong; Chen, Jake; Chen, Gennan; Chen, Wei; Chen, Kewei; Chen, Shuzhong; Chen, Minhua; Cheng, Wei-Chen; Cherkas, Yauheniya; Chertkow, Howard; Cheung, Charlton; Cheung, Vinci; Chiang, Gloria; Chiba, Koji; Chin, Simon; Chisholm, Jane; Cho, Youngsang; Choe, John; Choubey, Suresh; Chowbina, Sudhir; Christensen, Anette Luther; Clark, David; Clark, Chris; Clarkson, Matt; Clayton, David; Clunie, David; Coen, Michael; Coimbra, Alexandre; Compton, David; Coppola, Giovanni; Coulin, Samuel; Cover, Keith S.; Crane, Paul; Crans, Gerald; Croop, Robert; Crowther, Daniel; Crum, William; Cui, Yue; Curry, Charles; Curtis, Steven; Cutter, Gary; Daiello, Lori; Dake, Michael; Dale, Anders; Daliri, Mohammad Reza; Damato, Vito Domenico; Darby, Eveleen; Darkner, Sune; Davatzikos, Christos; Dave, Jay; David, Renaud; DavidPrakash, Bhaskaran; Davidson, Julie; de Bruijne, Marleen; de Meyer, Geert; de Nunzio, Giorgio; Decarli, Charles; Dechairo, Bryan; DeDuck, Kristina; Dehghan, Hossein; Dejkam, Arsalan; Delfino, Manuel; Della Rosa, Pasquale Anthony; Dellavedova, Luca; Delpassand, Ebrahim; Delrieu, Julien; DeOrchis, Vincent; Depy Carron, Delphine; deToledo-Morrell, Leyla; Devanand, Davangere; Devanarayan, Viswanath; DeVous, Michael; Diaz-Arrastia, Ramon; Bradford, Dickerson; Ding, Xiaobo; Dinov, Ivo; Dobson, Howard; Dodge, Hiroko; Donohue, Michael; Dore, Vincent; Dorflinger, Ernest; Dowling, Maritza; Duan, Xujun; Dubal, Dena; Duchesne, Simon; Duff, Kevin; Dukart, Jrgen; Durazzo, Timothy; Dykstra, Kevin; Earl, Nancy; Edula, Goutham; Ekin, Ahmet; Elcoroaristizabal, Xabier; Emahazion, Tesfai; Engelman, Corinne; Epstein, Noam; Erten-Lyons, Deniz; Eskildsen, Simon; Falcone, Guido; Fan, Lingzhong; Fan, Yong; Farahibozorg, Seyedehrezvan; Farb, Norman; Farnum, Michael; Farrer, Lindsay; Farzan, Ali; Faux, Noel; Feldman, Betsy; Feldman, Howard; Feldman, Susan; Fennema-Notestine, Christine; Fernandes, Michel; Fernandez, Elsa; Ferrarini, Luca; Ferreira, Manuel Joao; Ferrer, Eugene; Figurski, Michal; Filipovych, Roman; Fillit, Howard; Finch, Stephen; Finlay, Daniel; Fiot, Jean-Baptiste; Flenniken, Derek; Fletcher, P. Thomas; Fletcher, Evan; Flynn Longmire, Crystal; Focke, Niels; Forman, Mark; Forsythe, Alan; Fox, Steven; Fox-Bosetti, Sabrina; Francis, Alexander L.; Franco-Villalobos, Conrado; Franko, Edit; Freeman, Stefanie; Friedrich, Christoph M.; Friesenhahn, Michel; Frings, Lars; Frisoni, Giovanni; Fritzsche, Klaus; Fujimoto, Yoko; Fujiwara, Ken; Fullerton, Terence; Furney, Simon; Gallins, Paul; Galvin, Ben; Gamst, Anthony; Gan, Ke; Garcia, Maria Teresa; Garg, Gaurav; Gaser, Christian; Gastineau, Edward; Gauthier, Serge; Gavett, Brandon; Gavidia, Giovana; Gazdzinski, Stefan; Ge, Qi; Ge, Tian; Gemme, Gianluca; Geraci, Joseph; Ghassabi, Zeinab; Gieschke, Ronald; Gil, Juan E.; Gill, Ryan; Gitelman, Darren; Gleason, Carey; Glymour, M. Maria; Godbey, Michael; Goghari, Vina; Gold, Michael; Goldberg, Terry; Goldman, Jennifer; Gomeni, Roberto; Gong, Shangwenyan; Gonzales, Celedon; Goodro, Robert; Gordon, Brian; Gore, Chris; Gorriz, Juan Manuel; Grachev, Igor; Grandey, Emily; Grasela, Thaddeus; Gratt, Jeremy; Gray, Katherine; Greenberg, Barry; Gregg, Keith; Gregory, Erik; Greicius, Michael; Greve, Douglas; Grill, Joshua; Gross, Alden; Gross, Alan; Guignot, Isabelle; Guo, Jeffrey; Guo, Qimiao; Guo, Hongbin; Guo, Lianghao; Habeck, Christian; Hai, Yizhen; Haight, Thaddeus; Hammarstrom, Per; Hampel, Harald; Han, Duke; Han, Jian; Han, Tony; Hanif, Muhammad; Hanna, Yousef; Hardy, Peter; Harvey, Danielle; Hasan, Md Kamrul; Hayashi, Toshihiro; Hazart, Aurelien; He, Huiguang; He, Yong; Head, Denise; Heckemann, Rolf; Heidebrink, Judith; Henderson, David; Henrard, Sebastien; Herholz, Karl; Hernandez, Monica; Herskovits, A. Zara; Hess, Christopher; Hildenbrand, Maike; Hobart, Jeremy; Hoffman, John; Holder, Daniel; Hollingworth, Paul; Holmes, Robin; Honigberg, Lee; Hoppin, Jack; Hou, Yangyang; Hsu, Ailing; Hsu, Wei-Wen; Hu, Xiaolan; Hu, Zhiwei; Hu, William; Huang, Juebin; Huang, Chien-Chih; Huang, Chingwen; Huang, Shuai; Huang, Yifan; Huang, Fude; Huang, Chun-Jung; Huang, Shu-Pang; Hubbard, Rebecca; Huentelman, Matthew; Hui, Shen; Huppertz, Hans-Jürgen; Hurko, Orest; Hurt, Stephen; Huyck, Susan; Hwang, Scott; Hyun, JungMoon; Ifeachor, Emmanuel; Iglesias, Martina; Ikari, Yasuhiko; Ikonomidou, Vasiliki; Imani, Farzin; Immermann, Fred; Inlow, Mark; Inoue, Lurdes; Insel, Philip; Irizarry, Michael; Irungu, Benson mwangi; Ishibashi, Taro; Ishii, Kenji; Ismail, Sara; Ismail, Shahina; Ito, Kaori; Iturria-Medina, Yasser; Iwatsubo, Takeshi; Jacobson, Mark; Jacqmin, Philippe; Jafari, Aria; Jafari-Khouzani, Kourosh; Jaffe, Carl; Jara, Hernan; Jasperse, Bas; Jedynak, Bruno; Jefferson, Angela; Jennings, J. Richard; Jessen, Walter; Jia, Fucang; Jiang, Tianzi; Jing, Huang; Johnson, Julene; Johnson, Sterling; Johnson, David K.; Jones, Richard; Juengling, Freimut; Juh, Rahyeong; Julin, Per; Kadish, Bill; Kahle-Wrobleski, Kristin; Kallam, Hanimi Reddy; Kamboh, M. Ilyas; Kaneko, Tomoki; Kaneta, Tomohiro; Kang, Ju Hee; Karageorgiou, Elissaios; Karantzoulis, Stella; Karlawish, Jason; Katz, Elyse; Kaushik, Sandeep S.; Kauwe, John; Kawakami, Hirofumi; Kazimipoor, Borhan; Kelleher, Thomas; Kennedy, Richard; Kerchner, Geoffrey; Kerrouche, Nacer; Khalil, Iya; Khalil, Andre; Killeen, Neil; Killiany, Ron; Kim, Jong Hun; Kim, Heeyoung; Kim, Ana; Kim, Yeonhee; Kim, Hyoungkyu; Kim, Seongkyun; Kim, Hyewon; Kimberg, Daniel; Kimura, Tokunori; King, Richard; Kirby, Justin; Kirsch, Wolff; Klimas, Michael; Kline, Richard; Kling, Mitchel; Klopfenstein, Erin; Koikkalainen, Juha; Kokomoor, Anders; Kolasny, Anthony; Koppel, Jeremy; Korolev, Igor; Kotran, Nickolas; Kouassi, Alex; Kowalczyk, Adam; Kozma, Lynn; Krams, Michael; Kratzer, Martina; Kuceyeski, Amy; Kuhn, Felix Pierre; Kumar, Sreedhar; Kuo, Hsun Ting; Kuo, Julie; Kurosawa, Ken; Kwon, Oh Hun; Labrish, Catherine; Laforet, Genevieve; Lai, Song; Lakatos, Anita; Lam, On Ki; Lampron, Antoine; Landau, Susan; Landen, Jaren; Lane, Richard; Langbaum, Jessica; Langford, Dianne; Lanius, Vivian; Laxamana, Joel; Le, Trung; Leahy, Richard; Lee, Jong-Min; Lee, Vita; Lee, Joseph H.; Lee, Grace; Lee, Dongsoo; Lee, Noah; Lefkimmiatis, Stamatis; Lemaitre, Herve; Lenfant, Pierre; Lenz, Robert; Leoutsakos, Jeannie-Marie; Lester, Gayle; Levey, Allan; Li, Shi-jiang; Li, Shanshan; Li, Wenjun; Li, Chin-Shang; Li, Xiaodong; Li, Rui; Li, Ming; Li, Lexin; Li, Jinhe; Li, Yi; Li, Quanzheng; Li, Gang; Liang, Kuchang; Liang, Peipeng; Liang, Lichen; Liao, Yuan-Lin; Lin, Ling-chih; Lin, Lan; Lin, Mingkuan; Lin, Ai-Ling; Liu, Songling; Liu, Yuan; Liu, Tianming; Liu, Meijie; Liu, Xiuwen; Liu, Li; Liu, Honggang; Liu, Pu; Liu, Tao; Liu, Sophia; Liu, Dazhong; Lo, Raymond; Lobanov, Victor; Loewenstein, David; Logovinsky, Veronika; Long, Xiaojing; Long, Ziyi; Looi, Jeffrey; Lu, Po-Haong; Lukic, Ana; Lull, Juan J.; Luo, Xiongjian; Lynch, John; Ma, Lei; Mackin, Scott; Mada, Marius; Magda, Sebastian; Maglio, Silvio; Maikusa, Norihide; Mak, Henry Ka-Fung; Malave, Vicente; Maldjian, Joseph; Mandal, Pravat; Mangin, Jean-Francois; Manjon, Jose; Mantri, Ninad; Manzour, Amir; Marambaud, Philippe; Marchewka, Artur; Marek, Kenneth; Markind, Samuel; Marshall, Gad; Martinez Torteya, Antonio; Mather, Mara; Mathis, Chester; Matoug, Sofia; Matsuo, Yoshiyuki; Mattei, Peter; Matthews, Dawn; McArdle, John; McCarroll, Steven; McEvoy, Linda; McGeown, William; McGonigle, John; McIntyre, John; McLaren, Donald; McQuail, Joseph; Meadowcroft, Mark; Meda, Shashwath; Mehta, Nirav; Melie-Garcia, Lester; Melrose, Rebecca; Mendonca, Brian; Menendez, Manuel; Meredith, Jere; Merrill, David; Mesulam, Marek-Marsel; Metti, Andrea; Meyer, Carsten; Mez, Jesse; Mickael, Guedj; Miftahof, Roustem; Mikhno, Arthur; Miller, David; Millikin, Colleen; Min, Ye; Mirza, Mubeena; Mistridis, Panagiota; Mitchell, Meghan; Mitsis, Effie; Mohan, Ananth; Moore, Dana; Moradi Birgani, Parmida; Moratal, David; Morimoto, Bruce; Mormino, Elizabeth; Mortamet, Benedicte; Moscato, Pablo; Mueller, Kathyrne; Mueller, Susanne; Mueller, Notger; Mukherjee, Shubhabrata; Mulder, Emma; Murayama, Shigeo; Murphy, Michael; Murray, Brian; Musiek, Erik; Myers, Amanda; Najafi, Shahla; Nazarparvar, Babak; Nazeri, Arash; Nettiksimmons, Jasmine; Neu, Scott; Ng, Yen-Bee; Nguyen, Nghi; Nguyen Xuan, Tuong; Nichols, Thomas; Nicodemus, Kristin; Niecko, Timothy; Nielsen, Casper; Notomi, Keiji; Nutakki, Gopi Chand; O'Bryant, Sid; O'Neil, Alison; Obisesan, Thomas; Oh, Dong Hoon; Oh, Joonmi; Okonkwo, Ozioma; Olde Rikkert, Marcel; Olmos, Salvador; Ortner, Marion; Ostrowitzki, Susanne; Oswald, Annahita; Ott, Brian; Ourselin, Sebastien; Ouyang, Gaoxiang; Paiva, Renata; Pan, Zhifang; Pande, Yogesh; Pardo, Jose; Pardoe, Heath; Park, Hyunjin; Park, Lovingly; Park, Moon Ho; Park, Sang hyun; Park, Kee Hyung; Park, Sujin; Parsey, Ramin; Parveen, Riswana; Paskavitz, James; Patel, Yogen; Patil, Manasi; Pawlak, Mikolaj; Payoux, Pierre; Pearson, Jim; Peavy, Guerry; Pell, Gaby; Peng, Yahong; Pennec, Xavier; Pepin, Jean louis; Perea, Rodrigo; Perneczky, Robert; Petitti, Diana; Petrella, Jeffrey; Peyrat, Jean-Marc; Pezoa, Jorge; Pham, Chi-Tuan; Phillips, Justin; Phillips, Nicole; Pierson, Ronald; Piovezan, Mauro; Podhorski, Adam; Pollari, Mika; Pontecorvo, Michael; Poppenk, Jordan; Posner, Holly; Potkin, Steven; Potter, Guy; Potter, Elizabeth; Poulin, Stephane; Prasad, Gautam; Prenger, Kurt; Prince, Jerry; Priya, Anandh; Puchakayala, Shashidhar Reddy; Qiu, Ruolun; Qiu, Anqi; Qiu, Wendy; Qualls, Constance Dean; Rabie, Huwaida; Rajeesh, Rajeesh; Rallabandi, V. P. Subramanyam; Ramage, Amy; Randolph, Christopher; Rao, Anil; Rao, Divya; Raubertas, Richard; Ray, Debashis; Razak, Hana; Redolfi, Alberto; Reed, Bruce; Reid, Andrew; Reilhac, Anthonin; Reinsberger, Claus; Restrepo, Lucas; Retico, Alessandra; Richards, John; Riddle, William; Ries, Michele; Rincon, Mariano; Rischall, Matt; Rizk-Jackson, Angela; Robieson, Weining; Rocha-Rego, Vanessa; Rogalski, Emily; Rogers, Elizabeth; Rojas, Ignacio; Rojas Balderrama, Javier; Romero, Klaus; Rorden, Chris; Rosand, Jonathan; Rosen, Allyson; Rosen, Ori; Rosenberg, Paul; Ross, David; Roubini, Eli; Rousseau, François; Rowe, Christopher; Rubin, Daniel; Rubright, Jonathan; Ruiz, Agustin; Rusinek, Henry; Ryan, Laurie; Saad, Ahmed; Sabbagh, Marway; Sabuncu, Mert; Sachs, Michael; Sadeghi, Ali; Said, Yasmine; Saint-Aubert, Laure; Sakata, Muneyuki; Salat, David; Salmon, David; Salter, Hugh; Samwald, Matthias; Sanchez, Luciano; Sanders, Elizabeth; Sanjo, Nobuo; Sarnel, Haldun; Sato, Hajime; Sato, Shinji; Saumier, Daniel; Savio, Alexandre; Sawada, Ikuhisa; Saykin, Andrew; Schaffer, J. David; Scharre, Douglas; Schegerin, Marc; Schlosser, Gretchen; Schmand, Ben; Schmansky, Nick; Schmidt, Mark; Schmidt-Wilcke, Tobias; Schneider, Lon; Schramm, Hauke; Schuerch, Markus; Schwartz, Eben; Schwartz, Craig; Schwarz, Adam; Seethamraju, Ravi; Seixas, Flavio; Selnes, Per; Senjem, Matthew; Senlin, Wang; Seo, Sang Won; Sethuraman, Gopalan; Sevigny, Jeffrey; Sfikas, Giorgos; Sghedoni, Roberto; Shah, Said Khalid; Shahbaba, Babak; Shams, Soheil; Shattuck, David; Shaw, Leslie; Sheela, Jaba; Shen, Weijia; Shen, Qian; Shera, David; Sherman, John; Sherva, Richard; Shi, Feng; Shukla, Vinay; Shuler, Catherine; Shulman, Joshua; Siegel, Rene; Siemers, Eric; Silveira, Margarida; Silver, Michael; Silverman, Daniel; Sim, Ida; Simmons, Andy; Simoes, Rita; Simon, Melvin; Simpson, Ivor; Singh, Simer Preet; Singh, Nikhil; Siuciak, Judy; Sjogren, Niclas; Skinner, Jeannine; Skup, Martha; Small, Gary; Smith, Michael; Smith, Benjamin; Smith, Charles; Smyth, Timothy; Snow, Sarah; Soares, Holly; Soldea, Octavian; Solomon, Paul; Solomon, Alan; Som, Subhojit; Song, Changhong; Song, Mingli; Sosova, Iveta; Soudah, Eduardo; Soydemir, Melih; Spampinato, Maria Vittoria; Spenger, Christian; Sperling, Reisa; Spiegel, Rene; Spies, Lothar; Squarcia, Sandro; Squire, Larry; Staff, Roger; Stern, Yaakov; Straw, Jack; Stricker, Nikki; Strittmatter, Stephen; Stühler, Elisabeth; Styren, Scot; Subramanian, Vijayalakshmi; Sugishita, Morihiro; Sukkar, Rafid; Sun, Jia; Sun, Ying; Sun, Yu; Sundell, Karen; Suri, Muhammad; Suzuki, Akiyuki; Svetnik, Vladimir; Swan, Melanie; Takahasi, Tetsuhiko; Takeuchi, Tomoko; Tanaka, Shoji; Tanchi, Chaturaphat; Tancredi, Daniel; Tao, Wenwen; Tao, Dacheng; Taylor-Reinwald, Lisa; Teng, Edmond; Terlizzi, Rita; Thames, April; Thiele, Frank; Thomas, Benjamin; Thomas, Ronald; Thompson, Paul; Thompson, Wesley; Thornton-Wells, Tricia; Thorvaldsson, Valgeir; Thurfjell, Lennart; Titeux, Laurence; Tokuda, Takahiko; Toledo, Juan B.; Tolli, Tuomas; Toma, Ahmed; Tomita, Naoki; Toro, Roberto; Torrealdea, Patxi; Tousian, Mona; Toussaint, Paule; Toyoshiba, Hiroyoshi; Tractenberg, Rochelle E.; Trittschuh, Emily; Trojanowski, John; Truran, Diana; Tsechpenakis, Gavriil; Tucker-Drob, Elliot; Tufail, Ahsan; Tung, Joyce; Turken, And; Ueda, Yoji; Ullrich, Lauren; Umadevi Venkataraju, Kannan; Umar, Nisser; Uzunbas, Gokhan; van de Nes, Joseph; van der Brug, Marcel; van Horn, John; van Leemput, Koen; van Train, Kenneth; van Zeeland, Ashley; Vasanawala, Minal; Vemuri, Prashanthi; Verwaerde, Philippe; Videbaek, Charlotte; Vidoni, Eric; Villanueva-Meyer, Javier; Visser, Pieter Jelle; Vitolo, Ottavio; Vounou, Maria; Wade, Sara; Walhovd, Kristine B.; Wan, Hong; Wang, Huanli; Wang, Yongmei Michelle; Wang, Yalin; Wang, Angela; Wang, Lei; Wang, Yue; Wang, Xu; Wang, Ze; Wang, Yaping; Wang, Tiger; Wang, Alex; Wang, Huali; Wang, Li-San; Wang, Wei; Wang, Li; Ward, Michael; Warfield, Simon; Waring, Stephen; Watanabe, Toshiyuki; Webb, David; Wei, Lili; Weiner, Michael; Wen, Shu-Hui; Wenjing, Li; Wenzel, Fabian; Westlye, Lars T.; Whitcher, Brandon; Whitlow, Christopher; Whitwell, Jennifer; Wilhelmsen, Kirk; Williams, David; Wilmot, Beth; Wimsatt, Matt; Wingo, Thomas; Wiste, Heather; Wolfson, Tanya; Wolke, Ira; Wolz, Robin; Woo, Jongwook; Woo, Ellen; Woods, Lynn; Worth, Andrew; Worth, Eric; Wouters, Hans; Wu, Teresa; Wu, Yi-Gen; Wu, Liang; Wu, Xiaoling; Wyman, Bradley; Wyss-Coray, Tony; Xiao, Guanghua; Xiao, Liu; Xie, Sharon; Xu, Shunbin; Xu, Ye; Xu, Yi-Zheng; Xu, Guofan; Xu, Jun; Yamane, Tomohiko; Yamashita, Fumio; Yan, Yunyi; Yan, Pingkun; Yang, Eric; Yang, Jinzhong; Yang, Qing X.; Yang, Zijiang; Yang, Guang; Yang, Zhitong; Yang, Wenlu; Ye, Liang; Ye, Byoung Seok; Ye, Jieping; Ye, Jong; Yee, Laura; Yesavage, Jerome; Ying, Song; Yoo, Bongin; Young, Jonathan; Yu, Shiwei; Yu, Dongchuan; Yuan, Guihong; Yuan, Kai; Yushkevich, Paul; Zaborszky, Laszlo; Zagorodnov, Vitali; Zagorski, Michael; Zawadzki, Rezi; Zeitzer, Jamie; Zelinski, Elizabeth; Zhang, Kurt; Zhang, Huixiong; Zhang, Tianhao; Zhang, Xin; Zhang, Ping; Zhang, Bin; Zhang, Jing; Zhang, Linda; Zhang, Lijun; Zhang, Zhiguo; Zhao, Qinying; Zhao, Jim; Zhao, Peng; Zhen, Xiantong; Zheng, Yuanjie; Zhijun, Yao; Zhou, Bin; Zhou, Sheng; Zhu, Wen; Zhu, Hongtu; Zhu, Wanlin; Zilka, Samantha; Zito, Giancarlo; Zou, Heng

    2011-01-01

    Amyloid-β accumulation in the brain is thought to be one of the earliest events in Alzheimer's disease, possibly leading to synaptic dysfunction, neurodegeneration and cognitive/functional decline. The earliest detectable changes seen with neuroimaging appear to be amyloid-β accumulation detected by

  18. Effect of neonatal beta-endorphin imprinting on sexual behavior and brain serotonin level in adult rats.

    Science.gov (United States)

    Csaba, G; Knippel, Barbara; Karabélyos, Cs; Inczefi-Gonda, Agnes; Hantos, Monika; Tóthfalusi, L; Tekes, Kornélia

    2003-05-23

    A single dose (3 microg) beta-endorphin was administered to newborn female and male rats (hormonal imprinting). In adult age (at 5 months) sexual behavior, steroid hormone binding capacity and brain serotonin content was studied. Females' sexual activity (lordosis quotient) significantly decreased and more animals protested against mounting (ratio of kicking and crying 21/24 vs. 8/24; p < 0.001). Males' sexual activity did not change, however more males were aggressive (4/10 vs. 1/10). Uterine estrogen receptor density significantly increased and affinity decreased. There was no change in the binding capacity of thymic glucocorticoid receptors. In the brain, five regions were studied for serotonin content. There was a gender difference in serotonin level and the intragroup differences were also high. In the endorphin treated males the serotonin level was significantly lower than in the controls. In the endorphin treated females the intragroup scattering has been significantly reduced. Nociceptin content of the cerebrospinal fluid was not changed. The experiments call attention to the possibility of adjustment of sexual and behavioral sphere by the individually different endorphin surge during labor.

  19. Effects of pituitary beta-endorphin secretagogues on the concentration of beta-endorphin in rat cerebrospinal fluid : evidence for a role of vasopressin in the regulation of brain beta-endorphin release

    NARCIS (Netherlands)

    Barna, I; Sweep, C G; Veldhuis, H D; Wiegant, V M; De Wied, D

    The concentration of beta-endorphin-immunoreactivity (beta E-IR) in cerebrospinal fluid (CSF) and plasma of rats was determined following intracerebroventricular (ICV) treatment of conscious animals with substances known to stimulate the release of beta E and other pro-opiomelanocortin

  20. 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.

  1. The brain-specific Beta4 subunit downregulates BK channel cell surface expression.

    Directory of Open Access Journals (Sweden)

    Sonal Shruti

    Full Text Available The large-conductance K(+ channel (BK channel can control neural excitability, and enhanced channel currents facilitate high firing rates in cortical neurons. The brain-specific auxiliary subunit β4 alters channel Ca(++- and voltage-sensitivity, and β4 knock-out animals exhibit spontaneous seizures. Here we investigate β4's effect on BK channel trafficking to the plasma membrane. Using a novel genetic tag to track the cellular location of the pore-forming BKα subunit in living cells, we find that β4 expression profoundly reduces surface localization of BK channels via a C-terminal ER retention sequence. In hippocampal CA3 neurons from C57BL/6 mice with endogenously high β4 expression, whole-cell BK channel currents display none of the characteristic properties of BKα+β4 channels observed in heterologous cells. Finally, β4 knock-out animals exhibit a 2.5-fold increase in whole-cell BK channel current, indicating that β4 also regulates current magnitude in vivo. Thus, we propose that a major function of the brain-specific β4 subunit in CA3 neurons is control of surface trafficking.

  2. Organization and chromosomal localization of Я-tubulin genes in ...

    Indian Academy of Sciences (India)

    tribpo

    Abstract. The genomic organization and chromosomal location of the Я-tubulin isogenes in Leishmania donovani promastigotes has been studied by nucleic acid hybridization techniques using a cloned Я-tubulin gene. We have cloned a Я-tubulin gene fragment, 3·3 kbp long, from genomic DNA of Leishmania donovani ...

  3. Rapid modulation of TRH and TRH-like peptide release in rat brain, pancreas, and testis by a GSK-3beta inhibitor.

    Science.gov (United States)

    Pekary, Albert Eugene; Stevens, Schetema A; Blood, James D; Sattin, Albert

    2010-06-01

    Antidepressants have been shown to be neuroprotective and able to reverse damage to glia and neurons. Thyrotropin-releasing hormone (TRH) is an endogenous antidepressant-like neuropeptide that reduces the expression of glycogen synthase kinase-3beta (GSK-3beta), an enzyme that hyperphosphorylates tau and is implicated in bipolar disorder, diabetes and Alzheimer's disease. In order to understand the potential role of GSK-3beta in the modulation of depression by TRH and TRH-like peptides and the therapeutic potential of GSK-3beta inhibitors for neuropsychiatric and metabolic diseases, young adult male Sprague-Dawley (SD) rats were (a) injected ip with 1.8mg/kg of GSK-3beta inhibitor VIII (GSKI) and sacrificed 0, 2, 4, 6, and 8h later or (b) injected with 0, 0.018, 0.18 or 1.8mg/kg GSKI and bled 4h later. Levels of TRH and TRH-like peptides were measured in various brain regions involved in mood regulation, pancreas and reproductive tissues. Large, 3-15-fold, increases of TRH and TRH-like peptide levels in cerebellum, for example, as well as other brain regions were noted at 2 and 4h. In contrast, a nearly complete loss of TRH and TRH-like peptides from testis within 2h and pancreas by 4h following GSKI injection was observed. We have previously reported similar acute effects of corticosterone in brain and peripheral tissues. Incubation of a decapsulated rat testis with either GSKI or corticosterone accelerated release of TRH, and TRH-like peptides. Glucocorticoids, via inhibition of GSK3-beta activity, may thus be involved in the inhibition of TRH and TRH-like peptide release in brain, thereby contributing to the depressogenic effect of this class of steroids. Corticosterone-induced acceleration of release of these peptides from testis may contribute to the decline in reproductive function and redirection of energy needed during life-threatening emergencies. These contrasting effects of glucocorticoid on peptide release appear to be mediated by GSK-3beta. Published

  4. Estrogen activates rapid signaling in the brain: role of estrogen receptor alpha and estrogen receptor beta in neurons and glia.

    Science.gov (United States)

    Mhyre, A J; Dorsa, D M

    2006-01-01

    The aging process is known to coincide with a decline in circulating sex hormone levels in both men and women. Due to an increase in the average lifespan, a growing number of post-menopausal women are now receiving hormone therapy for extended periods of time. Recent findings of the Women's Health Initiative, however, have called into question the benefits of long-term hormone therapy for treating symptoms of menopause. The results of this study are still being evaluated, but it is clear that a better understanding of the molecular effects of estradiol is needed in order to develop new estrogenic compounds that activate specific mechanisms but lack adverse side effects. Traditionally, the effects of estradiol treatment have been ascribed to changes in gene expression, namely transcription at estrogen response elements. This review focuses on emerging information that estradiol can also activate a repertoire of membrane-initiated signaling pathways and that these rapid signaling events lead to functional changes at the cellular level. The various types of cells in the brain can respond differently to estradiol treatment based on the signaling properties of the cell, as well as which receptor, estrogen receptor alpha and/or estrogen receptor beta, is expressed. Taken together, these findings suggest that the estradiol-induced activation of membrane-initiated signaling pathways occurs in a cell-type specific manner and can differentially influence how the cells respond to various insults.

  5. 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.

  6. 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

  7. The Brain of Binge Drinkers at Rest: Alterations in Theta and Beta Oscillations in First-Year College Students with a Binge Drinking Pattern

    Directory of Open Access Journals (Sweden)

    Eduardo López-Caneda

    2017-09-01

    Full Text Available Background: Previous studies have reported anomalous resting brain activity in the electroencephalogram (EEG of alcoholics, often reflected as increased power in the beta and theta frequency bands. The effects of binge drinking, the most common pattern of excessive alcohol consumption during adolescence and youth, on brain activity at rest is still poorly known. In this study, we sought to assess the pattern of resting-state EEG oscillations in college-aged binge drinkers (BDs.Methods: Resting-state brain activity during eyes-open and eyes-closed conditions was recorded from 60 channels in 80 first-year undergraduate students (40 controls and 40 BDs. Cortical sources activity of EEG rhythms was estimated using exact Low-Resolution Electromagnetic Tomography (eLORETA analysis.Results: EEG-source localization analysis revealed that BDs showed, in comparison with controls, significantly higher intracranial current density in the beta frequency band over the right temporal lobe (parahippocampal and fusiform gyri during eyes-open resting state as well as higher intracranial current density in the theta band over the bilateral occipital cortex (cuneus and lingual gyrus during eyes-closed resting condition.Conclusions: These findings are in line with previous results observing increased beta and/or theta power following chronic or heavy alcohol drinking in alcohol-dependent subjects and BDs. Increased tonic beta and theta oscillations are suggestive of an augmented cortical excitability and of potential difficulties in the information processing capacity in young BDs. Furthermore, enhanced EEG power in these frequency bands may respond to a neuromaturational delay as a result of excessive alcohol consumption during this critical brain developmental period.

  8. Microtubule nucleation by γ-tubulin complexes.

    Science.gov (United States)

    Kollman, Justin M; Merdes, Andreas; Mourey, Lionel; Agard, David A

    2011-10-12

    Microtubule nucleation is regulated by the γ-tubulin ring complex (γTuRC) and related γ-tubulin complexes, providing spatial and temporal control over the initiation of microtubule growth. Recent structural work has shed light on the mechanism of γTuRC-based microtubule nucleation, confirming the long-standing hypothesis that the γTuRC functions as a microtubule template. The first crystallographic analysis of a non-γ-tubulin γTuRC component (γ-tubulin complex protein 4 (GCP4)) has resulted in a new appreciation of the relationships among all γTuRC proteins, leading to a refined model of their organization and function. The structures have also suggested an unexpected mechanism for regulating γTuRC activity via conformational modulation of the complex component GCP3. New experiments on γTuRC localization extend these insights, suggesting a direct link between its attachment at specific cellular sites and its activation.

  9. Effects of halothane and methoxyflurane on regional brain and spinal cord substance P-like and beta-endorphin-like immunoreactivities in the rat.

    Science.gov (United States)

    Karuri, A R; Agarwal, R K; Engelking, L R; Kumar, M S

    1998-03-15

    Effects of acute exposure (2 hr) to either 1.5% halothane or 0.5% methoxyflurane were investigated in the Sprague Dawley rat. Pituitary (PIT) and central nervous system (CNS) substance P (SP)-like and beta-endorphin (beta-end)-like immunoreactivities were evaluated immediately after anesthetic exposure (2 h), after righting reflex (4 h) or 24 hr postexposure (24 h). Only halothane significantly reduced SP-like immunoreactivity in olfactory bulbs in both the 2-h and 4-h groups. Halothane elevated SP-like immunoreactivity of hippocampus at all three time periods, and in the hypothalamus at 2 h. Both anesthetics significantly depleted thalamic concentrations of SP-like immunoreactivity. Methoxyflurane anesthesia resulted in a drastic decrease in SP-like immunoreactivity in PIT at all three time periods periods, while halothane elevated PIT concentrations of this peptide at 4 h. Both anesthetics significantly decreased beta-end-like immunoreactivity in the olfactory bulbs and thalami at 2, 4, and 24 h. However, halothane alone significantly elevated beta-end-like immunoreactivity in the spinal cord at 24 h. Halothane significantly elevated PIT beta-end-like immunoreactivity at 2 and 24 h, while methoxyflurane significantly lowered it in the 4-h group, but elevated the levels of the same in the 24-h group. Brain stem beta-end immunoreactivity were significantly reduced at 2 h by both anesthetics, and at 4 h by methoxyflurane. Results indicate that halothane and methoxyflurane may differ significantly in their actions on SP and beta-end secreting neurons in the CNS.

  10. Brain serotonin depletion enhances the sodium appetite induced by sodium depletion or beta-adrenergic stimulation

    Directory of Open Access Journals (Sweden)

    Hawlinston R. C. Lima

    2004-03-01

    Full Text Available We investigate the influence of brain serotonin depletion on the sodium appetite. Rats depleted of serotonin through the systemic administration of p-chlorophenylalanine (300 mg/kg, ip, for 2 days showed an intense natriorexigenic response induced by sodium depletion (furosemide, 20 mg/kg, sc, 24 h before water and 1.8% NaCl presentation. Intake of 1.8% NaCl was always higher than that observed for the control group (12.9 ± 1.4 and 21.4 ± 3.0 mL vs 5.7 ± 1.2 and 12.7 ± 1.6 mL, 30 and 300 min after water and saline presentation. After 24 h, the natriorexigenic response continued to be significantly higher compared to control (33.6±5.1 vs 21.9±3.6 mL,P Objetivamos avaliar a influência da depleção cerebral de serotonina no apetite por sódio. Ratos depletados de serotonina através da administração sistêmica de paraclorofenilalanina (300 mg/kg, ip, por 2 dias exibiram intensa resposta natriorexigênica induzida pela depleção de sódio (furosemida, 20 mg/kg, sc, 24 h antes da oferta de água e NaCl 1.8%. A ingestão de NaCl 1,8% atingiu valores sempre acima do grupo controle (12,9 ±1,4 e 21,4 ±3,0 mL vs 5,7 ±1,2 e 12,7 ±1,6 mL, 30 e 300 min após apresentação de água e salina hipertônica, P < 0,05. Ao final de 24 h a resposta natriorexigênica ainda mantinha-se significativamente mais elevada em relação aos controles (33,6 ±5,1 vs 21,9 ±3,6 mL, P < 0,05 e comparável aos controles no 14° dia. Ratos depletados de serotonina exibiram uma precoce resposta natriorexigênica após administração de isoproterenol, no terceiro dia após a primeira injeção de paraclorofenilalanina. O aumento da ingestão de NaCl 1,8% iniciou-se aos 120 min (1,9 ±0,3 vs 0,45 ±0,3 mL, P < 0,05 e manteve-se elevada ao final de 24 h (17,3 ±3,2 vs 1,1 ±0,5 mL, P < 0,05 após a oferta de fluidos. Decorridos sete e 14 dias a resposta natriorexigênica tornou-se comparável à dos controles. Os dados apresentados demonstram que a depleção de

  11. Binding of (/sup 3/H)ethyl-. beta. -carboline-3-carboxylate to brain benzodiazepine receptors. Effect of drugs and anions

    Energy Technology Data Exchange (ETDEWEB)

    Williams, E.F.; Paul, S.M.; Rice, K.C.; Skolnick, P. (National Institutes of Health, Bethesda, MD (USA)); Cain, M. (Wisconsin Univ., Milwaukee (USA). Dept. of Chemistry)

    1981-09-28

    It is reported that in contrast to the changes in affinity of (/sup 3/H)benzodiazepines elicited by halide ions, barbiturates, and pyrazolopyridines, the apparent affinity of ..beta..-(/sup 3/H)CCE (ethyl-..beta..-carboline-3-carboxylate) is unaffected by these agents. Furthermore, Scatchard analysis of ..beta..-(/sup 3/H)CCE binding to cerebral cortical and cerebellar membranes revealed a significantly greater number of binding sites than was observed with either (/sup 3/H)diazepam or (/sup 3/H)flunitazepam, suggesting that at low concentrations benzodiazepines selectively label a subpopulation of the receptors labelled with ..beta..-(/sup 3/H)CCE. Alternatively, ..beta..-(/sup 3/H)CCE may bind to sites that are distinct from those labelled with (/sup 3/H)-benzodiazepines.

  12. Tubulin glycylation controls primary cilia length.

    Science.gov (United States)

    Gadadhar, Sudarshan; Dadi, Hala; Bodakuntla, Satish; Schnitzler, Anne; Bièche, Ivan; Rusconi, Filippo; Janke, Carsten

    2017-09-04

    As essential components of the eukaryotic cytoskeleton, microtubules fulfill a variety of functions that can be temporally and spatially controlled by tubulin posttranslational modifications. Tubulin glycylation has so far been mostly found on motile cilia and flagella, where it is involved in the stabilization of the axoneme. In contrast, barely anything is known about the role of glycylation in primary cilia because of limitations in detecting this modification in these organelles. We thus developed novel glycylation-specific antibodies with which we detected glycylation in many primary cilia. Glycylation accumulates in primary cilia in a length-dependent manner, and depletion or overexpression of glycylating enzymes modulates the length of primary cilia in cultured cells. This strongly suggests that glycylation is essential for the homeostasis of primary cilia, which has important implications for human disorders related to primary cilia dysfunctions, such as ciliopathies and certain types of cancer. © 2017 Gadadhar et al.

  13. Total synthesis and evaluation of C25-benzyloxyepothilone C for tubulin assembly and cytotoxicity against MCF-7 breast cancer cells.

    Science.gov (United States)

    Hutt, Oliver E; Reddy, Bollu S; Nair, Sajiv K; Reiff, Emily A; Henri, John T; Greiner, Jack F; Chiu, Ting-Lan; Vandervelde, David G; Amin, Elizabeth A; Himes, Richard H; Georg, Gunda I

    2008-09-01

    The total synthesis of C25-benzyloxy epothilone C is described. A sequential Suzuki-Aldol-Yamaguchi macrolactonization strategy was utilized employing a novel derivatized C8-C12 fragment. The C25-benzyloxy analog exhibited significantly reduced biological activity in microtubule assembly and cytotoxicity assays. Molecular modeling simulations indicated that excessive steric bulk in the C25 position may reduce activity by disrupting key hydrogen bonds that are crucial for epothilone binding to beta-tubulin.

  14. Tubulin isotype specificity in neuronal migration: Tuba8 can't fill in for Tuba1a.

    Science.gov (United States)

    Kawauchi, Takeshi

    2017-08-07

    Several tubulin isotypes, including Tuba1a, are associated with brain malformations. In this issue, Belvindrah et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201607074) show that Tuba1a and Tuba8 differentially regulate microtubule organization in neurons, and they provide insights into the mechanisms by which Tuba1a mutations disrupt adult mouse brain morphology. © 2017 Kawauchi.

  15. A Mutation in the Tubulin-Encoding Gene Causes Complex Cortical Malformations and Unilateral Hypohidrosis

    Directory of Open Access Journals (Sweden)

    Shinobu Fukumura MD

    2016-08-01

    Full Text Available Recent studies have emphasized the association between tubulin gene mutations and developmental abnormalities of the cortex. In this study, the authors identified a mutation in the tubulin-encoding class III β-tubulin ( TUBB3 gene in a 4-year-old boy presenting with brain abnormalities and unilateral hypohidrosis. The patient showed a left internal strabismus, moderate developmental delay, and congenital hypohidrosis of the right side of the body. Magnetic resonance imaging disclosed gyral disorganization mainly in the left perisylvian region, dysmorphic and hypertrophic basal ganglia with fusion between the putamen and caudate nucleus without affecting the anterior limb of the internal capsule, and moderate hypoplasia of the right brain stem and cerebellum. Diffusion tensor imaging studies revealed disorganization of the pyramidal fibers. The amplitude of the sympathetic skin response was low in the right arm, which led to a diagnosis of focal autonomic neuropathy. Sequencing the TUBB3 gene revealed a de novo missense mutation, c.862G>A (p.E288K.

  16. Mutation of the α-tubulin Tuba1a leads to straighter microtubules and perturbs neuronal migration.

    Science.gov (United States)

    Belvindrah, Richard; Natarajan, Kathiresan; Shabajee, Preety; Bruel-Jungerman, Elodie; Bernard, Jennifer; Goutierre, Marie; Moutkine, Imane; Jaglin, Xavier H; Savariradjane, Mythili; Irinopoulou, Theano; Poncer, Jean-Christophe; Janke, Carsten; Francis, Fiona

    2017-08-07

    Brain development involves extensive migration of neurons. Microtubules (MTs) are key cellular effectors of neuronal displacement that are assembled from α/β-tubulin heterodimers. Mutation of the α-tubulin isotype TUBA1A is associated with cortical malformations in humans. In this study, we provide detailed in vivo and in vitro analyses of Tuba1a mutants. In mice carrying a Tuba1a missense mutation (S140G), neurons accumulate, and glial cells are dispersed along the rostral migratory stream in postnatal and adult brains. Live imaging of Tuba1a-mutant neurons revealed slowed migration and increased neuronal branching, which correlated with directionality alterations and perturbed nucleus-centrosome (N-C) coupling. Tuba1a mutation led to increased straightness of newly polymerized MTs, and structural modeling data suggest a conformational change in the α/β-tubulin heterodimer. We show that Tuba8, another α-tubulin isotype previously associated with cortical malformations, has altered function compared with Tuba1a. Our work shows that Tuba1a plays an essential, noncompensated role in neuronal saltatory migration in vivo and highlights the importance of MT flexibility in N-C coupling and neuronal-branching regulation during neuronal migration. © 2017 Belvindrah et al.

  17. Effect of a hypertonic balanced ketone solution on plasma, CSF and brain beta-hydroxybutyrate levels and acid-base status.

    Science.gov (United States)

    White, Hayden; Venkatesh, Balasubramanian; Jones, Mark; Worrall, Simon; Chuah, Teong; Ordonez, Jenny

    2013-04-01

    Although glucose is the main source of energy for the human brain, ketones play an important role during starvation or injury. The purpose of our study was to investigate the metabolic effects of a novel hypertonic sodium ketone solution in normal animals. Adult Sprague-Dawley rats (420-570 g) were divided into three groups of five, one control and two study arms. The control group received an intravenous infusion of 3 % NaCl at 5 ml/kg/h. The animals in the two study arms were assigned to receive one of the two formulations of ketone solutions, containing hypertonic saline with 40 and 120 mmol/l beta-hydroxybutyrate, respectively. This was infused for 6 h and then the animal was euthanized and brains removed and frozen. Both blood and cerebrospinal fluid (CSF) levels of beta-hydroxybutyrate (BHB) demonstrated strong evidence of a change over time (p < 0.0001). There was also strong evidence of a difference between groups (p < 0.0001). Multiple comparisons showed all these means were statistically different (p < 0.05). Measurement of BHB levels in brain tissue found strong evidence of a difference between groups (p < 0.0001) with control: 0.15 mmol/l (0.01), BHB 40: 0.19 mmol/l (0.01), and BHB 120: 0.28 mmol/l (0.01). Multiple comparisons showed all these means were statistically different (p < 0.05). There were no differences over time (p = 0.31) or between groups (p = 0.33) or an interaction between groups and time (p = 0.47) for base excess. The IV infusions of hypertonic saline/BHB are feasible and lead to increased plasma, CSF and brain levels of BHB without significant acid/base effects.

  18. 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

  19. Structures of potent anticancer compounds bound to tubulin.

    Science.gov (United States)

    McNamara, Dan E; Senese, Silvia; Yeates, Todd O; Torres, Jorge Z

    2015-07-01

    Small molecules that bind to tubulin exert powerful effects on cell division and apoptosis (programmed cell death). Cell-based high-throughput screening combined with chemo/bioinformatic and biochemical analyses recently revealed a novel compound MI-181 as a potent mitotic inhibitor with heightened activity towards melanomas. MI-181 causes tubulin depolymerization, activates the spindle assembly checkpoint arresting cells in mitosis, and induces apoptotic cell death. C2 is an unrelated compound previously shown to have lethal effects on microtubules in tumorigenic cell lines. We report 2.60 Å and 3.75 Å resolution structures of MI-181 and C2, respectively, bound to a ternary complex of αβ-tubulin, the tubulin-binding protein stathmin, and tubulin tyrosine ligase. In the first of these structures, our crystallographic results reveal a unique binding mode for MI-181 extending unusually deep into the well-studied colchicine-binding site on β-tubulin. In the second structure the C2 compound occupies the colchicine-binding site on β-tubulin with two chemical moieties recapitulating contacts made by colchicine, in combination with another system of atomic contacts. These insights reveal the source of the observed effects of MI-181 and C2 on microtubules, mitosis, and cultured cancer cell lines. The structural details of the interaction between tubulin and the described compounds may guide the development of improved derivative compounds as therapeutic candidates or molecular probes to study cancer cell division. © 2015 The Protein Society.

  20. Radiosynthesis of [{sup 18}F] N-(3-Fluoropropyl)-2-{beta}-Carbomethoxy-3-{beta}-(4-Bromophenyl) Nortropane and the regional brain uptake in non human primate using PET

    Energy Technology Data Exchange (ETDEWEB)

    Chaly, Thomas E-mail: tchaly@nshs.edu; Baldwin, R.M.; Neumeyer, John L.; Hellman, Matthew J.; Dhawan, Vijay; Garg, Pradeep K.; Tamagnan, Gilles; Staley, Julie K.; Al-Tikriti, Mohammed S.; Hou, Yankun; Zoghbi, Sami S.; Gu Xiaohui; Zong, R.; Eidelberg, David

    2004-01-01

    A synthetic procedure for the preparation of [{sup 18}F]FPCBT, an imaging agent for the dopamine transporter (DAT), has been developed. The radiosynthesis was carried out in a two step procedure. Even though the yield was low, we were able to prepare 20 to 30mCi of the product, which was enough for two or three studies. The radiochemical purity was greater than 96%. The in vivo properties of this radiotracer were evaluated using baboon and it showed highest uptake in the striatum. The studies also revealed that the maximum uptake was reached within 7 to 10 minutes post injection. Plasma metabolite analysis indicated that there is only one metabolite and it is less lipophilic than the parent compound. [{sup 18}F]FPCBT displayed good brain uptake and its high target to non target ratio indicate that it is a potential candidate for DAT imaging.

  1. Different methods for administering 17[beta]-estradiol to ovariectomized rats result in opposite effects on ischemic brain damage

    National Research Council Canada - National Science Library

    Strom, Jakob O; Theodorsson, Elvar; Holm, Lovisa; Theodorsson, Annette

    2010-01-01

    .... The discordant results observed in rat brain ischemia models may be a consequence of discrepancies in estrogen administration modes resulting in plasma concentration profiles far from those intended...

  2. Molecular size of alpha 1- and beta-adrenoceptors in rat brain cortex as determined by a radiation inactivation method.

    Science.gov (United States)

    Mogilnicka, E; Nielsen, M

    1986-04-02

    Frozen whole rat cerebral cortex was exposed to 10 MeV electrons from a linear accelerator. Based on the theory of target size analysis, the in situ molecular weight of alpha 1-adrenoceptors (labelled by [3H]prazosin) and beta-adrenoceptors (labelled by [3H]dihydroalprenolol) was 57 800 daltons and 42 600 daltons, respectively.

  3. Circumventricular organs: a novel site of neural stem cells in the adult brain.

    Science.gov (United States)

    Bennett, Lori; Yang, Ming; Enikolopov, Grigori; Iacovitti, Lorraine

    2009-07-01

    Neurogenesis in the adult mammalian nervous system is now well established in the subventricular zone of the anterolateral ventricle and subgranular zone of the hippocampus. In these regions, neurons are thought to arise from neural stem cells, identified by their expression of specific intermediate filament proteins (nestin, vimentin, GFAP) and transcription factors (Sox2). In the present study, we show that in adult rat and mouse, the circumventricular organs (CVOs) are rich in nestin+, GFAP+, vimentin+ cells which express Sox2 and the cell cycle-regulating protein Ki67. In culture, these cells proliferate as neurospheres and express neuronal (doublecortin+, beta-tubulin III+) and glial (S100beta+, GFAP+, RIP+) phenotypic traits. Further, our in vivo studies using bromodeoxyuridine show that CVO cells proliferate and undergo constitutive neurogenesis and gliogenesis. These findings suggest that CVOs may constitute a heretofore unknown source of stem/progenitor cells, capable of giving rise to new neurons and/or glia in the adult brain.

  4. 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.

  5. Acetylated alpha-tubulin in Trypanosoma cruzi: immunocytochemical localization

    Directory of Open Access Journals (Sweden)

    Thais Souto-Padron

    1993-12-01

    Full Text Available We have used monoclonal antibodies specific for acetylated and non-acetylated alpha-tubulin to localize microtubules containing acetylated alpha-tubulin in all developmental forms of the life cycle of Trypanosoma cruzi. This was demonstrated using immunofluorescence and by transmission electron microscopy of thin sections, negative stained cells, and replicas of whole Triton X-100 extracted cells immunolabeled with antibody-gold complex. The antibody specific for acetylated alpha-tubulin (6-11B-1 binds to the flagellar, as well as to the sub-pellicular microtubules. The extent of labeling of the sub-pellicular microtubules with the monoclonal antibody recognized alpha-acetylated tubulin was smaller than that observed with the antibody which recognizes all tubulin isoforms. In relation to the developmental forms, the extent of labeling of the microtubules with antibody 6-11B-1 was larger in epimastigote and trypomastigote than in amastigote forms. Incubation of the parasites for 1 h at 0º C or in the presence of either colchicine or vinblastine did not interfere with the sub-pellicular microtubules. These observations, in agreement with those reported for Trypanosoma brucei brucei (Schneider et al., 1987; Schulze et al., 1987; Sasse per cent Gull, 1988 indicate that the sub-pellicular microtubules of trypanosomatids represent stable microtubules containing acetylated alpha-tubulin (or the alpha 3-tubulin isotype.

  6. Inhibition of tubulin polymerization by hypochlorous acid and chloramines.

    Science.gov (United States)

    Landino, Lisa M; Hagedorn, Tara D; Kim, Shannon B; Hogan, Katherine M

    2011-04-15

    Protein thiol oxidation and modification by nitric oxide and glutathione are emerging as common mechanisms to regulate protein function and to modify protein structure. Also, thiol oxidation is a probable outcome of cellular oxidative stress and is linked to degenerative disease progression. We assessed the effect of the oxidants hypochlorous acid and chloramines on the cytoskeletal protein tubulin. Total cysteine oxidation by the oxidants was monitored by labeling tubulin with the thiol-selective reagent 5-iodoacetamidofluorescein; by reaction with Ellman's reagent, 5,5'-dithiobis(2-nitrobenzoic acid); and by detecting interchain tubulin disulfides by Western blot under nonreducing conditions. Whereas HOCl induced both cysteine and methionine oxidation of tubulin, chloramines were predominantly cysteine oxidants. Cysteine oxidation of tubulin, rather than methionine oxidation, was associated with loss of microtubule polymerization activity, and treatment of oxidized tubulin with disulfide reducing agents restored a considerable portion of the polymerization activity that was lost after oxidation. By comparing the reactivity of hypochlorous acid and chloramines with the previously characterized oxidants, peroxynitrite and the nitroxyl donor Angeli's salt, we have identified tubulin thiol oxidation, not methionine oxidation or tyrosine nitration, as a common outcome responsible for decreased polymerization activity. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Heterogeneous Tau-Tubulin Complexes Accelerate Microtubule Polymerization.

    Science.gov (United States)

    Li, Xiao-Han; Rhoades, Elizabeth

    2017-06-20

    Tau is an intrinsically disordered protein with a central role in the pathology of a number of neurodegenerative diseases. Tau normally functions to stabilize neuronal microtubules, although the mechanism underlying this function is not well understood. Of note is that the interaction between tau and soluble tubulin, which has implications both in understanding tau function as well as its role in disease, is underexplored. Here we investigate the relationship between heterogeneity in tau-tubulin complexes and tau function. Specifically, we created a series of truncated and scrambled tau constructs and characterized the size and heterogeneity of the tau-tubulin complexes formed under nonpolymerizing conditions. Function of the constructs was verified by tubulin polymerization assays. We find that, surprisingly, the pseudo-repeat region of tau, which flanks the core microtubule-binding domain of tau, contributes largely to the formation of large, heterogeneous tau tubulin complexes; additional independent tubulin binding sites exist in repeats two and three of the microtubule binding domain. Of particular interest is that we find positive correlation between the size and heterogeneity of the complexes and rate of tau-promoted microtubule polymerization. We propose that tau-tubulin can be described as a "fuzzy" complex, and our results demonstrate the importance of heterogeneous complex formation in tau function. This work provides fundamental insights into the functional mechanism of tau, and more broadly underscores the relevance of heterogeneous and dynamic complexes in the functions of intrinsically disordered proteins. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  8. 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...... markers synapsin and postsynaptic density protein 95 (PSD95), in beta-tubulin III-negative filopodia-like protrusions. There was coexistance between MAP1S and NR3A immunoreactivity in neurite shafts and occasionally in filopodia-like processes. MAP1S potentially links NR3A to the cytoskeleton, and may......When screening a brain cDNA library, we found that the N-methyl-D-aspartate receptor subunit NR3A binds to microtubule-associated protein (MAP) 1S/chromosome 19 open reading frame 5 (C19ORF5). The interaction was confirmed in vitro and in vivo, and binding of MAP1S was localized to the membrane...

  9. Brain oscillatory activity during motor preparation: Effect of directional uncertainty on beta, but not alpha, frequency band

    Directory of Open Access Journals (Sweden)

    Charidimos eTzagarakis

    2015-07-01

    Full Text Available In time-constraint activities, such as sports, it is advantageous to be prepared to act even before knowing precisely what action will be needed. Here, we studied the relation between neural oscillations during motor preparation and amount of uncertainty about the direction of the upcoming target. Ten right-handed volunteers participated in a cued center-out task. A brief visual cue identified the region of space in which the target would appear. Three cue sizes were used to vary the amount of information about the direction of the upcoming target. The target appeared at a random location within the region indicated by the cue, and the participants moved a joystick-controlled cursor towards it. Time-frequency analyses showed phasic increases of power in low (delta/theta: 30 Hz frequency-bands in relation to the onset of visual stimuli and of the motor response. More importantly in regard to motor preparation, there was a tonic reduction of power in the alpha (8-12 Hz and beta (14-30 Hz bands during the period between cue presentation and target onset. During motor preparation, the main source of change of power of the alpha band was localized over the contralateral sensorimotor region and both parietal cortices, whereas for the beta-band the main source was the contralateral sensorimotor region. During cue presentation, the reduction of power of the alpha-band in the occipital lobe showed a brief differentiation of condition: the wider the visual cue, the more the power of the alpha-band decreased. However during motor preparation, only the power of the beta-band was dependent on directional uncertainty: the less the directional uncertainty, the more the power of the beta-band decreased. In conclusion, the results indicate that the power in the alpha-band is associated briefly with cue size, but is otherwise an undifferentiated indication of neural activation, whereas the power of the beta-band reflects the level of motor preparation.

  10. Tubulin Post-Translational Modifications and Microtubule Dynamics

    Directory of Open Access Journals (Sweden)

    Dorota Wloga

    2017-10-01

    Full Text Available Microtubules are hollow tube-like polymeric structures composed of α,β-tubulin heterodimers. They play an important role in numerous cellular processes, including intracellular transport, cell motility and segregation of the chromosomes during cell division. Moreover, microtubule doublets or triplets form a scaffold of a cilium, centriole and basal body, respectively. To perform such diverse functions microtubules have to differ in their properties. Post-translational modifications are one of the factors that affect the properties of the tubulin polymer. Here we focus on the direct and indirect effects of post-translational modifications of tubulin on microtubule dynamics.

  11. Beta Blockers

    Science.gov (United States)

    Beta blockers Beta blockers, also called beta-adrenergic blocking agents, treat a variety of conditions, such as high blood pressure and migraines. ... this class of medication. By Mayo Clinic Staff Beta blockers, also known as beta-adrenergic blocking agents, are ...

  12. Brain glucose utilization in mice with a targeted mutation in the thyroid hormone alpha or beta receptor gene.

    Science.gov (United States)

    Itoh, Y; Esaki, T; Kaneshige, M; Suzuki, H; Cook, M; Sokoloff, L; Cheng, S Y; Nunez, J

    2001-08-14

    Brain glucose utilization is markedly depressed in adult rats made cretinous after birth. To ascertain which subtype of thyroid hormone (TH) receptors, TRalpha1 or TRbeta, is involved in the regulation of glucose utilization during brain development, we used the 2-[(14)C]deoxyglucose method in mice with a mutation in either their TRalpha or TRbeta gene. A C insertion produced a frameshift mutation in their carboxyl terminus. These mutants lacked TH binding and transactivation activities and exhibited potent dominant negative activity. Glucose utilization in the homozygous TRbetaPV mutant mice and their wild-type siblings was almost identical in 19 brain regions, whereas it was markedly reduced in all brain regions of the heterozygous TRalpha1PV mice. These suggest that the alpha1 receptor mediates the TH effects in brain. Inasmuch as local cerebral glucose utilization is closely related to local synaptic activity, we also examined which thyroid hormone receptor is involved in the expression of synaptotagmin-related gene 1 (Srg1), a TH-positively regulated gene involved in the formation and function of synapses [Thompson, C. C. (1996) J. Neurosci. 16, 7832-7840]. Northern analysis showed that Srg1 expression was markedly reduced in the cerebellum of TRalpha(PV/+) mice but not TRbeta(PV/PV) mice. These results show that the same receptor, TRalpha1, is involved in the regulation by TH of both glucose utilization and Srg1 expression.

  13. Seminal role of deletion of amino acid residues in H1-S2 and S-loop regions in eukaryotic β-tubulin investigated from docking and dynamics perspective.

    Science.gov (United States)

    Selvaa Kumar, C; Gadewal, Nikhil; Mohammed, Sudheer Mm

    2015-08-07

    Tubulin is the fundamental unit of microtubules. It is reported to effect different functions like cell division, chromosomal segregation, motility and intracellular transportation. α- and β-tubulin associate laterally and longitudinally to form protofilaments. Both the subunits are structurally identical to each other except for the deletions reported in H1-S2 and S loop regions in eukaryotic β-tubulin. These deletions mimic the ancestral tubulin protein named Latest Common FtsZ-Tubulin Ancestor (LCFTA) with a shorter S-loop region resulting in weak dimerization. However, in eukaryotic beta tubulin, the significance of this shorter region remains elusive till date. The main objective of this study was to model variants of beta tubulin (βmut1, βmut2 and βmut3) with inserts that lengthened the loop, and to compare them with the native α- and β-subunits to understand their biological significance. Further, one more mutant was modeled with the intention of understanding the counter effect of additional deletion of amino acid residues from both H1-S2 and S-loop regions; this mutant was designated as βmut4. Our study confirms that the insertion of amino acid residues considerably increases the protein-protein interactions in βmut1-βmut1, βmut2-βmut2 and βmut3-βmut3 compared to their native β-subunit. Similarly, the binding affinity of GTP also increases in βmut2 and βmut3 as compared to the wild type. However, these deletions result in decreased protein-protein and ligand interactions in wild beta tubulin and βmut4, as compared to βmut1, βmut2,and βmut3. Therefore, we conclude here that residual inserts in the H1-S2 and S loop sub segments bring about conformational changes in regions critically involved in lateral interactions and in the nucleotide binding site, thus altering the binding affinities between the dimers and the ligands. Regarding the biological importance of such deletions in wild beta tubulin, these deletions result in flexible M

  14. The effect of focal brain injury on beta-amyloid plaque deposition, inflammation and synapses in the APP/PS1 mouse model of Alzheimer's disease.

    Science.gov (United States)

    Collins, Jessica M; King, Anna E; Woodhouse, Adele; Kirkcaldie, Matthew T K; Vickers, James C

    2015-05-01

    Traumatic brain injury is a risk factor for Alzheimer's disease (AD), however the effect of such neural damage on the onset and progression of beta-amyloid (Aβ) plaque pathology is not well understood. This study utilized an in vivo model of focal brain injury to examine how localized damage may acutely affect the onset and progression of Aβ plaque deposition as well as inflammatory and synaptic changes, in the APP/PS1 (APPSWE, PSEN1dE9) transgenic model of AD relative to wild-type (Wt) mice. Acute focal brain injury in 3- and 9-month-old APP/PS1 and Wt mice was induced by insertion of a needle into the somatosensory neocortex, as compared to sham surgery, and examined at 24h and 7d post-injury (PI). Focal brain injury did not induce thioflavine-S stained or (pan-Aβ antibody) MOAB-2-labeled plaques at either 24h or 7d PI in 3-month-old APP/PS1 mice or Wt mice. Nine-month-old APP/PS1 mice demonstrate cortical Aβ plaques but focal injury had no statistically significant (p>0.05) effect on thioflavine-S or MOAB-2 plaque load surrounding the injury site at 24h PI or 7d PI. There was a significant (p0.05). For both Wt and APP/PS1 mice alike, synaptophysin puncta near the injury site were significantly reduced 24h PI (compared to sites distant to the injury and the corresponding area in sham mice; p0.05). There was no significant effect of genotype on this response (p>0.05). These results indicate that focal brain injury and the associated microglial response do not acutely alter Aβ plaque deposition in the APP/PS1 mouse model. Furthermore the current study demonstrated that the brains of both Wt and APP/PS1 mice are capable of recovering lost synaptophysin immunoreactivity post-injury, the latter in the presence of Aβ plaque pathology that causes synaptic degeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. 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.

  16. Resolving controversy of unusually high refractive index of a tubulin

    Science.gov (United States)

    Krivosudský, O.; Dráber, P.; Cifra, M.

    2017-02-01

    The refractive index of a tubulin is an important parameter underlying fundamental electromagnetic and biophysical properties of microtubules - protein fibers essential for several cell functions including cell division. Yet, the only experimental data available in the current literature show values of the tubulin refractive index (n=2.36\\text{--}2.90) which are much higher than what the established theories predict based on the weighted contribution of the polarizability of individual amino acids constituting the protein. To resolve this controversy, we report here modeling and rigorous experimental analysis of the refractive index of a purified tubulin dimer. Our experimental data revealed that the refractive index of the tubulin is n=1.64 at wavelength 589 nm and 25 °C, that is much closer to the values predicted by the established theories than what the earlier experimental data provide.

  17. Beta-Amyloid Downregulates MDR1-P-Glycoprotein (Abcb1 Expression at the Blood-Brain Barrier in Mice

    Directory of Open Access Journals (Sweden)

    Anja Brenn

    2011-01-01

    Full Text Available Neurovascular dysfunction is an important component of Alzheimer's disease, leading to reduced clearance across the blood-brain barrier and accumulation of neurotoxic β-amyloid (Aβ peptides in the brain. It has been shown that the ABC transport protein P-glycoprotein (P-gp, ABCB1 is involved in the export of Aβ from the brain into the blood. To determine whether Aβ influences the expression of key Aβ transporters, we studied the effects of 1-day subcutaneous Aβ1-40 and Aβ1-42 administration via Alzet mini-osmotic pumps on P-gp, BCRP, LRP1, and RAGE expression in the brain of 90-day-old male FVB mice. Our results demonstrate significantly reduced P-gp, LRP1, and RAGE mRNA expression in mice treated with Aβ1-42 compared to controls, while BCRP expression was not affected. The expression of the four proteins was unchanged in mice treated with Aβ1-40 or reverse-sequence peptides. These findings indicate that, in addition to the age-related decrease of P-gp expression, Aβ1-42 itself downregulates the expression of P-gp and other Aβ-transporters, which could exacerbate the intracerebral accumulation of Aβ and thereby accelerate neurodegeneration in Alzheimer's disease and cerebral β-amyloid angiopathy.

  18. 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.

  19. Dietary antioxidant curcumin inhibits microtubule assembly through tubulin binding.

    Science.gov (United States)

    Gupta, Kamlesh K; Bharne, Shubhada S; Rathinasamy, Krishnan; Naik, Nishigandha R; Panda, Dulal

    2006-12-01

    Curcumin, a component of turmeric, has potent antitumor activity against several tumor types. However, its molecular target and mechanism of antiproliferative activity are not clear. Here, we identified curcumin as a novel antimicrotubule agent. We have examined the effects of curcumin on cellular microtubules and on reconstituted microtubules in vitro. Curcumin inhibited HeLa and MCF-7 cell proliferation in a concentration-dependent manner with IC(50) of 13.8 +/- 0.7 microm and 12 +/- 0.6 microm, respectively. At higher inhibitory concentrations (> 10 microm), curcumin induced significant depolymerization of interphase microtubules and mitotic spindle microtubules of HeLa and MCF-7 cells. However, at low inhibitory concentrations there were minimal effects on cellular microtubules. It disrupted microtubule assembly in vitro, reduced GTPase activity, and induced tubulin aggregation. Curcumin bound to tubulin at a single site with a dissociation constant of 2.4 +/- 0.4 microm and the binding of curcumin to tubulin induced conformational changes in tubulin. Colchicine and podophyllotoxin partly inhibited the binding of curcumin to tubulin, while vinblastine had no effect on the curcumin-tubulin interactions. The data together suggested that curcumin may inhibit cancer cells proliferation by perturbing microtubule assembly dynamics and may be used to develop efficacious curcumin analogues for cancer chemotherapy.

  20. The role of γ-tubulin in centrosomal microtubule organization.

    Directory of Open Access Journals (Sweden)

    Eileen O'Toole

    Full Text Available As part of a multi-subunit ring complex, γ-tubulin has been shown to promote microtubule nucleation both in vitro and in vivo, and the structural properties of the complex suggest that it also seals the minus ends of the polymers with a conical cap. Cells depleted of γ-tubulin, however, still display many microtubules that participate in mitotic spindle assembly, suggesting that γ-tubulin is not absolutely required for microtubule nucleation in vivo, and raising questions about the function of the minus end cap. Here, we assessed the role of γ-tubulin in centrosomal microtubule organisation using three-dimensional reconstructions of γ-tubulin-depleted C. elegans embryos. We found that microtubule minus-end capping and the PCM component SPD-5 are both essential for the proper placement of microtubules in the centrosome. Our results further suggest that γ-tubulin and SPD-5 limit microtubule polymerization within the centrosome core, and we propose a model for how abnormal microtubule organization at the centrosome could indirectly affect centriole structure and daughter centriole replication.

  1. 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.

  2. 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

  3. Neuropep-1 ameliorates learning and memory deficits in an Alzheimer's disease mouse model, increases brain-derived neurotrophic factor expression in the brain, and causes reduction of amyloid beta plaques.

    Science.gov (United States)

    Shin, Min-Kyoo; Kim, Hong-Gi; Baek, Seung-Hyun; Jung, Woo-Ram; Park, Dong-Ik; Park, Jong-Sung; Jo, Dong-Gyu; Kim, Kil-Lyong

    2014-05-01

    Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloid beta (Aβ) deposits, hyperphosphorylated tau deposition, and cognitive dysfunction. Abnormalities in the expression of brain-derived neurotrophic factor (BDNF), which plays an important role in learning and memory formation, have been reported in the brains of AD patients. A BDNF modulating peptide (Neuropep-1) was previously identified by positional-scanning synthetic peptide combinatorial library. Here we examine the neuroprotective effects of Neuropep-1 on several in vitro neurotoxic insults, and triple-transgenic AD mouse model (3xTg-AD). Neuropep-1 protects cultured neurons against oligomeric Aβ1-42, 1-methyl-4-phenylpyridinium, and glutamate-induced neuronal cell death. Neuropep-1 injection also significantly rescues the spatial learning and memory deficits of 3xTg-AD mice compared with vehicle-treated control group. Neuropep-1 treatment markedly increases hippocampal and cortical BDNF levels. Furthermore, we found that Neuropep-1-injected 3xTg-AD mice exhibit dramatically reduced Aβ plaque deposition and Aβ levels without affecting tau pathology. Neuropep-1 treatment does not alter the expression or activity of full-length amyloid precursor protein, α-, β-, or γ-secretase, but levels of insulin degrading enzyme, an Aβ degrading enzyme, were increased. These findings suggest Neuropep-1 may be a therapeutic candidate for the treatment of AD. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Effect of anti-inflammatory agents on transforming growth factor beta over-expressing mouse brains: a model revised

    Directory of Open Access Journals (Sweden)

    Landreth Gary E

    2004-07-01

    Full Text Available Abstract Background The over-expression of transforming growth factor β-1(TGF-β1 has been reported to cause hydrocephalus, glia activation, and vascular amyloidβ (Aβ deposition in mouse brains. Since these phenomena partially mimic the cerebral amyloid angiopathy (CAA concomitant to Alzheimer's disease, the findings in TGF-β1 over-expressing mice prompted the hypothesis that CAA could be caused or enhanced by the abnormal production of TGF-β1. This idea was in accordance with the view that chronic inflammation contributes to Alzheimer's disease, and drew attention to the therapeutic potential of anti-inflammatory drugs for the treatment of Aβ-elicited CAA. We thus studied the effect of anti-inflammatory drug administration in TGF-β1-induced pathology. Methods Two-month-old TGF-β1 mice and littermate controls were orally administered pioglitazone, a peroxisome proliferator-activated receptor-γ agonist, or ibuprofen, a non steroidal anti-inflammatory agent, for two months. Glia activation was assessed by immunohistochemistry and western blot analysis; Aβ precursor protein (APP by western blot analysis; Aβ deposition by immunohistochemistry, thioflavin-S staining and ELISA; and hydrocephalus by measurements of ventricle size on autoradiographies of brain sections. Results are expressed as means ± SD. Data comparisons were carried with the Student's T test when two groups were compared, or ANOVA analysis when more than three groups were analyzed. Results Animals displayed glia activation, hydrocephalus and a robust thioflavin-S-positive vascular deposition. Unexpectedly, these deposits contained no Aβ or serum amyloid P component, a common constituent of amyloid deposits. The thioflavin-S-positive material thus remains to be identified. Pioglitazone decreased glia activation and basal levels of Aβ42- with no change in APP contents – while it increased hydrocephalus, and had no effect on the thioflavin-S deposits. Ibuprofen mimicked

  5. {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.

  6. Does early beta-blockade in isolated severe traumatic brain injury reduce the risk of post traumatic depression?

    Science.gov (United States)

    Ahl, Rebecka; Sjolin, Gabriel; Mohseni, Shahin

    2017-01-01

    Depressive symptoms occur in approximately half of trauma patients, negatively impacting on functional outcome and quality of life following severe head injury. Pontine noradrenaline has been shown to increase upon trauma and associated β-adrenergic receptor activation appears to consolidate memory formation of traumatic events. Blocking adrenergic activity reduces physiological stress responses during recall of traumatic memories and impairs memory, implying a potential therapeutic role of β-blockers. This study examines the effect of pre-admission β-blockade on post-traumatic depression. All adult trauma patients (≥18 years) with severe, isolated traumatic brain injury (intracranial Abbreviated Injury Scale score (AIS) ≥3 and extracranial AIS depression was defined as the prescription of antidepressants within one year of trauma. Patients with and without pre-admission β-blockers were matched 1:1 by age, gender, Glasgow Coma Scale, Injury Severity Score and head AIS. Analysis was carried out using McNemar's and Student's t-test for categorical and continuous data, respectively. A total of 545 patients met the study criteria. Of these, 15% (n=80) were prescribed β-blockers. After propensity matching, 80 matched pairs were analyzed. 33% (n=26) of non β-blocked patients developed post-traumatic depression, compared to only 18% (n=14) in the β-blocked group (p=0.04). There were no significant differences in ICU (mean days: 5.8 (SD 10.5) vs. 5.6 (SD 7.2), p=0.85) or hospital length of stay (mean days: 21 (SD 21) vs. 21 (SD 20), p=0.94) between cohorts. β-blockade appears to act prophylactically and significantly reduces the risk of post-traumatic depression in patients suffering from isolated severe traumatic brain injuries. Further prospective randomized studies are warranted to validate this finding. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. 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.; 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

  8. Regulation of microtubule motors by tubulin isotypes and post-translational modifications

    OpenAIRE

    Vale, Ronald; M. SIRAJUDDIN; Rice, LM; Vale, RD

    2014-01-01

    The 'tubulin-code' hypothesis proposes that different tubulin genes or post-translational modifications (PTMs), which mainly confer variation in the carboxy-terminal tail (CTT), result in unique interactions with microtubule-associated proteins for specifi

  9. Neurofibrillary tangles and the deposition of a beta amyloid peptide with a novel N-terminal epitope in the brains of wild Tsushima leopard cats.

    Science.gov (United States)

    Chambers, James K; Uchida, Kazuyuki; Harada, Tomoyuki; Tsuboi, Masaya; Sato, Masumi; Kubo, Masahito; Kawaguchi, Hiroaki; Miyoshi, Noriaki; Tsujimoto, Hajime; Nakayama, Hiroyuki

    2012-01-01

    Beta amyloid (Aβ) deposits are seen in aged individuals in many of the mammalian species that possess the same Aβ amino acid sequence as humans. Conversely, neurofibrillary tangles (NFT), the other hallmark lesion of Alzheimer's disease (AD), are extremely rare in these animals. We detected Aβ deposits in the brains of Tsushima leopard cats (Prionailurus bengalensis euptilurus) that live exclusively on Tsushima Island, Japan. Aβ42 was deposited in a granular pattern in the neuropil of the pyramidal cell layer, but did not form argyrophilic senile plaques. These Aβ deposits were not immunolabeled with antibodies to the N-terminal of human Aβ. Sequence analysis of the amyloid precursor protein revealed an amino acid substitution at the 7th residue of the Aβ peptide. In a comparison with other mammalian animals that do develop argyrophilic senile plaques, we concluded that the alternative Aβ amino acid sequence displayed by leopard cats is likely to be related to its distinctive deposition pattern. Interestingly, most of the animals with these Aβ deposits also developed NFTs. The distributions of hyperphosphorylated tau-positive cells and the two major isoforms of aggregated tau proteins were quite similar to those seen in Alzheimer's disease. In addition, the unphosphorylated form of GSK-3β colocalized with hyperphosphorylated tau within the affected neurons. In conclusion, this animal species develops AD-type NFTs without argyrophilic senile plaques.

  10. Neurofibrillary tangles and the deposition of a beta amyloid peptide with a novel N-terminal epitope in the brains of wild Tsushima leopard cats.

    Directory of Open Access Journals (Sweden)

    James K Chambers

    Full Text Available Beta amyloid (Aβ deposits are seen in aged individuals in many of the mammalian species that possess the same Aβ amino acid sequence as humans. Conversely, neurofibrillary tangles (NFT, the other hallmark lesion of Alzheimer's disease (AD, are extremely rare in these animals. We detected Aβ deposits in the brains of Tsushima leopard cats (Prionailurus bengalensis euptilurus that live exclusively on Tsushima Island, Japan. Aβ42 was deposited in a granular pattern in the neuropil of the pyramidal cell layer, but did not form argyrophilic senile plaques. These Aβ deposits were not immunolabeled with antibodies to the N-terminal of human Aβ. Sequence analysis of the amyloid precursor protein revealed an amino acid substitution at the 7th residue of the Aβ peptide. In a comparison with other mammalian animals that do develop argyrophilic senile plaques, we concluded that the alternative Aβ amino acid sequence displayed by leopard cats is likely to be related to its distinctive deposition pattern. Interestingly, most of the animals with these Aβ deposits also developed NFTs. The distributions of hyperphosphorylated tau-positive cells and the two major isoforms of aggregated tau proteins were quite similar to those seen in Alzheimer's disease. In addition, the unphosphorylated form of GSK-3β colocalized with hyperphosphorylated tau within the affected neurons. In conclusion, this animal species develops AD-type NFTs without argyrophilic senile plaques.

  11. Long-Term Supplementation with Beta Serum Concentrate (BSC), a Complex of Milk Lipids, during Post-Natal Brain Development Improves Memory in Rats.

    Science.gov (United States)

    Guan, Jian; MacGibbon, Alastair; Fong, Bertram; Zhang, Rong; Liu, Karen; Rowan, Angela; McJarrow, Paul

    2015-06-05

    We have previously reported that the supplementation of ganglioside-enriched complex-milk-lipids improves cognitive function and that a phospholipid-enriched complex-milk-lipid prevents age-related cognitive decline in rats. This current study evaluated the effects of post-natal supplementation of ganglioside- and phospholipid-enriched complex-milk-lipids beta serum concentrate (BSC) on cognitive function in young rats. The diet of male rats was supplemented with either gels formulated BSC (n = 16) or blank gels (n = 16) from post-natal day 10 to day 70. Memory and anxiety-like behaviors were evaluated using the Morris water maze, dark-light boxes, and elevated plus maze tests. Neuroplasticity and white matter were measured using immunohistochemical staining. The overall performance in seven-day acquisition trials was similar between the groups. Compared with the control group, BSC supplementation reduced the latency to the platform during day one of the acquisition tests. Supplementation improved memory by showing reduced latency and improved path efficiency to the platform quadrant, and smaller initial heading error from the platform zone. Supplemented rats showed an increase in striatal dopamine terminals and hippocampal glutamate receptors. Thus BSC supplementation during post-natal brain development improved learning and memory, independent from anxiety. The moderately enhanced neuroplasticity in dopamine and glutamate may be biological changes underlying the improved cognitive function.

  12. 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

    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...... AND METHODS: All the 28 Finnish patients participating in the Nordic multicentre trial on the clinical efficacy of weekly IFN-beta-1a (Rebif) 22 microg in SPMS were studied neurologically and by volumetric MRI during a 3-year follow-up. The levels of MMP-9 in serum were measured over the 3-year study. RESULTS......: 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...

  13. Therapeutic effect of beta-blocker in patients with traumatic brain injury: A systematic review and meta-analysis.

    Science.gov (United States)

    Chen, Zaifeng; Tang, Linjun; Xu, Xinlong; Wei, Xiaojie; Wen, Lutong; Xie, Qingsong

    2017-10-01

    β-Blocker exposure has been shown to reduce mortality in traumatic brain injury (TBI); however, the efficacy of β-blockers remains inconclusive. Therefore, a meta-analysis was conducted in this paper to evaluate the safety and efficacy of β-blocker therapy on patients with TBI. The electronic databases were systemically retrieved from construction to February 2017. The odds ratio (OR), mean difference (MD) and 95% confidence intervals (CI) were determined. A total of 13 observational cohort studies involving 15,734 cases were enrolled. The results indicated that β-blocker therapy had remarkably reduced the in-hospital mortality (OR 0.33; 95% CI 0.27-0.40; pblocker therapy was also associated with increased infection rate (OR 2.01; 95% CI 1.50-2.69; pblocker therapy also led to longer period of ventilator support (MD=2.70; 95% CI=1.81, 3.59; pblockers are effective in lowering mortality in patients with TBI. However, β-blocker therapy has markedly increased the infection rate and requires a longer period of ventilator support, intensive care management as well as length of stay. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The Tubulin Code: A Navigation System for Chromosomes during Mitosis.

    Science.gov (United States)

    Barisic, Marin; Maiato, Helder

    2016-10-01

    Before chromosomes segregate during mitosis in metazoans, they align at the cell equator by a process known as chromosome congression. This is in part mediated by the coordinated activities of kinetochore motors with opposite directional preferences that transport peripheral chromosomes along distinct spindle microtubule populations. Because spindle microtubules are all made from the same α/β-tubulin heterodimers, a critical longstanding question has been how chromosomes are guided to specific locations during mitosis. This implies the existence of spatial cues/signals on specific spindle microtubules that are read by kinetochore motors on chromosomes and ultimately indicate the way towards the equator. Here, we discuss the emerging concept that tubulin post-translational modifications (PTMs), as part of the so-called tubulin code, work as a navigation system for kinetochore-based chromosome motility during early mitosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Synthesis of different heterocycles-linked chalcone conjugates as cytotoxic agents and tubulin polymerization inhibitors.

    Science.gov (United States)

    Shankaraiah, Nagula; Nekkanti, Shalini; Brahma, Uma Rani; Praveen Kumar, Niggula; Deshpande, Namrata; Prasanna, Daasi; Senwar, Kishna Ram; Jaya Lakshmi, Uppu

    2017-09-01

    A series of new heterocycles-linked chalcone conjugates has been designed and synthesized by varying different alkane spacers. These conjugates were tested for their in vitro cytotoxic potential against a panel of selected human cancer cell lines namely, lung (A549 and NCI-H460), prostate (DU-145 and PC-3), colon (HCT-15 and HCT-116), and brain (U-87 glioblastoma) by MTT assay. Notably, among all the tested compounds, 4a exhibited potent cytotoxicity on NCI-H460 (lung cancer) cells with IC50 of 1.48±0.19µM. The compound 4a showed significant inhibition of tubulin polymerization and disruption of the formation of microtubules (IC50 of 9.66±0.06μM). Moreover, phase contrast microscopy and DAPI staining studies indicated that compound 4a can induce apoptosis in NCI-H460 cells. Further, the flow-cytometry analysis revealed that compound 4a arrests NCI-H460 cells in the G2/M phase of the cell cycle. In addition, molecular docking studies of the most active compounds 4a and 4b into the colchicine site of the tubulin, revealed the possible mode of interaction by these new conjugates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Intraventricular brain injection of adeno-associated virus type 1 (AAV1) in neonatal mice results in complementary patterns of neuronal transduction to AAV2 and total long-term correction of storage lesions in the brains of beta-glucuronidase-deficient mice.

    Science.gov (United States)

    Passini, Marco A; Watson, Deborah J; Vite, Charles H; Landsburg, Daniel J; Feigenbaum, Alyson L; Wolfe, John H

    2003-06-01

    Inherited metabolic disorders that affect the central nervous system typically result in pathology throughout the brain; thus, gene therapy strategies need to achieve widespread delivery. We previously found that although intraventricular injection of the neonatal mouse brain with adeno-associated virus serotype 2 (AAV2) results in dispersed gene delivery, many brain structures were poorly transduced. This limitation may be overcome by using different AAV serotypes because the capsid proteins use different cellular receptors for entry, which may allow enhanced global targeting of the brain. We tested this with AAV1 and AAV5 vectors. AAV5 showed very limited brain transduction after neonatal injection, even though it has different transduction patterns than AAV2 in adult brain injections. In contrast, AAV1 vectors, which have not been tested in the brain, showed robust widespread transduction. Complementary patterns of transduction between AAV1 and AAV2 were established and maintained in the adult brain after neonatal injection. In the majority of structures, AAV1 transduced many more cells than AAV2. Both vectors transduced mostly neurons, indicating that differential expression of receptors on the surfaces of neurons occurs in the developing brain. The number of cells positive for a vector-encoded secreted enzyme (beta-glucuronidase) was notably greater and more widespread in AAV1-injected brains. A comprehensive analysis of AAV1-treated brains from beta-glucuronidase-deficient mice (mucopolysaccharidosis type VII) showed complete reversal of pathology in all areas of the brain for at least 1 year, demonstrating that the combination of this serotype and experimental strategy is therapeutically effective for treating global neurometabolic disorders.

  17. [Protective effect of adeno-associated viral vector-mediated expression of human brain-derived neurotrophic factor in rat neurons against beta-amyloid-induced Alzheimer's disease in vitro].

    Science.gov (United States)

    Liu, Zhao-hui; Ma, Dong-liang; Jin, Hui; Ma, Yan-bing; Hu, Hai-tao

    2006-10-01

    To achieve expression of human brain-derived neurotrophic factor (hBDNF) mediated by recombinant adeno-associated virus (rAAV) and explore the mechanism of its neuroprotective effects in rat neurons against beta-amyloid-induced Alzheimer's disease. Using molecular cloning technique, rAAV vector containing hBDNF gene (AAV-hBDNF) was constructed to transfect SD rat hippocampal neurons exposed to beta-amyloid treatment. The changes in cell apoptosis were observed by MTT assay and flow cytometry, and the expression of hBDNF and Bcl-2 protein were determined by immunocytochemical staining. Laser scanning confocal microscopy (LSCM) was used to observe the changes of [Ca(2+)](i). The cultured rat hippocampal neurons were effectively transfected with AAV-hBDNF and expression of BDNF protein was obviously increased. hBNDF expression showed significant protective effects against beta-amyloid-induced neuronal damage, and the expression of Bcl-2 protein was increased significantly and the balance of [Ca(2+)](i) was maintained in BDNF-treated cells with beta-amyloid exposure. hBDNF expression can effectively protect cultured rat hippocampal cells from beta-amyloid-induced apoptosis through inhibiting the intracellular calcium overload and increasing the expression of Bcl-2 protein.

  18. Synapse Formation and Cognitive Brain Development: effect of docosahexaenoic (DHA) and other dietary constituents

    Science.gov (United States)

    Wurtman, R. J.

    2008-01-01

    The brain is unusual among organs in that the rates of many of its characteristic enzymatic reactions are controlled by the local concentrations of their substrates, which also happen to be nutrients that cross the blood-brain barrier. Thus, for example, brain levels of tryptophan, tyrosine, or choline can control the rates at which neurons synthesize serotonin, dopamine, or acetylcholine, respectively. The rates at which brain cells produce membrane phospholipids like phosphatidylcholine (PC) are also under such control, both in adult animals and, especially, during early development. If pregnant rats are fed the three dietary constituents needed for PC synthesis - docosahexaenoic acid (DHA), uridine, and choline - starting 10 days before parturition and continuing for 20 days during nursing, brain levels of PC and of the other membrane phosphatides (per cell or per mg protein) are increased by 50% or more. In adult animals this treatment is also known to increase synaptic proteins (e.g. synapsin-l; syntaxin-3; GluR-l; PSD-95) but not ubiquitous proteins like beta-tubulin, and to increase (by 30% or more) the number of dendritic spines on hippocampal neurons. DHA currently is widely used, in human infants, to diminish the negative effects of prematurity on cognitive development. Moreover, DHA, uridine (as UMP), and choline are all found in mother's milk, and included in most infant formulas. It is proposed that these substances are part of a regulatory mechanism through which plasma composition influences brain development. PMID:18803968

  19. Anticancer Activity of Chamaejasmine: Effect on Tubulin Protein

    Directory of Open Access Journals (Sweden)

    Yingkun Nie

    2011-07-01

    Full Text Available In this work, the anticancer activity of chamaejasmine was studied by evaluating its in vitro cytotoxicity against several human cancer cell lines (MCF-7, A549, SGC-7901, HCT-8, HO-4980, Hela, HepG2, PC-3, LNCap, Vero and MDCK using the MTT assay. Results indicated chamaejasmine showed more notable anticancer activity than taxol against PC-3 cells, with IC50 values of 2.28 and 3.98 µM, respectively. Furthermore, Western blot analysis showed that chamaejasmine was able to increase the expression of β-tubulin, but not α-tubulin. In silico simulations indicated that chamaejasmine specifically interacts with the active site which is located at the top of β-tubulin, thanks to the presence of strong hydrophobic effects between the core templates and the hydrophobic surface of the TB active site. The binding energy (Einter was calculated to be −164.77 kcal·mol−1. Results presented here suggest that chamaejasmine possesses anti-cancer properties relating to β-tubulin depolymerization inhibition, and therefore is a potential source of anticancer leads for the pharmaceutical industry.

  20. Accumulation and post-translational modifications of plant tubulins.

    Science.gov (United States)

    Parrotta, L; Cresti, M; Cai, G

    2014-05-01

    The microtubular cytoskeleton of plant cells provides support for several functions (including the anchoring of proteins, assembly of the mitotic spindle, cytoplasmic streaming and construction of cell walls). Both α- and β-tubulins are encoded through multigene families that are differentially expressed in different organs and tissues. To increase the variability of expression, both protein subunits are subjected to post-translational modifications, which could contribute to the assembly of specific microtubule structures. This review aims to highlight the role of specific post-translational modifications of tubulin in plant cells. We initially describe the expression and accumulation of α- and β-tubulin isoforms in different plants and at different stages of plant development. Second, we discuss the different types of post-translational modifications that, by adding or removing specific functional groups, increase the isoform heterogeneity and functional variability of tubulin. Modifications are proposed to form a 'code' that can be read by proteins interacting with microtubules. Therefore, the subpopulations of microtubules may bind to different associated proteins (motor and non-motor), thus creating the physical support for various microtubule functions. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. Cytoplasmic carboxypeptidase 5 regulates tubulin glutamylation and zebrafish cilia formation and function

    Science.gov (United States)

    Pathak, Narendra; Austin-Tse, Christina A.; Liu, Yan; Vasilyev, Aleksandr; Drummond, Iain A.

    2014-01-01

    Glutamylation is a functionally important tubulin posttranslational modification enriched on stable microtubules of neuronal axons, mitotic spindles, centrioles, and cilia. In vertebrates, balanced activities of tubulin glutamyl ligase and cytoplasmic carboxypeptidase deglutamylase enzymes maintain organelle- and cell type–specific tubulin glutamylation patterns. Tubulin glutamylation in cilia is regulated via restricted subcellular localization or expression of tubulin glutamyl ligases (ttlls) and nonenzymatic proteins, including the zebrafish TPR repeat protein Fleer/Ift70. Here we analyze the expression patterns of ccp deglutamylase genes during zebrafish development and the effects of ccp gene knockdown on cilia formation, morphology, and tubulin glutamylation. The deglutamylases ccp2, ccp5, and ccp6 are expressed in ciliated cells, whereas ccp1 expression is restricted to the nervous system. Only ccp5 knockdown increases cilia tubulin glutamylation, induces ciliopathy phenotypes, including axis curvature, hydrocephalus, and pronephric cysts, and disrupts multicilia motility, suggesting that Ccp5 is the principal tubulin deglutamylase that maintains functional levels of cilia tubulin glutamylation. The ability of ccp5 knockdown to restore cilia tubulin glutamylation in fleer/ift70 mutants and rescue pronephric multicilia formation in both fleer- and ift88-deficient zebrafish indicates that tubulin glutamylation is a key driver of ciliogenesis. PMID:24743595

  2. Anesthetic Alterations of Collective Terahertz Oscillations in Tubulin Correlate with Clinical Potency: Implications for Anesthetic Action and Post-Operative Cognitive Dysfunction.

    Science.gov (United States)

    Craddock, Travis J A; Kurian, Philip; Preto, Jordane; Sahu, Kamlesh; Hameroff, Stuart R; Klobukowski, Mariusz; Tuszynski, Jack A

    2017-08-29

    Anesthesia blocks consciousness and memory while sparing non-conscious brain activities. While the exact mechanisms of anesthetic action are unknown, the Meyer-Overton correlation provides a link between anesthetic potency and solubility in a lipid-like, non-polar medium. Anesthetic action is also related to an anesthetic's hydrophobicity, permanent dipole, and polarizability, and is accepted to occur in lipid-like, non-polar regions within brain proteins. Generally the protein target for anesthetics is assumed to be neuronal membrane receptors and ion channels, however new evidence points to critical effects on intra-neuronal microtubules, a target of interest due to their potential role in post-operative cognitive dysfunction (POCD). Here we use binding site predictions on tubulin, the protein subunit of microtubules, with molecular docking simulations, quantum chemistry calculations, and theoretical modeling of collective dipole interactions in tubulin to investigate the effect of a group of gases including anesthetics, non-anesthetics, and anesthetic/convulsants on tubulin dynamics. We found that these gases alter collective terahertz dipole oscillations in a manner that is correlated with their anesthetic potency. Understanding anesthetic action may help reveal brain mechanisms underlying consciousness, and minimize POCD in the choice and development of anesthetics used during surgeries for patients suffering from neurodegenerative conditions with compromised cytoskeletal microtubules.

  3. Expression of Ki-67, Oct-4, γ-tubulin and α-tubulin in human tooth development.

    Science.gov (United States)

    Kero, Darko; Novakovic, Josip; Vukojevic, Katarina; Petricevic, Josko; Kalibovic Govorko, Danijela; Biocina-Lukenda, Dolores; Saraga-Babic, Mirna

    2014-11-01

    To analyze factors controlling cell proliferation and differentiation, and appearance of primary cilia during the cap and bell stages of incisor or/and canine human enamel organs. Qualitative and quantitative analysis of proliferating Ki-67 positive cells and expression of γ-tubulin, α-tubulin and Oct-4 was immunohistochemically analyzed in the cap an bell stages of 10 developing human incisor and canine germs, 8-21 weeks old. During the analyzed period, ratio of Ki-67 positive cells changed in outer enamel epithelium from 48.86% to 24.52%, in inner enamel epithelium increased from 56.11% to 60.06% and then dropped to 44.24%. While in dental papilla proliferation first increased from 46.26% to 55.45%, and then dropped to 22.08%, a constant decrease of proliferation characterized enamel reticulum (from 46.26% to 15.49%). Strong cytoplasmic Oct-4 expression characterized epithelial parts of enamel organ, particularly the differentiating ameloblasts. During further development, Oct-4 expression shifted to both nuclear and cytoplasmic expression in mesenchymal tooth components. Primary cilia characterized most of the cells in developing enamel organ. While non-ciliated (proliferating) cells mainly contained two centrioles (γ-tubulin), the primary cilia (α-tubulin) were arising from basal bodies (γ-tubulin) of non-proliferating cells. We suggest that increase in cell proliferation enables growth of enamel organ, while its selective decrease leads to disintegration of some tooth parts. Drop of proliferation coincided with initiation of ameloblast and odontoblast differentiation. Additionally, cell differentiation was accompanied by increased expression of Oct-4 and probably by signalling via primary cilia, both regulating processes of cell proliferation and differentiation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Domain analysis of the tubulin cofactor system: a model for tubulin folding and dimerization

    Directory of Open Access Journals (Sweden)

    Jaroszewski Lukasz

    2003-10-01

    Full Text Available Abstract Background The correct folding and dimerization of tubulins, before their addition to the microtubular structure, needs a group of conserved proteins called cofactors A to E. The biochemical analysis of cofactors gave an insight to their general functions, however not much is known about the domain structure and detailed, molecular function of these proteins. Results Combining modelling and fold prediction tools, we present 3D models of all cofactors, including several previously unannotated domains of cofactors B-E. Apart from the new HEAT and Armadillo domains in cofactor D and an unusual spectrin-like domain in cofactor C, we have identified a new subfamily of ubiquitin-like domains in cofactors B and E. Together, these observations provide a reliable, molecular level model of cofactor complex. Conclusion Distant homology searches allowed the identification of unknown regions of cofactors as self-reliant domains and allow us to present a detailed hypothesis of how a cofactor complex performs its function.

  5. 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

  6. Valeriana amurensis improves Amyloid-beta 1-42 induced cognitive deficit by enhancing cerebral cholinergic function and protecting the brain neurons from apoptosis in mice.

    Science.gov (United States)

    Wang, Qiuhong; Wang, Changfu; Shu, Zunpeng; Chan, Kelvin; Huang, Shuming; Li, Yan; Xiao, Yang; Wu, Lihua; Kuang, Haixue; Sun, Xiaobo

    2014-04-28

    Valeriana amurensis, a perennial medicinal herb, has been widely used as anxiolytic, antidepressant, antispasmodic, and sedative in traditional Chinese medicines (TCMs). Moreover, it has been used to treat dementia in Mongolia preparations. In our previous study, we reported that AD-effective fraction of Valeriana amurensis (AD-EFV) has protective effect on Aβ-induced toxicity in PC12 cells. Up to now, however, the therapeutic effect of Valeriana amurensis on Alzheimer disease (AD) has not been explored. This study was designed to determine whether the AD-EFV could improve the Amyloid-beta (Aβ)-induced cognitive deficit and to explore the mechanism of AD-EFV improves cognitive deficit in intact animals. The constituents of AD-EFV were isolated with silica gel, octadecyl silica gel (ODS) column chromatography (CC) and preparative HPLC. The structures of compounds were determined by detailed NMR and ESI-MS data analyses. AD mice model was established by injecting A(β1-42) (1 μL, 200 μmol) into the bilateral ventricle. Cognitive performance was evaluated by the Morris water maze (MWM) test. The level of cerebral acetylcholine (ACh), the activities of acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) were investigated using Enzyme-linked immunoassay (ELISA) kits. Brain sections were processed and neuronal apoptosis in hippocampus were evaluated by Hematoxylin and Eosin (HE), Nissl, and Tunel stainings. The analyses of p-ERK/ERK and Bcl-2/Bax protein expression by western blot assay were used to explore the anti-neuronal apoptosis mechanism of AD-EFV. Seventeen compounds (15 lignans and two iridoids) were isolated from AD-EFV. A significant improvement in cognitive function was observed in administrated AD-EFV AD model mice. AD-EFV increased the ACh level by enhancing the ChAT activity but has no effect on AChE activity in the cerebral cortex and hippocampus in mice. Moreover, the histological injury in hippocampus CA1 induced by A(β1-42) was

  7. Emerging roles for tubulin folding cofactors at the centrosome

    Science.gov (United States)

    Fanarraga, Mónica López; Carranza, Gerardo; Castaño, Raquel; Jiménez, Victoria; Villegas, Juan Carlos

    2010-01-01

    Despite its fundamental role in centrosome biology, procentriole formation, both in the canonical and in the de novo replication pathways, remains poorly understood, and the molecular components that are involved in human cells are not well established. We found that one of the tubulin cofactors, TBCD, is localized at centrosomes and the midbody, and is required for spindle organization, cell abscission, centriole formation and ciliogenesis. Our studies have established a molecular link between the centriole and the midbody, demonstrating that this cofactor is also necessary for microtubule retraction during cell abscission. TBCD is the first centriolar protein identified that plays a role in the assembly of both “centriolar rosettes” during early ciliogenesis, and at the procentriole budding site by S/G2, a discovery that directly implicates tubulin cofactors in the cell division, cell migration and cell signaling research fields. PMID:20798813

  8. Pironetin reacts covalently with cysteine-316 of α-tubulin to destabilize microtubule

    Science.gov (United States)

    Yang, Jianhong; Wang, Yuxi; Wang, Taijing; Jiang, Jian; Botting, Catherine H.; Liu, Huanting; Chen, Qiang; Yang, Jinliang; Naismith, James H.; Zhu, Xiaofeng; Chen, Lijuan

    2016-06-01

    Molecules that alter the normal dynamics of microtubule assembly and disassembly include many anticancer drugs in clinical use. So far all such therapeutics target β-tubulin, and structural biology has explained the basis of their action and permitted design of new drugs. However, by shifting the profile of β-tubulin isoforms, cancer cells become resistant to treatment. Compounds that bind to α-tubulin are less well characterized and unexploited. The natural product pironetin is known to bind to α-tubulin and is a potent inhibitor of microtubule polymerization. Previous reports had identified that pironetin reacts with lysine-352 residue however analogues designed on this model had much lower potency, which was difficult to explain, hindering further development. We report crystallographic and mass spectrometric data that reveal that pironetin forms a covalent bond to cysteine-316 in α-tubulin via a Michael addition reaction. These data provide a basis for the rational design of α-tubulin targeting chemotherapeutics.

  9. Tubulin dynamics during the cytoplasmic cohesiveness cycle in artificially activated sea urchin eggs.

    Science.gov (United States)

    Coffe, G; Foucault, G; Raymond, M N; Pudles, J

    1983-12-01

    Sedimentation studies and [3H]colchicine-binding assays have demonstrated a relationship between the cytoplasmic cohesiveness cycles and the changes in tubulin organization in Paracentrotus lividus eggs activated by 2.5 mM procaine. The same amount of tubulin (20-25% of the total egg tubulin) is involved in these cyclic process and appears to undergo polymerization and depolymerization cycles. Electron microscopy studies reveal that the microtubules formed during these cytoplasmic cohesiveness cycles are under a particulate form which is sedimentable at low speed. Activation experiments carried out in the presence of cytochalasin B (CB) show that the increase in the cytoplasmic cohesiveness is highly reduced while tubulin polymerization and depolymerization cycles and pronuclear centration are not affected. Although tubulin or actin polymerization can be independently triggered in procaine-activated eggs, the increase in cytoplasmic cohesiveness requires the polymerization of both proteins. However, the cytoplasmic cohesiveness cycles appear to be regulated by tubulin polymerization and depolymerization cycles.

  10. Neural development in the tardigrade Hypsibius dujardini based on anti-acetylated α-tubulin immunolabeling.

    Science.gov (United States)

    Gross, Vladimir; Mayer, Georg

    2015-01-01

    The tardigrades (water bears) are a cosmopolitan group of microscopic ecdysozoans found in a variety of aquatic and temporarily wet environments. They are members of the Panarthropoda (Tardigrada + Onychophora + Arthropoda), although their exact position within this group remains contested. Studies of embryonic development in tardigrades have been scarce and have yielded contradictory data. Therefore, we investigated the development of the nervous system in embryos of the tardigrade Hypsibius dujardini using immunohistochemical techniques in conjunction with confocal laser scanning microscopy in an effort to gain insight into the evolution of the nervous system in panarthropods. An antiserum against acetylated α-tubulin was used to visualize the axonal processes and general neuroanatomy in whole-mount embryos of the eutardigrade H. dujardini. Our data reveal that the tardigrade nervous system develops in an anterior-to-posterior gradient, beginning with the neural structures of the head. The brain develops as a dorsal, bilaterally symmetric structure and contains a single developing central neuropil. The stomodeal nervous system develops separately and includes at least four separate, ring-like commissures. A circumbuccal nerve ring arises late in development and innervates the circumoral sensory field. The segmental trunk ganglia likewise arise from anterior to posterior and establish links with each other via individual pioneering axons. Each hemiganglion is associated with a number of peripheral nerves, including a pair of leg nerves and a branched, dorsolateral nerve. The revealed pattern of brain development supports a single-segmented brain in tardigrades and challenges previous assignments of homology between tardigrade brain lobes and arthropod brain segments. Likewise, the tardigrade circumbuccal nerve ring cannot be homologized with the arthropod 'circumoral' nerve ring, suggesting that this structure is unique to tardigrades. Finally, we propose

  11. In vivo turnover of tau and APP metabolites in the brains of wild-type and Tg2576 mice: greater stability of sAPP in the beta-amyloid depositing mice.

    Directory of Open Access Journals (Sweden)

    Jose Morales-Corraliza

    2009-09-01

    Full Text Available The metabolism of the amyloid precursor protein (APP and tau are central to the pathobiology of Alzheimer's disease (AD. We have examined the in vivo turnover of APP, secreted APP (sAPP, Abeta and tau in the wild-type and Tg2576 mouse brain using cycloheximide to block protein synthesis. In spite of overexpression of APP in the Tg2576 mouse, APP is rapidly degraded, similar to the rapid turnover of the endogenous protein in the wild-type mouse. sAPP is cleared from the brain more slowly, particularly in the Tg2576 model where the half-life of both the endogenous murine and transgene-derived human sAPP is nearly doubled compared to wild-type mice. The important Abeta degrading enzymes neprilysin and IDE were found to be highly stable in the brain, and soluble Abeta40 and Abeta42 levels in both wild-type and Tg2576 mice rapidly declined following the depletion of APP. The cytoskeletal-associated protein tau was found to be highly stable in both wild-type and Tg2576 mice. Our findings unexpectedly show that of these various AD-relevant protein metabolites, sAPP turnover in the brain is the most different when comparing a wild-type mouse and a beta-amyloid depositing, APP overexpressing transgenic model. Given the neurotrophic roles attributed to sAPP, the enhanced stability of sAPP in the beta-amyloid depositing Tg2576 mice may represent a neuroprotective response.

  12. Interaction of tubulin and protein kinase CK2 in Trypanosoma equiperdum.

    Science.gov (United States)

    Boscán, Beatriz E; Uzcanga, Graciela L; Calabokis, Maritza; Camargo, Rocío; Aponte, Frank; Bubis, José

    2017-10-26

    A polypeptide band with an apparent molecular weight of 55,000 was phosphorylated in vitro in whole-cell lysates of Trypanosoma equiperdum. This band corresponds to tubulin as demonstrated by immunoprecipitation of the phosphorylated polypeptide from T. equiperdum extracts when anti-α and anti-β tubulin monoclonal antibodies were employed. A parasite protein kinase CK2 was in charge of modifying tubulin given that common mammalian CK2 inhibitors such as emodin and GTP, hindered the phosphorylation of tubulin and exogenously added casein. Interestingly, a divalent cation-dependent translocation of the T. equiperdum tubulin and the CK2 responsible for its phosphorylation was noticed, suggesting a direct interaction between these two proteins. Additionally, this fraction of tubulin and its kinase coeluted using separations based on parameters as different as charge (DEAE-Sepharose anion-exchange chromatography) and size (Sephacryl S-300 gel filtration chromatography). Analyses by non-denaturing polyacrylamide gel electrophoresis and immunoblot of the purified and radioactively labeled fraction containing both tubulin and the CK2 enzyme, established the phosphorylation of a single band that was recognized by anti-CK2 α-subunit and anti-tubulin antibodies. All these findings revealed a physical association between a pool of tubulin and a CK2 in T. equiperdum.

  13. The C-terminal tails of heterotrimeric kinesin-2 motor subunits directly bind to α-tubulin1: Possible implications for cilia-specific tubulin entry.

    Science.gov (United States)

    Girotra, Mukul; Srivastava, Shalini; Kulkarni, Anuttama; Barbora, Ayan; Bobra, Kratika; Ghosal, Debnath; Devan, Pavithra; Aher, Amol; Jain, Akanksha; Panda, Dulal; Ray, Krishanu

    2017-02-01

    The assembly of microtubule-based cytoskeleton propels the cilia and flagella growth. Previous studies have indicated that the kinesin-2 family motors transport tubulin into the cilia through intraflagellar transport. Here, we report a direct interaction between the C-terminal tail fragments of heterotrimeric kinesin-2 and α-tubulin1 isoforms in vitro. Blot overlay screen, affinity purification from tissue extracts, cosedimentation with subtilisin-treated microtubule and LC-ESI-MS/MS characterization of the tail-fragment-associated tubulin identified an association between the tail domains and α-tubulin1A/D isotype. The interaction was confirmed by Forster's resonance energy transfer assay in tissue-cultured cells. The overexpression of the recombinant tails in NIH3T3 cells affected the primary cilia growth, which was rescued by coexpression of a α-tubulin1 transgene. Furthermore, fluorescent recovery after photobleach analysis in the olfactory cilia of Drosophila indicated that tubulin is transported in a non-particulate form requiring kinesin-2. These results provide additional new insight into the mechanisms underlying selective tubulin isoform enrichment in the cilia. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. In inflammatory reactive astrocytes co-cultured with brain endothelial cells nicotine-evoked Ca(2+) transients are attenuated due to interleukin-1beta release and rearrangement of actin filaments.

    Science.gov (United States)

    Delbro, D; Westerlund, A; Björklund, U; Hansson, E

    2009-03-17

    The aim of this study was to investigate whether nicotine acetylcholine receptors (nAChRs) are expressed in a more pronounced way in astrocytes co-cultured with microvascular endothelial cells from adult rat brain, compared with monocultured astrocytes, as a sign of a more developed signal transduction system. Also investigated was whether nicotine plays a role in the control of neuroinflammatory reactivity in astrocytes. Ca(2+) imaging experiments were performed using cells loaded with the Ca(2+) indicator Fura-2/AM. Co-cultured astrocytes responded to lower concentrations of nicotine than did monocultured astrocytes, indicating that they are more sensitive to nicotine. Co-cultured astrocytes also expressed a higher selectivity for alpha7nAChR and alpha4/beta2 subunits and evoked higher Ca(2+) transients compared with monocultured astrocytes. The Ca(2+) transients referred to are activators of Ca(2+)-induced Ca(2+) release from intracellular stores, both IP(3) and ryanodine, triggered by influx through receptor channels. The nicotine-induced Ca(2+) transients were attenuated after incubation with the inflammatory mediator lipopolysaccharide (LPS), but were not attenuated after incubation with the pain-transmitting peptides substance P and calcitonin-gene-related peptide, nor with the infection and inflammation stress mediator, leptin. Furthermore, LPS-induced release of interleukin-1beta (IL-1beta) measured by enzyme-linked immunosorbent assay (ELISA) was more pronounced in co-cultured versus monocultured astrocytes. Incubation with both LPS and IL-1beta further attenuated nicotine-induced Ca(2+) response. We also found that LPS and IL-1beta induced rearrangement of the F-actin filaments, as measured with an Alexa488-conjugated phalloidin probe. The rearrangements consisted of increases in ring formations and a more dispersed appearance of the filaments. These results indicate that there is a connection between a dysfunction of nicotine Ca(2+) signaling in

  15. Connexin-43 interactions with ZO-1 and alpha- and beta-tubulin

    NARCIS (Netherlands)

    Giepmans, B N; Verlaan, I; Moolenaar, W H

    2001-01-01

    Gap junctions are composed of connexins that form transmembrane channels between adjacent cells. The C-terminal tail of connexin-43 (Cx43), the most widely expressed connexin member, has been implicated in the regulation of Cx43 channel gating. Interestingly, channel-independent processes regulated

  16. 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

    Members of Aspergillus section Fumigati are important animal pathogens and food contaminants. There is considerable variation among the 16 currently recognized species in this section, particularly in their mating systems: five are known to be strictly mitosporic, nine are homothallic, and two ar...

  17. Anastral spindle assembly and γ-tubulin in Drosophila oocytes

    Directory of Open Access Journals (Sweden)

    Hallen Mark A

    2011-01-01

    Full Text Available Abstract Background Anastral spindles assemble by a mechanism that involves microtubule nucleation and growth from chromatin. It is still uncertain whether γ-tubulin, a microtubule nucleator essential for mitotic spindle assembly and maintenance, plays a role. Not only is the requirement for γ-tubulin to form anastral Drosophila oocyte meiosis I spindles controversial, but its presence in oocyte meiosis I spindles has not been demonstrated and is uncertain. Results We show, for the first time, using a bright GFP fusion protein and live imaging, that the Drosophila maternally-expressed γTub37C is present at low levels in oocyte meiosis I spindles. Despite this, we find that formation of bipolar meiosis I spindles does not require functional γTub37C, extending previous findings by others. Fluorescence photobleaching assays show rapid recovery of γTub37C in the meiosis I spindle, similar to the cytoplasm, indicating weak binding by γTub37C to spindles, and fits of a new, potentially more accurate model for fluorescence recovery yield kinetic parameters consistent with transient, diffusional binding. Conclusions The FRAP results, together with its mutant effects late in meiosis I, indicate that γTub37C may perform a role subsequent to metaphase I, rather than nucleating microtubules for meiosis I spindle formation. Weak binding to the meiosis I spindle could stabilize pre-existing microtubules or position γ-tubulin for function during meiosis II spindle assembly, which follows rapidly upon oocyte activation and completion of the meiosis I division.

  18. [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).

  19. Heterogeneous and homogeneous nucleation of Taxol crystals in aqueous solutions and gels: effect of tubulin proteins.

    Science.gov (United States)

    Castro, Javier S; Deymier, Pierre A; Trzaskowski, Bartosz; Bucay, Jaim

    2010-03-01

    In this study we report crystallization of Taxol in pure water, aqueous solutions containing tubulin proteins and tubulin-containing agarose gels. We show that crystallization of Taxol in tubulin-free aqueous solutions occurs by the formation of sheaf-like crystals, while in the presence of tubulin Taxol crystallizes in the form of spherulites. Whereas sheaves are characteristic for crystals formed by homogeneous nucleation, the spherical symmetry of the Taxol crystal formed in the presence of tubulin suggests they result from heterogeneous nucleation. To explain the formation of tubulin-Taxol nuclei we suggest a new, secondary Taxol-binding site within the tubulin heterodimer. Contrary to the known binding site, where the Taxol molecule is almost completely buried in the protein, the Taxol molecule in the secondary binding site is partially exposed to the solution and may serve as a bridge, connecting other Taxol molecules. Results presented in this work are important for in vivo and in vitro microtubule studies due to the possibility of mistaking these Taxol spherulites for microtubule asters, moreover a novel variable is proposed in the study of cells treated with Taxol for cancer treatment via sequestration of tubulin.

  20. Polyglutamylated Tubulin Binding Protein C1orf96/CSAP Is Involved in Microtubule Stabilization in Mitotic Spindles.

    Directory of Open Access Journals (Sweden)

    Shinya Ohta

    Full Text Available The centrosome-associated C1orf96/Centriole, Cilia and Spindle-Associated Protein (CSAP targets polyglutamylated tubulin in mitotic microtubules (MTs. Loss of CSAP causes critical defects in brain development; however, it is unclear how CSAP association with MTs affects mitosis progression. In this study, we explored the molecular mechanisms of the interaction of CSAP with mitotic spindles. Loss of CSAP caused MT instability in mitotic spindles and resulted in mislocalization of Nuclear protein that associates with the Mitotic Apparatus (NuMA, with defective MT dynamics. Thus, CSAP overload in the spindles caused extensive MT stabilization and recruitment of NuMA. Moreover, MT stabilization by CSAP led to high levels of polyglutamylation on MTs. MT depolymerization by cold or nocodazole treatment was inhibited by CSAP binding. Live-cell imaging analysis suggested that CSAP-dependent MT-stabilization led to centrosome-free MT aster formation immediately upon nuclear envelope breakdown without γ-tubulin. We therefore propose that CSAP associates with MTs around centrosomes to stabilize MTs during mitosis, ensuring proper bipolar spindle formation and maintenance.

  1. Extracellular matrix controls tubulin monomer levels in hepatocytes by regulating protein turnover

    Science.gov (United States)

    Mooney, D. J.; Hansen, L. K.; Langer, R.; Vacanti, J. P.; Ingber, D. E.

    1994-01-01

    Cells have evolved an autoregulatory mechanism to dampen variations in the concentration of tubulin monomer that is available to polymerize into microtubules (MTs), a process that is known as tubulin autoregulation. However, thermodynamic analysis of MT polymerization predicts that the concentration of free tubulin monomer must vary if MTs are to remain stable under different mechanical loads that result from changes in cell adhesion to the extracellular matrix (ECM). To determine how these seemingly contradictory regulatory mechanisms coexist in cells, we measured changes in the masses of tubulin monomer and polymer that resulted from altering cell-ECM contacts. Primary rat hepatocytes were cultured in chemically defined medium on bacteriological petri dishes that were precoated with different densities of laminin (LM). Increasing the LM density from low to high (1-1000 ng/cm2), promoted cell spreading (average projected cell area increased from 1200 to 6000 microns2) and resulted in formation of a greatly extended MT network. Nevertheless, the steady-state mass of tubulin polymer was similar at 48 h, regardless of cell shape or ECM density. In contrast, round hepatocytes on low LM contained a threefold higher mass of tubulin monomer when compared with spread cells on high LM. Furthermore, similar results were obtained whether LM, fibronectin, or type I collagen were used for cell attachment. Tubulin autoregulation appeared to function normally in these cells because tubulin mRNA levels and protein synthetic rates were greatly depressed in round cells that contained the highest level of free tubulin monomer. However, the rate of tubulin protein degradation slowed, causing the tubulin half-life to increase from approximately 24 to 55 h as the LM density was lowered from high to low and cell rounding was promoted. These results indicate that the set-point for the tubulin monomer mass in hepatocytes can be regulated by altering the density of ECM contacts and

  2. Novel drug design for Chagas disease via targeting Trypanosoma cruzi tubulin: Homology modeling and binding pocket prediction on Trypanosoma cruzi tubulin polymerization inhibition by naphthoquinone derivatives.

    Science.gov (United States)

    Ogindo, Charles O; Khraiwesh, Mozna H; George, Matthew; Brandy, Yakini; Brandy, Nailah; Gugssa, Ayele; Ashraf, Mohammad; Abbas, Muneer; Southerland, William M; Lee, Clarence M; Bakare, Oladapo; Fang, Yayin

    2016-08-15

    Chagas disease, also called American trypanosomiasis, is a parasitic disease caused by Trypanosoma cruzi (T. cruzi). Recent findings have underscored the abundance of the causative organism, (T. cruzi), especially in the southern tier states of the US and the risk burden for the rural farming communities there. Due to a lack of safe and effective drugs, there is an urgent need for novel therapeutic options for treating Chagas disease. We report here our first scientific effort to pursue a novel drug design for treating Chagas disease via the targeting of T. cruzi tubulin. First, the anti T. cruzi tubulin activities of five naphthoquinone derivatives were determined and correlated to their anti-trypanosomal activities. The correlation between the ligand activities against the T. cruzi organism and their tubulin inhibitory activities was very strong with a Pearson's r value of 0.88 (P value cruzi tubulin polymerization inhibition. Subsequent molecular modeling studies were carried out to understand the mechanisms of the anti-tubulin activities, wherein, the homology model of T. cruzi tubulin dimer was generated and the putative binding site of naphthoquinone derivatives was predicted. The correlation coefficient for ligand anti-tubulin activities and their binding energies at the putative pocket was found to be r=0.79, a high correlation efficiency that was not replicated in contiguous candidate pockets. The homology model of T. cruzi tubulin and the identification of its putative binding site lay a solid ground for further structure based drug design, including molecular docking and pharmacophore analysis. This study presents a new opportunity for designing potent and selective drugs for Chagas disease. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Analysis of music-brain interaction with simultaneous measurement of regional cerebral blood flow and electroencephalogram beta rhythm in human subjects.

    Science.gov (United States)

    Nakamura, S; Sadato, N; Oohashi, T; Nishina, E; Fuwamoto, Y; Yonekura, Y

    1999-11-19

    To elucidate the neural substrates of the receptive aspect of music, we measured regional cerebral blood flow (rCBF) with positron emission tomography (PET) and simultaneously recorded the electroencephalogram (EEG) in eight normal volunteers. Compared with the rest condition, listening to music caused a significant increase in EEG beta power spectrum (13-30 Hz) averaged over the posterior two third of the scalp. The averaged beta power spectrum was positively correlated with rCBF in the premotor cortex and adjacent prefrontal cortices bilaterally, the anterior portion of the precuneus and the anterior cingulate cortex in both the rest and the music conditions. Listening to music newly recruited the posterior portion of the precuneus bilaterally. This may reflect the interaction of the music with the cognitive processes, such as music-evoked memory recall or visual imagery.

  4. Effect of O-methyl-.beta.-cyclodextrin-modified magnetic nanoparticles on the uptake and extracellular level of L-glutamate in brain nerve terminals

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Beneš, Milan J.; Procházková, Zuzana; Trchová, Miroslava; Borysov, A.; Pastukhov, A.; Paliienko, K.; Borisova, T.

    2017-01-01

    Roč. 149, 1 January (2017), s. 64-71 ISSN 0927-7765 R&D Projects: GA ČR(CZ) GC16-01128J; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61389013 Keywords : glutamate * cholesterol * O-methyl-beta-cyclodextrin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.887, year: 2016

  5. Beta vulgaris

    African Journals Online (AJOL)

    Heat treated Beetroot have the highest value for ABTS scavenging ability. ... powdered sample was stored in a clean dry plastic container at room ..... Nutritional value and economic feasibility of red beetroot. (Beta vulgaris L. ssp. vulgaris Rote Kugel) from different production systems. African Journal of. Agricultural ...

  6. Misato Controls Mitotic Microtubule Generation by Stabilizing the TCP-1 Tubulin Chaperone Complex [corrected].

    Science.gov (United States)

    Palumbo, Valeria; Pellacani, Claudia; Heesom, Kate J; Rogala, Kacper B; Deane, Charlotte M; Mottier-Pavie, Violaine; Gatti, Maurizio; Bonaccorsi, Silvia; Wakefield, James G

    2015-06-29

    Mitotic spindles are primarily composed of microtubules (MTs), generated by polymerization of α- and β-Tubulin hetero-dimers. Tubulins undergo a series of protein folding and post-translational modifications in order to fulfill their functions. Defects in Tubulin polymerization dramatically affect spindle formation and disrupt chromosome segregation. We recently described a role for the product of the conserved misato (mst) gene in regulating mitotic MT generation in flies, but the molecular function of Mst remains unknown. Here, we use affinity purification mass spectrometry (AP-MS) to identify interacting partners of Mst in the Drosophila embryo. We demonstrate that Mst associates stoichiometrically with the hetero-octameric Tubulin Chaperone Protein-1 (TCP-1) complex, with the hetero-hexameric Tubulin Prefoldin complex, and with proteins having conserved roles in generating MT-competent Tubulin. We show that RNAi-mediated in vivo depletion of any TCP-1 subunit phenocopies the effects of mutations in mst or the Prefoldin-encoding gene merry-go-round (mgr), leading to monopolar and disorganized mitotic spindles containing few MTs. Crucially, we demonstrate that Mst, but not Mgr, is required for TCP-1 complex stability and that both the efficiency of Tubulin polymerization and Tubulin stability are drastically compromised in mst mutants. Moreover, our structural bioinformatic analyses indicate that Mst resembles the three-dimensional structure of Tubulin monomers and might therefore occupy the TCP-1 complex central cavity. Collectively, our results suggest that Mst acts as a co-factor of the TCP-1 complex, playing an essential role in the Tubulin-folding processes required for proper assembly of spindle MTs. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    Science.gov (United States)

    Ledda, F D; Ramoino, P; Ravera, S; Perino, E; Bianchini, P; Diaspro, A; Gallus, L; Pronzato, R; Manconi, R

    2013-09-15

    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 CdCl2, there were progressive shifts in the levels of some tubulin isoforms. Exposure for 24h 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(2+)-treated cells indicates that divalent Cd ions stabilize microtubules. The possibility that Cd(2+) may increase the stability of cytoplasmic microtubules was tested by exposing Cd(2+)-treated cells to a cold temperature (0°C). As shown, the microtubule bundles induced by Cd(2+), which were labeled by the monoclonal antibodies against acetylated and detyrosinated α-tubulin, were resistant to cold. Copyright

  8. Methanolic extract of Piper nigrum fruits improves memory impairment by decreasing brain oxidative stress in amyloid beta(1-42) rat model of Alzheimer's disease.

    Science.gov (United States)

    Hritcu, Lucian; Noumedem, Jaurès A; Cioanca, Oana; Hancianu, Monica; Kuete, Victor; Mihasan, Marius

    2014-04-01

    The present study analyzed the possible memory-enhancing and antioxidant proprieties of the methanolic extract of Piper nigrum L. fruits (50 and 100 mg/kg, orally, for 21 days) in amyloid beta(1-42) rat model of Alzheimer's disease. The memory-enhancing effects of the plant extract were studied by means of in vivo (Y-maze and radial arm-maze tasks) approaches. Also, the antioxidant activity in the hippocampus was assessed using superoxide dismutase-, catalase-, glutathione peroxidase-specific activities and the total content of reduced glutathione, malondialdehyde, and protein carbonyl levels. The amyloid beta(1-42)-treated rats exhibited the following: decrease of spontaneous alternations percentage within Y-maze task and increase of working memory and reference memory errors within radial arm-maze task. Administration of the plant extract significantly improved memory performance and exhibited antioxidant potential. Our results suggest that the plant extract ameliorates amyloid beta(1-42)-induced spatial memory impairment by attenuation of the oxidative stress in the rat hippocampus.

  9. A brain-specific transcription activator.

    Science.gov (United States)

    Korner, M; Rattner, A; Mauxion, F; Sen, R; Citri, Y

    1989-11-01

    We have identified a DNA binding protein, named BETA, that interacts with the same (B) transcriptional regulatory sequence as the known transcription factor NF-kappa B. BETA is found only in gray matter throughout the brain, and not in a variety of other rat tissues. Two binding sites for BETA are present adjacent to the promoter of the rat proenkephalin gene. Transfection of primary brain cultures that express BETA, with a reporter gene driven by the SV40 promoter linked to BETA DNA binding sites, results in transcriptional activation. We infer that BETA is a brain-specific transcription activator.

  10. 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.

  11. Microtubules in bacteria: Ancient tubulins build a five-protofilament homolog of the eukaryotic cytoskeleton.

    Directory of Open Access Journals (Sweden)

    Martin Pilhofer

    2011-12-01

    Full Text Available Microtubules play crucial roles in cytokinesis, transport, and motility, and are therefore superb targets for anti-cancer drugs. All tubulins evolved from a common ancestor they share with the distantly related bacterial cell division protein FtsZ, but while eukaryotic tubulins evolved into highly conserved microtubule-forming heterodimers, bacterial FtsZ presumably continued to function as single homopolymeric protofilaments as it does today. Microtubules have not previously been found in bacteria, and we lack insight into their evolution from the tubulin/FtsZ ancestor. Using electron cryomicroscopy, here we show that the tubulin homologs BtubA and BtubB form microtubules in bacteria and suggest these be referred to as "bacterial microtubules" (bMTs. bMTs share important features with their eukaryotic counterparts, such as straight protofilaments and similar protofilament interactions. bMTs are composed of only five protofilaments, however, instead of the 13 typical in eukaryotes. These and other results suggest that rather than being derived from modern eukaryotic tubulin, BtubA and BtubB arose from early tubulin intermediates that formed small microtubules. Since we show that bacterial microtubules can be produced in abundance in vitro without chaperones, they should be useful tools for tubulin research and drug screening.

  12. Structural Model for Tubulin Recognition and Deformation by Kinesin-13 Microtubule Depolymerases

    Directory of Open Access Journals (Sweden)

    Ana B. Asenjo

    2013-03-01

    Full Text Available To elucidate the structural basis of the mechanism of microtubule depolymerization by kinesin-13s, we analyzed complexes of tubulin and the Drosophila melanogaster kinesin-13 KLP10A by electron microscopy (EM and fluorescence polarization microscopy. We report a nanometer-resolution (1.1 nm cryo-EM three-dimensional structure of the KLP10A head domain (KLP10AHD bound to curved tubulin. We found that binding of KLP10AHD induces a distinct tubulin configuration with displacement (shear between tubulin subunits in addition to curvature. In this configuration, the kinesin-binding site differs from that in straight tubulin, providing an explanation for the distinct interaction modes of kinesin-13s with the microtubule lattice or its ends. The KLP10AHD-tubulin interface comprises three areas of interaction, suggesting a crossbow-type tubulin-bending mechanism. These areas include the kinesin-13 family conserved KVD residues, and as predicted from the crossbow model, mutating these residues changes the orientation and mobility of KLP10AHDs interacting with the microtubule.

  13. Novel α-Tubulin Mutations Conferring Resistance to Dinitroaniline Herbicides in Lolium rigidum

    Directory of Open Access Journals (Sweden)

    Zhizhan Chu

    2018-02-01

    Full Text Available The dinitroaniline herbicides (particularly trifluralin have been globally used in many crops for selective grass weed control. Consequently, trifluralin resistance has been documented in several important crop weed species and has recently reached a level of concern in Australian Lolium rigidum populations. Here, we report novel mutations in the L. rigidum α-tubulin gene which confer resistance to trifluralin and other dinitroaniline herbicides. Nucleotide mutations at the highly conserved codon Arg-243 resulted in amino acid substitutions of Met or Lys. Rice calli transformed with the mutant 243-Met or 243-Lys α-tubulin genes were 4- to 8-fold more resistant to trifluralin and other dinitroaniline herbicides (e.g., ethalfluralin and pendimethalin compared to calli transformed with the wild type α-tubulin gene from L. rigidum. Comprehensive modeling of molecular docking predicts that Arg-243 is close to the trifluralin binding site on the α-tubulin surface and that replacement of Arg-243 by Met/Lys-243 results in a spatial shift of the trifluralin binding domain, reduction of trifluralin-tubulin contacts, and unfavorable interactions. The major effect of these substitutions is a significant rise of free interaction energy between α-tubulin and trifluralin, as well as between trifluralin and its whole molecular environment. These results demonstrate that the Arg-243 residue in α-tubulin is a determinant for trifluralin sensitivity, and the novel Arg-243-Met/Lys mutations may confer trifluralin resistance in L. rigidum.

  14. The γ-tubulin-specific inhibitor gatastatin reveals temporal requirements of microtubule nucleation during the cell cycle.

    Science.gov (United States)

    Chinen, Takumi; Liu, Peng; Shioda, Shuya; Pagel, Judith; Cerikan, Berati; Lin, Tien-Chen; Gruss, Oliver; Hayashi, Yoshiki; Takeno, Haruka; Shima, Tomohiro; Okada, Yasushi; Hayakawa, Ichiro; Hayashi, Yoshio; Kigoshi, Hideo; Usui, Takeo; Schiebel, Elmar

    2015-10-27

    Inhibitors of microtubule (MT) assembly or dynamics that target α/β-tubulin are widely exploited in cancer therapy and biological research. However, specific inhibitors of the MT nucleator γ-tubulin that would allow testing temporal functions of γ-tubulin during the cell cycle are yet to be identified. By evolving β-tubulin-binding drugs we now find that the glaziovianin A derivative gatastatin is a γ-tubulin-specific inhibitor. Gatastatin decreased interphase MT dynamics of human cells without affecting MT number. Gatastatin inhibited assembly of the mitotic spindle in prometaphase. Addition of gatastatin to preformed metaphase spindles altered MT dynamics, reduced the number of growing MTs and shortened spindle length. Furthermore, gatastatin prolonged anaphase duration by affecting anaphase spindle structure, indicating the continuous requirement of MT nucleation during mitosis. Thus, gatastatin facilitates the dissection of the role of γ-tubulin during the cell cycle and reveals the sustained role of γ-tubulin.

  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. 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.

  17. The interplay between tubulins and P450 cytochromes during Plasmodium berghei invasion of Anopheles gambiae midgut.

    Directory of Open Access Journals (Sweden)

    Rute C Félix

    Full Text Available BACKGROUND: Plasmodium infection increases the oxidative stress inside the mosquito, leading to a significant alteration on transcription of Anopheles gambiae detoxification genes. Among these detoxification genes several P450 cytochromes and tubulins were differently expressed, suggesting their involvement in the mosquito's response to parasite invasion. P450 cytochromes are usually involved in the metabolism and detoxification of several compounds, but are also regulated by several pathogens, including malaria parasite. Tubulins are extremely important as components of the cytoskeleton, which rearrangement functions as a response to malaria parasite invasion. METHODOLOGY/PRINCIPAL FINDINGS: Gene silencing methods were used to uncover the effects of cytochrome P450 reductase, tubulinA and tubulinB silencing on the A. gambiae response to Plasmodium berghei invasion. The role of tubulins in counter infection processes was also investigated by inhibiting their effect. Colchicine, vinblastine and paclitaxel, three different tubulin inhibitors were injected into A. gambiae mosquitoes. Twenty-four hours post injection these mosquitoes were infected with P. berghei through a blood meal from infected CD1 mice. Cytochrome P450 gene expression was measured using RT-qPCR to detect differences in cytochrome expression between silenced, inhibited and control mosquitoes. Results showed that cytochrome P450 reductase silencing, as well as tubulin (A and B silencing and inhibition affected the efficiency of Plasmodium infection. Silencing and inhibition also affected the expression levels of cytochromes P450. CONCLUSIONS: Our results suggest the existence of a relationship between tubulins and P450 cytochromes during A. gambiae immune response to P. berghei invasion. One of the P450 cytochromes in this study, CYP6Z2, stands out as the potential link in this association. Further work is needed to fully understand the role of tubulin genes in the response to

  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. Atorvastatin prevents age-related and amyloid-beta-induced microglial activation by blocking interferon-gamma release from natural killer cells in the brain

    LENUS (Irish Health Repository)

    Lyons, Anthony

    2011-03-31

    Abstract Background Microglial function is modulated by several factors reflecting the numerous receptors expressed on the cell surface, however endogenous factors which contribute to the age-related increase in microglial activation remain largely unknown. One possible factor which may contribute is interferon-γ (IFNγ). IFNγ has been shown to increase in the aged brain and potently activates microglia, although its endogenous cell source in the brain remains unidentified. Methods Male Wistar rats were used to assess the effect of age and amyloid-β (Aβ) on NK cell infiltration into the brain. The effect of the anti-inflammatory compound, atorvastatin was also assessed under these conditions. We measured cytokine and chemokine (IFNγ, IL-2, monocyte chemoattractant protein-1 (MCP-1) and IFNγ-induced protein 10 kDa (IP-10)), expression in the brain by appropriate methods. We also looked at NK cell markers, CD161, NKp30 and NKp46 using flow cytometry and western blot. Results Natural killer (NK) cells are a major source of IFNγ in the periphery and here we report the presence of CD161+ NKp30+ cells and expression of CD161 and NKp46 in the brain of aged and Aβ-treated rats. Furthermore, we demonstrate that isolated CD161+ cells respond to interleukin-2 (IL-2) by releasing IFNγ. Atorvastatin, the HMG-CoA reductase inhibitor, attenuates the increase in CD161 and NKp46 observed in hippocampus of aged and Aβ-treated rats. This was paralleled by a decrease in IFNγ, markers of microglial activation and the chemokines, MCP-1 and IP-10 which are chemotactic for NK cells. Conclusions We propose that NK cells contribute to the age-related and Aβ-induced neuroinflammatory changes and demonstrate that these changes can be modulated by atorvastatin treatment.

  20. ATP Induces Disruption of Tight Junction Proteins via IL-1 Beta-Dependent MMP-9 Activation of Human Blood-Brain Barrier In Vitro

    Directory of Open Access Journals (Sweden)

    Fuxing Yang

    2016-01-01

    Full Text Available Disruption of blood-brain barrier (BBB follows brain trauma or central nervous system (CNS stress. However, the mechanisms leading to this process or the underlying neural plasticity are not clearly known. We hypothesized that ATP/P2X7R signaling regulates the integrity of BBB. Activation of P2X7 receptor (P2X7R by ATP induces the release of interleukin-1β (IL-1β, which in turn enhances the activity of matrix metalloproteinase-9 (MMP-9. Degradation of tight junction proteins (TJPs such as ZO-1 and occludin occurs, which finally contributes to disruption of BBB. A contact coculture system using human astrocytes and hCMEC/D3, an immortalized human brain endothelial cell line, was used to mimic BBB in vitro. Permeability was used to evaluate changes in the integrity of TJPs. ELISA, Western blot, and immunofluorescent staining procedures were used. Our data demonstrated that exposure to the photoreactive ATP analog, 3′-O-(4-benzoylbenzoyl adenosine 5′-triphosphate (BzATP, induced a significant decrease in ZO-1 and occludin expression. Meanwhile, the decrease of ZO-1 and occludin was significantly attenuated by P2X7R inhibitors, as well as IL-1R and MMP antagonists. Further, the induction of IL-1β and MMP-9 was closely linked to ATP/P2X7R-associated BBB leakage. In conclusion, our study explored the mechanism of ATP/P2X7R signaling in the disruption of BBB following brain trauma/stress injury, especially focusing on the relationship with IL-1β and MMP-9.

  1. Phosphorylation and oligomerization states of native pig brain HSP90 studied by mass spectrometry

    DEFF Research Database (Denmark)

    Garnier, C.; Lafitte, D.; Jorgensen, T.J.

    2001-01-01

    such as actin-microfilament, tubulin-microtubule and intermediate filaments, and also exhibits conventional chaperone functions. This protein exists in two isoforms alpha-HSP90 and beta-HSP90, and it forms dimers which are crucial species for its biological activity. PAGE, ESI-MS and MALDI-MS were used to study...

  2. Centaurin-α₂ interacts with β-tubulin and stabilizes microtubules.

    Directory of Open Access Journals (Sweden)

    Paola Zuccotti

    Full Text Available Centaurin-α₂ is a GTPase-activating protein for ARF (ARFGAP showing a diffuse cytoplasmic localization capable to translocate to membrane, where it binds phosphatidylinositols. Taking into account that Centaurin-α₂ can localize in cytoplasm and that its cytoplasmatic function is not well defined, we searched for further interactors by yeast two-hybrid assay to investigate its biological function. We identified a further Centaurin-α₂ interacting protein, β-Tubulin, by yeast two-hybrid assay. The interaction, involving the C-terminal region of β-Tubulin, has been confirmed by coimmunoprecipitation experiments. After Centaurin-α₂ overexpression in HeLa cells and extraction of soluble (αβ dimers and insoluble (microtubules fractions of Tubulin, we observed that Centaurin-α₂ mainly interacts with the polymerized Tubulin fraction, besides colocalizing with microtubules (MTs in cytoplasm accordingly. Even following the depolimerizing Tubulin treatments Centaurin-α₂ remains mainly associated to nocodazole- and cold-resistant MTs. We found an increase of MT stability in transfected HeLa cells, evaluating as marker of stability the level of MT acetylation. In vitro assays using purified Centaurin-α₂ and tubulin confirmed that Centaurin-α₂ promotes tubulin assembly and increases microtubule stability. The biological effect of Centaurin-α₂ overexpression, assessed through the detection of an increased number of mitotic HeLa cells with bipolar spindles and with the correct number of centrosomes in both dividing and not dividing cells, is consistent with the Centaurin-α₂ role on MT stabilization. Centaurin-α₂ interacts with β-Tubulin and it mainly associates to MTs, resistant to destabilizing agents, in vitro and in cell. We propose Centaurin-α₂ as a new microtubule-associated protein (MAP increasing MT stability.

  3. 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.

  4. 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.

  5. Microtubule-associated proteins and tubulin interaction by isothermal titration calorimetry.

    Science.gov (United States)

    Tsvetkov, P O; Barbier, P; Breuzard, G; Peyrot, V; Devred, F

    2013-01-01

    Microtubules play an important role in a number of vital cell processes such as cell division, intracellular transport, and cell architecture. The highly dynamic structure of microtubules is tightly regulated by a number of stabilizing and destabilizing microtubule-associated proteins (MAPs), such as tau and stathmin. Because of their importance, tubulin-MAPs interactions have been extensively studied using various methods that provide researchers with complementary but sometimes contradictory thermodynamic data. Isothermal titration calorimetry (ITC) is the only direct thermodynamic method that enables a full thermodynamic characterization (stoichiometry, enthalpy, entropy of binding, and association constant) of the interaction after a single titration experiment. This method has been recently applied to study tubulin-MAPs interactions in order to bring new insights into molecular mechanisms of tubulin regulation. In this chapter, we review the technical specificity of this method and then focus on the use of ITC in the investigation of tubulin-MAPs binding. We describe technical issues which could arise during planning and carrying out the ITC experiments, in particular with fragile proteins such as tubulin. Using examples of stathmin and tau, we demonstrate how ITC can be used to gain major insights into tubulin-MAP interaction. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. A vital role of tubulin-tyrosine-ligase for neuronal organization

    Science.gov (United States)

    Erck, Christian; Peris, Leticia; Andrieux, Annie; Meissirel, Claire; Gruber, Achim D.; Vernet, Muriel; Schweitzer, Annie; Saoudi, Yasmina; Pointu, Hervé; Bosc, Christophe; Salin, Paul A.; Job, Didier; Wehland, Juergen

    2005-01-01

    Tubulin is subject to a special cycle of detyrosination/tyrosination in which the C-terminal tyrosine of α-tubulin is cyclically removed by a carboxypeptidase and readded by a tubulin-tyrosine-ligase (TTL). This tyrosination cycle is conserved in evolution, yet its physiological importance is unknown. Here, we find that TTL suppression in mice causes perinatal death. A minor pool of tyrosinated (Tyr-)tubulin persists in TTL null tissues, being present mainly in dividing TTL null cells where it originates from tubulin synthesis, but it is lacking in postmitotic TTL null cells such as neurons, which is apparently deleterious because early death in TTL null mice is, at least in part, accounted for by a disorganization of neuronal networks, including a disruption of the cortico-thalamic loop. Correlatively, cultured TTL null neurons display morphogenetic anomalies including an accelerated and erratic time course of neurite outgrowth and a premature axonal differentiation. These anomalies may involve a mislocalization of CLIP170, which we find lacking in neurite extensions and growth cones of TTL null neurons. Our results demonstrate a vital role of TTL for neuronal organization and suggest a requirement of Tyr-tubulin for proper control of neurite extensions. PMID:15899979

  7. Alzheimer's Disease Brain-Derived Amyloid-{beta}-Mediated Inhibition of LTP In Vivo Is Prevented by Immunotargeting Cellular Prion Protein.

    LENUS (Irish Health Repository)

    Barry, Andrew E

    2011-05-18

    Synthetic amyloid-β protein (Aβ) oligomers bind with high affinity to cellular prion protein (PrP(C)), but the role of this interaction in mediating the disruption of synaptic plasticity by such soluble Aβ in vitro is controversial. Here we report that intracerebroventricular injection of Aβ-containing aqueous extracts of Alzheimer\\'s disease (AD) brain robustly inhibits long-term potentiation (LTP) without significantly affecting baseline excitatory synaptic transmission in the rat hippocampus in vivo. Moreover, the disruption of LTP was abrogated by immunodepletion of Aβ. Importantly, intracerebroventricular administration of antigen-binding antibody fragment D13, directed to a putative Aβ-binding site on PrP(C), prevented the inhibition of LTP by AD brain-derived Aβ. In contrast, R1, a Fab directed to the C terminus of PrP(C), a region not implicated in binding of Aβ, did not significantly affect the Aβ-mediated inhibition of LTP. These data support the pathophysiological significance of SDS-stable Aβ dimer and the role of PrP(C) in mediating synaptic plasticity disruption by soluble Aβ.

  8. Cystatin C modulates cerebral beta-amyloidosis.

    Science.gov (United States)

    Kaeser, Stephan A; Herzig, Martin C; Coomaraswamy, Janaky; Kilger, Ellen; Selenica, Maj-Linda; Winkler, David T; Staufenbiel, Matthias; Levy, Efrat; Grubb, Anders; Jucker, Mathias

    2007-12-01

    The CST3 Thr25 allele of CST3, which encodes cystatin C, leads to reduced cystatin C secretion and conveys susceptibility to Alzheimer's disease. Here we show that overexpression of human cystatin C in brains of APP-transgenic mice reduces cerebral amyloid-beta deposition and that cystatin C binds amyloid-beta and inhibits its fibril formation. Our results suggest that cystatin C concentrations modulate cerebral amyloidosis risk and provide an opportunity for genetic risk assessment and therapeutic interventions.

  9. Tubulin C-terminal post-translational modifications do not occur in wood forming tissue of Populus

    Directory of Open Access Journals (Sweden)

    Hao Hu

    2016-10-01

    Full Text Available Cortical microtubules (MTs are evolutionarily conserved cytoskeletal components with specialized roles in plants, including regulation of cell wall biogenesis. MT functions and dynamics are dictated by the composition of their monomeric subunits, α- (TUA and β-tubulins (TUB, which in animals and protists are subject to both transcriptional regulation and post-translational modifications (PTM. While spatiotemporal regulation of tubulin gene expression has been reported in plants, whether and to what extent tubulin PTMs occur in these species remain poorly understood. We chose the woody perennial Populus for investigation of tubulin PTMs in this study, with a particular focus on developing xylem where high tubulin transcript levels support MT-dependent secondary cell wall deposition. Mass spectrometry and immunodetection concurred that detyrosination, nontyrosination and glutamylation were essentially absent in tubulins isolated from wood-forming tissues of Populus deltoides and P. tremula  alba. Label-free quantification of tubulin isotypes and RNA-Seq estimation of tubulin transcript abundance were largely consistent with transcriptional regulation. However, two TUB isoypes were detected at noticeably lower levels than expected based on RNA-Seq transcript abundance in both Populus species. These findings led us to conclude that MT composition during wood formation depends exclusively on transcriptional and, to a lesser extent, translational regulation of tubulin isotypes.

  10. Molecular Karyotype and Chromosomal Localization of Genes Encoding -tubulin, Cysteine Proteinase, hsp 70 and Actin in Trypanosoma rangeli

    National Research Council Canada - National Science Library

    CB Toaldo; M Steindel; MA Sousa; CC Tavares

    2001-01-01

    The molecular karyotype of nine Trypanosoma rangeli strains was analyzed by contour-clamped homogeneous electric field electrophoresis, followed by the chromosomal localization of -tubulin, cysteine...

  11. Exploring β-Tubulin Inhibitors from Plant Origin using Computational Approach.

    Science.gov (United States)

    Verma, Kanika; Kannan, Kaavya; V, Shanthi; R, Sethumadhavan; V, Karthick; K, Ramanathan

    2017-05-01

    β-Tubulin is an important target for the binding of anti-cancer drugs, in particular, paclitaxel (taxol), vinblastine and epothilone. However, mutations in β-tubulin structure give resistance to chemotherapeutic agents. Notably, mutations at R306C, F270 V, L217R, L228F, A185T and A248V positions in β-tubulin give high resistance for paclitaxel binding. To discover novel inhibitors of β-tubulin from natural sources, particularly alkaloids, using a virtual screening approach. A virtual screening approach was employed to find potent lead molecules from the Naturally-occurring Plant-based Anti-cancer Compound-activity Target (NPACT) database. Alkaloids have great potential to be anti-cancer agents. Therefore, we have screened all alkaloids from a total of 1574 molecules from the NPACT database for our study. Initially, Molinspiration and DataWarrior programs were utilised to calculate pharmacokinetics and toxicity risks of the alkaloids, respectively. Subsequently, AutoDock algorithm was employed to understand the binding efficiency of alkaloids against β-tubulin. The binding affinity of the docked complex was confirmed by means of an intermolecular interaction study. Moreover, oral toxicity was predicted by using ProTox program. Further, metabolising capacity of drugs was studied by using SmartCYP software. Additionally, scaffold analysis was done with the help of scaffold trees and dendrograms, providing knowledge about the building blocks for parent-compound synthesis. Overall, the results of our computational analysis indicate that isostrychnine, obtained from Strychnosnux-vomica, satisfies pharmacokinetic and bioavailability properties, binds efficiently with β-tubulin. Thus, it could be a promising lead for the treatment of paclitaxel resistant cancer types. This is the first observation of inhibitory activity of isostrychnine against β-tubulin and warrants further experimental investigation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016

  12. Tau overexpression in transgenic mice induces glycogen synthase kinase 3beta and beta-catenin phosphorylation.

    Science.gov (United States)

    Shim, S B; Lim, H J; Chae, K R; Kim, C K; Hwang, D Y; Jee, S W; Lee, S H; Sin, J S; Leem, Y H; Lee, S H; Cho, J S; Lee, H H; Choi, S Y; Kim, Y K

    2007-05-11

    The abnormal phosphorylations of tau, GSK3beta, and beta-catenin have been shown to perform a crucial function in the neuropathology of Alzheimer's disease (AD). The primary objective of the current study was to determine the manner in which overexpressed htau23 interacts and regulates the behavior and phosphorylation characteristics of tau, GSK3beta, and beta-catenin. In order to accomplish this, transgenic mice expressing neuron-specific enolase (NSE)-controlled human wild-type tau (NSE/htau23) were created. Transgenic mice evidenced the following: (i) tendency toward memory impairments at later stages, (ii) dramatic overexpression of the tau transgene, coupled with increased tau phosphorylation and paired helical filaments (PHFs), (iii) high levels of GSK3beta phosphorylation with advanced age, resulting in increases in the phosphorylations of tau and beta-catenin, (iv) an inhibitory effect of lithium on the phosphorylations of tau, GSK3beta, and beta-catenin, but not in the non-transgenic littermate group. Therefore, the overexpression of NSE/htau23 in the brains of transgenic mice induces abnormal phosphorylations of tau, GSK3beta, and beta-catenin, which are ultimately linked to neuronal degeneration in cases of AD. These transgenic mice are expected to prove useful for the development of new drugs for the treatment of AD.

  13. Some Brain Peptides Regulating the Secretion of Digestive Enzymes in the Indian Meal Moth, Plodia Interpunctella (Lepidoptera: Pyralidae)

    National Research Council Canada - National Science Library

    Sajjadian, SeyedeMinoo; Hosseininaveh, Vahid; Jahromi, Khalil Talebi

    2014-01-01

    .... The brain extract showed increasing dose-dependent effects on alpha -amylase, alpha -glucosidase, beta -glucosidase, alpha -galactosidase, beta -galactosidase, and trypsin secretion in the larval midgut...

  14. 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.

  15. 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.

  16. Gene expression profiling in the stress control brain region hypothalamic paraventricular nucleus reveals a novel gene network including Amyloid beta Precursor Protein

    Directory of Open Access Journals (Sweden)

    Deussing Jan M

    2010-10-01

    Full Text Available Abstract Background The pivotal role of stress in the precipitation of psychiatric diseases such as depression is generally accepted. This study aims at the identification of genes that are directly or indirectly responding to stress. Inbred mouse strains that had been evidenced to differ in their stress response as well as in their response to antidepressant treatment were chosen for RNA profiling after stress exposure. Gene expression and regulation was determined by microarray analyses and further evaluated by bioinformatics tools including pathway and cluster analyses. Results Forced swimming as acute stressor was applied to C57BL/6J and DBA/2J mice and resulted in sets of regulated genes in the paraventricular nucleus of the hypothalamus (PVN, 4 h or 8 h after stress. Although the expression changes between the mouse strains were quite different, they unfolded in phases over time in both strains. Our search for connections between the regulated genes resulted in potential novel signalling pathways in stress. In particular, Guanine nucleotide binding protein, alpha inhibiting 2 (GNAi2 and Amyloid β (A4 precursor protein (APP were detected as stress-regulated genes, and together with other genes, seem to be integrated into stress-responsive pathways and gene networks in the PVN. Conclusions This search for stress-regulated genes in the PVN revealed its impact on interesting genes (GNAi2 and APP and a novel gene network. In particular the expression of APP in the PVN that is governing stress hormone balance, is of great interest. The reported neuroprotective role of this molecule in the CNS supports the idea that a short acute stress can elicit positive adaptational effects in the brain.

  17. Multielement analysis of swiss mice brains with Alzheimer's disease induced by beta amyloid oligomers using a portable total reflection X-ray fluorescence system

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Danielle S.; Brigido, Matheus M.; Anjos, Marcelino J.; Ferreira, Sergio S.; Souza, Amanda S.; Lopes, Ricardo T., E-mail: ricardo@lin.ufrj.br, E-mail: marcelin@uerj.br, E-mail: amandass@bioqmed.ufrj.br, E-mail: ferreira@bioqmed.ufrj.br, E-mail: amandass@bioqmed.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil); Instituto de Fisica Armando Dias Tavares (Brazil)

    2017-11-01

    Alzheimer's disease (AD) is a progressive dementia that, in early stages, manifests as a profound inability to form new memories. The pathological features of AD include β-amyloid (Aβ) plaques, intracellular neurofibrillary tangles, loss of neurons and synapses, and activation of glia cells. Recently, several groups have raised the 'metal hypothesis' of AD. Metal ions, such as Cu and Zn, have been demonstrated to modulate amyloid aggregation along different pathways. Extensive research has been conducted on the effects of metals on Aβ aggregation and all of them have shown that both Cu and Zn accelerate the aggregation by shortening, or eliminating, the lag phase associated with the amyloid fibrillation process. The metal ions mentioned previously may have an important impact on the protein misfolding and the progression of the neurodegenerative process. The TXRF technique is very important, because can be used to identify and quantify trace elements present in the sample at very low concentrations (μg.g{sup -1}). In this work, three groups of females were studied: control, AD10 and AD100. The groups AD10 and AD100 were given a single intracerebroventricular injection of 10 pmol and 100 pmol of oligomers of β-amyloid peptide respectively to be induced AD. The TXRF measurements were performed using a portable total reflection X-ray fluorescence system developed in the Laboratory of Nuclear Instrumentation (LIN/UFRJ) that uses an X-ray tube with a molybdenum anode operating at 40 kV and 500 mA used for the excitation and a detector Si-PIN with energy resolution of 145 eV at 200 eV. It was possible to determine the concentrations of the following elements: P, S, K, Fe, Cu, Zn and Rubidium. Results showed differences in the elemental concentration in some brain regions between the AD groups and the control group. (author)

  18. Conformational changes in tubulin in GMPCPP and GDP-taxol microtubules observed by cryoelectron microscopy

    Science.gov (United States)

    Yajima, Hiroaki; Ogura, Toshihiko; Nitta, Ryo; Okada, Yasushi; Sato, Chikara

    2012-01-01

    Microtubules are dynamic polymers that stochastically switch between growing and shrinking phases. Microtubule dynamics are regulated by guanosine triphosphate (GTP) hydrolysis by β-tubulin, but the mechanism of this regulation remains elusive because high-resolution microtubule structures have only been revealed for the guanosine diphosphate (GDP) state. In this paper, we solved the cryoelectron microscopy (cryo-EM) structure of microtubule stabilized with a GTP analogue, guanylyl 5′-α,β-methylenediphosphonate (GMPCPP), at 8.8-Å resolution by developing a novel cryo-EM image reconstruction algorithm. In contrast to the crystal structures of GTP-bound tubulin relatives such as γ-tubulin and bacterial tubulins, significant changes were detected between GMPCPP and GDP-taxol microtubules at the contacts between tubulins both along the protofilament and between neighboring protofilaments, contributing to the stability of the microtubule. These findings are consistent with the structural plasticity or lattice model and suggest the structural basis not only for the regulatory mechanism of microtubule dynamics but also for the recognition of the nucleotide state of the microtubule by several microtubule-binding proteins, such as EB1 or kinesin. PMID:22851320

  19. Binding of dihydroxynaphthyl aryl ketones to tubulin colchicine site inhibits microtubule assembly.

    Science.gov (United States)

    Gutierrez, Eunices; Benites, Julio; Valderrama, Jaime A; Calderon, Pedro Buc; Verrax, Julien; Nova, Esteban; Villanelo, Felipe; Maturana, Daniel; Escobar, Cristian; Lagos, Rosalba; Monasterio, Octavio

    2015-10-23

    Dihydroxynaphthyl aryl ketones 1-5 have been evaluated for their abilities to inhibit microtubule assembly and the binding to tubulin. Compounds 3, 4 and 5 displayed competitive inhibition against colchicine binding, and docking analysis showed that they bind to the tubulin colchicine-binding pocket inducing sheets instead of microtubules. Remarkable differences in biological activity observed among the assayed compounds seem to be related to the structure and position of the aryl substituent bonded to the carbonyl group. Compounds 2, 3 and 4, which contain a heterocyclic ring, presented higher affinity for tubulin compared to the carbocyclic analogue 5. Compound 4 showed the best affinity of the series, with an IC50 value of 2.1 μM for microtubule polymerization inhibition and a tubulin dissociation constant of 1.0 ± 0.2 μM, as determined by thermophoresis. Compound 4 was more efficacious in disrupting microtubule assembly in vitro than compound 5 although it contains the trimethoxyphenyl ring present in colchicine. Hydrogen bonds with Asn101 of α-tubulin seem to be responsible for the higher affinity of compound 4 respects to the others. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Septin cooperation with tubulin polyglutamylation contributes to cancer cell adaptation to taxanes

    Science.gov (United States)

    Froidevaux-Klipfel, Laurence; Targa, Benjamin; Cantaloube, Isabelle; Ahmed-Zaïd, Hayat; Poüs, Christian; Baillet, Anita

    2015-01-01

    The mechanisms of cancer cell adaptation to the anti-microtubule agents of the taxane family are multifaceted and still poorly understood. Here, in a model of breast cancer cells which display amplified microtubule dynamics to resist Taxol®, we provide evidence that septin filaments containing high levels of SEPT9_i1 bind to microtubules in a way that requires tubulin long chain polyglutamylation. Reciprocally, septin filaments provide a scaffold for elongating and trimming polyglutamylation enzymes to finely tune the glutamate side-chain length on microtubules to an optimal level. We also demonstrate that tubulin retyrosination and/or a high level of tyrosinated tubulin is crucial to allow the interplay between septins and polyglutamylation on microtubules and that together, these modifications result in an enhanced CLIP-170 and MCAK recruitment to microtubules. Finally, the inhibition of tubulin retyrosination, septins, tubulin long chain polyglutamylation or of both CLIP-170 and MCAK allows the restoration of cell sensitivity to taxanes, providing evidence for a new integrated mechanism of resistance. PMID:26460824

  1. BRCA1-dependent ubiquitination of gamma-tubulin regulates centrosome number.

    Science.gov (United States)

    Starita, Lea M; Machida, Yuka; Sankaran, Satish; Elias, Joshua E; Griffin, Karen; Schlegel, Brian P; Gygi, Steven P; Parvin, Jeffrey D

    2004-10-01

    Proper centrosome duplication and spindle formation are crucial for prevention of chromosomal instability, and BRCA1 plays a role in this process. In this study, transient inhibition of BRCA1 function in cell lines derived from mammary tissue caused rapid amplification and fragmentation of centrosomes. Cell lines tested that were derived from nonmammary tissues did not amplify the centrosome number in this transient assay. We tested whether BRCA1 and its binding partner, BARD1, ubiquitinate centrosome proteins. Results showed that centrosome components, including gamma-tubulin, are ubiquitinated by BRCA1/BARD1 in vitro. The in vitro ubiquitination of gamma-tubulin was specific, and function of the carboxy terminus was necessary for this reaction; truncated BRCA1 did not ubiquitinate gamma-tubulin. BRCA1/BARD1 ubiquitinated lysines 48 and 344 of gamma-tubulin in vitro, and expression in cells of gamma-tubulin K48R caused a marked amplification of centrosomes. This result supports the notion that the modification of these lysines in living cells is critical in the maintenance of centrosome number. One of the key problems in understanding the biology of BRCA1 has been the identification of a specific target of BRCA1/BARD1 ubiquitination and its effect on mammary cell biology. The results of this study identify a ubiquitination target and suggest a biological impact important in the etiology of breast cancer.

  2. BRCA1-Dependent Ubiquitination of γ-Tubulin Regulates Centrosome Number

    Science.gov (United States)

    Starita, Lea M.; Machida, Yuka; Sankaran, Satish; Elias, Joshua E.; Griffin, Karen; Schlegel, Brian P.; Gygi, Steven P.; Parvin, Jeffrey D.

    2004-01-01

    Proper centrosome duplication and spindle formation are crucial for prevention of chromosomal instability, and BRCA1 plays a role in this process. In this study, transient inhibition of BRCA1 function in cell lines derived from mammary tissue caused rapid amplification and fragmentation of centrosomes. Cell lines tested that were derived from nonmammary tissues did not amplify the centrosome number in this transient assay. We tested whether BRCA1 and its binding partner, BARD1, ubiquitinate centrosome proteins. Results showed that centrosome components, including γ-tubulin, are ubiquitinated by BRCA1/BARD1 in vitro. The in vitro ubiquitination of γ-tubulin was specific, and function of the carboxy terminus was necessary for this reaction; truncated BRCA1 did not ubiquitinate γ-tubulin. BRCA1/BARD1 ubiquitinated lysines 48 and 344 of γ-tubulin in vitro, and expression in cells of γ-tubulin K48R caused a marked amplification of centrosomes. This result supports the notion that the modification of these lysines in living cells is critical in the maintenance of centrosome number. One of the key problems in understanding the biology of BRCA1 has been the identification of a specific target of BRCA1/BARD1 ubiquitination and its effect on mammary cell biology. The results of this study identify a ubiquitination target and suggest a biological impact important in the etiology of breast cancer. PMID:15367667

  3. 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.

  4. Cerebrospinal Fluid A beta(1-40) Improves Differential Dementia Diagnosis in Patients with Intermediate P-tau(181P) Levels

    NARCIS (Netherlands)

    Slaets, Sylvie; Le Bastard, Nathalie; Martin, Jean-Jacques; Sleegers, Kristel; Van Broeckhoven, Christine; De Deyn, Peter Paul; Engelborghs, Sebastiaan

    2013-01-01

    It is assumed that the concentration of amyloid-beta(1-40) (A beta(1-40)) in cerebrospinal fluid (CSF) reflects the total amount of A beta protein in the brain and thus allows a better interpretation of inter-individual differences in A beta quantity than the A beta(1-42) concentration. In this

  5. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    -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......-looking betas contain information relevant for forecasting future betas that is not contained in historical betas....

  6. 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.

  7. 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

  8. 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

  9. Tubulin perturbation leads to unexpected cell wall modifications and affects stomatal behaviour in Populus.

    Science.gov (United States)

    Swamy, Prashant S; Hu, Hao; Pattathil, Sivakumar; Maloney, Victoria J; Xiao, Hui; Xue, Liang-Jiao; Chung, Jeng-Der; Johnson, Virgil E; Zhu, Yingying; Peter, Gary F; Hahn, Michael G; Mansfield, Shawn D; Harding, Scott A; Tsai, Chung-Jui

    2015-10-01

    Cortical microtubules are integral to plant morphogenesis, cell wall synthesis, and stomatal behaviour, presumably by governing cellulose microfibril orientation. Genetic manipulation of tubulins often leads to abnormal plant development, making it difficult to probe additional roles of cortical microtubules in cell wall biogenesis. Here, it is shown that expressing post-translational C-terminal modification mimics of α-tubulin altered cell wall characteristics and guard cell dynamics in transgenic Populus tremula x alba that otherwise appear normal. 35S promoter-driven transgene expression was high in leaves but unusually low in xylem, suggesting high levels of tubulin transgene expression were not tolerated in wood-forming tissues during regeneration of transformants. Cellulose, hemicellulose, and lignin contents were unaffected in transgenic wood, but expression of cell wall-modifying enzymes, and extractability of lignin-bound pectin and xylan polysaccharides were increased in developing xylem. The results suggest that pectin and xylan polysaccharides deposited early during cell wall biogenesis are more sensitive to subtle tubulin perturbation than cellulose and matrix polysaccharides deposited later. Tubulin perturbation also affected guard cell behaviour, delaying drought-induced stomatal closure as well as light-induced stomatal opening in leaves. Pectins have been shown to confer cell wall flexibility critical for reversible stomatal movement, and results presented here are consistent with microtubule involvement in this process. Taken together, the data show the value of growth-compatible tubulin perturbations for discerning microtubule functions, and add to the growing body of evidence for microtubule involvement in non-cellulosic polysaccharide assembly during cell wall biogenesis. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  10. Tubulin polymerization by paclitaxel (taxol) phosphate prodrugs after metabolic activation with alkaline phosphatase.

    Science.gov (United States)

    Mamber, S W; Mikkilineni, A B; Pack, E J; Rosser, M P; Wong, H; Ueda, Y; Forenza, S

    1995-08-01

    Paclitaxel (taxol) phosphate derivatives BMY46366, BMY-46489, BMS180661 and BMS180820 were used to determine the ability of alkaline phosphatase to convert these water-soluble potential prodrugs to tubulin-polymerizing metabolites (i.e., paclitaxel). Compounds were treated up to 180 min with an in vitro metabolic activation system composed of 10% bovine alkaline phosphatase in 0.2 M tris, pH 7.4, or in 0.2 M glycine, pH 8.8, plus 0.05 M MgCl2. Samples were tested (either by direct addition or after methylene chloride extraction/dimethyl-sulfoxide resuspension) in spectrophotometric tubulin polymerization assays utilizing bovine-derived microtubule protein. Pretreatment of 2'- and 7-phosphonoxyphenylpropionate prodrugs BMS180661 and BMS180820 with alkaline phosphatase for 30 to 120 min yielded relative initial slopes of about 20 to 100% at test concentrations equimolar to paclitaxel. High-performance liquid chromatography/mass spectrometry of BMS180661 treated with alkaline phosphatase confirmed the production of paclitaxel from the prodrug. In contrast, 2'- and 7-phosphate analogs BMY46366 and BMY46489 treated with alkaline phosphatase were not active in tubulin assays. None of the paclitaxel phosphate prodrugs polymerized tubulin in the absence of metabolic activation. The differences in tubulin polymerization with metabolic activation may be related both to accessibility of the phosphate group to the enzyme and to anionic charge effects. These results demonstrate that certain paclitaxel phosphate prodrugs can be metabolized by alkaline phosphatase to yield effective tubulin polymerization.

  11. Complementary DNA cloning of the alternatively expressed endothelial cell glycoprotein Ib beta (GPIb beta) and localization of the GPIb beta gene to chromosome 22.

    Science.gov (United States)

    Kelly, M D; Essex, D W; Shapiro, S S; Meloni, F J; Druck, T; Huebner, K; Konkle, B A

    1994-01-01

    Glycoprotein Ib beta (GPIb beta) exists in platelets disulfide-linked to glycoprotein Ib alpha (GPIb alpha), a major receptor for von Willebrand factor. Both GPIb alpha and GPIb beta are expressed in endothelial cells (EC). While the GPIb alpha mRNA and protein appear similar in platelets and EC, EC GPIb beta mRNA is larger than platelet GPIb beta and encodes a larger protein. We have cloned and sequenced EC GPIb beta cDNA and report a 2793-nucleotide sequence which contains a 411-amino acid open reading frame. The EC sequence contains all of the platelet cDNA sequence and all but three amino acids of the primary translation product. Like the genes encoding GPIb alpha, GPIX, and GPV, the GPIb beta gene appears simple in structure. Using human hamster hybrids, we have localized the GPIb beta gene to chromosome 22pter-->22q11.2. When we examined poly (A)+ RNA from several human tissues for GPIb beta mRNA expression, we found that GPIb beta mRNA was expressed in a variety of tissues but was most abundant in heart and brain, while GPIb alpha and GPIX mRNA expression was found only in lung and placenta at very low levels. The broad distribution of GPIb beta mRNA suggests that it may be playing a role different than or additional to its function in platelets. Images PMID:8200976

  12. Structures and functions of calcium channel beta subunits.

    Science.gov (United States)

    Birnbaumer, L; Qin, N; Olcese, R; Tareilus, E; Platano, D; Costantin, J; Stefani, E

    1998-08-01

    Calcium channel beta subunits have profound effects on how alpha1 subunits perform. In this article we summarize our present knowledge of the primary structures of beta subunits as deduced from cDNAs and illustrate their different properties. Upon co-expression with alpha1 subunits, the effects of beta subunits vary somewhat between L-type and non-L-type channels mostly because the two types of channels have different responses to voltage which are affected by beta subunits, such as long-lasting prepulse facilitation of alpha1C (absent in alpha1E) and inhibition by G protein betagamma dimer of alpha1E, absent in alpha1C. One beta subunit, a brain beta2a splice variant that is palmitoylated, has several effects not seen with any of the others, and these are due to palmitoylation. We also illustrate the finding that functional expression of alpha1 in oocytes requires a beta subunit even if the final channel shows no evidence for its presence. We propose two structural models for Ca2+ channels to account for "alpha1 alone" channels seen in cells with limited beta subunit expression. In one model, beta dissociates from the mature alpha1 after proper folding and membrane insertion. Regulated channels seen upon co-expression of high levels of beta would then have subunit composition alpha1beta. In the other model, the "chaperoning" beta remains associated with the mature channel and "alpha1 alone" channels would in fact be alpha1beta channels. Upon co-expression of high levels of beta the regulated channels would have composition [alpha1beta]beta.

  13. Neuroprotective approaches in experimental models of beta-amyloid neurotoxicity : Relevance to Alzheimer's disease

    NARCIS (Netherlands)

    Harkany, T.; Hortobágyi, Tibor; Sasvari, M.; Konya, C.; Penke, B; Luiten, P.G.M.; Nyakas, Csaba

    1. beta-Amyloid peptides (A beta s) accumulate abundantly in the Alzheimer's disease (AD) brain in areas subserving information acquisition arid processing, and memory formation. A beta fragments are producedin a process of abnormal proteolytic cleavage of their precursor, the amyloid precursor

  14. Realized Beta GARCH

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri Radkov

    2014-01-01

    as the beta. We apply the model to a large set of assets and find the conditional betas to be far more variable than usually found with rolling-window regressions based exclusively on daily returns. In the empirical part of the paper, we examine the cross-sectional as well as the time variation...... of the conditional beta series during the financial crises....

  15. Structural and Biochemical Characterization of the Interaction of Tubulin with Potent Natural Analogues of Podophyllotoxin.

    Science.gov (United States)

    Antúnez-Mojica, Mayra; Rodríguez-Salarichs, Javier; Redondo-Horcajo, Mariano; León, Alejandra; Barasoain, Isabel; Canales, Ángeles; Cañada, F J; Jiménez-Barbero, Jesús; Alvarez, Laura; Díaz, J Fernando

    2016-08-26

    Four natural analogues of podophyllotoxin obtained from the Mexican medicinal plant Bursera fagaroides, namely, acetyl podophyllotoxin (2), 5'-desmethoxy-β-peltatin A methyl ether (3), 7',8'-dehydro acetyl podophyllotoxin (4), and burseranin (5), have been characterized, and their interactions with tubulin have been investigated. Cytotoxic activity measurements, followed by immunofluorescence microscopy and flow cytometry studies, demonstrated that these compounds disrupt microtubule networks in cells and cause cell cycle arrest in the G2/M phase in the A549 cell line. A tubulin binding assay showed that compounds 1-4 were potent assembly inhibitors, displaying binding to the colchicine site with Kb values ranging from 11.75 to 185.0 × 10(5) M(-1). In contrast, burseranin (5) was not able to inhibit tubulin assembly. From the structural perspective, the ligand-binding epitopes of compounds 1-3 have been mapped using STD-NMR, showing that B and E rings are the major points for interaction with the protein. The obtained results indicate that the inhibition of tubulin assembly of this family of compounds is more effective when there are at least two methoxyl groups at the E ring, along with a trans configuration of the lactone ring in the aryltetralin lignan core.

  16. Tubulin glutamylation regulates ciliary motility by altering inner dynein arm activity.

    Science.gov (United States)

    Suryavanshi, Swati; Eddé, Bernard; Fox, Laura A; Guerrero, Stella; Hard, Robert; Hennessey, Todd; Kabi, Amrita; Malison, David; Pennock, David; Sale, Winfield S; Wloga, Dorota; Gaertig, Jacek

    2010-03-09

    How microtubule-associated motor proteins are regulated is not well understood. A potential mechanism for spatial regulation of motor proteins is provided by posttranslational modifications of tubulin subunits that form patterns on microtubules. Glutamylation is a conserved tubulin modification [1] that is enriched in axonemes. The enzymes responsible for this posttranslational modification, glutamic acid ligases (E-ligases), belong to a family of proteins with a tubulin tyrosine ligase (TTL) homology domain (TTL-like or TTLL proteins) [2]. We show that in cilia of Tetrahymena, TTLL6 E-ligases generate glutamylation mainly on the B-tubule of outer doublet microtubules, the site of force production by ciliary dynein. Deletion of two TTLL6 paralogs caused severe deficiency in ciliary motility associated with abnormal waveform and reduced beat frequency. In isolated axonemes with a normal dynein arm composition, TTLL6 deficiency did not affect the rate of ATP-induced doublet microtubule sliding. Unexpectedly, the same TTLL6 deficiency increased the velocity of microtubule sliding in axonemes that also lack outer dynein arms, in which forces are generated by inner dynein arms. We conclude that tubulin glutamylation on the B-tubule inhibits the net force imposed on sliding doublet microtubules by inner dynein arms.

  17. 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....

  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. Synthesis and evaluation of stilbene and dihydrostilbene derivatives as potential anticancer agents that inhibit tubulin polymerization.

    Science.gov (United States)

    Cushman, M; Nagarathnam, D; Gopal, D; Chakraborti, A K; Lin, C M; Hamel, E

    1991-08-01

    An array of cis-, trans-, and dihydrostilbenes and some N-arylbenzylamines were synthesized and evaluated for their cytotoxicity in the five cancer cell cultures A-549 lung carcinoma, MCF-7 breast carcinoma, HT-29 colon adenocarcinoma, SKMEL-5 melanoma, and MLM melanoma. Several cis-stilbenes, structurally similar to combretastatins, were highly cytotoxic in all five cell lines and these were also found to be active as inhibitors of tubulin polymerization. The most active compounds also inhibited the binding of colchicine to tubulin. The most potent of the new compounds, both as a tubulin polymerization inhibitor and as a cytotoxic agent, was (Z)-1-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)ethene (5a). This substance was almost as potent as combretastatin A-4 (1a), the most active of the combretastatins, as a tubulin polymerization inhibitor. Compound 5a was found to be approximately 140 times more cytotoxic against HT-29 colon adenocarcinoma cells and about 10 times more cytotoxic against MCF-7 breast carcinoma cells than combretastatin A-4. However, 5a was found to be about 20 times less cytotoxic against A-549 lung carcinoma cells, 30 times less cytotoxic against SKMEL-5 melanoma cells, and 7 times less cytotoxic against MLM melanoma cells than combretastatin A-4. The relative potencies 5a greater than 8a greater than 6a for the cis, dihydro, and trans compounds, respectively, as inhibitors of tubulin polymerization are in agreement with the relative potencies previously observed for combretastatin A-4 (1a), dihydrocombretastatin A-4 (1c), and trans-combretastatin A-4 (1b). The relative potencies 5a greater than 8a greater than 6a were also reflected in the results of the cytotoxicity assays. Structure-activity relationships of this group of compounds are also discussed.

  20. Multiple functionally divergent and conserved copies of alpha tubulin in bdelloid rotifers.

    Science.gov (United States)

    Eyres, Isobel; Frangedakis, Eftychios; Fontaneto, Diego; Herniou, Elisabeth A; Boschetti, Chiara; Carr, Adrian; Micklem, Gos; Tunnacliffe, Alan; Barraclough, Timothy G

    2012-08-17

    Bdelloid rotifers are microscopic animals that have apparently survived without sex for millions of years and are able to survive desiccation at all life stages through a process called anhydrobiosis. Both of these characteristics are believed to have played a role in shaping several unusual features of bdelloid genomes discovered in recent years. Studies into the impact of asexuality and anhydrobiosis on bdelloid genomes have focused on understanding gene copy number. Here we investigate copy number and sequence divergence in alpha tubulin. Alpha tubulin is conserved and normally present in low copy numbers in animals, but multiplication of alpha tubulin copies has occurred in animals adapted to extreme environments, such as cold-adapted Antarctic fish. Using cloning and sequencing we compared alpha tubulin copy variation in four species of bdelloid rotifers and four species of monogonont rotifers, which are facultatively sexual and cannot survive desiccation as adults. Results were verified using transcriptome data from one bdelloid species, Adineta ricciae. In common with the typical pattern for animals, monogonont rotifers contain either one or two copies of alpha tubulin, but bdelloid species contain between 11 and 13 different copies, distributed across five classes. Approximately half of the copies form a highly conserved group that vary by only 1.1% amino acid pairwise divergence with each other and with the monogonont copies. The other copies have divergent amino acid sequences that evolved significantly faster between classes than within them, relative to synonymous changes, and vary in predicted biochemical properties. Copies of each class were expressed under the laboratory conditions used to construct the transcriptome. Our findings are consistent with recent evidence that bdelloids are degenerate tetraploids and that functional divergence of ancestral copies of genes has occurred, but show how further duplication events in the ancestor of bdelloids

  1. Antitumor Activity of IMC-038525, a Novel Oral Tubulin Polymerization Inhibitor.

    Science.gov (United States)

    Tuma, Maria Carolina; Malikzay, Asra; Ouyang, Xiaohu; Surguladze, David; Fleming, James; Mitelman, Stan; Camara, Margarita; Finnerty, Bridget; Doody, Jacqueline; Chekler, Eugene L P; Kussie, Paul; Tonra, James R

    2010-10-01

    Microtubules are a well-validated target for anticancer therapy. Molecules that bind tubulin affect dynamic instability of microtubules causing mitotic arrest of proliferating cells, leading to cell death and tumor growth inhibition. Natural antitubulin agents such as taxanes and Vinca alkaloids have been successful in the treatment of cancer; however, several limitations have encouraged the development of synthetic small molecule inhibitors of tubulin function. We have previously reported the discovery of two novel chemical series of tubulin polymerization inhibitors, triazoles (Ouyang et al. Synthesis and structure-activity relationships of 1,2,4-triazoles as a novel class of potent tubulin polymerization inhibitors. Bioorg Med Chem Lett. 2005; 15:5154-5159) and oxadiazole derivatives (Ouyang et al. Oxadiazole derivatives as a novel class of antimitotic agents: synthesis, inhibition of tubulin polymerization, and activity in tumor cell lines. Bioorg Med Chem Lett. 2006; 16:1191-1196). Here, we report on the anticancer effects of a lead oxadiazole derivative in vitro and in vivo. In vitro, IMC-038525 caused mitotic arrest at nanomolar concentrations in epidermoid carcinoma and breast tumor cells, including multidrug-resistant cells. In vivo, IMC-038525 had a desirable pharmacokinetic profile with sustained plasma levels after oral dosing. IMC-038525 reduced subcutaneous xenograft tumor growth with significantly greater efficacy than the taxane paclitaxel. At efficacious doses, IMC-038525 did not cause substantial myelosuppression or peripheral neurotoxicity, as evaluated by neutrophil counts and changes in myelination of the sciatic nerve, respectively. These data indicate that IMC-038525 is a promising candidate for further development as a chemotherapeutic agent.

  2. 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......-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...... and explanatory variables previously associated with the cross-section of expected stock returns....

  3. 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.

  4. Ependymin, a brain extracellular glycoprotein, and CNS plasticity.

    Science.gov (United States)

    Shashoua, V E

    1991-01-01

    Ependymin, a glycoprotein of the brain ECF, has been implicated in the neurochemistry of memory and neuronal regeneration. Three behavioral experiments (swimming with a float, avoidance conditioning, and classical conditioning) in the goldfish and one in the mouse (T-maze learning) indicate that ependymin has a role in the synaptic changes that take place in the consolidation step of memory formation and the activity-dependent phase of sharpening of goldfish retinotectal connections during neuronal regeneration. The ECF concentration of the protein was found to decrease after the goldfish learned to associate a light stimulus (CS) with the subsequent arrival of a shock (US): paired CS-US gave changes whereas an unpaired presentation of CS-US gave no changes relative to the unstimulated controls. Ependymin is present in ECF as a mixture of three disulfide-linked dimers of two acidic (alpha and beta) polypeptide chains (37 kDa and 31 kDa). Upon removal of its N-linked glycan fragment by N-glycosidase F, the beta chain yields gamma-ependymin (26 kDa). Determinations of the amino acid sequence of gamma-ependymin indicate that it is a unique protein with no long sequence homologies to any known polypeptide. There are, however, small segments (5-7 amino acids long) with homologies to fibronectin, laminin, and tubulin. Ependymin has the capacity to polymerize into FIP (after activation by phosphorylation) in response to events that deplete ECF calcium. FIP is insoluble in 2% SDS in 6 M urea, 10 mM Ca2+Ac2, 100% acetic acid, chloroform/methanol (2/1), saturated KCNS, and even 100% trifluoroacetic acid. FIP was found to be present in goldfish brain and to be formed as a labeled product in vivo. Ependymin's FIP-forming property was used to propose a molecular hypothesis for generating synaptic changes in response to local extracellular depletions of calcium at sites of "associating inputs." The model assumes that, following NMDA receptor stimulation, the translocated PKC

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

    NARCIS (Netherlands)

    Flex, E.; Niceta, M.; Cecchetti, S.; Thiffault, I.; Au, M.G.; Capuano, A.; Piermarini, E.; Ivanova, A.A.; Francis, J.W.; Chillemi, G.; Chandramouli, B.; Carpentieri, G.; Haaxma, C.A.; Ciolfi, A.; Pizzi, S.; Douglas, G.V.; Levine, K.; Sferra, A.; Dentici, M.L.; Pfundt, R.R.; Pichon, J.B. Le; Farrow, E.; Baas, F.; Piemonte, F.; Dallapiccola, B.; Graham, J.M.; Saunders, C.J.; Bertini, E.; Kahn, R.A.; Koolen, D.A.; Tartaglia, M.

    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

  6. 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

  7. 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.......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...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets....

  8. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    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) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically...... for US 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 of the BAB factor is low. (4) Increased funding liquidity risk compresses betas toward one. (5) More constrained investors hold riskier assets....

  9. Beta-Ketothiolase Deficiency

    Directory of Open Access Journals (Sweden)

    Elsayed Abdelkreem MD, MSc

    2016-03-01

    Full Text Available Beta-ketothiolase deficiency is an inherited disorder of ketone body metabolism and isoleucine catabolism. It typically manifests as recurrent ketoacidotic episodes with characteristic abnormalities in the urinary organic acid profile. However, several challenges in the diagnosis of beta-ketothiolase deficiency have been encountered: atypical presentations have been reported and some other disorders, such as succinyl-CoA:3-oxoacid CoA transferase and 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiencies, can mimic the clinical and/or biochemical signs of beta-ketothiolase deficiency. A final diagnosis of beta-ketothiolase deficiency requires an enzymatic assay and/or a molecular analysis, but some caveats must be considered. Despite the reported missed cases, screening programs have successfully identified an increasing number of patients with beta-ketothiolase deficiency. Early diagnosis and management of beta-ketothiolase deficiency will enable prevention of its serious acute and chronic complications and ultimately improve the prognosis.

  10. Tivantinib (ARQ 197) exhibits antitumor activity by directly interacting with tubulin and overcomes ABC transporter-mediated drug resistance.

    Science.gov (United States)

    Aoyama, Aki; Katayama, Ryohei; Oh-Hara, Tomoko; Sato, Shigeo; Okuno, Yasushi; Fujita, Naoya

    2014-12-01

    Tivantinib (ARQ197) was first reported as a highly selective inhibitor of c-MET and is currently being investigated in a phase III clinical trial. However, as recently reported by us and another group, tivantinib showed cytotoxic activity independent of cellular c-MET status and also disrupted microtubule dynamics. To investigate if tivantinib exerts its cytotoxic activity by disrupting microtubules, we quantified polymerized tubulin in cells and xenograft tumors after tivantinib treatment. Consistent with our previous report, tivantinib reduced tubulin polymerization in cells and in mouse xenograft tumors in vivo. To determine if tivantinib directly binds to tubulin, we performed an in vitro competition assay. Tivantinib competitively inhibited colchicine but not vincristine or vinblastine binding to purified tubulin. These results imply that tivantinib directly binds to the colchicine binding site of tubulin. To predict the binding mode of tivantinib with tubulin, we performed computer simulation of the docking pose of tivantinib with tubulin using GOLD docking program. Computer simulation predicts tivantinib fitted into the colchicine binding pocket of tubulin without steric hindrance. Furthermore, tivantinib showed similar IC50 values against parental and multidrug-resistant cells. In contrast, other microtubule-targeting drugs, such as vincristine, paclitaxel, and colchicine, could not suppress the growth of cells overexpressing ABC transporters. Moreover, the expression level of ABC transporters did not correlate with the apoptosis-inducing ability of tivantinib different from other microtubule inhibitor. These results suggest that tivantinib can overcome ABC transporter-mediated multidrug-resistant tumor cells and is potentially useful against various tumors. ©2014 American Association for Cancer Research.

  11. Phylogenetic Characterization of β-Tubulins and Development of Pyrosequencing Assays for Benzimidazole Resistance in Cattle Nematodes

    Science.gov (United States)

    Demeler, Janina; Krüger, Nina; Krücken, Jürgen; von der Heyden, Vera C.; Ramünke, Sabrina; Küttler, Ursula; Miltsch, Sandra; López Cepeda, Michael; Knox, Malcolm; Vercruysse, Jozef; Geldhof, Peter; Harder, Achim; von Samson-Himmelstjerna, Georg

    2013-01-01

    Control of helminth infections is a major task in livestock production to prevent health constraints and economic losses. However, resistance to established anthelmintic substances already impedes effective anthelmintic treatment in many regions worldwide. Thus, there is an obvious need for sensitive and reliable methods to assess the resistance status of at least the most important nematode populations. Several single nucleotide polymorphisms (SNPs) in the β-tubulin isotype 1 gene of various nematodes correlate with resistance to benzimidazoles (BZ), a major anthelmintic class. Here we describe the full-length β-tubulin isotype 1 and 2 and α-tubulin coding sequences of the cattle nematode Ostertagia ostertagi. Additionally, the Cooperia oncophora α-tubulin coding sequence was identified. Phylogenetic maximum-likelihood analysis revealed that both isotype 1 and 2 are orthologs to the Caenorhabditis elegans ben-1 gene which is also associated with BZ resistance upon mutation. In contrast, a Trichuris trichiura cDNA, postulated to be β-tubulin isotype 1 involved in BZ resistance in this human parasite, turned out to be closely related to C. elegans β-tubulins tbb-4 and mec-7 and would therefore represent the first non-ben-1-like β-tubulin to be under selection through treatment with BZs. A pyrosequencing assay was established to detect BZ resistance associated SNPs in β-tubulin isotype 1 codons 167, 198 and 200 of C. oncophora and O. ostertagi. PCR-fragments representing either of the two alleles were combined in defined ratios to evaluate the pyrosequencing assay. The correlation between the given and the measured allele frequencies of the respective SNPs was very high. Subsequently laboratory isolates and field populations with known resistance status were analyzed. With the exception of codon 167 in Cooperia, increases of resistance associated alleles were detected for all codons in at least one of the phenotypically resistant population. Pyrosequencing

  12. Phylogenetic characterization of β-tubulins and development of pyrosequencing assays for benzimidazole resistance in cattle nematodes.

    Directory of Open Access Journals (Sweden)

    Janina Demeler

    Full Text Available Control of helminth infections is a major task in livestock production to prevent health constraints and economic losses. However, resistance to established anthelmintic substances already impedes effective anthelmintic treatment in many regions worldwide. Thus, there is an obvious need for sensitive and reliable methods to assess the resistance status of at least the most important nematode populations. Several single nucleotide polymorphisms (SNPs in the β-tubulin isotype 1 gene of various nematodes correlate with resistance to benzimidazoles (BZ, a major anthelmintic class. Here we describe the full-length β-tubulin isotype 1 and 2 and α-tubulin coding sequences of the cattle nematode Ostertagia ostertagi. Additionally, the Cooperia oncophora α-tubulin coding sequence was identified. Phylogenetic maximum-likelihood analysis revealed that both isotype 1 and 2 are orthologs to the Caenorhabditis elegans ben-1 gene which is also associated with BZ resistance upon mutation. In contrast, a Trichuris trichiura cDNA, postulated to be β-tubulin isotype 1 involved in BZ resistance in this human parasite, turned out to be closely related to C. elegans β-tubulins tbb-4 and mec-7 and would therefore represent the first non-ben-1-like β-tubulin to be under selection through treatment with BZs. A pyrosequencing assay was established to detect BZ resistance associated SNPs in β-tubulin isotype 1 codons 167, 198 and 200 of C. oncophora and O. ostertagi. PCR-fragments representing either of the two alleles were combined in defined ratios to evaluate the pyrosequencing assay. The correlation between the given and the measured allele frequencies of the respective SNPs was very high. Subsequently laboratory isolates and field populations with known resistance status were analyzed. With the exception of codon 167 in Cooperia, increases of resistance associated alleles were detected for all codons in at least one of the phenotypically resistant population

  13. The tubulin repertoire of Caenorhabditis elegans sensory neurons and its context‑dependent role in process outgrowth

    Science.gov (United States)

    Lockhead, Dean; Schwarz, Erich M.; O’Hagan, Robert; Bellotti, Sebastian; Krieg, Michael; Barr, Maureen M.; Dunn, Alexander R.; Sternberg, Paul W.; Goodman, Miriam B.

    2016-01-01

    Microtubules contribute to many cellular processes, including transport, signaling, and chromosome separation during cell division. They comprise αβ‑tubulin heterodimers arranged into linear protofilaments and assembled into tubes. Eukaryotes express multiple tubulin isoforms, and there has been a longstanding debate as to whether the isoforms are redundant or perform specialized roles as part of a tubulin code. Here we use the well‑characterized touch receptor neurons (TRNs) of Caenorhabditis elegans to investigate this question through genetic dissection of process outgrowth both in vivo and in vitro. With single‑cell RNA-seq, we compare transcription profiles for TRNs with those of two other sensory neurons and present evidence that each sensory neuron expresses a distinct palette of tubulin genes. In the TRNs, we analyze process outgrowth and show that four tubulins (tba‑1, tba‑2, tbb‑1, and tbb‑2) function partially or fully redundantly, whereas two others (mec‑7 and mec‑12) perform specialized, context‑dependent roles. Our findings support a model in which sensory neurons express overlapping subsets of tubulin genes whose functional redundancy varies among cell types and in vivo and in vitro contexts. PMID:27654945

  14. Tubulin, actin and heterotrimeric G proteins: coordination of signaling and structure.

    Science.gov (United States)

    Schappi, Jeffrey M; Krbanjevic, Aleksandar; Rasenick, Mark M

    2014-02-01

    G proteins mediate signals from membrane G protein coupled receptors to the cell interior, evoking significant regulation of cell physiology. The cytoskeleton contributes to cell morphology, motility, division, and transport functions. This review will discuss the interplay between heterotrimeric G protein signaling and elements of the cytoskeleton. Also described and discussed will be the interplay between tubulin and G proteins that results in atypical modulation of signaling pathways and cytoskeletal dynamics. This will be extended to describe how tubulin and G proteins act in concert to influence various aspects of cellular behavior. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters.This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé. © 2013.

  15. 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

    and tubulin cytoskeleton. Rho GTPases, such as RhoA, Rac1, and Cdc42, are important regulators of cytoskeletal rearrangements in platelets; however, the specific roles of these proteins during platelet production have not been established. Using conditional knockout mice, we show here that Rac1 and Cdc42...... possess redundant functions in platelet production and function. In contrast to a single-deficiency of either protein, a double-deficiency of Rac1 and Cdc42 in MKs resulted in macrothrombocytopenia, abnormal platelet morphology, and impaired platelet function. Double-deficient bone marrow MKs matured...... 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...

  16. Fibrils connect microtubule tips with kinetochores: a mechanism to couple tubulin dynamics to chromosome motion.

    Science.gov (United States)

    McIntosh, J Richard; Grishchuk, Ekaterina L; Morphew, Mary K; Efremov, Artem K; Zhudenkov, Kirill; Volkov, Vladimir A; Cheeseman, Iain M; Desai, Arshad; Mastronarde, David N; Ataullakhanov, Fazly I

    2008-10-17

    Kinetochores of mitotic chromosomes are coupled to spindle microtubules in ways that allow the energy from tubulin dynamics to drive chromosome motion. Most kinetochore-associated microtubule ends display curving "protofilaments," strands of tubulin dimers that bend away from the microtubule axis. Both a kinetochore "plate" and an encircling, ring-shaped protein complex have been proposed to link protofilament bending to poleward chromosome motion. Here we show by electron tomography that slender fibrils connect curved protofilaments directly to the inner kinetochore. Fibril-protofilament associations correlate with a local straightening of the flared protofilaments. Theoretical analysis reveals that protofilament-fibril connections would be efficient couplers for chromosome motion, and experimental work on two very different kinetochore components suggests that filamentous proteins can couple shortening microtubules to cargo movements. These analyses define a ring-independent mechanism for harnessing microtubule dynamics directly to chromosome movement.

  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. Phosphatase inhibitor 2 promotes acetylation of tubulin in the primary cilium of human retinal epithelial cells

    Directory of Open Access Journals (Sweden)

    Wang Weiping

    2008-11-01

    Full Text Available Abstract Background Primary cilia are flagella-like projections from the centriole of mammalian cells that have a key role in cell signaling. Human diseases are linked to defects in primary cilia. Microtubules make up the axoneme of cilia and are selectively acetylated and this is thought to contribute to the stability of the structure. However, mechanisms to regulate tubulin acetylation in cilia are poorly understood. Results Endogenous phosphatase inhibitor-2 (I-2 was found concentrated in cilia of human epithelial cells, and was localized to cilia early in the process of formation, prior to the full acetylation of microtubules. Knockdown of I-2 by siRNA significantly reduced the acetylation of microtubules in cilia, without a net decrease in whole cell tubulin acetylation. There was a reduction in the percentage of I-2 knockdown cells with a primary cilium, but no apparent alteration in the cilium length, suggesting no change in microtubule-based transport processes. Inhibition of either histone deacetylases with trichostatin A, or protein phosphatase-1 with calyculin A in I-2 knockdown cells partially rescued the acetylation of microtubules in cilia and the percentage of cells with a primary cilium. Conclusion The regulatory protein I-2 localizes to the primary cilium where it affects both Ser/Thr phosphorylation and is required for full tubulin acetylation. Rescue of tubulin acetylation in I-2 knockdown cells by different chemical inhibitors shows that deacetylases and phosphatases are functionally interconnected to regulate microtubules. As a multifunctional protein, I-2 may link cell cycle progression to structure and stability of the primary cilium.

  19. DNA sequence and pattern of expression of the sea urchin (Paracentrotus lividus) alpha-tubulin genes.

    Science.gov (United States)

    Gianguzza, F; Di Bernardo, M G; Sollazzo, M; Palla, F; Ciaccio, M; Carra, E; Spinelli, G

    1989-01-01

    To study the molecular aspects of the regulation of transcription of a multigene family, we have isolated and sequenced cDNA and genomic clones coding for the alpha-tubulin of the sea urchin Paracentrotus lividus. Two cDNA clones, P alpha 10 and P alpha 4, contain respectively the coding information for 391 C-terminal and for 338 N-terminal amino acids of the 452 residues that constitute the complete protein. They show silent nucleotide substitutions only, suggesting that P alpha 10 and P alpha 4 represent the cloned copies of two allelic gene transcripts, which encode for two alpha-tubulin isoforms with identical amino acid sequence in the region of the overlap. The comparison of the predicted amino acid sequence of the composite P alpha 4-10 and of the mouse M alpha-6 (Villasante et al., Mol Cell Biol 1986; 6:2409-2419) reveals a conservation of 97% between the two polypeptides. By RNA blotting hybridization six major alpha-tubulin transcripts were identified. Two, of 3.5 kb and 2.0 kb, are expressed in the unfertilized eggs and during early cleavage. The other two maternal mRNAs, of 2.4 kb and 1.8 kb, are expressed in both early and late cleavage embryos, but in the intestine the 1.8 kb RNA, which specifically reacted with the 3' specific probe of the P alpha 10 cDNA, is the only transcript detected. Finally, the 1.5 kb and 1.9 kb mRNAs represent the transcription of stage- and tissue-specific genes, respectively. In fact, the former becomes detectable at blastula stage and accumulates during late development, whereas the latter is found in the testis only. The sequence data of the 3' terminus of the alpha-3 genomic clone suggests that it encodes for a divergent alpha-tubulin, and it most probably corresponds to the testis-specific gene.

  20. Tubulin Bond Energies and Microtubule Biomechanics Determined from Nanoindentation in Silico

    Science.gov (United States)

    2015-01-01

    Microtubules, the primary components of the chromosome segregation machinery, are stabilized by longitudinal and lateral noncovalent bonds between the tubulin subunits. However, the thermodynamics of these bonds and the microtubule physicochemical properties are poorly understood. Here, we explore the biomechanics of microtubule polymers using multiscale computational modeling and nanoindentations in silico of a contiguous microtubule fragment. A close match between the simulated and experimental force–deformation spectra enabled us to correlate the microtubule biomechanics with dynamic structural transitions at the nanoscale. Our mechanical testing revealed that the compressed MT behaves as a system of rigid elements interconnected through a network of lateral and longitudinal elastic bonds. The initial regime of continuous elastic deformation of the microtubule is followed by the transition regime, during which the microtubule lattice undergoes discrete structural changes, which include first the reversible dissociation of lateral bonds followed by irreversible dissociation of the longitudinal bonds. We have determined the free energies of dissociation of the lateral (6.9 ± 0.4 kcal/mol) and longitudinal (14.9 ± 1.5 kcal/mol) tubulin–tubulin bonds. These values in conjunction with the large flexural rigidity of tubulin protofilaments obtained (18,000–26,000 pN·nm2) support the idea that the disassembling microtubule is capable of generating a large mechanical force to move chromosomes during cell division. Our computational modeling offers a comprehensive quantitative platform to link molecular tubulin characteristics with the physiological behavior of microtubules. The developed in silico nanoindentation method provides a powerful tool for the exploration of biomechanical properties of other cytoskeletal and multiprotein assemblies. PMID:25389565

  1. Acyl peptide hydrolase degrades monomeric and oligomeric amyloid-beta peptide

    Directory of Open Access Journals (Sweden)

    O'Connor Peter B

    2009-07-01

    Full Text Available Abstract Background The abnormal accumulation of amyloid-beta peptide is believed to cause malfunctioning of neurons in the Alzheimer's disease brain. Amyloid-beta exists in different assembly forms in the aging mammalian brain including monomers, oligomers, and aggregates, and in senile plaques, fibrils. Recent findings suggest that soluble amyloid-beta oligomers may represent the primary pathological species in Alzheimer's disease and the most toxic form that impairs synaptic and thus neuronal function. We previously reported the isolation of a novel amyloid-beta-degrading enzyme, acyl peptide hydrolase, a serine protease that degrades amyloid-beta, and is different in structure and activity from other amyloid-beta-degrading enzymes. Results Here we report the further characterization of acyl peptide hydrolase activity using mass spectrometry. Acyl peptide hydrolase cleaves the amyloid-beta peptide at amino acids 13, 14 and 19. In addition, by real-time PCR we found elevated acyl peptide hydrolase expression in brain areas rich in amyloid plaques suggesting that this enzyme's levels are responsive to increases in amyloid-beta levels. Lastly, tissue culture experiments using transfected CHO cells expressing APP751 bearing the V717F mutation indicate that acyl peptide hydrolase preferentially degrades dimeric and trimeric forms of amyloid-beta. Conclusion These data suggest that acyl peptide hydrolase is involved in the degradation of oligomeric amyloid-beta, an activity that, if induced, might present a new tool for therapy aimed at reducing neurodegeneration in the Alzheimer's brain.

  2. Kinesin-13 regulates the quantity and quality of tubulin inside cilia

    Science.gov (United States)

    Vasudevan, Krishna Kumar; Jiang, Yu-Yang; Lechtreck, Karl F.; Kushida, Yasuharu; Alford, Lea M.; Sale, Winfield S.; Hennessey, Todd; Gaertig, Jacek

    2015-01-01

    Kinesin-13, an end depolymerizer of cytoplasmic and spindle microtubules, also affects the length of cilia. However, in different models, depletion of kinesin-13 either lengthens or shortens cilia, and therefore the exact function of kinesin-13 in cilia remains unclear. We generated null mutations of all kinesin-13 paralogues in the ciliate Tetrahymena. One of the paralogues, Kin13Ap, localizes to the nuclei and is essential for nuclear divisions. The remaining two paralogues, Kin13Bp and Kin13Cp, localize to the cell body and inside assembling cilia. Loss of both Kin13Bp and Kin13Cp resulted in slow cell multiplication and motility, overgrowth of cell body microtubules, shortening of cilia, and synthetic lethality with either paclitaxel or a deletion of MEC-17/ATAT1, the α-tubulin acetyltransferase. The mutant cilia assembled slowly and contained abnormal tubulin, characterized by altered posttranslational modifications and hypersensitivity to paclitaxel. The mutant cilia beat slowly and axonemes showed reduced velocity of microtubule sliding. Thus kinesin-13 positively regulates the axoneme length, influences the properties of ciliary tubulin, and likely indirectly, through its effects on the axonemal microtubules, affects the ciliary dynein-dependent motility. PMID:25501369

  3. Local Nucleation of Microtubule Bundles through Tubulin Concentration into a Condensed Tau Phase

    Directory of Open Access Journals (Sweden)

    Amayra Hernández-Vega

    2017-09-01

    Full Text Available Non-centrosomal microtubule bundles play important roles in cellular organization and function. Although many diverse proteins are known that can bundle microtubules, biochemical mechanisms by which cells could locally control the nucleation and formation of microtubule bundles are understudied. Here, we demonstrate that the concentration of tubulin into a condensed, liquid-like compartment composed of the unstructured neuronal protein tau is sufficient to nucleate microtubule bundles. We show that, under conditions of macro-molecular crowding, tau forms liquid-like drops. Tubulin partitions into these drops, efficiently increasing tubulin concentration and driving the nucleation of microtubules. These growing microtubules form bundles, which deform the drops while remaining enclosed by diffusible tau molecules exhibiting a liquid-like behavior. Our data suggest that condensed compartments of microtubule bundling proteins could promote the local formation of microtubule bundles in neurons by acting as non-centrosomal microtubule nucleation centers and that liquid-like tau encapsulation could provide both stability and plasticity to long axonal microtubule bundles.

  4. Local Nucleation of Microtubule Bundles through Tubulin Concentration into a Condensed Tau Phase.

    Science.gov (United States)

    Hernández-Vega, Amayra; Braun, Marcus; Scharrel, Lara; Jahnel, Marcus; Wegmann, Susanne; Hyman, Bradley T; Alberti, Simon; Diez, Stefan; Hyman, Anthony A

    2017-09-05

    Non-centrosomal microtubule bundles play important roles in cellular organization and function. Although many diverse proteins are known that can bundle microtubules, biochemical mechanisms by which cells could locally control the nucleation and formation of microtubule bundles are understudied. Here, we demonstrate that the concentration of tubulin into a condensed, liquid-like compartment composed of the unstructured neuronal protein tau is sufficient to nucleate microtubule bundles. We show that, under conditions of macro-molecular crowding, tau forms liquid-like drops. Tubulin partitions into these drops, efficiently increasing tubulin concentration and driving the nucleation of microtubules. These growing microtubules form bundles, which deform the drops while remaining enclosed by diffusible tau molecules exhibiting a liquid-like behavior. Our data suggest that condensed compartments of microtubule bundling proteins could promote the local formation of microtubule bundles in neurons by acting as non-centrosomal microtubule nucleation centers and that liquid-like tau encapsulation could provide both stability and plasticity to long axonal microtubule bundles. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Mechanism of Catalytic Microtubule Depolymerization via KIF2-Tubulin Transitional Conformation

    Directory of Open Access Journals (Sweden)

    Tadayuki Ogawa

    2017-09-01

    Full Text Available Microtubules (MTs are dynamic structures that are fundamental for cell morphogenesis and motility. MT-associated motors work efficiently to perform their functions. Unlike other motile kinesins, KIF2 catalytically depolymerizes MTs from the peeled protofilament end during ATP hydrolysis. However, the detailed mechanism by which KIF2 drives processive MT depolymerization remains unknown. To elucidate the catalytic mechanism, the transitional KIF2-tubulin complex during MT depolymerization was analyzed through multiple methods, including atomic force microscopy, size-exclusion chromatography, multi-angle light scattering, small-angle X-ray scattering, analytical ultracentrifugation, and mass spectrometry. The analyses outlined the conformation in which one KIF2core domain binds tightly to two tubulin dimers in the middle pre-hydrolysis state during ATP hydrolysis, a process critical for catalytic MT depolymerization. The X-ray crystallographic structure of the KIF2core domain displays the activated conformation that sustains the large KIF2-tubulin 1:2 complex.

  6. A bacteriophage tubulin harnesses dynamic instability to center DNA in infected cells

    Science.gov (United States)

    Erb, Marcella L; Kraemer, James A; Coker, Joanna K C; Chaikeeratisak, Vorrapon; Nonejuie, Poochit; Agard, David A; Pogliano, Joe

    2014-01-01

    Dynamic instability, polarity, and spatiotemporal organization are hallmarks of the microtubule cytoskeleton that allow formation of complex structures such as the eukaryotic spindle. No similar structure has been identified in prokaryotes. The bacteriophage-encoded tubulin PhuZ is required to position DNA at mid-cell, without which infectivity is compromised. Here, we show that PhuZ filaments, like microtubules, stochastically switch from growing in a distinctly polar manner to catastrophic depolymerization (dynamic instability) both in vitro and in vivo. One end of each PhuZ filament is stably anchored near the cell pole to form a spindle-like array that orients the growing ends toward the phage nucleoid so as to position it near mid-cell. Our results demonstrate how a bacteriophage can harness the properties of a tubulin-like cytoskeleton for efficient propagation. This represents the first identification of a prokaryotic tubulin with the dynamic instability of microtubules and the ability to form a simplified bipolar spindle. DOI: http://dx.doi.org/10.7554/eLife.03197.001 PMID:25429514

  7. Beta-Carotene

    Science.gov (United States)

    ... to long-term liver disease, a disease called amyotrophic lateral sclerosis (ALS), and the enlargement of a blood vessel ... of beta-carotene daily doesnt have any benefit. Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). Taking beta-carotene supplements ...

  8. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given. Keywords. Double beta ...

  9. Ausência de associação entre polimorfismo do gene da interleucina-1 beta e o prognóstico de pacientes com traumatismo crânio-encefálico grave Lack of association between interleukin-1 gene polymorphism and prognosis in severe traumatic brain injury patients

    Directory of Open Access Journals (Sweden)

    Taís Frederes Krämer Alcalde

    2009-12-01

    Full Text Available OBJETIVO: O traumatismo crânio-encefálico é a principal causa de óbito em indivíduos com idade entre 1 a 45 anos. O desfecho do traumatismo crânio-encefálico pode estar relacionado, além de fatores pré-morbidade e gravidade do dano, com fatores genéticos. Genes que podem ter relação com o resultado pós-trauma vêm sendo estudados, porém, ainda existem poucas informações sobre a associação entre polimorfismos genéticos e o desfecho do traumatismo crânio-encefálico. O gene da interleucina-1 beta (IL-1B é um dos genes estudados, pois esta citocina encontra-se em níveis elevados após o traumatismo crânio-encefálico e pode afetar de forma negativa seu desfecho. O objetivo do presente estudo foi analisar o polimorfismo -31C/T, localizado na região promotora do gene IL-1B, em pacientes com traumatismo crânio-encefálico grave visando correlacioná-lo com o desfecho primário precoce (alta do centro de terapia intensiva ou morte. MÉTODOS: Foram estudados 69 pacientes internados por traumatismo crânio-encefálico grave em três hospitais de Porto Alegre e região metropolitana. O polimorfismo foi analisado através da reação em cadeia da polimerase, seguida da digestão com enzima de restrição. RESULTADOS: O traumatismo crânio-encefálico grave foi associado a uma mortalidade de 45%. Não foram observadas diferenças significativas nas frequências alélicas e genotípicas entre os grupos de pacientes divididos pelo desfecho do traumatismo crânio-encefálico. CONCLUSÃO: Nossos resultados sugerem que o polimorfismo -31C/T do gene IL-1B não tem impacto significativo no desfecho fatal dos pacientes com traumatismo crânio-encefálico grave.OBJECTIVE: Traumatic brain injury is the major cause of death among individuals between 1-45 years-old. The outcome of traumatic brain injury may be related to brain susceptibility to the injury and genetic factors. Genes that may affect traumatic brain injury outcome are being

  10. 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.

  11. 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

  12. 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.

  13. Modulation of tubulin-nucleotide interactions by metal ions: comparison of beryllium with magnesium and initial studies with other cations.

    Science.gov (United States)

    Hamel, E; Lin, C M; Kenney, S; Skehan, P; Vaughns, J

    1992-06-01

    With microtubule-associated proteins (MAPs) BeSO4 and MgSO4 stimulated tubulin polymerization as compared to a reaction mixture without exogenously added metal ion, while beryllium fluoride had no effect (E. Hamel et al., 1991, Arch. Biochem. Biophys. 286, 57-69). Effects of both cations were most dramatic at GTP concentrations in the same molar range as the tubulin concentration. We have now compared effects of beryllium and magnesium on tubulin-nucleotide interactions in both unpolymerized tubulin and in polymer. Polymer formed with magnesium had properties similar to those of polymer formed without exogenous cation, except for a 20% lower stoichiometry of exogenous GTP incorporated into the latter. In both polymers the incorporated GTP was hydrolyzed to GDP. Stoichiometry of GTP incorporation into polymers formed with beryllium or magnesium was identical, but much of the GTP in the beryllium polymer was not hydrolyzed. The beryllium polymer was more stable than the magnesium polymer. Beryllium also differed from magnesium in only weakly enhancing the binding of GTP in the exchangeable site of unpolymerized tubulin, while neither cation affected GDP exchange at the site. If both cations were present in a reaction mixture, polymer stability was little changed from that of the beryllium polymer, but most of the GTP incorporated into polymer was hydrolyzed. Six additional metal salts (AlCl3, CdCl2, CoCl2, MnCl2, SnCl2, and ZnCl2) also stimulated MAP-dependent tubulin polymerization, but enhanced polymer stability did not correlate with polymer GTP content. We postulate that enhanced polymer stability is a consequence of cation binding directly to tubulin and/or polymer while deficient GTP hydrolysis in the presence of beryllium, as well as aluminum and tin, is a consequence of tight binding of cation to GTP in the exchangeable site.

  14. Tubulin tail sequences and post-translational modifications regulate closure of mitochondrial voltage-dependent anion channel (VDAC).

    Science.gov (United States)

    Sheldon, Kely L; Gurnev, Philip A; Bezrukov, Sergey M; Sackett, Dan L

    2015-10-30

    It was previously shown that tubulin dimer interaction with the mitochondrial outer membrane protein voltage-dependent anion channel (VDAC) blocks traffic through the channel and reduces oxidative metabolism and that this requires the unstructured anionic C-terminal tail peptides found on both α- and β-tubulin subunits. It was unclear whether the α- and β-tubulin tails contribute equally to VDAC blockade and what effects might be due to sequence variations in these tail peptides or to tubulin post-translational modifications, which mostly occur on the tails. The nature of the contribution of the tubulin body beyond acting as an anchor for the tails had not been clarified either. Here we present peptide-protein chimeras to address these questions. These constructs allow us to easily combine a tail peptide with different proteins or combine different tail peptides with a particular protein. The results show that a single tail grafted to an inert protein is sufficient to produce channel closure similar to that observed with tubulin. We show that the β-tail is more than an order of magnitude more potent than the α-tail and that the lower α-tail activity is largely due to the presence of a terminal tyrosine. Detyrosination activates the α-tail, and activation is reversed by the removal of the glutamic acid penultimate to the tyrosine. Nitration of tyrosine reverses the tyrosine inhibition of binding and even induces prolonged VDAC closures. Our results demonstrate that small changes in sequence or post-translational modification of the unstructured tails of tubulin result in substantial changes in VDAC closure. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Brain Basics

    Medline Plus

    Full Text Available ... About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain Brain ... called the hypothalamic-pituitary-adrenal (HPA) axis. Brain Basics in Real Life Brain Basics in Real Life— ...

  16. Zinc, the brain and behavior.

    Science.gov (United States)

    Pfeiffer, C C; Braverman, E R

    1982-04-01

    The total content of zinc in the adult human body averages almost 2 g. This is approximately half the total iron content and 10 to 15 times the total body copper. In the brain, zinc is with iron, the most concentrated metal. The highest levels of zinc are found in the hippocampus in synaptic vesicles, boutons, and mossy fibers. Zinc is also found in large concentrations in the choroid layer of the retina which is an extension of the brain. Zinc plays an important role in axonal and synaptic transmission and is necessary for nucleic acid metabolism and brain tubulin growth and phosphorylation. Lack of zinc has been implicated in impaired DNA, RNA, and protein synthesis during brain development. For these reasons, deficiency of zinc during pregnancy and lactation has been shown to be related to many congenital abnormalities of the nervous system in offspring. Furthermore, in children insufficient levels of zinc have been associated with lowered learning ability, apathy, lethargy, and mental retardation. Hyperactive children may be deficient in zinc and vitamin B-6 and have an excess of lead and copper. Alcoholism, schizophrenia, Wilson's disease, and Pick's disease are brain disorders dynamically related to zinc levels. Zinc has been employed with success to treat Wilson's disease, achrodermatitis enteropathica, and specific types of schizophrenia.

  17. Distinct functional roles of β-tubulin isotypes in microtubule arrays of Tetrahymena thermophila, a model single-celled organism.

    Science.gov (United States)

    Pucciarelli, Sandra; Ballarini, Patrizia; Sparvoli, Daniela; Barchetta, Sabrina; Yu, Ting; Detrich, H William; Miceli, Cristina

    2012-01-01

    The multi-tubulin hypothesis proposes that each tubulin isotype performs a unique role, or subset of roles, in the universe of microtubule function(s). To test this hypothesis, we are investigating the functions of the recently discovered, noncanonical β-like tubulins (BLTs) of the ciliate, Tetrahymena thermophila. Tetrahymena forms 17 distinct microtubular structures whose assembly had been thought to be based on single α- and β-isotypes. However, completion of the macronuclear genome sequence of Tetrahymena demonstrated that this ciliate possessed a β-tubulin multigene family: two synonymous genes (BTU1 and BTU2) encode the canonical β-tubulin, BTU2, and six genes (BLT1-6) yield five divergent β-tubulin isotypes. In this report, we examine the structural features and functions of two of the BLTs (BLT1 and BLT4) and compare them to those of BTU2. With respect to BTU2, BLT1 and BLT4 had multiple sequence substitutions in their GTP-binding sites, in their interaction surfaces, and in their microtubule-targeting motifs, which together suggest that they have specialized functions. To assess the roles of these tubulins in vivo, we transformed Tetrahymena with expression vectors that direct the synthesis of GFP-tagged versions of the isotypes. We show that GFP-BLT1 and GFP-BLT4 were not detectable in somatic cilia and basal bodies, whereas GFP-BTU2 strongly labeled these structures. During cell division, GFP-BLT1 and GFP-BLT4, but not GFP-BTU2, were incorporated into the microtubule arrays of the macronucleus and into the mitotic apparatus of the micronucleus. GFP-BLT1 also participated in formation of the microtubules of the meiotic apparatus of the micronucleus during conjugation. Partitioning of the isotypes between nuclear and ciliary microtubules was confirmed biochemically. We conclude that Tetrahymena uses a family of distinct β-tubulin isotypes to construct subsets of functionally different microtubules, a result that provides strong support for the multi-tubulin

  18. 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.

  19. PASK (proline-alanine-rich Ste20-related kinase) binds to tubulin and microtubules and is involved in microtubule stabilization.

    Science.gov (United States)

    Tsutsumi, Tomonari; Kosaka, Takamitsu; Ushiro, Hiroshi; Kimura, Kazushi; Honda, Tomoyuki; Kayahara, Tetsuro; Mizoguchi, Akira

    2008-09-15

    Proline-alanine-rich Ste20-related kinase (PASK, also referred to as SPAK) has been linked to ion transport regulation. Here, we report two novel activities of PASK: binding to tubulin and microtubules and the promotion of microtubule assembly. Tubulin binding assay showed that full-length PASK and its kinase domain bound to purified tubulin whereas the N-terminal or C-terminal non-catalytic domains of PASK did not. The full-length PASK and its kinase domain were sedimented with paclitaxel-stabilized microtubules by ultracentrifugation. These results indicate that the kinase domain of PASK can interact directly with both microtubules and soluble tubulin in vitro. Truncated PASK lacking the N-terminal non-catalytic domain promoted microtubule assembly at a subcritical concentration of purified tubulin. FLAG-PASK expressed in COS-7 cells translocated to the cytoskeleton when the cells were stimulated with hypertonic sodium chloride, and stabilized microtubules against depolymerization by nocodazole. Our findings suggest that PASK may regulate the cytoskeleton by modulating microtubule stability.

  20. Virtual and biophysical screening targeting the γ-tubulin complex--a new target for the inhibition of microtubule nucleation.

    Directory of Open Access Journals (Sweden)

    Olivier Cala

    Full Text Available Microtubules are the main constituents of mitotic spindles. They are nucleated in large amounts during spindle assembly, from multiprotein complexes containing γ-tubulin and associated γ-tubulin complex proteins (GCPs. With the aim of developing anti-cancer drugs targeting these nucleating complexes, we analyzed the interface between GCP4 and γ-tubulin proteins usually located in a multiprotein complex named γ-TuRC (γ-Tubulin Ring Complex. 10 ns molecular dynamics simulations were performed on the heterodimers to obtain a stable complex in silico and to analyze the residues involved in persistent protein-protein contacts, responsible for the stability of the complex. We demonstrated in silico the existence of a binding pocket at the interface between the two proteins upon complex formation. By combining virtual screening using a fragment-based approach and biophysical screening, we found several small molecules that bind specifically to this pocket. Sub-millimolar fragments have been experimentally characterized on recombinant proteins using differential scanning fluorimetry (DSF for validation of these compounds as inhibitors. These results open a new avenue for drug development against microtubule-nucleating γ-tubulin complexes.

  1. Microinjection of biotin-tubulin into anaphase cells induces transient elongation of kinetochore microtubules and reversal of chromosome-to-pole motion.

    Science.gov (United States)

    Shelden, E; Wadsworth, P

    1992-03-01

    During prometaphase and metaphase of mitosis, tubulin subunit incorporation into kinetochore microtubules occurs proximal to the kinetochore, at the plus-ends of kinetochore microtubules. During anaphase, subunit loss from kinetochore fiber microtubules is also thought to occur mainly from microtubule plus-ends, proximal to the kinetochore. Thus, the kinetochore can mediate both subunit addition and loss while maintaining an attachment to kinetochore microtubules. To examine the relationship between chromosome motion and tubulin subunit assembly in anaphase, we have injected anaphase cells with biotin-labeled tubulin subunits. The pattern of biotin-tubulin incorporation was revealed using immunoelectron and confocal fluorescence microscopy of cells fixed after injection; chromosome motion was analyzed using video records of living injected cells. When anaphase cells are examined approximately 30 s after injection with biotin-tubulin, bright "tufts" of fluorescence are detected proximal to the kinetochores. Electron microscopic immunocytochemistry further reveals that these tufts of biotin-tubulin-containing microtubules are continuous with unlabeled kinetochore fiber microtubules. Biotin-tubulin incorporation proximal to the kinetochore in anaphase cells is detected after injection of 3-30 mg/ml biotin-tubulin, but not in cells injected with 0.3 mg/ml biotin-tubulin. At intermediate concentrations of biotin-tubulin (3-5 mg/ml), incorporation at the kinetochore can be detected within 15 s after injection; by approximately 1 min after injection discrete tufts of fluorescence are no longer detected, although some incorporation throughout the kinetochore fiber and into nonkinetochore microtubules is observed. At higher concentrations of injected biotin-tubulin (13 mg/ml), incorporation at the kinetochore is more extensive and occurs for longer periods of time than at intermediate concentrations. Incorporation of biotin-tubulin proximal to the kinetochore can be

  2. Specific β-tubulin isotypes can functionally enhance or diminish epothilone B sensitivity in non-small cell lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Pei Pei Gan

    Full Text Available Epothilones are a new class of microtubule stabilizing agents with promising preclinical and clinical activity. Their cellular target is β-tubulin and factors influencing intrinsic sensitivity to epothilones are not well understood. In this study, the functional significance of specific β-tubulin isotypes in intrinsic sensitivity to epothilone B was investigated using siRNA gene knockdown against βII-, βIII- or βIVb-tubulins in two independent non-small cell lung cancer (NSCLC cell lines, NCI-H460 and Calu-6. Drug-treated clonogenic assays showed that sensitivity to epothilone B was not altered following knockdown of βII-tubulin in both NSCLC cell lines. In contrast, knockdown of βIII-tubulin significantly increased sensitivity to epothilone B. Interestingly, βIVb-tubulin knockdowns were significantly less sensitive to epothilone B, compared to mock- and control siRNA cells. Cell cycle analysis of βIII-tubulin knockdown cells showed a higher percentage of cell death with epothilone B concentrations as low as 0.5 nM. In contrast, βIVb-tubulin knockdown cells displayed a decrease in epothilone B-induced G(2-M cell cycle accumulation compared to control siRNA cells. Importantly, βIII-tubulin knockdowns displayed a significant dose-dependent increase in the percentage of apoptotic cells upon treatment with epothilone B, as detected using caspase 3/7 activity and Annexin-V staining. Higher concentrations of epothilone B were required to induce apoptosis in the βIVb-tubulin knockdowns compared to control siRNA, highlighting a potential mechanism underlying decreased sensitivity to this agent. This study demonstrates that specific β-tubulin isotypes can influence sensitivity to epothilone B and may influence differential sensitivity to this promising new agent.

  3. Beta Thalassemia (For Parents)

    Science.gov (United States)

    ... anemia or failure to thrive. If the doctor suspects beta thalassemia, he or she will take a ... test called a hemoglobin electrophoresis and/or a DNA test for abnormal hemoglobin genes. If both parents ...

  4. High beta multipoles

    Energy Technology Data Exchange (ETDEWEB)

    Prager, S C

    1982-05-01

    Multipoles are being employed as devices to study fusion issues and plasma phenomena at high values of beta (plasma pressure/magnetic pressure) in a controlled manner. Due to their large volume, low magnetic field (low synchrotron radiation) region, they are also under consideration as potential steady state advanced fuel (low neutron yield) reactors. Present experiments are investigating neoclassical (bootstrap and Pfirsch-Schlueter) currents and plasma stability at extremely high beta.

  5. Beta-thalassemia

    OpenAIRE

    Origa Raffaella; Galanello Renzo

    2010-01-01

    Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor...

  6. 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

  7. Neurosteroid biosynthesis and function in the brain of domestic birds

    Directory of Open Access Journals (Sweden)

    Kazuyoshi eTsutsui

    2011-09-01

    Full Text Available It is now established that the brain and other nervous systems have the capability of forming steroids de novo, the so-called neurosteroids. The pioneering discovery of Baulieu and his colleagues, using rodents, has opened the door to a new research field of "neurosteroids". In contrast to mammalian vertebrates, little has been known regarding de novo neurosteroidogenesis in the brain of birds. We therefore investigated neurosteroid formation and metabolism in the brain of quail, a domestic bird. Our studies over the past two decades demonstrated that the quail brain possesses cytochrome P450 side-chain cleavage enzyme (P450scc, 3beta-hydroxysteroid dehydrogenase/delta5-delta4-isomerase (3beta-HSD, 5beta-reductase, cytochrome P450 17alpha-hydroxylase/c17,20-lyase (P45017alpha,lyase, 17beta-HSD, etc., and produces pregnenolone, progesterone, 5beta-dihydroprogesterone (5beta-DHP, 3beta, 5beta-tetrahydroprogesterone (3beta, 5beta-THP, androstenedione, testosterone, and estradiol from cholesterol. Independently, Schlinger's laboratory demonstrated that the brain of zebra finch, a songbird, also produces various neurosteroids. Thus, the formation and metabolism of neurosteroids from cholesterol is now known to occur in the brain of birds. In addition, we recently found that the quail brain expresses cytochrome P4507alpha and produces 7alpha-and 7beta-hydroxypregnenolone, previously undescribed avian neurosteroids, from pregnenolone. This paper summarizes the advances made in our understanding of neurosteroid formation and metabolism in the brain of domestic birds. This paper also describes what are currently known about physiological changes in neurosteroid formation and biological functions of neurosteroids in the brain of domestic and other birds.

  8. Activation of the γ-tubulin complex by the Mto1/2 complex.

    Science.gov (United States)

    Lynch, Eric M; Groocock, Lynda M; Borek, Weronika E; Sawin, Kenneth E

    2014-04-14

    The multisubunit γ-tubulin complex (γ-TuC) is critical for microtubule nucleation in eukaryotic cells, but it remains unclear how the γ-TuC becomes active specifically at microtubule-organizing centers (MTOCs) and not more broadly throughout the cytoplasm. In the fission yeast Schizosaccharomyces pombe, the proteins Mto1 and Mto2 form the Mto1/2 complex, which interacts with the γ-TuC and recruits it to several different types of cytoplasmic MTOC sites. Here, we show that the Mto1/2 complex activates γ-TuC-dependent microtubule nucleation independently of localizing the γ-TuC. This was achieved through the construction of a "minimal" version of Mto1/2, Mto1/2[bonsai], that does not localize to any MTOC sites. By direct imaging of individual Mto1/2[bonsai] complexes nucleating single microtubules in vivo, we further determine the number and stoichiometry of Mto1, Mto2, and γ-TuC subunits Alp4 (GCP2) and Alp6 (GCP3) within active nucleation complexes. These results are consistent with active nucleation complexes containing ∼13 copies each of Mto1 and Mto2 per active complex and likely equimolar amounts of γ-tubulin. Additional experiments suggest that Mto1/2 multimers act to multimerize the fission yeast γ-tubulin small complex and that multimerization of Mto2 in particular may underlie assembly of active microtubule nucleation complexes. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  9. 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.

  10. Conservation of tubulin-binding sequences in TRPV1 throughout evolution.

    Directory of Open Access Journals (Sweden)

    Puspendu Sardar

    Full Text Available Transient Receptor Potential Vanilloid sub type 1 (TRPV1, commonly known as capsaicin receptor can detect multiple stimuli ranging from noxious compounds, low pH, temperature as well as electromagnetic wave at different ranges. In addition, this receptor is involved in multiple physiological and sensory processes. Therefore, functions of TRPV1 have direct influences on adaptation and further evolution also. Availability of various eukaryotic genomic sequences in public domain facilitates us in studying the molecular evolution of TRPV1 protein and the respective conservation of certain domains, motifs and interacting regions that are functionally important.Using statistical and bioinformatics tools, our analysis reveals that TRPV1 has evolved about ∼420 million years ago (MYA. Our analysis reveals that specific regions, domains and motifs of TRPV1 has gone through different selection pressure and thus have different levels of conservation. We found that among all, TRP box is the most conserved and thus have functional significance. Our results also indicate that the tubulin binding sequences (TBS have evolutionary significance as these stretch sequences are more conserved than many other essential regions of TRPV1. The overall distribution of positively charged residues within the TBS motifs is conserved throughout evolution. In silico analysis reveals that the TBS-1 and TBS-2 of TRPV1 can form helical structures and may play important role in TRPV1 function.Our analysis identifies the regions of TRPV1, which are important for structure-function relationship. This analysis indicates that tubulin binding sequence-1 (TBS-1 near the TRP-box forms a potential helix and the tubulin interactions with TRPV1 via TBS-1 have evolutionary significance. This interaction may be required for the proper channel function and regulation and may also have significance in the context of Taxol®-induced neuropathy.

  11. 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

  12. Insecticidal heterolignans--tubuline polymerization inhibitors with activity against chewing pests.

    Science.gov (United States)

    Frackenpohl, Jens; Adelt, Isabelle; Antonicek, Horst; Arnold, Christian; Behrmann, Patricia; Blaha, Nicole; Böhmer, Jutta; Gutbrod, Oliver; Hanke, Roman; Hohmann, Sabine; van Houtdreve, Marc; Lösel, Peter; Malsam, Olga; Melchers, Martin; Neufert, Valentina; Peschel, Elisabeth; Reckmann, Udo; Schenke, Thomas; Thiesen, Hans-Peter; Velten, Robert; Vogelsang, Kathrin; Weiss, Hans-Christoph

    2009-06-15

    Starting from natural product podophyllotoxin 1 substituted heterolignans were identified with promising insecticidal in vivo activity. The impact of substitution in each segment of the core structure was investigated in a detailed SAR study, and variation of substituents in both aromatic moieties afforded derivatives 5 and 43 with broad insecticidal activity against lepidopteran and coleopteran species. In vitro measurements supported by modeling studies indicate that heterolignans 3-134 act as tubuline polymerization inhibitors interacting with the colchicine-binding site. Insect specific structure-activity effects were observed showing that the insecticidal SAR described herein differs from reported cytotoxicity studies.

  13. Mathematical modeling of the microtubule dynamic instability: a new approch of GTP-tubulin hydrolysis

    Directory of Open Access Journals (Sweden)

    Barlukova Ayuna

    2015-01-01

    Full Text Available Microtubules, components of the cytosqueleton, play an important role in cell division, cell migration and thus in the cancer proccess through dynamic instability. Therefore they are an important target for anti-cancer treatment. Proper modelling of dynamic instability is a crucial tool to understand the mechanism of action of microtubule targeting agents. In this paper, we propose a new concept for GTP-tubulin hydrolysis which allow the model to accurately reproduce microtubule dynamics observed in vitro or in cells. This approach will be more appropriate to take study the effects of drugs.

  14. In vitro and in vivo evaluation of tubulin inhibitors with non-small cell lung cancer pre-clinical models

    Directory of Open Access Journals (Sweden)

    Lama R

    2015-05-01

    Full Text Available Synthetic small molecule tubulin inhibitors have many advantages as novel anti-cancer agents compared to the current tubulin inhibitors generated from natural products. Our previous studies led to the design and synthesis of a series of novel tubulin inhibitors. Some of these compounds also inhibited heat shock protein 27 (Hsp27, and showed promising in vitro anti-cancer activities in several breast cancer cell lines at sub nano-molar concentrations. However, whether these compounds could suppress tumor growth in animals was not investigated yet. In the current study, to identify the best drug candidates, therapeutic efficacy of the representative compounds from previous analyses was evaluated using non-small cell lung cancer preclinical models. These agents dose-dependently inhibited the growth of lung cancer cells in both monolayer cultures and three-dimensional multicellular spheroids. Several compounds also showed promising tumor growth suppressive activity in nude mice xenograft model

  15. 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

  16. 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

    2014-05-23

    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. © 2014. Published by The Company of Biologists Ltd.

  17. 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.

  18. Peripheral administration of the soluble TNF inhibitor XPro1595 modifies brain immune cell profiles, decreases beta-amyloid plaque load, and rescues impaired long-term potentiation in 5xFAD mice.

    Science.gov (United States)

    MacPherson, Kathryn P; Sompol, Pradoldej; Kannarkat, George T; Chang, Jianjun; Sniffen, Lindsey; Wildner, Mary E; Norris, Christopher M; Tansey, Malú G

    2017-06-01

    Clinical and animal model studies have implicated inflammation and peripheral immune cell responses in the pathophysiology of Alzheimer's disease (AD). Peripheral immune cells including T cells circulate in the cerebrospinal fluid (CSF) of healthy adults and are found in the brains of AD patients and AD rodent models. Blocking entry of peripheral macrophages into the CNS was reported to increase amyloid burden in an AD mouse model. To assess inflammation in the 5xFAD (Tg) mouse model, we first quantified central and immune cell profiles in the deep cervical lymph nodes and spleen. In the brains of Tg mice, activated (MHCII + , CD45 high , and Ly6C high ) myeloid-derived CD11b + immune cells are decreased while CD3 + T cells are increased as a function of age relative to non-Tg mice. These immunological changes along with evidence of increased mRNA levels for several cytokines suggest that immune regulation and trafficking patterns are altered in Tg mice. Levels of soluble Tumor Necrosis Factor (sTNF) modulate blood-brain barrier (BBB) permeability and are increased in CSF and brain parenchyma post-mortem in AD subjects and Tg mice. We report here that in vivo peripheral administration of XPro1595, a novel biologic that sequesters sTNF into inactive heterotrimers, reduced the age-dependent increase in activated immune cells in Tg mice, while decreasing the overall number of CD4 + T cells. In addition, XPro1595 treatment in vivo rescued impaired long-term potentiation (LTP) measured in brain slices in association with decreased Aβ plaques in the subiculum. Selective targeting of sTNF may modulate brain immune cell infiltration, and prevent or delay neuronal dysfunction in AD. Immune cells and cytokines perform specialized functions inside and outside the brain to maintain optimal brain health; but the extent to which their activities change in response to neuronal dysfunction and degeneration is not well understood. Our findings indicate that neutralization of s

  19. Restricted spontaneous in vitro differentiation and region-specific migration of long-term expanded fetal human neural precursor cells after transplantation into the adult rat brain.

    Science.gov (United States)

    Maciaczyk, Jaroslaw; Singec, Ilyas; Maciaczyk, Donata; Klein, Alexander; Nikkhah, Guido

    2009-09-01

    Human fetal neural stem/progenitor cells (hNSCs) are investigated for their potential as a cell source for cell-based therapies in neurodegenerative diseases. However, the limited availability of fetal tissue and insufficient understanding of the lineage-dependent pattern of survival, migration, and differentiation following engraftment are still unresolved issues. In the current study hNSCs derived from different brain regions were long-term expanded in vitro to yield proliferating neurospheres giving rise to neurons, astro-, and oligodendroglial cells and assessed for their potential for migration, differentiation, and anatomical integration following intracerebral grafting into rats. hNSCs isolated from neocortex, striatum, midbrain, and spinal cord (SC) proliferated following in vitro differentiation, and showed a significant decrease of newly formed neurons along the rostrocaudal axis of the developing central nervous system (CNS). Most of the mature neurons were positive for the neurotransmitter GABA. In vivo all cell types survived up to 9 weeks posttransplantation. Intrastriatally grafted hNSCs migrated extensively along white matter tracts reaching both rostral (forceps minor) and caudal (midbrain, cerebral peduncle) brain regions. The majority of migratory cells expressed the stem cell marker, nestin. A fraction of grafted cells acquired a neuronal phenotype expressing doublecortin, beta-III-tubulin, or GABA. These data demonstrate efficient in vitro propagation, region-specific long-term survival, long-distance migration, and neuronal differentiation of hNSCs after transplantation into the adult rat brain. The availability of a large pool of in vitro expanded nestin-positive cells offers the possibility for further ex vivo manipulations and the recruitment of different neuronal phenotypes for cell replacement strategies for CNS disorders.

  20. Cellular distribution of ferric iron, ferritin, transferrin and divalent metal transporter 1 (DMT1) in substantia nigra and basal ganglia of normal and β2-microglobulin deficient mouse brain

    DEFF Research Database (Denmark)

    Moos, Torben; Trinder, D.; Morgan, E.H.

    2000-01-01

    beta-2-microglobulin, blood-brain barrier, gene knock out, iron, neurodegenerative disorders, oxidative damage, subthalamic nucleus......beta-2-microglobulin, blood-brain barrier, gene knock out, iron, neurodegenerative disorders, oxidative damage, subthalamic nucleus...

  1. Brain Basics

    Medline Plus

    Full Text Available ... Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video Welcome. Brain Basics provides information on how the brain works, how mental illnesses ...

  2. Brain Basics

    Science.gov (United States)

    ... Events About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  3. Brain Basics

    Medline Plus

    Full Text Available ... Events About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  4. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... learning more about how the brain grows and works in healthy people, and how normal brain development ...

  5. 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

  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. The Lattice As Allosteric Effector: Structural Studies of Alphabeta- And Gamma-Tubulin Clarify the Role of GTP in Microtubule Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Rice, L.M.; Montabana, E.A.; Agard, D.A.

    2009-05-21

    GTP-dependent microtubule polymerization dynamics are required for cell division and are accompanied by domain rearrangements in the polymerizing subunit, alpha-tubulin. Two opposing models describe the role of GTP and its relationship to conformational change in alpha-tubulin. The allosteric model posits that unpolymerized alpha-tubulin adopts a more polymerization-competent conformation upon GTP binding. The lattice model posits that conformational changes occur only upon recruitment into the growing lattice. Published data support a lattice model, but are largely indirect and so the allosteric model has prevailed. We present two independent solution probes of the conformation of alpha-tubulin, the 2.3 A crystal structure of gamma-tubulin bound to GDP, and kinetic simulations to interpret the functional consequences of the structural data. These results (with our previous gamma-tubulin:GTPgammaS structure) support the lattice model by demonstrating that major domain rearrangements do not occur in eukaryotic tubulins in response to GTP binding, and that the unpolymerized conformation of alpha-tubulin differs significantly from the polymerized one. Thus, geometric constraints of lateral self-assembly must drive alpha-tubulin conformational changes, whereas GTP plays a secondary role to tune the strength of longitudinal contacts within the microtubule lattice. alpha-Tubulin behaves like a bent spring, resisting straightening until forced to do so by GTP-mediated interactions with the growing microtubule. Kinetic simulations demonstrate that resistance to straightening opposes microtubule initiation by specifically destabilizing early assembly intermediates that are especially sensitive to the strength of lateral interactions. These data provide new insights into the molecular origins of dynamic microtubule behavior.

  8. Multiple factors contribute to the peripheral induction of cerebral beta-amyloidosis

    OpenAIRE

    Eisele, Y.S.; Fritschi, S.K.; Hamaguchi, T.; Obermüller, U.; Füger, P.; Skodras, A.; Schäfer, C; Odenthal, J.; Heikenwalder, M.; Staufenbiel, M; Jucker, M.

    2014-01-01

    Deposition of aggregated amyloid-beta (Abeta) peptide in brain is an early event and hallmark pathology of Alzheimer's disease and cerebral Abeta angiopathy. Experimental evidence supports the concept that Abeta multimers can act as seeds and structurally corrupt other Abeta peptides by a self-propagating mechanism. Here we compare the induction of cerebral beta-amyloidosis by intraperitoneal applications of Abeta-containing brain extracts in three Abeta-precursor protein (APP) transgenic mou...

  9. EB1 recognizes the nucleotide state of tubulin in the microtubule lattice.

    Directory of Open Access Journals (Sweden)

    Marija Zanic

    Full Text Available Plus-end-tracking proteins (+TIPs are localized at the fast-growing, or plus end, of microtubules, and link microtubule ends to cellular structures. One of the best studied +TIPs is EB1, which forms comet-like structures at the tips of growing microtubules. The molecular mechanisms by which EB1 recognizes and tracks growing microtubule ends are largely unknown. However, one clue is that EB1 can bind directly to a microtubule end in the absence of other proteins. Here we use an in vitro assay for dynamic microtubule growth with two-color total-internal-reflection-fluorescence imaging to investigate binding of mammalian EB1 to both stabilized and dynamic microtubules. We find that under conditions of microtubule growth, EB1 not only tip tracks, as previously shown, but also preferentially recognizes the GMPCPP microtubule lattice as opposed to the GDP lattice. The interaction of EB1 with the GMPCPP microtubule lattice depends on the E-hook of tubulin, as well as the amount of salt in solution. The ability to distinguish different nucleotide states of tubulin in microtubule lattice may contribute to the end-tracking mechanism of EB1.

  10. The Centrosome Is a Selective Condensate that Nucleates Microtubules by Concentrating Tubulin.

    Science.gov (United States)

    Woodruff, Jeffrey B; Ferreira Gomes, Beatriz; Widlund, Per O; Mahamid, Julia; Honigmann, Alf; Hyman, Anthony A

    2017-06-01

    Centrosomes are non-membrane-bound compartments that nucleate microtubule arrays. They consist of nanometer-scale centrioles surrounded by a micron-scale, dynamic assembly of protein called the pericentriolar material (PCM). To study how PCM forms a spherical compartment that nucleates microtubules, we reconstituted PCM-dependent microtubule nucleation in vitro using recombinant C. elegans proteins. We found that macromolecular crowding drives assembly of the key PCM scaffold protein SPD-5 into spherical condensates that morphologically and dynamically resemble in vivo PCM. These SPD-5 condensates recruited the microtubule polymerase ZYG-9 (XMAP215 homolog) and the microtubule-stabilizing protein TPXL-1 (TPX2 homolog). Together, these three proteins concentrated tubulin ∼4-fold over background, which was sufficient to reconstitute nucleation of microtubule asters in vitro. Our results suggest that in vivo PCM is a selective phase that organizes microtubule arrays through localized concentration of tubulin by microtubule effector proteins. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Targeting Toxoplasma Tubules: Tubulin, Microtubules, and Associated Proteins in a Human Pathogen

    Science.gov (United States)

    2014-01-01

    Toxoplasma gondii is an obligate intracellular parasite that causes serious opportunistic infections, birth defects, and blindness in humans. Microtubules are critically important components of diverse structures that are used throughout the Toxoplasma life cycle. As in other eukaryotes, spindle microtubules are required for chromosome segregation during replication. Additionally, a set of membrane-associated microtubules is essential for the elongated shape of invasive “zoites,” and motility follows a spiral trajectory that reflects the path of these microtubules. Toxoplasma zoites also construct an intricate, tubulin-based apical structure, termed the conoid, which is important for host cell invasion and associates with proteins typically found in the flagellar apparatus. Last, microgametes specifically construct a microtubule-containing flagellar axoneme in order to fertilize macrogametes, permitting genetic recombination. The specialized roles of these microtubule populations are mediated by distinct sets of associated proteins. This review summarizes our current understanding of the role of tubulin, microtubule populations, and associated proteins in Toxoplasma; these components are used for both novel and broadly conserved processes that are essential for parasite survival. PMID:25380753

  12. 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.

  13. Liposomes bi-functionalized with phosphatidic acid and an ApoE-derived peptide affect A beta aggregation features and cross the blood-brain-barrier: Implications for therapy of Alzheimer disease

    NARCIS (Netherlands)

    Bana, l.; Minniti, S.; Sesana, S.; Zambelli, V.; Cagnotto, A.; Orlando, A.; Cazzaniga, M.; Zwart, R.; Scheper, W.; Masserini, M.; Re, F.

    2014-01-01

    Targeting amyloid-β peptide (Aβ) within the brain is a strategy actively sought for therapy of Alzheimer's disease (AD). We investigated the ability of liposomes bi-functionalized with phosphatidic acid and with a modified ApoE-derived peptide (mApoE-PA-LIP) to affect Aβ aggregation/disaggregation

  14. EEG Alpha and Beta Activity in Normal and Deaf Subjects.

    Science.gov (United States)

    Waldron, Manjula; And Others

    Electroencephalogram and task performance data were collected from three groups of young adult males: profoundly deaf Ss who signed from an early age, profoundly deaf Ss who only used oral (speech and speedreading) methods of communication, and normal hearing Ss. Alpha and Beta brain wave patterns over the Wernicke's area were compared across…

  15. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...

  16. Assignment of human protein phosphatase 2A regulatory subunit genes B56{alpha}, B56{beta}, B56{gamma}, B56{delta}, and B56{epsilon} (PPP2R5A-PPP2R5E), highly expressed in muscle and brain, to chromosome regions 1q41, 11q12, 3p21, 6p21.1, and 7p11.1 {r_arrow} p12

    Energy Technology Data Exchange (ETDEWEB)

    McCright, B.; Virshup, D.M.; Brothman, A.R. [Univ. of Utah School of Medicine, Salt Lake City, UT (United States)

    1996-08-15

    The activity of the major intracellular protein phosphatase, protein phosphatase 2A WPM, is determined by the nature of the associated regulatory subunit. A new family of human PP2A regulatory subunits has recently been identified. Three of these subunits, B56{beta}, B56{delta}, and B56{epsilon}, are most highly expressed in brain, while the B56{alpha} and B56{gamma} isoforms are highly expressed in cardiac and skeletal muscle. Genes PPP2R5A-PPP2R5E encoding the phosphatase regulatory proteins B56{alpha}, B56{beta}, B56{gamma}, B56{delta}, and B56{epsilon} have now been mapped by fluorescence in situ hybridization to chromosome regions 1q41, 11q12, 3p21, 6p21.1, and 7p11.2-p12, respectively. 16 refs., 1 fig.

  17. Class III β-tubulin in advanced NSCLC of adenocarcinoma subtype predicts superior outcome in a randomized trial

    DEFF Research Database (Denmark)

    Vilmar, Adam Christian; Santoni-Rugiu, Eric; Sørensen, Jens Benn

    2011-01-01

    Platinum-based doublets are the cornerstone of treatment in advanced non-small-cell lung cancer (NSCLC) and often include vinorelbine or taxanes. A predictive biomarker is greatly needed to select chemotherapy-sensitive patients for these microtubule-interfering agents. Class III β-tubulin (TUBB3...

  18. Class III β-tubulin in advanced NSCLC of adenocarcinoma subtype predicts superior outcome in a randomized trial

    DEFF Research Database (Denmark)

    Vilmar, Adam Christian; Santoni-Rugiu, Eric; Sørensen, Jens Benn

    2011-01-01

    Platinum-based doublets are the cornerstone of treatment in advanced non-small-cell lung cancer (NSCLC) and often include vinorelbine or taxanes. A predictive biomarker is greatly needed to select chemotherapy-sensitive patients for these microtubule-interfering agents. Class III ß-tubulin (TUBB3...

  19. Mutation detection on isotype-1 β tubulin genes of Haemonchus contortus resistant strain to benzimidazole using single strand conformation polymorphism

    Directory of Open Access Journals (Sweden)

    Dyah Haryuningtyas

    2005-10-01

    Full Text Available Evidence of anthelmintic resistance of Haemonchus contortus to benzimidazole groups based on Larval development assay (LDA and Fecal egg count reduction test (FECRT test has been reported in some areas in Indonesia. Studies on sheep parasite H. contortus have shown that resistance to benzimidazole drugs is correlated with selection for individuals in the population possesing a spesific isotype-1 β tubulin gene. The aim of this study was to determine mutation on central part of isotype-1 β tubulin gene of benzimidazole resistant strain H. contortus using Single Strand Conformation Polymorphism (SSCP. H. contortus worms were isolated from four sheep from two government farms that resistance to benzimidazole have been occurred (SPTD Trijaya, Kuningan, West Java and UPTD Pelayanan Kesehatan Hewan, Bantul, Yogyakarta and one sheep that susceptible from Cicurug, Bogor, West Java as a kontrol. Resistance status to benzimidazole was reexamined individually with LDA and FECRT before sheep slaughtered. DNA was extracted from female H. contortus worms. A fragment of 520 bp isotype- 1 β tubulin gene was amplified using Polymerase chain reaction (PCR and then analyze using SSCP. The results showed that there were polymorphism in isotype-1 β tubulin gene among H. contortus susceptible (Cicurug, Bogor, Jawa Barat and two H. contortus resistant strains from SPTD Trijaya, Kuningan, West Java and UPTD Pelayanan Kesehatan Hewan, Bantul, Yogyakarta. Mutation occurred in the different nucleotide of the two resistant strain.

  20. Species identification of Wickerhamomyces anomalus and related taxa using β-tubulin (β-tub) DNA barcode marker.

    Science.gov (United States)

    Huang, Chien-Hsun; Chang, Mu-Tzu; Huang, Lina

    2012-12-01

    Wickerhamomyces anomalus is used in food and feed processing, although the species has been reported as an opportunistic human pathogen, predominantly in neonates. Neither phenotypic nor the most frequently applied genotypic marker (D1/D2 LSU ribosomal DNA) provide sufficient resolution for accurate identification of this yeast. In this study, the β-tubulin gene was used for species identification by direct DNA sequencing and as marker in a species-specific PCR assay. The results showed that all examined W. anomalus strains were clearly distinguished from the closely related species by comparative sequence analysis of the β-tubulin gene. In addition, the species-specific primers were also developed based on the β-tubulin gene, which was employed for polymerase chain reaction with the template DNA of Wickerhamomyces strains. A single 218 bp species-specific band was found only in W. anomalus. Our data indicate that the phylogenetic relationships between these strains are easily resolved by sequencing of the β-tubulin gene and combined with species-specific PCR assay. Copyright © 2012 John Wiley & Sons, Ltd.

  1. Refining the phenotype of alpha-1a Tubulin (TUBA1A) mutation in patients with classical lissencephaly

    NARCIS (Netherlands)

    Morris-Rosendahl, D.J.; Najm, J.; Lachmeijer, A.M.A.; Sztriha, L.; Martins, M.; Kuechler, A.; Haug, V.; Zeschnigk, C.; Martin, P.; Santos, M.; Vasconcelos, C.; Omran, H.; Kraus, U.; van der Knaap, M.S.; Schuierer, G.; Kutsche, K.; Uyanik, G.

    2008-01-01

    Mutations in the α-1a Tubulin (TUBA1A) gene have recently been found to cause cortical malformations resemblant of classical lissencephaly but with a specific combination of features. To date, TUBA1A mutations have been described in five patients and three foetuses. Our aims were to establish how

  2. The actin-MRTF-SRF transcriptional circuit controls tubulin acetylation via α-TAT1 gene expression.

    Science.gov (United States)

    Fernández-Barrera, Jaime; Bernabé-Rubio, Miguel; Casares-Arias, Javier; Rangel, Laura; Fernández-Martín, Laura; Correas, Isabel; Alonso, Miguel A

    2018-01-10

    The role of formins in microtubules is not well understood. In this study, we have investigated the mechanism by which INF2, a formin mutated in degenerative renal and neurological hereditary disorders, controls microtubule acetylation. We found that silencing of INF2 in epithelial RPE-1 cells produced a dramatic drop in tubulin acetylation, increased the G-actin/F-actin ratio, and impaired myocardin-related transcription factor (MRTF)/serum response factor (SRF)-dependent transcription, which is known to be repressed by increased levels of G-actin. The effect on tubulin acetylation was caused by the almost complete absence of α-tubulin acetyltransferase 1 (α-TAT1) messenger RNA (mRNA). Activation of the MRTF-SRF transcriptional complex restored α-TAT1 mRNA levels and tubulin acetylation. Several functional MRTF-SRF-responsive elements were consistently identified in the α-TAT1 gene. The effect of INF2 silencing on microtubule acetylation was also observed in epithelial ECV304 cells, but not in Jurkat T cells. Therefore, the actin-MRTF-SRF circuit controls α-TAT1 transcription. INF2 regulates the circuit, and hence microtubule acetylation, in cell types where it has a prominent role in actin polymerization. © 2018 Fernández-Barrera et al.

  3. Trichoderma .beta.-glucosidase

    Science.gov (United States)

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  4. Beta thalassemia - a review

    Directory of Open Access Journals (Sweden)

    R Jha

    2014-09-01

    Full Text Available Thalassemia is a globin gene disorder that results in a diminished rate of synthesis of one or more of the globin chains. About 1.5% of the global population (80 to 90 million people are carriers of beta Thalassemia. More than 200 mutations are described in beta thalassemia. However not all mutations are common in different ethnic groups. The only effective way to reduce burden of thalassemia is to prevent birth of homozygotes. Diagnosis of beta thalassemia can be done by fetal DNA analysis for molecular defects of beta thalassemia or by fetal blood analysis. Hematopoietic stem cell transplantation is the only available curative approach for Thalassemia. Many patients with thalassemia in underdeveloped nations die in childhood or adolescence. Programs that provide acceptable care, including transfusion of safe blood and supportive therapy including chelation must be established.DOI: http://dx.doi.org/10.3126/jpn.v4i8.11609 Journal of Pathology of Nepal; Vol.4,No. 8 (2014 663-671

  5. beta nur pratiwi

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. BETA NUR PRATIWI. Articles written in Pramana – Journal of Physics. Volume 88 Issue 2 February 2017 pp 25 Regular. Asymptotic iteration method for the modified Pöschl–Teller potential and trigonometric Scarf II non-central potential in the Dirac equation spin symmetry.

  6. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... Abstract. The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  7. Double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Bryman, D.; Picciotto, C.

    1978-01-01

    The problem of double beta decay is reviewed with emphasis on its relevance to lepton number conservation. Recently, the ratio of the double beta-decay half-lives of /sup 128/Te and /sup 130/Te has been measured in a geological experiment and a limit for the ratio of the neutrinoless rate to the total rate for /sup 82/Se decay has been obtained from a direct-detection experiment. For the first time, these results show conclusively that double beta decay is not primarily a lepton-number-violating neutrinoless process. However, they also do not agree with calculations which assume that only lepton-number-conserving two-neutrino double beta decay occurs. The conclusion that lepton number conservation is violated is suggested by limited experimental information. By considering contributions to the total rate from both the two-neutrino and the neutrinoless channels, we obtain data which are consistent with a lepton nonconservation parameter of order eta=3.5 x 10/sup -5/. Roughly the same value of eta is obtained by assuming that the decay occurs either via lepton emission from two nucleons or via emission from a resonance in the nucleus.

  8. Beta Cell Breakthroughs

    Science.gov (United States)

    ... raise the hopes of people with type 1 diabetes that a cure is right around the corner. First the beta ... element: Two of his children have type 1 diabetes. After his son was diagnosed with the disease as an infant, Melton devoted his career to searching for a cure. More than 20 years have gone by, but ...

  9. Beta limits for torsatrons

    Science.gov (United States)

    Bauer, F.; Betancourt, O.; Garabedian, P.; Shohet, J. L.

    1981-01-01

    An ideal magnetohydrodynamic equilibrium and stability code is used to study ballooning modes in torsatrons. The most dangerous modes turn out to be those with low poloidal and toroidal wave numbers. Beta limits for equilibrium and stability are determined for an [unk] = 2 ultimate torsatron with large [unk] = 1 and [unk] = 3 sidebands. PMID:16592941

  10. Brain herniation

    Science.gov (United States)

    ... herniation; Uncal herniation; Subfalcine herniation; Tonsillar herniation; Herniation - brain ... Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most ...

  11. 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....

  12. 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...

  13. mRNA and Protein Levels for GABA[subscript A][alpha]4, [alpha]5, [beta]1 and GABA[subscript B]R1 Receptors are Altered in Brains from Subjects with Autism

    Science.gov (United States)

    Fatemi, S. Hossein; Reutiman, Teri J.; Folsom, Timothy D.; Rooney, Robert J.; Patel, Diven H.; Thuras, Paul D.

    2010-01-01

    We have shown altered expression of gamma-aminobutyric acid A (GABA[subscript A]) and gamma-aminobutyric acid B (GABA[subscript B]) receptors in the brains of subjects with autism. In the current study, we sought to verify our western blotting data for GABBR1 via qRT-PCR and to expand our previous work to measure mRNA and protein levels of 3…

  14. Dependency of microtubule-associated proteins (MAPs) for tubulin stability and assembly; use of estramustine phosphate in the study of microtubules.

    Science.gov (United States)

    Fridén, B; Wallin, M

    1991-07-10

    Microtubule-associated proteins (MAPs) were separated from tubulin with several different methods. The ability of the isolated MAPs to reinduce assembly of phosphocellulose purified tubulin differed markedly between the different methods. MAPs isolated by addition of 0.35 M NaCl to taxol-stabilized microtubules stimulated tubulin assembly most effectively, while addition of 0.6 M NaCl produced MAPs with a substantially lower ability to stimulate tubulin assembly. The second best preparation was achieved with phosphocellulose chromatographic separation of MAPs with 0.6 M NaCl elution. The addition of estramustine phosphate to microtubules reconstituted of MAPs prepared by 0.35 M NaCl or phosphocellulose chromatography, induced less disassembly than for microtubules assembled from unseparated proteins, and was almost without effect on microtubules reconstituted from MAPs prepared by taxol and 0.6 M NaCl. Estramustine phosphate binds to the tubulin binding part of the MAPs, and the results do therefore indicate that the MAPs are altered by the separation methods. Since the MAPs are regarded as highly stable molecules, one probable alteration could be aggregation of the MAPs, as also indicated by the results. The purified tubulin itself seemed not to be affected by the phosphocellulose purification, since the microtubule proteins were unchanged by the low buffer strenght used during the cromatography. However, the assembly competence after a prolonged incubation of the microtubule proteins at 4 degrees C was dependent on intact bindings between the tubulin and MAPs.

  15. Distribution of gamma-tubulin in multipolar spindles and multinucleated cells induced by dimethylarsinic acid, a methylated derivative of inorganic arsenics, in Chinese hamster V79 cells.

    Science.gov (United States)

    Ochi, T; Nakajima, F; Nasui, M

    1999-08-31

    Localization of gamma-tubulin, a well-characterized component of microtubule-organizing centers (MTOCs), was investigated because of interest in the mechanism of the induction of aberrant mitotic spindles in Chinese hamster V79 cells exposed to dimethylarsinic acid (DMAA). In control cultures, gamma-tubulin in interphase cells was located as a perinuclear dot on which the microtubules were nucleated. In metaphase cells, the location of gamma-tubulin coincided with that of the mitotic spindle poles. DMAA caused mitotic delay and aberrant spindles, such as tripolar- and quadripolar spindles, in the mitotic cells. Gamma-tubulin was co-localized with the aberrant spindles induced by DMAA. The incidence of gamma-tubulin in the mitotic cells coincided with that of the aberrant spindles and rose with an increasing concentration of DMAA. By contrast, DMAA did not influence the number and location of gamma-tubulin signals in interphase cells. These results suggest that multiple microtubule nucleation sites were induced by DMAA during transition from interphase to mitotic phase. DMAA-induced multiple signals of gamma-tubulin were integrated into one signal at the center of multinucleated cells, surrounded by multiple nuclei as the cell cycle progressed to the next interphase, suggesting the presence of a self-integration mechanism of centrosomal MTOCs during the cell cycle.

  16. [BETA-ADRENERGIC REGULATION OF THE ADENYLYL CYCLASE SIGNALING SYSTEM IN MYOCARDIUM AND BRAIN OF RATS WITH OBESITY AND TYPES 2 DIABETES MELLITUS AND THE EFFECT OF LONG-TERM INTRANASAL INSULIN TREATMENT].

    Science.gov (United States)

    Kuznetsova, L A; Sharova, T S; Pertseva, M N; Shpakov, A O

    2015-01-01

    The stimulating effect of norepinephrine, isoproterenol and selective β-adrenoceptor (β3-AR) agonists BRL 37344 and CL 316.243 on the adenylyl cyclase signaling system (ACSS) in the brain and myocardium of young and mature rats (disease induction at 2 and 4 months, respectively) with experimental obesity and type 2 diabetes mellitus (DM2), and the influence of long-term treatment of animals with intranasal insulin (I-I) were studied. The AC stimulatory effects of β-agonist isoproterenol in animals with obesity and DM2 was shown to be practically unchanged. The respective effects of norepinephrine on the AC activity were attenuated in the brain of young and mature rats and in the myocardium if mature rats, and the I-I treatment led to their partial recovery. In the brain and myocardium of mature rats with obesity and DM2, the enhancement of the AC stimulatory effects of β3-AR agonists was observed, white in young rats the influence of the same pathological conditions was lacking. The I-I treatment decreased the AC stimulatory effects of β3-agonists to their levels in the control. Since functional disruption of the adrenergic agonist-sensitive ACSS can lead to metabolic syndrome and DM2, the recovery of this system by the I-I treatment offers one of the ways to correct these diseases and their complications in the nervous and cardiovascular systems.

  17. Beta emitters and radiation protection

    DEFF Research Database (Denmark)

    Jødal, Lars

    2009-01-01

    BACKGROUND. Beta emitters, such as 90Y, are increasingly being used for cancer treatment. However, beta emitters demand other precautions than gamma emitters during preparation and administration, especially concerning shielding. AIM. To discuss practical precautions for handling beta emitters...... on the outside of the primary shielding material. If suitable shielding is used and larger numbers of handlings are divided among several persons, then handling of beta emitters can be a safe procedure....

  18. In silico inspired design and synthesis of a novel tubulin-binding anti-cancer drug: folate conjugated noscapine (Targetin)

    Science.gov (United States)

    Naik, Pradeep K.; Lopus, Manu; Aneja, Ritu; Vangapandu, Surya N.; Joshi, Harish C.

    2012-02-01

    Our screen for tubulin-binding small molecules that do not depolymerize bulk cellular microtubules, but based upon structural features of well known microtubule-depolymerizing colchicine and podophyllotoxin, revealed tubulin binding anti-cancer property of noscapine (Ye et al. in Proc Natl Acad Sci USA 95:2280-2286, 1998). Guided by molecular modelling calculations and structure-activity relationships we conjugated at C9 of noscapine, a folate group—a ligand for cellular folate receptor alpha (FRα). FRα is over-expressed on some solid tumours such as ovarian epithelial cancers. Molecular docking experiments predicted that a folate conjugated noscapine (Targetin) accommodated well inside the binding cavity (docking score -11.295 kcal/mol) at the interface between α- and β-tubulin. The bulky folate moiety of Targetin is extended toward lumen of microtubules. The binding free energy (Δ G bind) computed based on molecular mechanics energy minimization was -221.01 kcal/mol that revealed favourable interaction of Targetin with the receptor. Chemical synthesis, tubulin-binding experiments, and anti-cancer activity in vitro corroborate fully well with the molecular modelling experiments. Targetin binds tubulin with a dissociation constant ( K d value) of 149 ± 3.0 μM and decreases the transition frequencies between growth and shortening phases of microtubule assembly dynamics at concentrations that do not alter the total polymer mass. Cancer cells in general were more sensitive to Targetin compared with the founding compound noscapine (IC50 in the range of 15-40 μM). Quite strikingly, ovarian cancer cells (SKOV3 and A2780), known to overexpress FRα, were much more sensitive to targetin (IC50 in the range of 0.3-1.5 μM).

  19. Brain Basics

    Medline Plus

    Full Text Available ... PDF, 10 pages) Introduction Watch the Brain Basics video Welcome. Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, and ongoing research that helps ...

  20. Brain Basics

    Medline Plus

    Full Text Available ... Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video Welcome. Brain Basics ... depression experience when starting treatment. Gene Studies ... medication. This information may someday make it possible to predict who ...

  1. Brain Basics

    Medline Plus

    Full Text Available ... Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video Welcome. Brain Basics ... fear hub," which activates our natural "fight-or-flight" response to confront or escape from a dangerous ...

  2. Brain Lesions

    Science.gov (United States)

    Symptoms Brain lesions By Mayo Clinic Staff A brain lesion is an abnormality seen on a brain-imaging test, such as ... tomography (CT). On CT or MRI scans, brain lesions appear as dark or light spots that don' ...

  3. Brain Basics

    Medline Plus

    Full Text Available ... Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle- ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ...

  4. Tubulin bond energies and microtubule biomechanics determined from nanoindentation in silico

    CERN Document Server

    Kononova, Olga; Theisen, Kelly E; Marx, Kenneth A; Dima, Ruxandra I; Ataullakhanov, Fazly I; Grishchuk, Ekaterina L; Barsegov, Valeri

    2015-01-01

    Microtubules, the primary components of the chromosome segregation machinery, are stabilized by longitudinal and lateral non-covalent bonds between the tubulin subunits. However, the thermodynamics of these bonds and the microtubule physico-chemical properties are poorly understood. Here, we explore the biomechanics of microtubule polymers using multiscale computational modeling and nanoindentations in silico of a contiguous microtubule fragment. A close match between the simulated and experimental force-deformation spectra enabled us to correlate the microtubule biomechanics with dynamic structural transitions at the nanoscale. Our mechanical testing revealed that the compressed MT behaves as a system of rigid elements interconnected through a network of lateral and longitudinal elastic bonds. The initial regime of continuous elastic deformation of the microtubule is followed by the transition regime, during which the microtubule lattice undergoes discrete structural changes, which include first the reversib...

  5. ESTs library from embryonic stages reveals tubulin and reflectin diversity in Sepia officinalis (Mollusca — Cephalopoda).

    Science.gov (United States)

    Bassaglia, Yann; Bekel, Thomas; Da Silva, Corinne; Poulain, Julie; Andouche, Aude; Navet, Sandra; Bonnaud, Laure

    2012-05-01

    New molecular resources regarding the so-called “non-standard models” in biology extend the present knowledge and are essential for molecular evolution and diversity studies (especially during the development) and evolutionary inferences about these zoological groups, or more practically for their fruitful management. Sepia officinalis, an economically important cephalopod species, is emerging as a new lophotrochozoan developmental model. We developed a large set of expressed sequence tags (ESTs) from embryonic stages of S. officinalis, yielding 19,780 non-redundant sequences (NRS). Around 75% of these sequences have no homologs in existing available databases. This set is the first developmental ESTs library in cephalopods. By exploring these NRS for tubulin, a generic protein family, and reflectin, a cephalopod specific protein family,we point out for both families a striking molecular diversity in S. officinalis.

  6. Cell edges accumulate gamma tubulin complex components and nucleate microtubules following cytokinesis in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Chris Ambrose

    Full Text Available Microtubules emanate from distinct organizing centers in fungal and animal cells. In plant cells, by contrast, microtubules initiate from dispersed sites in the cell cortex, where they then self-organize into parallel arrays. Previous ultrastructural evidence suggested that cell edges participate in microtubule nucleation but so far there has been no direct evidence for this. Here we use live imaging to show that components of the gamma tubulin nucleation complex (GCP2 and GCP3 localize at distinct sites along the outer periclinal edge of newly formed crosswalls, and that microtubules grow predominantly away from these edges. These data confirm a role for cell edges in microtubule nucleation, and suggest that an asymmetric distribution of microtubule nucleation factors contributes to cortical microtubule organization in plants, in a manner more similar to other kingdoms than previously thought.

  7. Acute Blast Injury Reduces Brain Abeta in Two Rodent Species

    Science.gov (United States)

    2012-12-01

    Traumatic brain injury: football , warfare, and long- term effects. N. Engl. J. Med. 363, 1293–1296. Elder, G. A., Dorr, N. P., De Gasperi, R., Gama Sosa, M. A...al. (2012). Intranasal administration of nerve growth fac - tor ameliorate beta-amyloid deposi- tion after traumatic brain injury in rats. Brain Res

  8. Receptor tyrosine phosphatase beta is expressed in the form of proteoglycan and binds to the extracellular matrix protein tenascin

    DEFF Research Database (Denmark)

    Barnea, G; Grumet, M; Milev, P

    1994-01-01

    The extracellular domain of receptor type protein tyrosine phosphatase beta (RPTP beta) exhibits striking sequence similarity with a soluble, rat brain chondroitin sulfate proteoglycan (3F8 PG). Immunoprecipitation experiments of cells transfected with RPTP beta expression vector and metabolically...... labeled with [35S]sulfate and [35S]methionine indicate that the transmembrane form of RPTP beta is indeed a chondroitin sulfate proteoglycan. The 3F8 PG is therefore a variant form composed of the entire extracellular domain of RPTP beta probably generated by alternative RNA splicing. Previous...

  9. Brain Basics

    Medline Plus

    Full Text Available ... Mental Illnesses Clinical Trials Outreach Research Priorities Funding Labs at NIMH News & Events About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain Brain Basics in Real Life Brain Research Glossary Brain Basics (PDF, 10 pages) ...

  10. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  11. The beta Gumbel distribution

    Directory of Open Access Journals (Sweden)

    Saralees Nadarajah

    2004-01-01

    Full Text Available The Gumbel distribution is perhaps the most widely applied statistical distribution for problems in engineering. In this paper, we introduce a generalization—referred to as the beta Gumbel distribution—generated from the logit of a beta random variable. We provide a comprehensive treatment of the mathematical properties of this new distribution. We derive the analytical shapes of the corresponding probability density function and the hazard rate function and provide graphical illustrations. We calculate expressions for the nth moment and the asymptotic distribution of the extreme order statistics. We investigate the variation of the skewness and kurtosis measures. We also discuss estimation by the method of maximum likelihood. We hope that this generalization will attract wider applicability in engineering.

  12. Beta-thalassemia.

    Science.gov (United States)

    Galanello, Renzo; Origa, Raffaella

    2010-05-21

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  13. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A.; Pascual, P.

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  14. Inhibition of tubulin polymerization with ribose-modified analogs of GDP and GTP. Reduced inhibition with microtubule-associated proteins and magnesium.

    Science.gov (United States)

    Hamel, E; Lin, C M

    1984-01-24

    Inhibitory effects of ribose-modified GDP and GTP analogs on tubulin polymerization were examined to explore nucleotide structural requirements at the exchangeable GTP binding site. With microtubule-associated proteins and Mg2+, GTP-supported polymerization was only modestly inhibited by GDP, and still weaker inhibitory activity was found with two analogs, dGDP and 9-beta-D-arabinofuranosylguanine-5'-diphosphate (araGDP). Omission of Mg2+ significantly enhanced the inhibitory effects of GDP, dGDP and araGDP and resulted in weak inhibition of the reaction by several other GDP analogs. The relative inhibitory activity of the GDP analogs had no discernible relationship to the relative activity of cognate GTP analogs in supporting microtubule-associated protein-dependent polymerization. One GTP analog, 2',3'-dideoxyguanosine 5'-triphosphate (ddGTP), supports polymerization both with and without microtubule-associated proteins. The inhibitory activity of GDP and GDP analogs in ddGTP-supported polymerization was much greater in the absence of microtubule-associated proteins than in their presence; and both reactions were more readily inhibited than was microtubule-associated protein-dependent, GTP-supported polymerization. Microtubule-associated protein-independent, ddGTP-supported polymerization was also potently inhibited by GTP and a number of GTP analogs. GTP was in fact twice as inhibitory as GDP. The relative inhibitory activity of the GTP analogs was comparable to the relative inhibitory activity of the cognate GDP analogs and very different from their relative activity in supporting polymerization.

  15. Neurotoxicity of beta-lactam antibiotics: predisposing factors and pathogenesis.

    Science.gov (United States)

    Schliamser, S E; Cars, O; Norrby, S R

    1991-04-01

    Neurotoxic reactions caused by beta-lactam antibiotics occur frequently following direct application of antibiotic to the brain surface or into the cerebral cisterns. Epileptogenic reactions have also been observed after administration of very high systemic doses. There seem to be considerable differences in the neurotoxic potential of the various beta-lactams; benzylpenicillin, cefazolin and, lately, imipenem/cilastatin appear to be drugs with higher neurotoxic potential than other compounds. There is now strong evidence that the concentration of beta-lactam in the brain, and not that in the cerebrospinal fluid, is the decisive factor for the risk of neurotoxic reactions. Factors known to increase the risk of neurotoxicity are excessive doses, decreased renal function, damage to the blood-brain barrier, preexisting diseases of the central nervous system, old age and concurrent use of drugs that are nephrotoxic or that may lower the seizure threshold. Another factor that may be of importance is blockage of the transport system that is responsible for transport of beta-lactams out of the central nervous system.

  16. COM Support in BETA

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1999-01-01

    Component technologies based on binary units of independent production are some of the most important contributions to software architecture and reuse during recent years. Especially the COM technologies and the CORBA standard from the Object Management Group have contributed new and interesting ...... principles for software architecture, and proven to be useful in parctice. In this paper ongoing work with component support in the BETA language is described....

  17. Coroutine Sequencing in BETA

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    In object-oriented programming, a program execution is viewed as a physical model of some real or imaginary part of the world. A language supporting object-oriented programming must therefore contain comprehensive facilities for modeling phenomena and concepts form the application domain. Many ap...... applications in the real world consist of objects carrying out sequential processes. Coroutines may be used for modeling objects that alternate between a number of sequential processes. The authors describe coroutines in BETA...

  18. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    of language interoperability between Java and BETA is required. The first approach is to use the Java Native Interface and use C to bridge between Java and BETA. This results in a workable, but complicated solution. The second approach is to let the BETA compiler generate Java class files. With this approach......This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some form...... it is possible to implement plug-ins in BETA and even inherit from Java classes. In the paper the two approaches are described together with part of the mapping from BETA to Java class files. http://www.sciencedirect.com/science/journal/15710661...

  19. 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...

  20. 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.

  1. Developmental regulation of {beta}-hexosaminidase {alpha}- and {beta}-subunit gene expression in the rat reproductive system

    Energy Technology Data Exchange (ETDEWEB)

    Trasler, J.M.; Wakamatsu, N.; Gravel, R.A.; Benoit, G. [McGill-Montreal Chilrden`s Hospital Research Institute, Quebec (Canada)

    1994-09-01

    {beta}-Hexosaminidase is an essential lysosomal enzyme whose absence in man results in a group of disorders, the G{sub M2} gangliosidoses. Enzyme activity for {beta}-hexosaminidase is many fold higher in the epididymis than in other tissues, is present in sperm and is postulated to be required for mammalian fertilization. To better understand how {beta}-hexosaminidase is regulated in the reproductive system, we quantitated the mRNA expression of the {alpha}- and {beta}-subunits (Hex {alpha} and Hex {beta}) of the enzyme in the developing rat testis and epididymis. Hex {alpha} mRNA was differentially expressed and abundant in adult rat testis and epididymis, 13- and 2-fold brain levels, respectively. In contrast, Hex {beta} mRNA levels in the testis and epididymis were .3- and 5-fold brain levels. Within the epididymis both Hex {alpha} and Hex {beta} mRNA concentrations were highest in the corpus, 1.5-fold and 9-fold initial segment values, respectively. During testis development from 7-91 days of age, testis levels of Hex {alpha} mRNA increased 10-fold and coincided with the appearance of spermatocytes and spermatids in the epithelium. In isolated male germ cells, Hex {alpha} expression was most abundant in haploid round spermatids. Hex {alpha} mRNA was undetectable after hypophysectomy and returned to normal after testosterone administration and the return of advanced germ cells to the testis. Hex {beta} mRNA was expressed at constant low levels throughout testis development. In the caput-corpus and cauda regions of the epididymis Hex {alpha} mRNA levels increased 2-fold between 14 and 91 days; during the same developmental period epididymal Hex {beta} mRNA levels increased dramatically, by 10-20 fold. In summary, Hex {alpha} and Hex {beta} mRNAs are differentially and developmentally expressed at high levels in the rat testis and epididymis and augur for an important role for {beta}-hexosaminidase in normal male reproductive function.

  2. Brain Pyroglutamate Amyloid-Beta is Produced by Cathepsin B and is Reduced by the Cysteine Protease Inhibitor E64d, Representing a Potential Alzheimer’s Disease Therapeutic

    Science.gov (United States)

    Hook, Gregory; Yu, Jin; Toneff, Thomas; Kindy, Mark; Hook, Vivian

    2014-01-01

    Pyroglutamate amyloid-β peptides (pGlu-Aβ) are particularly pernicious forms of amyloid-β peptides (Aβ) present in Alzheimer’s disease (AD) brains. pGlu-Aβ peptides are N-terminally truncated forms of full-length Aβ peptides (flAβ(1-40/42)) in which the N-terminal glutamate is cyclized to pyroglutamate to generate pGlu-Aβ(3-40/42). β-secretase cleavage of amyloid-β precursor protein (AβPP) produces flAβ(1-40/42), but it is not yet known whether the β-secretase BACE1 or the alternative β-secretase cathepsin B (CatB) participate in the production of pGlu-Aβ. Therefore, this study examined the effects of gene knockout of these proteases on brain pGlu-Aβ levels in transgenic AβPPLon mice, which express AβPP isoform 695 and have the wild-type (wt) β-secretase activity found in most AD patients. Knockout or overexpression of the CatB gene reduced or increased, respectively, pGlu-Aβ(3-40/42), flAβ(1-40/42), and pGlu-Aβ plaque load, but knockout of the BACE1 gene had no effect on those parameters in the transgenic mice. Treatment of AβPPLon mice with E64d, a cysteine protease inhibitor of CatB, also reduced brain pGlu-Aβ(3-42), flAβ(1-40/42), and pGlu-Aβ plaque load. Treatment of neuronal-like chromaffin cells with CA074Me, an inhibitor of CatB, resulted in reduced levels of pGlu-Aβ(3-40) released from the activity-dependent, regulated secretory pathway. Moreover, CatB knockout and E64d treatment has been previously shown to improve memory deficits in the AβPPLon mice. These data illustrate the role of CatB in producing pGlu-Aβ and flAβ that participate as key factors in the development of AD. The advantages of CatB inhibitors, especially E64d and its derivatives, as alternatives to BACE1 inhibitors in treating AD patients are discussed. PMID:24595198

  3. 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.

  4. Beta8 integrin binds Rho GDP dissociation inhibitor-1 and activates Rac1 to inhibit mesangial cell myofibroblast differentiation.

    Science.gov (United States)

    Lakhe-Reddy, Sujata; Khan, Shenaz; Konieczkowski, Martha; Jarad, George; Wu, Karen L; Reichardt, Louis F; Takai, Yoshimi; Bruggeman, Leslie A; Wang, Bingcheng; Sedor, John R; Schelling, Jeffrey R

    2006-07-14

    Alpha(v)beta8 integrin expression is restricted primarily to kidney, brain, and placenta. Targeted alpha(v) or beta8 deletion is embryonic lethal due to defective placenta and brain angiogenesis, precluding investigation of kidney alpha(v)beta8 function. We find that kidney beta8 is localized to glomerular mesangial cells, and expression is decreased in mouse models of glomerulosclerosis, suggesting that beta8 regulates normal mesangial cell differentiation. To interrogate beta8 signaling pathways, yeast two-hybrid and co-precipitation studies demonstrated beta8 interaction with Rho guanine nucleotide dissociation inhibitor-1 (GDI). Selective beta8 stimulation enhanced beta8-GDI interaction as well as Rac1 (but not RhoA) activation and lamellipodia formation. Mesangial cells from itgb8-/- mice backcrossed to a genetic background that permitted survival, or gdi-/- mice, which develop glomerulosclerosis, demonstrated RhoA (but not Rac1) activity and alpha-smooth muscle actin assembly, which characterizes mesangial cell myofibroblast transformation in renal disease. To determine whether Rac1 directly modulates RhoA-associated myofibroblast differentiation, mesangial cells were transduced with inhibitory Rac peptide fused to human immunodeficiency virus-Tat, resulting in enhanced alpha-smooth muscle actin organization. We conclude that the beta8 cytosolic tail in mesangial cells organizes a signaling complex that culminates in Rac1 activation to mediate wild-type differentiation, whereas decreased beta8 activation shifts mesangial cells toward a RhoA-dependent myofibroblast phenotype.

  5. Induction of striatal neurogenesis enhances functional recovery in an adult animal model of neonatal hypoxic-ischemic brain injury.

    Science.gov (United States)

    Im, S H; Yu, J H; Park, E S; Lee, J E; Kim, H O; Park, K I; Kim, G W; Park, C I; Cho, S-R

    2010-08-11

    While intraventricular administration of epidermal growth factor (EGF) expands the proliferation of neural stem/progenitor cells in the subventricular zone (SVZ), overexpression of brain-derived neurotrophic factor (BDNF) is particularly effective in enhancing striatal neurogenesis. We assessed the induction of striatal neurogenesis and consequent functional recovery after chronic infusion of BDNF and EGF in an adult animal model of neonatal hypoxic-ischemic (HI) brain injury. Permanent brain damage was induced in CD-1 (ICR) mice (P7) by applying the ligation of unilateral carotid artery and hypoxic condition. At 6 weeks of age, the mice were randomly assigned to groups receiving a continuous 2-week infusion of one of the following treatments into the ventricle: BDNF, EGF, BDNF/EGF, or phosphate buffered saline (PBS). Two weeks after treatment, immunohistochemical analysis revealed an increase in the number of BrdU(+) cells in the SVZ and striata of BDNF/EGF-treated mice. The number of new neurons co-stained with BrdU and betaIII-tubulin was also significantly increased in the neostriata of BDNF/EGF-treated mice, compared with PBS group. In addition, the newly generated cells were expressed as migrating neuroblasts labeled with PSA-NCAM or doublecortin in the SVZ and the ventricular side of neostriata. The new striatal neurons were also differentiated as mature neurons co-labeled with BrdU(+)/NeuN(+). When evaluated post-surgical 8 weeks, BDNF/EGF-treated mice exhibited significantly longer rotarod latencies at constant speed (48 rpm) and under accelerating condition (4-80 rpm), relative to PBS and untreated controls. In the forelimb-use asymmetry test, BDNF/EGF-treated mice showed significant improvement in the use of the contralateral forelimb. In contrast, this BDNF/EGF-associated functional recovery was abolished in mice receiving a co-infusion of 2% cytosine-b-d-arabinofuranoside (Ara-C), a mitotic inhibitor. Induction of striatal neurogenesis by the

  6. Pharmacologic differences between beta blockers.

    Science.gov (United States)

    Wood, A J

    1984-10-01

    All of the beta blockers act by antagonizing the actions of the endogenous adrenergic agonists epinephrine and norepinephrine at the beta-adrenergic receptors. However, a number of pharmacologic differences exist between the various agents. Some drugs, such as atenolol and metoprolol, are relatively selective for the beta-1-adrenergic receptors, requiring higher concentrations to block beta-2-adrenergic receptors than are required to block beta-1 receptors. It should be noted, however, that these selective beta blockers all block beta-2 receptors when their concentrations are high enough. When patients with asthma must receive a beta blocker, low doses of a selective drug should be used. Recent studies, however, have suggested that the use of a nonselective beta blocker may be desirable to antagonize some beta-2-mediated metabolic effects, such as hypokalemia, induced by epinephrine. Pindolol is the only beta-receptor antagonist available in the United States with intrinsic sympathomimetic, or partial agonist, activity. Such drugs, because of their partial agonist activity, cause some sympathetic stimulation under conditions of low endogenous sympathetic tone, such as while subjects are at rest in the supine position. Under conditions of higher sympathetic tone, pindolol blocks the effects of the endogenous agonists, producing the characteristic effects of a beta blocker. Membrane-stabilizing activity was first recognized with propranolol, and the value of this property has been a source of controversy ever since, but recent studies suggest that propranolol may induce electrophysiologic effects by mechanisms other than beta blockade. Pharmacokinetic differences between the drugs are also of importance.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. 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.

  8. [Beta-blocker intoxication].

    Science.gov (United States)

    Joye, F

    2000-05-20

    Beta-blocker intoxication is not frequent but can produce particularly severe or fatal conditions which must not be underestimated. Severity of beta-blocker intoxication varies from one compound to another. The more toxic drugs are propranolol, sotalol, oxprenolol, metoprolol, atenolol, acebutolol, labetalol, and carvedilol. Besides the drug type, history taking can provide a precise assessment of risk, particularly important in when elderly patients with a cardiovascular history have taken more than 20 tablets, when emergency care is provided late, and when other cardiotoxic or psychotoxic drugs have been coingested. The diagnosis of beta-blocker intoxication must be suspected in any case associating hypotension and bradycardia. The main cardiovascular complications are cardiogenic shock, atrio-ventricular conduction disorders, and obviously life-threatening ventricular arrhythmia with cardiac arrest. Centrally induced respiratory arrest is a rare but dreadful consequence which can occur suddenly even without hemodynamic failure. Neurologic toxicity is mainly expressed by consciousness disorders and more sporadically by seizures. Laboratory tests show variable serum potassium, lactic acidosis, hypoxia-hypercapnia resulting from hypoventilation, and rarely hypoglycemia. The ECG should be recorded early because electrocardiographic signs usually appear before clinical signs and QRS enlargement is a factor predictive of severe ventricular arrhythmia. The patient must be placed in an intensive care unit for continuous multiparametric monitoring. Besides gastric evacuation and symptomatic measures, treatment essentially requires glucagon for its positive inotropic effect after high intravenous doses. If glucagon infusion is ineffective or unavailable, an alternative would be to use high doses of vasoactive agents, choosing isoproterenol or epinephrine as the first intention drugs.

  9. Synthesis and preliminary evaluation of (S)-[C-11]-exaprolol, a novel beta-adrenoceptor ligand for PET

    NARCIS (Netherlands)

    van Waarde, Aren; Doorduin, Janine; de Jong, Johan R.; Dierckx, Rudi A.; Elsinga, Philip H.

    2008-01-01

    Positron-emitting beta-adrenoceptor ligands for the CNS could allow determination of changes in P-adrenoceptor availability after treatment of patients with norepinephrine reuptake inhibitors or tricyclic antidepressants, and differential diagnosis between multiple sclerosis and other brain

  10. Brain Tumors

    Science.gov (United States)

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  11. Brain Basics

    Medline Plus

    Full Text Available ... Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video Welcome. Brain Basics ... basic, working unit of the brain and nervous system, which processes and transmits information. neurotransmitter —A chemical produced by neurons that carries ...

  12. Brain Basics

    Medline Plus

    Full Text Available ... learning more about how the brain grows and works in healthy people, and how normal brain development and function can go awry, leading to mental illnesses. Brain Basics will introduce you to some of this science, such as: ... of the brain communicate and work with each other How changes in the brain ...

  13. Conditional Betas and Investor Uncertainty

    OpenAIRE

    Fernando D. Chague

    2013-01-01

    We derive theoretical expressions for market betas from a rational expectation equilibrium model where the representative investor does not observe if the economy is in a recession or an expansion. Market betas in this economy are time-varying and related to investor uncertainty about the state of the economy. The dynamics of betas will also vary across assets according to the assets' cash-flow structure. In a calibration exercise, we show that value and growth firms have cash-flow structures...

  14. ACCOUNTING INFORMATION AND MARKET BETA

    OpenAIRE

    Amorim, Ana Luísa Gambi Cavallari; Lima, Iran Siqueira; Pimenta Junior,Tabajara

    2014-01-01

    The efficient market hypothesis and various models of asset pricing brought the concept of the new relevant information has an immediate effect on the price of a security by changing expectations about their risk: market beta. The accounting numbers seem to exhibit a relationship with the market risk of firms and thus can provide a supplementary estimate to help reduce the error of estimation of market betas. This work was to investigate whether the accounting betas have a business relationsh...

  15. Changes in ?B-crystallin, tubulin, and MHC isoforms by hindlimb unloading show different expression patterns in various hindlimb muscles

    OpenAIRE

    Jee, Hyunseok; Sakurai, Takashi; Lim, Jae-Young; Hatta, Hideo

    2014-01-01

    [Purpose] ?B-crystallin is a small heat shock protein that acts as a molecular chaperone under various stress conditions. Microtubules, which consist of tubulin, are related to maintain the intracellular organelles and cellular morphology. These two proteins have been shown to be related to the properties of different types of myofibers based on their contractile properties. The response of these proteins during muscular atrophy, which induces a myofibril component change, is not clearly unde...

  16. Molecular karyotype and chromosomal localization of genes encoding ß-tubulin, cysteine proteinase, hsp 70 and actin in Trypanosoma rangeli

    OpenAIRE

    CB Toaldo; Steindel, M; MA Sousa; CC Tavares

    2001-01-01

    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...

  17. The chemical complexity of cellular microtubules: tubulin post-translational modification enzymes and their roles in tuning microtubule functions

    Science.gov (United States)

    Garnham, Christopher P.; Roll-Mecak, Antonina

    2012-01-01

    Cellular microtubules are marked by abundant and evolutionarily conserved post-translational modifications that have the potential to tune their functions. This review focuses on the astonishing chemical complexity introduced in the tubulin heterodimer at the post-translational level and summarizes the recent advances in identifying the enzymes responsible for these modifications and deciphering the consequences of tubulin’s chemical diversity on the function of molecular motors and microtubule associated proteins. PMID:22422711

  18. 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.

  19. Expression of separate isoforms of human tau protein: correlation with the tau pattern in brain and effects on tubulin polymerization

    National Research Council Canada - National Science Library

    Goedert, M; Jakes, R

    1990-01-01

    ...–67 kd and with a characteristic pattern of spacings. Four of these bands aligned with the major tau bands found in adult human cerebral cortex following perchloric acid extraction and alkaline phosphatase treatment...

  20. Islet Brain 1 Protects Insulin Producing Cells against Lipotoxicity

    OpenAIRE

    Saška Brajkovic; Mourad Ferdaoussi; Valérie Pawlowski; Hélène Ezanno; Valérie Plaisance; Erik Zmuda; Tsonwin Hai; Jean-Sébastien Annicotte; Gérard Waeber; Amar Abderrahmani

    2015-01-01

    Chronic intake of saturated free fatty acids is associated with diabetes and may contribute to the impairment of functional beta cell mass. Mitogen activated protein kinase 8 interacting protein 1 also called islet brain 1 (IB1) is a candidate gene for diabetes that is required for beta cell survival and glucose-induced insulin secretion (GSIS). In this study we investigated whether IB1 expression is required for preserving beta cell survival and function in response to palmitate. Chronic exp...

  1. Supersymmetry Inspired QCD Beta Function

    CERN Document Server

    Ryttov, Thomas A

    2008-01-01

    We propose an all orders beta function for ordinary Yang-Mills theories with or without fermions inspired by the Novikov-Shifman-Vainshtein-Zakharov beta function of N=1 supersymmetric gauge theories. The beta function allows us to bound the conformal window. When restricting to one adjoint Weyl fermion we show how the proposed beta function matches the one of supersymmetric Yang-Mills theory. The running of the pure Yang-Mills coupling is computed and the deviation from the two loop result is presented. We then compare the deviation with the one obtained from lattice data also with respect to the two loop running.

  2. Supersymmetry Inspired QCD Beta Function

    DEFF Research Database (Denmark)

    Ryttov, Thomas; Sannino, Francesco

    2008-01-01

    We propose an all orders beta function for ordinary Yang-Mills theories with or without fermions inspired by the Novikov-Shifman-Vainshtein-Zakharov beta function of N=1 supersymmetric gauge theories. The beta function allows us to bound the conformal window. When restricting to one adjoint Weyl...... fermion we show how the proposed beta function matches the one of supersymmetric Yang-Mills theory. The running of the pure Yang-Mills coupling is computed and the deviation from the two loop result is presented. We then compare the deviation with the one obtained from lattice data also with respect...

  3. De novo production of K-alpha1 tubulin-specific antibodies: role in chronic lung allograft rejection.

    Science.gov (United States)

    Goers, Trudie A; Ramachandran, Sabarinathan; Aloush, Aviva; Trulock, Elbert; Patterson, G Alexander; Mohanakumar, Thalachallour

    2008-04-01

    Lung transplantation is the treatment option for a variety of end-stage pulmonary diseases. Posttransplant development of Abs against donor HLA and non-HLA Ags have been associated with acute and chronic rejection of transplanted organs. Development of bronchiolitis obliterans syndrome (BOS) following lung transplantation has been correlated with de novo production of anti-donor-HLA Abs. However, only a portion of the patients with BOS demonstrate detectable anti-donor-HLA Abs. Airway epithelium is considered as a major target for lung allograft rejection. In this study we demonstrate that many BOS(+) patients (12 of 36) develop Abs reactive to epithelial cell Ag that are distinct from HLA. Furthermore, de novo production of antiepithelial cell Ab precedes clinical onset of BOS. N-terminal sequencing and blastx analysis as well as blocking with K-alpha1 tubulin-specific Ab identified the epithelial Ag as K-alpha1 tubulin. Binding of the de novo-produced anti-K-alpha1 tubulin Abs to the airway epithelial cells resulted in the increased expression of transcription factors (TCF5 and c-Myc), leading to increased expression of fibrogenic growth factors, activation of cell cycle signaling, and fibroproliferation, the central events in immunopathogenesis of BOS following human lung transplantation.

  4. 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.

  5. Synthesis and evaluation of a series of resveratrol analogues as potent anti-cancer agents that target tubulin.

    Science.gov (United States)

    Madadi, Nikhil R; Zong, Hongliang; Ketkar, Amit; Zheng, Chen; Penthala, Narsimha R; Janganati, Venumadhav; Bommagani, Shobanbabu; Eoff, Robert L; Guzman, Monica L; Crooks, Peter A

    2015-05-01

    A series of novel diarylacrylonitrile and trans-stilbene analogues of resveratrol has been synthesized and evaluated for their anticancer activities against a panel of 60 human cancer cell lines. The diarylacrylonitrile analogues 3b and 4a exhibited the most potent anticancer activity of all the analogues synthesized in this study, with GI50 values of < 10 nM against almost all the cell lines in the human cancer cell panel. Compounds 3b and 4a were also screened against the acute myeloid leukemia (AML) cell line, MV4-11, and were found to have potent cytotoxic properties that are likely mediated through inhibition of tubulin polymerization. Results from molecular docking studies indicate a common binding site for 4a and 3b on the 3,3-tubulin heterodimer, with a slightly more favorable binding for 3b compared to 4a; this is consistent with the results from the microtubule assays, which demonstrate that 4a is more potent than 3b in inhibiting tubulin polymerization in MV4-11 cells. Taken together, these data suggest that diarylacrylonitriles 3b and 4a may have potential as antitubulin therapeutics for treatment of both solid and hematological tumors.

  6. Brain Malformations

    Science.gov (United States)

    Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it ... medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, ...

  7. Brain surgery

    Science.gov (United States)

    Craniotomy; Surgery - brain; Neurosurgery; Craniectomy; Stereotactic craniotomy; Stereotactic brain biopsy; Endoscopic craniotomy ... cut depends on where the problem in the brain is located. The surgeon creates a hole in ...

  8. Brain Basics

    Medline Plus

    Full Text Available ... Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a ... brain. DNA —The "recipe of life," containing inherited genetic information that helps to define physical and some ...

  9. Brain Basics

    Medline Plus

    Full Text Available ... brain's structure, studies show that brain growth in children with autism appears to peak early. And as ... grow there are differences in brain development in children who develop bipolar disorder than children who do ...

  10. Brain Basics

    Medline Plus

    Full Text Available ... brain's structure, studies show that brain growth in children with autism appears to peak early. And as they grow there are differences in brain development in children who develop bipolar disorder than children ...

  11. Brain Basics

    Medline Plus

    Full Text Available ... imaging (MRI), which uses magnetic fields to take pictures of the brain's structure, studies show that brain ... imaging technique that uses magnetic fields to take pictures of the brain's structure. mutation —A change in ...

  12. Brain Basics

    Medline Plus

    Full Text Available ... as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are the basic working unit of the brain ... specialized for the function of conducting messages. A neuron has three basic parts: Cell body which includes ...

  13. Brain Basics

    Medline Plus

    Full Text Available ... of the brain's structure, studies show that brain growth in children with autism appears to peak early. And as they grow there are differences in brain development in children who develop bipolar disorder than children ...

  14. Brain Basics

    Medline Plus

    Full Text Available ... science, such as: How the brain develops How genes and the environment affect the brain The basic ... that with brain development in people mental disorders. Genes and environmental cues both help to direct this ...

  15. Brain Basics

    Medline Plus

    Full Text Available ... the Brain Meet Sarah Sarah is a middle-aged woman who seemed to have it all. She ... brain's structure, studies show that brain growth in children with autism appears to peak early. And as ...

  16. Brain Basics

    Medline Plus

    Full Text Available ... about how the brain grows and works in healthy people, and how normal brain development and function ... chart how the brain develops over time in healthy people and are working to compare that with ...

  17. Brain Basics

    Medline Plus

    Full Text Available ... Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle- ... unit of the brain and nervous system, which processes and transmits information. neurotransmitter —A chemical produced by ...

  18. Brain Basics

    Medline Plus

    Full Text Available ... Mental Illnesses Clinical Trials Outreach Outreach Home Stakeholder Engagement Outreach Partnership Program Alliance for Research Progress Coalition ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ...

  19. Brain Basics

    Medline Plus

    Full Text Available ... in Real Life Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video ... and epigenetic changes can be passed on to future generations. Further understanding of genes and epigenetics may ...

  20. Brain Basics

    Medline Plus

    Full Text Available ... can lead to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits ... tailored treatments, and possibly prevention of such illnesses. The Working Brain Neurotransmitters Everything we do relies on ...

  1. Identification of active anti-inflammatory principles of beta- beta ...

    African Journals Online (AJOL)

    Purpose: To identify the anti-inflammatory components of beta-beta (Lunasia amara Blanco.) wood. Methods: The wood material was extracted with 96 % ethanol and fractionated with dichloromethane using a liquid-liquid continuous extraction (LLCE). The fractions were subjected to silica gel column chromatography.

  2. Beta section beta : biogeographical patterns of variation, and taxonomy

    NARCIS (Netherlands)

    Letschert, J.P.W.

    1993-01-01

    In Chapter 1 an account is given of the historical subdivision of the genus Beta and its sections, and the relations of the sections are discussed. Emphasis is given to the taxonomic treatment of wild section Beta by various authors. The Linnaean

  3. Inhibition of cathepsin B reduces beta-amyloid production in regulated secretory vesicles of neuronal chromaffin cells: evidence for cathepsin B as a candidate beta-secretase of Alzheimer's disease.

    Science.gov (United States)

    Hook, Vivian; Toneff, Thomas; Bogyo, Matthew; Greenbaum, Doron; Medzihradszky, Katalin F; Neveu, John; Lane, William; Hook, Gregory; Reisine, Terry

    2005-09-01

    The regulated secretory pathway of neurons is the major source of extracellular A beta that accumulates in Alzheimer's disease (AD). Extracellular A beta secreted from that pathway is generated by beta-secretase processing of amyloid precursor protein (APP). Previously, cysteine protease activity was demonstrated as the major beta-secretase activity in regulated secretory vesicles of neuronal chromaffin cells. In this study, the representative cysteine protease activity in these secretory vesicles was purified and identified as cathepsin B by peptide sequencing. Immunoelectron microscopy demonstrated colocalization of cathepsin B with A beta in these vesicles. The selective cathepsin B inhibitor, CA074, blocked the conversion of endogenous APP to A beta in isolated regulated secretory vesicles. In chromaffin cells, CA074Me (a cell permeable form of CA074) reduced by about 50% the extracellular A beta released by the regulated secretory pathway, but CA074Me had no effect on A beta released by the constitutive pathway. Furthermore, CA074Me inhibited processing of APP into the COOH-terminal beta-secretase-like cleavage product. These results provide evidence for cathepsin B as a candidate beta-secretase in regulated secretory vesicles of neuronal chromaffin cells. These findings implicate cathepsin B as beta-secretase in the regulated secretory pathway of brain neurons, suggesting that inhibitors of cathepsin B may be considered as therapeutic agents to reduce A beta in AD.

  4. 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...

  5. A new screening method for antimitotic substances and isolation of glycolipids as stimulators of tubulin polymerization from Okinawan sponge Pseudoceratina sp.

    Science.gov (United States)

    Meguro, Shiori; Namikoshi, Michio; Kobayashi, Hisayoshi

    2002-03-01

    A new screening method to detect antimitotic substances utilizing purified porcine brain microtubule proteins was developed. This method observes the inhibitory and stimulatory activities on microtubule polymerization and inhibitory activity on depolymerization in sequence. Two glycolipids, 1-O-beta-D-galactopyranosyl-2,3-di-O-acylglycerol and 1-O-tetrahydroxycyclopentyl-2-O-acyl-3-O-alkylglycerol were isolated from Okinawan marine sponge Pseudoceratina sp. by this screening method. These compounds stimulated the microtubule polymerization at 10 degrees C.

  6. Bacterial Tubulins A and B Exhibit Polarized Growth, Mixed-Polarity Bundling, and Destabilization by GTP Hydrolysis.

    Science.gov (United States)

    Díaz-Celis, César; Risca, Viviana I; Hurtado, Felipe; Polka, Jessica K; Hansen, Scott D; Maturana, Daniel; Lagos, Rosalba; Mullins, R Dyche; Monasterio, Octavio

    2017-10-01

    Bacteria of the genus Prosthecobacter express homologs of eukaryotic α- and β-tubulin, called BtubA and BtubB (BtubA/B), that have been observed to assemble into filaments in the presence of GTP. BtubA/B polymers are proposed to be composed in vitro by two to six protofilaments in contrast to that in vivo , where they have been reported to form 5-protofilament tubes named bacterial microtubules (bMTs). The btubAB genes likely entered the Prosthecobacter lineage via horizontal gene transfer and may be derived from an early ancestor of the modern eukaryotic microtubule (MT). Previous biochemical studies revealed that BtubA/B polymerization is reversible and that BtubA/B folding does not require chaperones. To better understand BtubA/B filament behavior and gain insight into the evolution of microtubule dynamics, we characterized in vitro BtubA/B assembly using a combination of polymerization kinetics assays and microscopy. Like eukaryotic microtubules, BtubA/B filaments exhibit polarized growth with different assembly rates at each end. GTP hydrolysis stimulated by BtubA/B polymerization drives a stochastic mechanism of filament disassembly that occurs via polymer breakage and/or fast continuous depolymerization. We also observed treadmilling (continuous addition and loss of subunits at opposite ends) of BtubA/B filament fragments. Unlike MTs, polymerization of BtubA/B requires KCl, which reduces the critical concentration for BtubA/B assembly and induces it to form stable mixed-orientation bundles in the absence of any additional BtubA/B-binding proteins. The complex dynamics that we observe in stabilized and unstabilized BtubA/B filaments may reflect common properties of an ancestral eukaryotic tubulin polymer. IMPORTANCE Microtubules are polymers within all eukaryotic cells that perform critical functions; they segregate chromosomes, organize intracellular transport, and support the flagella. These functions rely on the remarkable range of tunable dynamic

  7. Novel tubulin polymerization inhibitors overcome multidrug resistance and reduce melanoma lung metastasis.

    Science.gov (United States)

    Wang, Zhao; Chen, Jianjun; Wang, Jin; Ahn, Sunjoo; Li, Chien-Ming; Lu, Yan; Loveless, Vivian S; Dalton, James T; Miller, Duane D; Li, Wei

    2012-11-01

    To evaluate abilities of 2-aryl-4-benzoyl-imidazoles (ABI) to overcome multidrug resistance (MDR), define their cellular target, and assess in vivo antimelanoma efficacy. MDR cell lines that overexpressed P-glycoprotein, MDR-associated proteins, and breast cancer resistance protein were used to evaluate ABI ability to overcome MDR. Cell cycle analysis, molecular modeling, and microtubule imaging were used to define ABI cellular target. SHO mice bearing A375 human melanoma xenograft were used to evaluate ABI in vivo antitumor activity. B16-F10/C57BL mouse melanoma lung metastasis model was used to test ABI efficacy to inhibit tumor lung metastasis. ABIs showed similar potency to MDR cells compared to matching parent cells. ABIs were identified to target tubulin on the colchicine binding site. After 31 days of treatment, ABI-288 dosed at 25 mg/kg inhibited melanoma tumor growth by 69%; dacarbazine at 60 mg/kg inhibited growth by 52%. ABI-274 dosed at 25 mg/kg showed better lung metastasis inhibition than dacarbazine at 60 mg/kg. This new class of antimitotic compounds can overcome several clinically important drug resistant mechanisms in vitro and are effective in inhibiting melanoma lung metastasis in vivo, supporting their further development.

  8. Architecture of the ring formed by the tubulin homologue FtsZ in bacterial cell division

    Science.gov (United States)

    Szwedziak, Piotr; Wang, Qing; Bharat, Tanmay A M; Tsim, Matthew; Löwe, Jan

    2014-01-01

    Membrane constriction is a prerequisite for cell division. The most common membrane constriction system in prokaryotes is based on the tubulin homologue FtsZ, whose filaments in E. coli are anchored to the membrane by FtsA and enable the formation of the Z-ring and divisome. The precise architecture of the FtsZ ring has remained enigmatic. In this study, we report three-dimensional arrangements of FtsZ and FtsA filaments in C. crescentus and E. coli cells and inside constricting liposomes by means of electron cryomicroscopy and cryotomography. In vivo and in vitro, the Z-ring is composed of a small, single-layered band of filaments parallel to the membrane, creating a continuous ring through lateral filament contacts. Visualisation of the in vitro reconstituted constrictions as well as a complete tracing of the helical paths of the filaments with a molecular model favour a mechanism of FtsZ-based membrane constriction that is likely to be accompanied by filament sliding. DOI: http://dx.doi.org/10.7554/eLife.04601.001 PMID:25490152

  9. Beta Function and Anomalous Dimensions

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2011-01-01

    We demonstrate that it is possible to determine the coefficients of an all-order beta function linear in the anomalous dimensions using as data the two-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows to determine the anomalous...

  10. RAVEN Beta Release

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Congjian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Maljovec, Daniel Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, Paul William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  11. Lactate fuels the human brain during exercise

    DEFF Research Database (Denmark)

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

    2008-01-01

    lactate in proportion to the arterial concentration. Cerebral lactate uptake, together with glucose uptake, is larger than the uptake accounted for by the concomitant O(2) uptake, as reflected by the decrease in cerebral metabolic ratio (CMR) [the cerebral molar uptake ratio O(2)/(glucose+(1/2) lactate...... blockade but not with beta(1)-adrenergic blockade alone. Also, CMR decreases in response to epinephrine, suggesting that a beta(2)-adrenergic receptor mechanism enhances glucose and perhaps lactate transport across the blood-brain barrier. The pattern of CMR decrease under various forms of brain activation...

  12. 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.

  13. Beta Beams Implementation at CERN

    CERN Document Server

    Hansen, Christian

    2011-01-01

    Beta Beam,the concept of generating a pure and intense (anti) neutrino beam by letting accelerated radioactive ions beta decay in a storage ring, called Decay Ring (DR), is the base of one of the proposed next generation neutrino oscillation facilities, necessary for a complete study of the neutrino oscillation parameter space. Sensitivities of the unknown neutrino oscillation parameters depend on the Decay Ring's ion intensity and of it's duty factor (the filled ratio of the ring). Therefore efficient ion production, stripping, bunching, acceleration and storing are crucial sub-projects under study and development within the Beta Beam collaboration. Specifically the feasibility of these tasks as parts of a Beta Beam implementation at CERN will be discussed in this report. The positive impact of the large {\\theta}13 indications from T2K on the Beta Beam performance will also be discussed.

  14. 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.

  15. Brain networks modulated by subthalamic nucleus deep brain stimulation.

    Science.gov (United States)

    Accolla, Ettore A; Herrojo Ruiz, Maria; Horn, Andreas; Schneider, Gerd-Helge; Schmitz-Hübsch, Tanja; Draganski, Bogdan; Kühn, Andrea A

    2016-09-01

    Deep brain stimulation of the subthalamic nucleus is an established treatment for the motor symptoms of Parkinson's disease. Given the frequent occurrence of stimulation-induced affective and cognitive adverse effects, a better understanding about the role of the subthalamic nucleus in non-motor functions is needed. The main goal of this study is to characterize anatomical circuits modulated by subthalamic deep brain stimulation, and infer about the inner organization of the nucleus in terms of motor and non-motor areas. Given its small size and anatomical intersubject variability, functional organization of the subthalamic nucleus is difficult to investigate in vivo with current methods. Here, we used local field potential recordings obtained from 10 patients with Parkinson's disease to identify a subthalamic area with an analogous electrophysiological signature, namely a predominant beta oscillatory activity. The spatial accuracy was improved by identifying a single contact per macroelectrode for its vicinity to the electrophysiological source of the beta oscillation. We then conducted whole brain probabilistic tractography seeding from the previously identified contacts, and further described connectivity modifications along the macroelectrode's main axis. The designated subthalamic 'beta' area projected predominantly to motor and premotor cortical regions additional to connections to limbic and associative areas. More ventral subthalamic areas showed predominant connectivity to medial temporal regions including amygdala and hippocampus. We interpret our findings as evidence for the convergence of different functional circuits within subthalamic nucleus' portions deemed to be appropriate as deep brain stimulation target to treat motor symptoms in Parkinson's disease. Potential clinical implications of our study are illustrated by an index case where deep brain stimulation of estimated predominant non-motor subthalamic nucleus induced hypomanic behaviour. © The

  16. Analysis of three plasmid systems for use in DNA A beta 42 immunization as therapy for Alzheimer's disease.

    Science.gov (United States)

    Qu, Bao-Xi; Lambracht-Washington, Doris; Fu, Min; Eagar, Todd N; Stüve, Olaf; Rosenberg, Roger N

    2010-07-19

    In an effort to optimize DNA immunization-elicited antibody production responses against A beta 1-42 (A beta 42) as a therapy for Alzheimer's disease (AD), comparisons were made between three distinct plasmid systems using gene gun delivery. Plasmids encoding A beta 42 monomer and a novel A beta 42 trimeric fusion protein were evaluated in conjunction with CMV or Gal4/UAS promoter elements. It was found that vaccination A beta 42 trimer under the Gal4/UAS promoter elicited high levels of anti-A beta 42 antibody production. Serum antibody levels from Gal4/UAS-A beta 42 trimer immunized mice were found to be 16.6+/-5.5 microg/ml compared to 6.5+/-2.5 microg/ml with Gal4/UAS-A beta 42 monomer or even less with CMV-A beta 42 trimer. As compared to monomeric A beta 42 or A beta 42 trimer expressed under the CMV promoter, injection of the Gal4/UAS-A beta 42 trimer induced high levels of A beta 42 antigen expression in tissue suggesting a mechanism for the increase in anti-A beta 42 antibody. Antibodies were found to be primarily IgG1 suggesting a predominant Th2 response (IgG1/IgG2a ratio of 9). Serum from A beta 42 trimer-vaccinated mice was also found to identify amyloid plaques in the brains of APP/PS1 transgenic mice. These results demonstrate the potential therapeutic use of Gal4/UAS DNA A beta 42 trimer immunization in preventing Alzheimer's disease. (c) 2010 Elsevier Ltd. All rights reserved.

  17. Can Beta Blockers Cause Weight Gain?

    Science.gov (United States)

    Beta blockers: Do they cause weight gain? Can beta blockers cause weight gain? Answers from Sheldon G. Sheps, ... can occur as a side effect of some beta blockers, especially the older ones, such as atenolol (Tenormin) ...

  18. The novel beta-secretase inhibitor KMI-429 reduces amyloid beta peptide production in amyloid precursor protein transgenic and wild-type mice.

    Science.gov (United States)

    Asai, Masashi; Hattori, Chinatsu; Iwata, Nobuhisa; Saido, Takaomi C; Sasagawa, Noboru; Szabó, Beáta; Hashimoto, Yasuhiro; Maruyama, Kei; Tanuma, Sei-ichi; Kiso, Yoshiaki; Ishiura, Shoichi

    2006-01-01

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain. The major component of the plaques, amyloid beta peptide (Abeta), is generated from amyloid precursor protein (APP) by beta- and gamma-secretase-mediated cleavage. Because beta-secretase/beta-site APP cleaving enzyme 1 (BACE1) knockout mice produce much less Abeta and grow normally, a beta-secretase inhibitor is thought to be one of the most attractive targets for the development of therapeutic interventions for AD without apparent side-effects. Here, we report the in vivo inhibitory effects of a novel beta-secretase inhibitor, KMI-429, a transition-state mimic, which effectively inhibits beta-secretase activity in cultured cells in a dose-dependent manner. We injected KMI-429 into the hippocampus of APP transgenic mice. KMI-429 significantly reduced Abeta production in vivo in the soluble fraction compared with vehicle, but the level of Abeta in the insoluble fraction was unaffected. In contrast, an intrahippocampal injection of KMI-429 in wild-type mice remarkably reduced Abeta production in both the soluble and insoluble fractions. Our results indicate that the beta-secretase inhibitor KMI-429 is a promising candidate for the treatment of AD.

  19. 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.

  20. [Neurotoxicity of carbapenem compounds and other beta-lactam antibiotics].

    Science.gov (United States)

    Sunagawa, M; Nouda, H

    1996-01-01

    The neurotoxic potencies are considerably different among various beta-lactam antibiotics. Some carbapenem antibiotics, a new class beta-lactam antibiotic, also induce convulsion in human and laboratory animals. This article reviews the structure activity relationship for the neurotoxicity of beta-lactam antibiotics, especially carbapenems. As for the neurotoxicity of carbapenem antibiotics, the presence of amino group in the C-2 side chain is an important factor in inducing convulsion and the strength of basicity of the amino group is correlated with the convulsant activity. The beta-lactam ring of carbapenem is not necessary to evoke convulsions. The neurotoxicity of carbapenem antibiotics is related to only a part of the structure, including the C-2 side chain, but not to the carbapenem skeleton itself. In comparison with other beta-lactam antibiotics, it has been found that the structure responsible for the convulsive action of carbapenems is significantly different from penicillins and cephalosporins in which the beta-lactam ring is essential to evoke convulsion. The induction of convulsions by carbapenem antibiotics is predominantly caused through the inhibition of gamma aminobutyric acid receptor in a similar manner as with penicillins and cephalosporins. However, the detail mechanism may be different not only among carbapenems, cephalosporins, and penicillins but among carbapenem compounds themselves. It is important to know the neurotoxic potential of a compound by investigating the effect of direct administration into the central nervous system such as intraventricular administration, since the penetration through blood-brain barrier or the pharmacokinetic property is varied in seriously ill patients. Possible drug interactions regarding neurotoxicity are also discussed. We hope these findings described here will be helpful in developing more efficient and safer beta-lactam antibiotics of a new generation.

  1. Antibody-based PET imaging of amyloid beta in mouse models of Alzheimer's disease

    OpenAIRE

    Sehlin, Dag; Fang, Xiaotian T; Cato, Linda; Antoni, Gunnar; Lannfelt, Lars; Syvänen, Stina

    2016-01-01

    Owing to their specificity and high-affinity binding, monoclonal antibodies have potential as positron emission tomography (PET) radioligands and are currently used to image various targets in peripheral organs. However, in the central nervous system, antibody uptake is limited by the blood-brain barrier (BBB). Here we present a PET ligand to be used for diagnosis and evaluation of treatment effects in Alzheimer's disease. The amyloid beta (A beta) antibody mAb158 is radiolabelled and conjuga...

  2. Phase synchronization between alpha and beta oscillations in the human electroencephalogram.

    Science.gov (United States)

    Nikulin, V V; Brismar, T

    2006-01-01

    Coordination of neuronal oscillations generated at different frequencies has been hypothesized to be an important feature of integrative brain functions. The present study aimed at the evaluation of the cross-frequency phase synchronization between electroencephalographic alpha and beta oscillations. The amplitude and phase information were extracted from electroencephalograms recorded in 176 healthy human subjects using an analytic signal approach based on the Hilbert transform. The results reliably demonstrated the presence of phase synchronization between alpha and beta oscillations, with a maximum in the occipito-parietal areas. The phase difference between alpha and beta oscillations showed characteristic peaks at about 2 and -1 radians, which were common for many subjects and electrodes. A specific phase difference might reflect similarity in the organization and interconnections of the networks generating alpha and beta oscillations across the entire cortex. Beta oscillations, which are phase-locked to alpha oscillations--alpha-synchronous beta oscillations--were largest in the occipito-parietal area with a second smaller maximum in the frontal area, thus demonstrating a topography, which was different from the conventional alpha and beta oscillations. The strength of the alpha-synchronous beta oscillations was not exclusively defined by the amplitude of the alpha rhythm indicating that they represent a distinct feature of the spontaneous electroencephalogram, which allows for a refined discrimination of the dynamics of beta oscillations.

  3. Brain Basics

    Medline Plus

    Full Text Available ... pituitary-adrenal (HPA) axis. Brain Basics in Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah ... axis —A brain-body circuit which plays a critical role in the body's response to stress. impulse — ...

  4. Brain Basics

    Medline Plus

    Full Text Available ... time in healthy people and are working to compare that with brain development in people mental disorders. Genes and environmental ... the brain than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take pictures ...

  5. Brain Basics

    Medline Plus

    Full Text Available ... of cells in the body, the results can affect many aspects of life. Scientists are continually learning more about how the brain grows and works in healthy people, and how normal brain development and function can go awry, leading ... the environment affect the brain The basic structure of the brain ...

  6. Brain Basics

    Medline Plus

    Full Text Available ... basic working unit of the brain and nervous system. These cells are highly specialized for the function of conducting messages. ... specialized brain systems. We have many specialized brain systems that work ... research are listed below. Amygdala —The brain's "fear hub," which ...

  7. The role of amyloid-beta in the regulation of memory.

    Science.gov (United States)

    Morley, John E; Farr, Susan A

    2014-04-15

    In this review there is evidence that amyloid-beta peptide is a memory enhancer at physiological (picomolar) concentrations. Pathological overproduction of amyloid-beta leads to impaired memory, oxidative damage, damage to the blood brain barrier, neurofibrillary tangles and amyloid plaque formation. Antisenses to amyloid precursor protein (APP) can reverse these effects in mice when they lower amyloid-beta protein to physiological levels. Data suggests that overproduction of APP leads to oxidative stress producing a vicious cycle of neuronal damage. For these reasons we have revised the "amyloid cascade hypothesis" removing emphasis from the plaque to amyloid-beta overproduction and suggest that an "amyloid-beta mitochondrial vicious cycle" hypothesis may be a better pathophysiological model for understanding Alzheimer's disease. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Beta-3 adrenergic receptor is expressed in acetylcholine-containing nerve fibers of the human urinary bladder: An immunohistochemical study.

    Science.gov (United States)

    Coelho, Ana; Antunes-Lopes, Tiago; Gillespie, James; Cruz, Francisco

    2017-11-01

    To identify in the human bladder the structures which express the Beta-3 adrenoceptor (β3AR). Human bladders from cadaveric organ donors (equally balanced in sex and age) were collected. Bladders were immediately fixed in paraformaldehyde and further processed for cryostat sectioning. Single and double immunohistochemistry was performed using antibodies against β3AR C-terminal, β3AR N-terminal, a pan-neuronal marker (β3-Tubulin) and markers of cholinergic (Vesicular Acetylcholine Transporter), adrenergic (Tyrosine Hidroxylase), and peptidergic (Calcitonin Gene-Related Peptide) nerve fibers. Nerve fibers expressing immunoreactivity for β3AR were abundantly found in the mucosa and muscular layers of the human bladder. No β3AR-IR was detected on urothelial or smooth muscle cells. The presence of β3AR-IR in nerve fibers was confirmed by co-expression with β3-Tubulin. Nerve fibers expressing β3AR-IR were cholinergic, VAChT(+) , and abundantly observed in the suburothelium. The cholinergic fibers were in close proximity and intermingled with adrenergic TH(+) and peptidergic CGRP(+) fibers. We demonstrated that β3AR is abundantly located in acetylcholine-containing nerve fibers. These findings have important consequences to understand the mechanism of action of β3AR agonists currently used for the treatment of OAB. © 2017 Wiley Periodicals, Inc.

  9. 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.

  10. XMAP215 polymerase activity is built by combining multiple tubulin-binding TOG domains and a basic lattice-binding region.

    Science.gov (United States)

    Widlund, Per O; Stear, Jeffrey H; Pozniakovsky, Andrei; Zanic, Marija; Reber, Simone; Brouhard, Gary J; Hyman, Anthony A; Howard, Jonathon

    2011-02-15

    XMAP215/Dis1 family proteins positively regulate microtubule growth. Repeats at their N termini, called TOG domains, are important for this function. While TOG domains directly bind tubulin dimers, it is unclear how this interaction translates to polymerase activity. Understanding the functional roles of TOG domains is further complicated by the fact that the number of these domains present in the proteins of different species varies. Here, we take advantage of a recent crystal structure of the third TOG domain from Caenorhabditis elegans, Zyg9, and mutate key residues in each TOG domain of XMAP215 that are predicted to be important for interaction with the tubulin heterodimer. We determined the contributions of the individual TOG domains to microtubule growth. We show that the TOG domains are absolutely required to bind free tubulin and that the domains differentially contribute to XMAP215's overall affinity for free tubulin. The mutants' overall affinity for free tubulin correlates well with polymerase activity. Furthermore, we demonstrate that an additional basic region is important for targeting to the microtubule lattice and is critical for XMAP215 to function at physiological concentrations. Using this information, we have engineered a "bonsai" protein, with two TOG domains and a basic region, that has almost full polymerase activity.

  11. MOZART1 and γ-tubulin complex receptors are both required to turn γ-TuSC into an active microtubule nucleation template.

    Science.gov (United States)

    Lin, Tien-Chen; Neuner, Annett; Flemming, Dirk; Liu, Peng; Chinen, Takumi; Jäkle, Ursula; Arkowitz, Robert; Schiebel, Elmar

    2016-12-19

    MOZART1/Mzt1 is required for the localization of γ-tubulin complexes to microtubule (MT)-organizing centers from yeast to human cells. Nevertheless, the molecular function of MOZART1/Mzt1 is largely unknown. Taking advantage of the minimal MT nucleation system of Candida albicans, we reconstituted the interactions of Mzt1, γ-tubulin small complex (γ-TuSC), and γ-tubulin complex receptors (γ-TuCRs) Spc72 and Spc110 in vitro. With affinity measurements, domain deletion, and swapping, we show that Spc110 and Mzt1 bind to distinct regions of the γ-TuSC. In contrast, both Mzt1 and γ-TuSC interact with the conserved CM1 motif of Spc110/Spc72. Spc110/Spc72 and Mzt1 constitute "oligomerization chaperones," cooperatively promoting and directing γ-TuSC oligomerization into MT nucleation-competent rings. Consistent with the functions of Mzt1, human MOZART1 directly interacts with the CM1-containing region of the γ-TuCR CEP215. MOZART1 depletion in human cells destabilizes the large γ-tubulin ring complex and abolishes CEP215(CM1)-induced ectopic MT nucleation. Together, we reveal conserved functions of MOZART1/Mzt1 through interactions with γ-tubulin complex subunits and γ-TuCRs. © 2016 Lin et al.

  12. The GCP3-Interacting Proteins GIP1 and GIP2 Are Required for γ-Tubulin Complex Protein Localization, Spindle Integrity, and Chromosomal Stability[C][W

    Science.gov (United States)

    Janski, Natacha; Masoud, Kinda; Batzenschlager, Morgane; Herzog, Etienne; Evrard, Jean-Luc; Houlné, Guy; Bourge, Mickael; Chabouté, Marie-Edith; Schmit, Anne-Catherine

    2012-01-01

    Microtubules (MTs) are crucial for both the establishment of cellular polarity and the progression of all mitotic phases leading to karyokinesis and cytokinesis. MT organization and spindle formation rely on the activity of γ-tubulin and associated proteins throughout the cell cycle. To date, the molecular mechanisms modulating γ-tubulin complex location remain largely unknown. In this work, two Arabidopsis thaliana proteins interacting with GAMMA-TUBULIN COMPLEX PROTEIN3 (GCP3), GCP3-INTERACTING PROTEIN1 (GIP1) and GIP2, have been characterized. Both GIP genes are ubiquitously expressed in all tissues analyzed. Immunolocalization studies combined with the expression of GIP–green fluorescent protein fusions have shown that GIPs colocalize with γ-tubulin, GCP3, and/or GCP4 and reorganize from the nucleus to the prospindle and the preprophase band in late G2. After nuclear envelope breakdown, they localize on spindle and phragmoplast MTs and on the reforming nuclear envelope of daughter cells. The gip1 gip2 double mutants exhibit severe growth defects and sterility. At the cellular level, they are characterized by MT misorganization and abnormal spindle polarity, resulting in ploidy defects. Altogether, our data show that during mitosis GIPs play a role in γ-tubulin complex localization, spindle stability and chromosomal segregation. PMID:22427335

  13. Experiments on double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Busto, J. [Neuchatel Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The Double Beta Decay, and especially ({beta}{beta}){sub 0{nu}} mode, is an excellent test of Standard Model as well as of neutrino physics. From experimental point of view, a very large number of different techniques are or have been used increasing the sensitivity of this experiments quite a lot (the factor of 10{sup 4} in the last 20 years). In future, in spite of several difficulties, the sensitivity would be increased further, keeping the interest of this very important process. (author) 4 figs., 5 tabs., 21 refs.

  14. Variants of beta-glucosidase

    Energy Technology Data Exchange (ETDEWEB)

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2015-07-14

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  15. Variants of beta-glucosidases

    Energy Technology Data Exchange (ETDEWEB)

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2014-10-07

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  16. Variants of beta-glucosidase

    Science.gov (United States)

    Fidantsef, Ana [Davis, CA; Lamsa, Michael [Davis, CA; Gorre-Clancy, Brian [Elk Grove, CA

    2009-12-29

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  17. Dosimetry of {beta} extensive sources; Dosimetria de fuentes {beta} extensas

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E.L.; Lallena R, A.M. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)

    2002-07-01

    In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of {beta} extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

  18. Adhesion of Trypanosoma cruzi trypomastigotes to fibronectin or laminin modifies tubulin and paraflagellar rod protein phosphorylation.

    Directory of Open Access Journals (Sweden)

    Eliciane C Mattos

    Full Text Available BACKGROUND: The unicellular parasite Trypanosoma cruzi is the causative agent of Chagaś disease in humans. Adherence of the infective stage to elements of the extracellular matrix (ECM, as laminin and fibronectin, is an essential step in host cell invasion. Although members of the gp85/TS, as Tc85, were identified as laminin and fibronectin ligands, the signaling events triggered on the parasite upon binding to these molecules are largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Viable infective parasites were incubated with laminin, fibronectin or bovine serum albumin for different periods of time and the proteins were separated by bidimensional gels. The phosphoproteins were envisaged by specific staining and the spots showing phosphorylation levels significantly different from the control were excised and identified by MS/MS. The results of interest were confirmed by immunoblotting or immunoprecipitation and the localization of proteins in the parasite was determined by immunofluorescence. Using a host cell-free system, our data indicate that the phosphorylation contents of T. cruzi proteins encompassing different cellular functions are modified upon incubation of the parasite with fibronectin or laminin. CONCLUSIONS/SIGNIFICANCE: Herein it is shown, for the first time, that paraflagellar rod proteins and α-tubulin, major structural elements of the parasite cytoskeleton, are predominantly dephosphorylated during the process, probably involving the ERK1/2 pathway. It is well established that T. cruzi binds to ECM elements during the cell infection process. The fact that laminin and fibronectin induce predominantly dephosphorylation of the main cytoskeletal proteins of the parasite suggests a possible correlation between cytoskeletal modifications and the ability of the parasite to internalize into host cells.

  19. Subtype-selective modulation of human beta 1- and beta 2-adrenoceptor function by beta-adrenoceptor agonists and antagonists

    NARCIS (Netherlands)

    Brodde, O. E.; Daul, A.; Michel, M. C.

    1990-01-01

    In healthy volunteers a 14-day treatment with the selective beta 1-adrenoceptor agonist xamoterol (2 x 200 mg/day) desensitized beta 1-adrenoceptor-mediated physiological effects, but did not affect beta 2-adrenoceptor-mediated effects; in contrast, a 9-day treatment with the selective beta

  20. Selective regulation of beta 1- and beta 2-adrenoceptors in the human heart by chronic beta-adrenoceptor antagonist treatment

    NARCIS (Netherlands)

    Michel, M. C.; Pingsmann, A.; Beckeringh, J. J.; Zerkowski, H. R.; Doetsch, N.; Brodde, O. E.

    1988-01-01

    1. In 44 patients undergoing coronary artery bypass grafting, the effect of chronic administration of the beta-adrenoceptor antagonists sotalol, propranolol, pindolol, metoprolol and atenolol on beta-adrenoceptor density in right atria (containing 70% beta 1- and 30% beta 2-adrenoceptors) and in

  1. The cerebrospinal fluid amyloid beta42/40 ratio in the differentiation of Alzheimer's disease from non-Alzheimer's dementia

    NARCIS (Netherlands)

    Spies, P E; Slats, D; Sjögren, J M C; Kremer, B P H; Verhey, F R J; Rikkert, M G M Olde; Verbeek, M M

    BACKGROUND: Amyloid beta(40) (Abeta(40)) is the most abundant Abeta peptide in the brain. The cerebrospinal fluid (CSF) level of Abeta(40) might therefore be considered to most closely reflect the total Abeta load in the brain. Both in Alzheimer's disease (AD) and in normal aging the Abeta load in

  2. Design, synthesis, biological evaluation, and 3D-QSAR analysis of podophyllotoxin-dioxazole combination as tubulin targeting anticancer agents.

    Science.gov (United States)

    Wang, Zi-Zhen; Sun, Wen-Xue; Wang, Xue; Zhang, Ya-Han; Qiu, Han-Yue; Qi, Jin-Liang; Pang, Yan-Jun; Lu, Gui-Hua; Wang, Xiao-Ming; Yu, Fu-Gen; Yang, Yong-Hua

    2017-08-01

    The advancement of cancer-fighting drugs has never been a simple linear process. Those drug design professionals begin to find inspiration from the nature after failing to find the ideal products by creative drug design and high-throughput screening. To obtain new molecules for inhibiting tubulin, podophyllotoxin was adopted as the leading compound and 1,3,4-oxadiazole was brought in to the C-4 site of podophyllotoxin in this research. A series of seventeen podophyllotoxin-derived esters have been achieved and then evaluated their antitumor activities against four different cancer cell lines: A549, MCF-7, HepG2, and HeLa. Among all the compounds, compound 7c showed the best antiproliferating properties with IC50  = 2.54 ± 0.82 μm against MCF-7 cancer cell line. It was obvious that the content of ROS grew significantly in MCF-7 in a way depending on the dosage. The time- and dose-dependent cell cycle assays revealed that compound 7c could apparently block cell cycle in the phase of G2/M along with the upregulation of cyclin A2 and CDK2 protein. According to further studies, confocal microscopy experiment has certified that compound 7c could restrain cancer from growing by blocking the polymerization of microtubule. Meanwhile, compound 7c could be ideally integrated with the colchicine site of tubulin. In future, it would be feasible to selectively design tubulin inhibitors with the help of 3D-QSAR. This means that it is hopeful to develop compound 7c as a potential agent against cancer due to its biological characteristics. © 2017 John Wiley & Sons A/S.

  3. Beta-Testing Agreement | FNLCR

    Science.gov (United States)

    Beta-Testing Agreements are appropriate forlimited term evaluation and applications development of new software, technology, or equipment platforms by the Frederick National Labin collaboration with an external commercial partner. It may

  4. Beta-carotene blood test

    Science.gov (United States)

    .