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Sample records for brain beta tubulin

  1. Antibody formation against beta-tubulin class III in response to brain trauma

    Czech Academy of Sciences Publication Activity Database

    Škoda, D.; Kranda, K.; Bojar, M.; Glosová, L.; Bäurle, J.; Kenney, Jana; Romportl, D.; Pelichovská, M.; Cvachovec, K.

    2006-01-01

    Roč. 68, č. 4 (2006), s. 213-216. ISSN 0361-9230 R&D Projects: GA MZd(CZ) NR8114 Institutional research plan: CEZ:AV0Z5011922 Keywords : autoantibodies * beta–tubulin * brain injury Subject RIV: FH - Neurology Impact factor: 1.684, year: 2006

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

    Energy Technology Data Exchange (ETDEWEB)

    Tse, Cek-Fyne

    1978-01-01

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

  3. Phosphorylation of a neuronal-specific beta-tubulin isotype

    International Nuclear Information System (INIS)

    Adult rats were intracraneally injected with [32P] phosphate and brain microtubules isolated. The electrophoretically purified, in vivo phospholabeled, beta-tubulin was digested with the V8-protease and the labeled peptide purified by reversed-phase liquid chromatography. Its amino acid sequence corresponds to the COOH-terminal sequence of a minor neuronal beta 3-tubulin isoform from chicken and human. The phosphorylation site was at serine 444. A synthetic peptide with sequence EMYEDDEEESESQGPK, corresponding to that of the COOH terminus of beta 3-tubulin, was efficiently phosphorylated in vitro by casein kinase II at the same serine 444. The functional meaning of tubulin phosphorylation is still unclear. However, the modification of the protein takes place after microtubule assembly, and phosphorylated tubulin is mainly present in the assembled microtubule protein fraction

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

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

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

  5. 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.

  6. Regulation of five tubulin isotypes by thyroid hormone during brain development.

    Science.gov (United States)

    Aniello, F; Couchie, D; Gripois, D; Nunez, J

    1991-11-01

    Nucleic acid probes derived from the 3' noncoding region of five tubulin cDNAs were used to study the effects of thyroid hormone deficiency on the expression of the mRNAs encoding two alpha (alpha 1 and alpha 2)- and three beta (beta 2, beta 4, and beta 5)-tubulin isotypes in the developing cerebral hemispheres and cerebellum. The content of alpha 1, which markedly declines during development in both brain regions, is maintained at high levels in the hypothyroid cerebellum, whereas it is decreased in the cerebral hemispheres. The alpha 2 level also declines during development and is decreased in both regions by thyroid hormone deficiency, but only during the two first postnatal weeks. Thyroid hormone deficiency slightly increases at all stages the beta 2 level in the cerebellum, whereas a decrease is observed at early stages in the cerebral hemispheres. The beta 5 level seems to be independent of thyroid hormone in the cerebral hemispheres, whereas it decreases at early stages in the hypothyroid cerebellum. Finally, the expression of the brain-specific beta 4 isotype is markedly depressed by thyroid hormone deficiency, particularly in the cerebellum. These data suggest that the genes encoding the tubulin isotypes are, directly or not, differently regulated by thyroid hormone during brain development. This might contribute to abnormal neurite outgrowth seen in the hypothyroid brain and therefore to impairment in brain functions produced by thyroid hormone deficiency. PMID:1717658

  7. Identification of three coated vesicle components as alpha- and beta- tubulin linked to a phosphorylated 50,000-dalton polypeptide

    OpenAIRE

    1983-01-01

    Coated vesicles are involved in the intracellular transport of membrane proteins between a variety of membrane compartments. The coats of bovine brain coated vesicles contain at least six polypeptides in addition to an 180,000-dalton polypeptide called clathrin. In this report we show that the 54,000- and 56,000-dalton coated vesicle polypeptides are alpha- and beta-tubulin, determined by immunoblotting and two-dimensional gel electrophoresis. An affinity-purified tubulin antiserum can precip...

  8. DSC Study on Brain Tubulin and the Effect of Cisplatin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The thermal property of the polymerization of brain tubulin was studied by a high-sensitivity differential scanning calorimeter. The phenomenon that heat flows increased and decreased consistently and obviously was observed. This phenomenon was called heat flow oscillation. It was probably correlated to the dynamic instability of microtubules. The effect of cisplatin on it was reported, too.

  9. 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. PMID:27156446

  10. Brain tubulin and actin cDNA sequences: isolation of recombinant plasmids.

    OpenAIRE

    Ginzburg, I.(Sobolev Institute of Mathematics and Novosibirsk State University, 630090, Novosibirsk, Russia); de Baetselier, A; Walker, M D; Behar, L; Lehrach, H; Frischauf, A M; Littauer, U Z

    1980-01-01

    Rat brain mRNA enriched for tubulin and actin sequences was used to prepare double stranded cDNA. A library of recombinant clones was constructed by inserting the dsDNA into the Pst1 site of pBR322 plasmid and transformation of E. coli chi 1776 host. Clones bearing sequences coding for tubulin and actin were identified and characterized.

  11. 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

  12. Fodrin in centrosomes: implication of a role of fodrin in the transport of gamma-tubulin complex in brain.

    Directory of Open Access Journals (Sweden)

    Sasidharan Shashikala

    Full Text Available Gamma-tubulin is the major protein involved in the nucleation of microtubules from centrosomes in eukaryotic cells. It is present in both cytoplasm and centrosome. However, before centrosome maturation prior to mitosis, gamma-tubulin concentration increases dramatically in the centrosome, the mechanism of which is not known. Earlier it was reported that cytoplasmic gamma-tubulin complex isolated from goat brain contains non-erythroid spectrin/fodrin. The major role of erythroid spectrin is to help in the membrane organisation and integrity. However, fodrin or non-erythroid spectrin has a distinct pattern of localisation in brain cells and evidently some special functions over its erythroid counterpart. In this study, we show that fodrin and γ-tubulin are present together in both the cytoplasm and centrosomes in all brain cells except differentiated neurons and astrocytes. Immunoprecipitation studies in purified centrosomes from brain tissue and brain cell lines confirm that fodrin and γ-tubulin interact with each other in centrosomes. Fodrin dissociates from centrosome just after the onset of mitosis, when the concentration of γ-tubulin attains a maximum at centrosomes. Further it is observed that the interaction between fodrin and γ-tubulin in the centrosome is dependent on actin as depolymerisation of microfilaments stops fodrin localization. Image analysis revealed that γ-tubulin concentration also decreased drastically in the centrosome under this condition. This indicates towards a role of fodrin as a regulatory transporter of γ-tubulin to the centrosomes for normal progression of mitosis.

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

    OpenAIRE

    Buhr, T L; Dickman, M B

    1994-01-01

    Colletotrichum gloeosporioides f. sp. aeschynomene is a fungal plant pathogen of Aeschynomene virginica. A beta-tubulin-encoding gene (TUB2) from this pathogen was cloned and sequenced. The deduced amino acid sequence of TUB2 had a high degree of homology to other fungal beta-tubulins. A portion of TUB2 from a benomyl-resistant C. gloeosporioides f. sp. aeschynomene mutant was also cloned and sequenced. A point mutation resulting in a glutamic acid-to-lysine substitution at amino acid 198 lik...

  14. Efficient gusA Transient Expression in Porphyra yezoensis Protoplasts Mediated by Endogenous Beta-tubulin Flanking Sequences

    Institute of Scientific and Technical Information of China (English)

    GONG Qianhong; YU Wengong; DAI Jixun; LIU Hongquan; XU Rifu; GUAN Huashi; PAN Kehou

    2007-01-01

    Endogenous tubulin promoter has been widely used for expressing foreign genes in green algae, but the efficiency and feasibility of endogenous tubulin promoter in the economically important Porphyra yezoensis (Rhodophyta) are tmknown. In this study, the flanking sequences of beta-tubulin gene from P. yezoensis were amplified and two transient expression vectors were constructed to determine their transcription promoting feasibility for foreign gene gusA. The testing vector pATubGUS was constructed by inserting 5'- and 3'-flanking regions (Tub5'and Tub3') up- and down-stream of β-glucuronidase (GUS) gene (gusA), respectively,into pA, a derivative of pCAT(R)3-enhancer vector. The control construct, pAGUSTub3, contains only gusA and Tub3 '. These constructs were electroporated into P. yezoensis protoplasts and the GUS activities were quantitatively analyzed by spectrometry. The results demonstrated that gusA gene was efficiently expressed in P. yezoensis protoplasts under the regulation of 5'-flanking sequence of the beta-tubulin gene. More interestingly, the pATubGUS produced stronger GUS activity in P. yezoensis protoplasts when compared to the result from pBI221, in which the gusA gene was directed by a constitutive CaMV 35 S promoter. The data suggest that the integration of P. yezoensis protoplast and its endogenous beta-tubulin flanking sequences is a potential novel system for foreign gene expression.

  15. Efficient gusA transient expression in Porphyra yezoensis protoplasts mediated by endogenous beta-tubulin flanking sequences

    Science.gov (United States)

    Gong, Qianhong; Yu, Wengong; Dai, Jixun; Liu, Hongquan; Xu, Rifu; Guan, Huashi; Pan, Kehou

    2007-01-01

    Endogenous tubulin promoter has been widely used for expressing foreign genes in green algae, but the efficiency and feasibility of endogenous tubulin promoter in the economically important Porphyra yezoensis (Rhodophyta) are unknown. In this study, the flanking sequences of beta-tubulin gene from P. yezoensis were amplified and two transient expression vectors were constructed to determine their transcription promoting feasibility for foreign gene gusA. The testing vector pATubGUS was constructed by inserting 5'-and 3'-flanking regions ( Tub5' and Tub3') up-and down-stream of β-glucuronidase (GUS) gene ( gusA), respectively, into pA, a derivative of pCAT®3-enhancer vector. The control construct, pAGUSTub3, contains only gusA and Tub3'. These constructs were electroporated into P. yezoensis protoplasts and the GUS activities were quantitatively analyzed by spectrometry. The results demonstrated that gusA gene was efficiently expressed in P. yezoensis protoplasts under the regulation of 5'-flanking sequence of the beta-tubulin gene. More interestingly, the pATubGUS produced stronger GUS activity in P. yezoensis protoplasts when compared to the result from pBI221, in which the gusA gene was directed by a constitutive CaMV 35S promoter. The data suggest that the integration of P. yezoensis protoplast and its endogenous beta-tubulin flanking sequences is a potential novel system for foreign gene expression.

  16. 多疣壁虎tubulin beta 3基因克隆和多克隆抗体制备%Molecular cloning of tubulin beta 3 (TUBB3) in Gekkojaponicus and preparation of its polyclonal antibody

    Institute of Scientific and Technical Information of China (English)

    李静; 秦勇; 顾云; 刘炎; 刘梅

    2012-01-01

    The tubulin beta III (TUBB3) gene encodes a class III member of the beta tubulin protein family that is primarily expressed in neurons and is considered to play a critical role in proper axon guidance and maintenance. This protein is generally used as a specific marker of neurons in the central nervous system. We obtained the full length cDNA sequence of TUBB3 by using the RACE method based on the EST fragment from the brain and spinal cord cDNA library of Gekko japonicus. We further investigated the multi-tissue expression pattern by RT-PCR and identified one transcript of TUBB3 about 1.8 kb in the central nervous system of Gekko japonicus by Northern blotting. The completed cDNA of gecko TUBB3 is 1790 bp with an open reading frame of 1350 bp, encoding a 450 amino-acid protein. The recombinant plasmid of pET-32a-TUBB3 was constructed and induced to express His-tagged TUBB3 protein in prokaryotic BL21 cells. The purified TUBB3 protein was then used to immunize rabbits to generate polyclonal antisera. The titer of the antiserum was more than 1:65 536 determined by ELISA. The result of western blotting showed that the TUBB3 antibody could specifically recognize the recombinant TUBB3 protein and endogenous TUBB3 protein. Our findings provide the tools to further understand the TUBB3 gene and investigate the regeneration of the central nervous system in Gekko japonicas.%Tubulin beta 3 (TUBB3)是特异表达于神经元的微管蛋白tubulin beta家族成员,被认为在维持轴突正常状态起着重要作用,是神经元特异的标志蛋白.该研究旨在获得多疣壁虎TUBB3全长cDNA序列并制备其多克隆抗体,为进一步研究多疣壁虎断尾再生提供基因和抗体工具.根据多疣壁虎中枢神经组织cDNA文库中TUBB3的EST片段序列,采用RACE-PCR方法,获得了全长cDNA,序列全长1790 bp,编码450个氨基酸,与其他物种TUBB3蛋白高度同源;RT-PCR方法和Northern blotting检测了TUBB3组织表达谱及其转录本的大

  17. Beta tubulin isoforms are not interchangeable for rescuing impaired radial migration due to Tubb3 knockdown.

    Science.gov (United States)

    Saillour, Yoann; Broix, Loïc; Bruel-Jungerman, Elodie; Lebrun, Nicolas; Muraca, Giuseppe; Rucci, Julien; Poirier, Karine; Belvindrah, Richard; Francis, Fiona; Chelly, Jamel

    2014-03-15

    Over the last years, the critical role of cytoskeletal proteins in cortical development including neuronal migration as well as in neuronal morphology has been well established. Inputs from genetic studies were provided through the identification of several mutated genes encoding either proteins associated with microtubules (DCX, LIS1, KIF2A, KIF5C, DYNC1H1) or tubulin subunits (TUBA1A, TUBB2B, TUBB5 and TUBG1), in malformations of cortical development (MCD). We also reported the identification of missense mutations in TUBB3, the postmitotic neuronal specific tubulin, in six different families presenting either polymicrogyria or gyral disorganization in combination with cerebellar and basal ganglial abnormalities. Here, we investigate further the association between TUBB3 mutations and MCDs by analyzing the consequences of Tubb3 knockdown on cortical development in mice. Using the in utero-electroporation approach, we demonstrate that Tubb3 knockdown leads to delayed bipolar morphology and radial migration with evidence, suggesting that the neuronal arrest is a transient phenomenon overcome after birth. Silenced blocked cells display a round-shape and decreased number of processes and a delay in the acquisition of the bipolar morphology. Also, more Tbr2 positive cells are observed, although less cells express the proliferation marker Ki67, suggesting that Tubb3 inactivation might have an indirect effect on intermediate progenitor proliferation. Furthermore, we show by rescue experiments the non-interchangeability of other beta-tubulins which are unable to rescue the phenotype. Our study highlights the critical and specific role of Tubb3 on the stereotyped morphological changes and polarization processes that are required for initiating radial migration to the cortical plate. PMID:24179174

  18. 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. PMID:25724666

  19. Tubulin phosphorylation by casein kinase II is similar to that found in vivo

    OpenAIRE

    1987-01-01

    Purified brain tubulin subjected to an exhaustive phosphatase treatment can be rephosphorylated by casein kinase II. This phosphorylation takes place mainly on a serine residue, which has been located at the carboxy- terminal domain of the beta-subunit. Interestingly, tubulin phosphorylated by casein kinase II retains its ability to polymerize in accordance with descriptions by other authors of in vivo phosphorylated tubulin. Moreover, the V8 phosphopeptide patterns of both tubulin phosphoryl...

  20. Identification of microtubular structures in diverse plant and animal cells by immunological cross-reaction revealed in immunofluorescence microscopy using antibodies against tubulin from porcine brain

    OpenAIRE

    Weber, Klaus; Osborn, Mary; Franke, Werner W.; Seib, Erinita; Scheer, Ulrich; Herth, Werner

    2010-01-01

    Antibody against tubulin from porcine brain was used to evaluate the immunological cross reactivity of tubulin from a variety of animal and plant cells. Indirect immunofluorescence microscopy revealed microtubule-containing structures including cytoplasmic microtubules, spindle microtubules, cilia and fIagella. Thus tubulin from diverse species of both mammals and plants show immunological cross-reactivity with tubulin from porcine brain. Results obtained by immunofluorescence microscopy are ...

  1. Direct photoaffinity labeling of tubulin with colchicine

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, J.; Knipling, L.; Cahnmann, H.J.; Palumbo, G. (National Institutes of Health, Bethesda, MD (USA))

    1991-04-01

    Ultraviolet irradiation of the ({sup 3}H)colchicine-tubulin complex leads to direct photolabeling of tubulin with low but practicable efficiency. The bulk (70% to greater than 90%) of the labeling occurs on beta-tubulin and appears early after irradiation, whereas {alpha}-tubulin is labeled later. The labeling ratio of {beta}-tubulin to {alpha}-tubulin ({beta}/{alpha} ratio) is reduced by prolonged incubation, prolonged irradiation, urea, high ionic strength, the use of aged tubulin, dilution of tubulin, or large concentrations of colchicine or podophyllotoxin. Glycerol increases the {beta}/{alpha} ratio. Limited data with ({sup 3}H)podophyllotoxin show that it covalently bound with a similar {beta}/{alpha} distribution. Vinblastine, on the other hand, exhibits preferential attachment to {alpha}-tubulin. The possibilities that colchicine binds at the interface between {alpha}-tubulin and {beta}-tubulin, that the drug spans this interface, and that both subunits may contribute to the binding site are suggested.

  2. Tubulin as a molecular component of coated vesicles

    OpenAIRE

    1983-01-01

    Two proteins of 53,000 and 56,000 mol wt have been found to be associated with coated vesicles (CV) purified from bovine brain and chicken liver. These proteins share molecular weights, isoelectric points, and antigenic determinants with alpha- and beta-tubulins purified from bovine brain. Based on SDS PAGE and electron microscopic analysis of controlled pore glass bead exclusion column fractions, both the tubulins and the major CV polypeptide clathrin were found to chromatograph as component...

  3. Targeting beta III-tubulin in glioblastoma multiforme: from cell biology and histopathology to cancer therapeutics

    Czech Academy of Sciences Publication Activity Database

    Katsetos, C.D.; Dráber, Pavel; Kavallaris, M.

    2011-01-01

    Roč. 11, č. 8 (2011), s. 719-728. ISSN 1871-5206 R&D Projects: GA ČR GAP302/10/1759 Institutional research plan: CEZ:AV0Z50520514 Keywords : glioblastoma multiforme * tubulin binding agent * epothilones Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.862, year: 2011

  4. Development a diagnostic pan-dermatophyte TaqMan probe real-time PCR assay based on beta tubulin gene.

    Science.gov (United States)

    Mirhendi, Hossein; Motamedi, Marjan; Makimura, Koichi; Satoh, Kazuo

    2016-08-01

    Early differentiation of dermatophytosis from other cutaneous mycoses is essential to avoid inaccurate therapy. DNA-based techniques including real-time PCR have increasingly been considered for detection of fungal elements in clinical specimens. In this study, after partial sequence analysis of beta tubulin (BT2) gene in 13 common and rare pathogenic dermatophyte species, a pan-dermatophyte primer and probe set was designed in a TaqMan probe-based PCR format. The sensitivity and specificity of the system was tested with 22 reference strains of dermatophytes, 234 positive clinical specimens, 32 DNA samples extracted from normal nails, several fungi other than dermatophytes and human DNAs. Analytical detection limit of the designed PCR on serially diluted DNAs of prepared recombinant plasmid indicated that only five molecules per sample are the minimum number for reliable detection by the assay. A total of 226 out of 234 (96.5%) DNAs extracted from clinical samples, but none of the 32 nail samples, from healthy volunteers were positive in PCR. The real-time PCR targeted beta tubulin gene established in this study could be a sensitive diagnostic tool which is significantly faster than the conventional culture method and should be useful in the clinical settings, in large-scale epidemiological studies and in clinical trials of antifungal therapy. PMID:27071371

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

    International Nuclear Information System (INIS)

    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 α and β 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 α and β subunits with time were determined. The pattern of change was biphasic. During the first phase the ratio decreased; during the second phase the ratio increased continuously. An interpretation consistent with all the data in this study is that the α subunit is synthesized at a more rapid rate than the β subunit

  6. 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. PMID:18668337

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

    Czech Academy of Sciences Publication Activity Database

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

    2007-01-01

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

  8. A codon change in beta-tubulin which drastically affects microtubule structure in Drosophila melanogaster fails to produce a significant phenotype in Saccharomyces cerevisiae.

    OpenAIRE

    Praitis, V; Katz, W S; Solomon, F

    1991-01-01

    The relative uniformity of microtubule ultrastructure in almost all eukaryotic cells is thought to be a consequence of the conserved elements of tubulin sequence. In support of this idea, a mutation in a beta-tubulin gene of Drosophila melanogaster, occurring at a highly conserved position, produces U-shaped microtubules, suggesting a defect in either nucleation or packing during assembly (M. T. Fuller, J. H. Caulton, J. A. Hutchens, T. C. Kaufman, and E. C. Raff, J. Cell Biol. 104:385-394, 1...

  9. Hg sup 2+ induces GTP-tubulin interactions in rat brain similar to those observed in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Duhr, E.; Pendergrass, C.; Kasarskis, E.; Slevin, J.; Haley, B. (Univ. of Kentucky, Lexington (United States))

    1991-03-11

    The pathogenesis of Alzheimer's Disease (AD) is unknown. Using SDS-PAGE and autoradiography the authors' laboratory has shown: (1) that the tubulin in AD brain is less photolabeled by ({sup 32}P)8N{sub 3}GTP than is tubulin from control brain and (2) that low {mu}M levels of preformed Hg{sup 2+}EDTA specifically blocked interactions of tubulin-({sup 32}P)8N{sub 3}GTP in control human brain homogenates giving a photolabeling profile identical to AD brain. Elevated levels of Hg{sup 2+} have been reported in AD brain by others. Earlier work using ({sup 32}P)8N{sub 3}GTP with Al{sup 3+} treated rat and rabbit brain showed no differences from control with regards to tubulin photolabeling. However, our latest data show that brain samples from Hg{sup 2+} fed rats display an abolished GTP-tubulin interaction similar to AD brain samples as determined by ({sup 32}P)8N{sub 3}GTP photolabeling profiles. Removal of Hg{sup 2+} from treated rats did not reverse the effect. These results suggest that certain complexed forms of Hg{sup 2+} must be considered as a potential source for the etiology of AD.

  10. Paclitaxel-resistant cells have a mutation in the paclitaxel-binding region of beta-tubulin (Asp26Glu) and less stable microtubules.

    Science.gov (United States)

    Hari, Malathi; Loganzo, Frank; Annable, Tami; Tan, Xingzhi; Musto, Sylvia; Morilla, Daniel B; Nettles, James H; Snyder, James P; Greenberger, Lee M

    2006-02-01

    Resistance to paclitaxel-based therapy is frequently encountered in the clinic. The mechanisms of intrinsic or acquired paclitaxel resistance are not well understood. We sought to characterize the resistance mechanisms that develop upon chronic exposure of a cancer cell line to paclitaxel in the presence of the P-glycoprotein reversal agent, CL-347099. The epidermoid tumor line KB-3-1 was exposed to increasing concentrations of paclitaxel and 5 micromol/L CL-347099 for up to 1 year. Cells grown in 15 nmol/L paclitaxel plus CL-347099 (KB-15-PTX/099) developed 18-fold resistance to paclitaxel and were dependent upon paclitaxel for maximal growth. They grew well and retained resistance to paclitaxel when grown in athymic mice. Cross-resistance (3- to 5-fold) was observed in tissue culture to docetaxel, the novel taxane MAC-321, and epothilone B. Collateral sensitivity (approximately 3-fold) was observed to the depolymerizing agents vinblastine, dolastatin-10, and HTI-286. KB-15-PTX/099-resistant cells did not overexpress P-glycoprotein nor did they have an alteration of [14C]paclitaxel accumulation compared with parental cells. However, a novel point mutation (T to A) resulting in Asp26 to glutamate substitution in class I (M40) beta-tubulin was found. Based on an electron crystallography structure of Zn-stabilized tubulin sheets, the phenyl ring of C-3' NHCO-C6H5 of paclitaxel makes contact with Asp26 of beta-tubulin, suggesting a ligand-induced mutation. Optimized model complexes of paclitaxel, docetaxel, and MAC-321 in beta-tubulin show a novel hydrogen bonding pattern for the glutamate mutant and rationalize the observed resistance profiles. However, a mutation in the paclitaxel binding pocket does not explain the phenotype completely. KB-15-PTX/099 cells have impaired microtubule stability as determined by a reduced percentage of tubulin in microtubules and reflected by less acetylated tubulin. These results suggest that a mutation in tubulin might affect

  11. Genetic polymorphism of the beta-tubulin gene of Onchocerca volvulus in ivermectin naive patients from Cameroon, and its relationship with fertility of the worms

    OpenAIRE

    Bourguinat, C.; Pion, Sébastien; Kamgno, J.; Gardon, Jacques; Gardon Wendel, N.; Duke, B.O.L.; Prichard, R. K.; Boussinesq, Michel

    2006-01-01

    Observations of low response of patients infected with Onchocerca volvulus to ivermectin suggest that the parasite may be tinder a selection process toward potential resistance. To limit the extension of this phenomenon, it is crucial to characterize the genes of O. volvulus that are involved. For this, O. volvulus adult worms collected before the introduction of ivermectin in an onchocerciasis endemic area of central Cameroon were genotyped for beta-tubulin. To derive a baseline to investiga...

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

    Czech Academy of Sciences Publication Activity Database

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

  14. 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.

  15. Distribution of beta-amyloid in the canine brain.

    Science.gov (United States)

    Hou, Y; White, R G; Bobik, M; Marks, J S; Russell, M J

    1997-03-01

    The distribution of amyloid-beta protein (A beta) in the canine brain was demonstrated by immunochemistry on serially sectioned tissues from 10 aged mixed breed dogs. Summation of quantitative data and relegation to anatomical sites for the 10 dogs showed A beta to be widely distributed in the cortex and hippocampus while completely absent in the brain stem and cerebellum. The highest density of A beta was in the dentate gyrus of the hippocampus. Cortical areas exhibiting the greatest A beta deposition were the posterior and medial suprasylvius gyrus and the proreus gyrus of the frontal lobe. Unlike humans the canine entorhinal cortex, amygdala, basal ganglia and olfactory bulbs were rarely affected. This suggested that the highly developed olfactory pathways of the canine are generally spared from A beta deposition. PMID:9141082

  16. 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

  17. Axonal tubulin and axonal microtubules: biochemical evidence for cold stability

    OpenAIRE

    1984-01-01

    Nerve extracts containing tubulin labeled by axonal transport were analyzed by electrophoresis and differential extraction. We found that a substantial fraction of the tubulin in the axons of the retinal ganglion cell of guinea pigs is not solubilized by conventional methods for preparation of microtubules from whole brain. In two-dimensional polyacrylamide gel electrophoresis this cold-insoluble tubulin was biochemically distinct from tubulin obtained from whole brain microtubules prepared b...

  18. 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.

  19. Tubulin-perturbing naphthoquinone spiroketals.

    Science.gov (United States)

    Balachandran, Raghavan; Hopkins, Tamara D; Thomas, Catherine A; Wipf, Peter; Day, Billy W

    2008-02-01

    Several natural and synthetic naphthoquinone spiroketals are potent inhibitors of the thioredoxin-thioredoxin reductase redox system. Based on the antimitotic and weak antitubulin actions noted for SR-7 ([8-(furan-3-ylmethoxy)-1-oxo-1,4-dihydronaphthalene-4-spiro-2'-naphtho[1'',8''-de][1',3'][dioxin]), a library of related compounds was screened for tubulin-perturbing properties. Two compounds, TH-169 (5'-hydroxy-4'H-spiro[1,3-dioxolane-2,1'-naphthalen]-4'-one) and TH-223 (5'-methoxy-4'H-spiro[1,3-dioxane-2,1'-naphthalen]-4'-one), had substantial effects on tubulin assembly and were antiproliferative at low micromolar concentrations. TH-169 was the most potent at blocking GTP-dependent polymerization of 10 mum tubulin in vitro with a remarkable 50% inhibitory concentration of ca. 400 nm. It had no effect on paclitaxel-induced microtubule assembly and did not cause microtubule hypernucleation. TH-169 failed to compete with colchicine for binding to beta-tubulin. The 50% antiproliferative concentration of TH-169 against human cancer cells was at or slightly below 1 mum. Flow cytometry showed that 1 mum TH-169 caused an increase in G(2)/M and hypodiploid cells. TH-169 eliminated the PC-3 cells' polyploid population and increased their expression of p21(WAF1) and Hsp70 in a concentration-dependent manner. The antiproliferative effect of TH-169 was irreversible and independent of changes in caspases, actin, tubulin, glyceraldehyde phosphate dehydrogenase or Bcl-x(S/L). This structurally simple naphthoquinone spiroketal represents a small molecule, tubulin-interactive agent with a novel apoptotic pathway and attractive biological function. PMID:18194192

  20. Assembly Properties of Divergent Tubulin Isotypes and Altered Tubulin Polypeptides in Vivo

    Science.gov (United States)

    Gu, Wei

    1990-01-01

    Mbeta1 is one of the closely related (though distinct) gene products termed isotypes encoded by the mouse beta-tubulin multigene family. These isotypes typically share 95%-98% homology at the amino acid level. However, Mbeta 1 is unusual in its relatively high degree of divergence compared to other beta-tubulin isotypes; furthermore, its tissue-restricted pattern of expression (Mbeta1 is only expressed in hematopoietic tissue) led to speculation that this isotype might be specialized for assembly into unique microtubule structures (such as the marginal band in some erythropoietic cell types). To test if this isotype is capable of coassembly into microtubules in cell types other than those in which it is normally expressed, a method was developed for the generation of an anti-Mbeta1 specific antibody. The Mbeta1 tubulin isotype was introduced into tissue culture cells by transfection and its expression and assembly properties were studied in both transiently transfected cells and stable cell lines using the anti -Mbeta1 specific antibody. The successful expression and coassembly of a 'foreign' tubulin isotype into microtubules in tissue culture cells and the generation of an antibody that can specifically recognize this isotype provided an approach to study the properties of altered beta-tubulin polypeptides in vivo. beta-tubulin synthesis in eukaryotic cells is autoregulated by a posttranscriptional mechanism in which the first four amino acids are responsible for determining the stability of beta -tubulin mRNA. To test if the beta -tubulin amino-terminal regulatory domain also contributes to the capacity of the tubulin monomer to polymerize into microtubules, altered sequences encoding Mbeta 1 but containing deletions encompassing amino acids 2-5 were expressed in HeLa cells. Stable cell lines expressing the altered Mbeta1 isotype were also generated. The assembly properties and stability of these altered Mbeta1 tubulin polypeptides were tested using the anti

  1. SIRT2 ablation has no effect on tubulin acetylation in brain, cholesterol biosynthesis or the progression of Huntington's disease phenotypes in vivo.

    Directory of Open Access Journals (Sweden)

    Anna Bobrowska

    Full Text Available Huntington's disease (HD is a devastating neurodegenerative disorder for which there are no disease-modifying treatments. The molecular pathogenesis of HD is complex and many mechanisms and cellular processes have been proposed as potential sites of therapeutic intervention. However, prior to embarking on drug development initiatives, it is essential that therapeutic targets can be validated in mammalian models of HD. Previous studies in invertebrate and cell culture HD models have suggested that inhibition of SIRT2 could have beneficial consequences on disease progression. SIRT2 is a NAD(+-dependent deacetylase that has been proposed to deacetylate α-tubulin, histone H4 K16 and to regulate cholesterol biogenesis - a pathway which is dysregulated in HD patients and HD mouse models. We have utilized mice in which SIRT2 has been reduced or ablated to further explore the function of SIRT2 and to assess whether SIRT2 loss has a beneficial impact on disease progression in the R6/2 mouse model of HD. Surprisingly we found that reduction or loss of SIRT2 had no effect on the acetylation of α-tubulin or H4K16 or on cholesterol biosynthesis in the brains of wild type mice. Equally, genetic reduction or ablation of SIRT2 had no effect on HD progression as assessed by a battery of physiological and behavioural tests. Furthermore, we observed no change in aggregate load or levels of soluble mutant huntingtin transprotein. Intriguingly, neither the constitutive genetic loss nor acute pharmacological inhibition of SIRT2 affected the expression of cholesterol biosynthesis enzymes in the context of HD. Therefore, we conclude that SIRT2 inhibition does not modify disease progression in the R6/2 mouse model of HD and SIRT2 inhibition should not be prioritised as a therapeutic option for HD.

  2. AMYLOID BETA ACCUMULATION IN HIV-1-INFECTED BRAIN: THE ROLE OF THE BLOOD BRAIN BARRIER

    OpenAIRE

    András, Ibolya E.; Toborek, Michal

    2012-01-01

    In recent years we face an increase in the aging of the HIV-1-infected population, which is not only due to effective antiretroviral therapy but also to new infections among older people. Even with the use of the antiretroviral therapy, HIV-associated neurocognitive disorders represent an increasing problem as the HIV-1-infected population ages. Increased amyloid beta (Aβ) deposition is characteristic of HIV-1-infected brains, and it has been hypothesized that brain vascular dysfunction contr...

  3. Evidence for the presence of beta 3-adrenergic receptor mRNA in the human brain.

    Science.gov (United States)

    Rodriguez, M; Carillon, C; Coquerel, A; Le Fur, G; Ferrara, P; Caput, D; Shire, D

    1995-04-01

    The beta 3-adrenergic receptor (AR) is widely distributed in peripheral tissues, but up to now it has not been detected in the central nervous system. By using the polymerase chain reaction (PCR) technique, we found the beta 3-AR mRNA to be present in all the regions of the human brain we investigated. The quantities found were very low compared to those of the beta 1-AR and beta 2-AR mRNAs, being hardly detectable in adult brain. In contrast, the brain of very young infants contained about 100 times more beta 3-AR mRNA than the adult brain, whereas the amounts of beta 1-AR and beta 2-AR transcripts were essentially the same. In addition, using PCR we have cloned a central beta 3-AR coding region from a human frontal cortex cDNA library and have found it to be identical to the corresponding peripheral sequence. PMID:7609625

  4. Purification and Fluorescent Labeling of Tubulin from Xenopus laevis Egg Extracts.

    Science.gov (United States)

    Groen, Aaron C; Mitchison, Timothy J

    2016-01-01

    For many years, microtubule research has depended on tubulin purified from cow and pig brains, which may not be ideal for experiments using proteins or extracts from non-brain tissues and cold-blooded organisms. Here, we describe a method to purify functional tubulin from the eggs of the frog, Xenopus laevis. This tubulin has many benefits for the study of microtubules and microtubule based structures assembled in vitro at room temperature. Frog tubulin lacks many of the highly stabilizing posttranslational modifications present in pig brain-derived tubulin, and polymerizes efficiently at room temperature. In addition, fluorescently labeled frog egg tubulin incorporates into meiotic spindles assembled in egg extract more efficiently than brain tubulin, and is thus superior as a probe for Xenopus egg extract experiments. Frog egg tubulin will provide excellent opportunities to identify active nucleation complexes and revisit microtubule polymerization dynamics in vitro. PMID:27193841

  5. βIII-Tubulin: A novel mediator of chemoresistance and metastases in pancreatic cancer.

    OpenAIRE

    Erkan, Murat Mert; McCarroll, Joshua A.; Sharbeen, George; Liu, Jie; Youkhana, Janet; Goldstein, David; McCarthy, Nigel; Limbri, Lydia F.; Dischl, Dominic; Ceyhan, Gueralp O.; Johns, Amber L.; Biankin, Andrew V.; Kavallaris, Maria; Phillips, Phoebe A.

    2015-01-01

    Pancreatic cancer is a leading cause of cancer-related deaths in Western societies. This poor prognosis is due to chemotherapeutic drug resistance and metastatic spread. Evidence suggests that microtubule proteins namely, beta-tubulins are dysregulated in tumor cells and are involved in regulating chemosensitivity. However, the role of beta-tubulins in pancreatic cancer are unknown. We measured the expression of different beta-tubulin isotypes in pancreatic adenocarcinoma tissue and pancreati...

  6. Tau-tubulin kinase

    Directory of Open Access Journals (Sweden)

    Seiko Ikezu

    2014-04-01

    Full Text Available Tau-tubulin kinase (TTBK belongs to casein kinase superfamily and can phosphorylate microtubule-associated protein tau and tubulin. TTBK has two isoforms, TTBK1 and TTBK2, which contain highly homologous catalytic domains but their non-catalytic domains are distinctly different. TTBK1 is expressed specifically in the central nervous system and is involved in phosphorylation and aggregation of tau. TTBK2 is ubiquitously expressed in multiple tissues and genetically linked to spinocerebellar ataxia type 11. TTBK1 directly phosphorylates tau protein, especially at Ser422, and also activates cycline-dependent kinase 5 in a unique mechanism. TTBK1 protein expression is significantly elevated in Alzheimer’s disease brains, and genetic variations of the TTBK1 gene are associated with late-onset Alzheimer’s disease in two cohorts of Chinese and Spanish populations. TTBK1 transgenic mice harboring the entire 55-kilobase genomic sequence of human TTBK1 show progression of tau accumulation, neuroinflammation, and neurodegeneration when crossed with tau mutant mice. Our recent study shows that there is a striking switch in mononuclear phagocyte and activation phenotypes in the anterior horn of the spinal cord from alternatively activated (M2-skewed microglia to pro-inflammatory (M1-skewed infiltrating peripheral monocytes in P301L tau mutant mice by crossing with TTBK1 transgenic mice. TTBK1 is responsible for mediating M1-activated microglia-induced neurotoxicity, and its overexpression induces axonal degeneration in vitro. These studies suggest that TTBK1 is an important molecule for the inflammatory axonal degeneration, which may be relevant to the pathobiology of tauopathy including Alzheimer’s disease.

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

    DEFF Research Database (Denmark)

    Sennvik, Kristina; Bogdanovic, N; Volkmann, Inga; Fastbom, J; Benedikz, Eirikur

    2004-01-01

    (beta-sAPP) in brain tissue sections from the frontal, temporal and occipital lobe. Strong granular beta-sAPP staining was found throughout the gray matter of all three areas, while white matter staining was considerably weaker. beta-sAPP was found to be localized in astrocytes and in axons. We found...... 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 and......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...

  8. A Unifying Hypothesis for the Conformational Change of Tubulin

    CERN Document Server

    Fygenson, D K

    2001-01-01

    Microtubule dynamic instability arises from the hydrolysis of GTP bound to the beta-monomer of the tubulin dimer. The conformational change induced by hydrolysis is unknown, but microtubules disassemble into protofilaments of GDP-bound tubulin that curve away from the microtubule axis. This paper presents the unfolding of a portion of the tubulin molecule into the microtubule interior as a plausible, unifying explanation for diverse structural and kinetic features of microtubules. This is the first specific structural hypothesis for the hydrolysis induced conformational change of tubulin that simultaneously explains weakening of lateral bonds, bending about longitudinal bonds, changes in protofilament supertwist associated with GTP hydrolysis, structural features of GDP-tubulin double rings, faster disassembly at higher temperatures and slower disassembly in the presence of glycerol and deuterium oxide. The hypothesis suggests further theoretical investigations and direct experimental tests.

  9. Characterization of recombinant RI beta and evaluation of the presence of RI beta protein in rat brain and testicular extracts.

    Science.gov (United States)

    DeManno, D A; Jackiw, V; Brooks, E; Hunzicker-Dunn, M

    1994-07-21

    Based upon recent reports that the mRNA from the regulatory (R) RI beta subunit of cAMP-dependent protein kinase (PKA) was expressed in testicular extracts, we determined whether testicular extracts exhibited RI beta protein. To accomplish this goal, we initially determined the fundamental labeling and ionic characteristics of recombinant RI beta. Recombinant RI beta eluted from DEAE-cellulose with a salt concentration (of 0.075 M) equivalent to its elution position from soluble mouse brain extracts with catalytic subunit-free RI alpha. As predicted by its amino acid sequence homology to RI alpha, recombinant RI beta was not phosphorylated by PKA but was labeled specifically with 8-azido-adenosine 3':5'-[32P]monophosphate (8-N3[32P]cAMP). Additionally, RI antisera reacted equally with RI alpha (47 kDa) and recombinant RI beta (53 kDa). However, recombinant RI beta exhibited an unexpectedly basic pI of 6.65-6.85. By using a pH gradient for isoelectric focussing that allowed for clear focussing of 8-N3[32P]cAMP-labeled recombinant RI beta, 8-N3[32P]cAMP-labeled RI beta was readily detected by two-dimensional gel electrophoresis in rat brain particulate extracts and exhibited a pI equivalent to that of recombinant RI beta. The 53-kDa RI beta was undetectable either by its immunoreactivity or upon photoaffinity labeling with 8-N3[32P]cAMP by one or two-dimensional gel electrophoresis in soluble or particulate extracts of testes of 14-day-old, 45-day-old, or adult rats or in epididymal sperm. However, 8-N3[32P]cAMP-labeled RI beta was detected, albeit in very small levels, by two-dimensional electrophoresis upon separation of PKAs in testes of 14-day-old rats by DEAE-cellulose chromatography but was absent in equivalent extracts from adult rat testes. These results demonstrate that the unexpectedly basic pI of RI beta allows for its clear separation by two-dimensional electrophoresis from the RII proteins and therefore allows for its unambiguous identification. Further

  10. Localisation spatio-temporelle de tubuline beta III au sein l'organe de Corti et au niveau du ganglion spiral entre le 18e jours embryonnaires (E18) et le 25e jours post-natal (P25) chez le rat

    OpenAIRE

    Johnen, Nicolas; Thelen, Nicolas; Cloes, Marie; Thiry, Marc

    2010-01-01

    The mammalian auditory organ, the organ of Corti (OC), is composed of mechanosensory hair cells and nonsensory supporting cell types. Based on their morphology and physiology, at least two types of sensory cells can be identified in the OC: inner and outer hair cells. The structure of this organ is well reported in adult but its development is still little-known. By using confocal microscopy, we studied the spatial-temporal distribution of beta tubulin III during the differentiation of th...

  11. 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

  12. Nucleolar gamma-tubulin

    Czech Academy of Sciences Publication Activity Database

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

    Shanghai : CSBMB (The Chinese Society of Biochemistry and Molecular Biology ), 2009. s. 86-86. [IUMB /21./ and FAOBMB International congress of Biochemistry and Molecular Biology /12./. 02.04.2009-07.04.2009, shanghai] R&D Projects: GA AV ČR KAN200520701; GA MŠk LC545 Institutional research plan: CEZ:AV0Z50520514 Keywords : gamma-tubulin * nucleolus Subject RIV: EB - Genetics ; Molecular Biology

  13. 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.

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

    OpenAIRE

    Alp, Harun; Varol, Sefer; Celik, Muhammet Murat; Altas, Murat; Evliyaoglu, Osman; Tokgoz, Orhan; Tanrıverdi, Mehmet Halis; Uzar, Ertugrul

    2012-01-01

    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 gl...

  15. [2,4-13 C2 ]-beta-Hydroxybutyrate metabolism in human brain.

    Science.gov (United States)

    Pan, Jullie W; de Graaf, Robin A; Petersen, Kitt F; Shulman, Gerald I; Hetherington, Hoby P; Rothman, Douglas L

    2002-07-01

    Infusions of [2,4-13C2]-beta-hydroxybutyrate and 1H-13C polarization transfer spectroscopy were used in normal human subjects to detect the entry and metabolism of beta-hydroxybutyrate in the brain. During the 2-hour infusion study, 13C label was detectable in the beta-hydroxybutyrate resonance positions and in the amino acid pools of glutamate, glutamine, and aspartate. With a plasma concentration of 2.25 +/- 0.24 mmol/L (four volunteers), the apparent tissue beta-hydroxybutyrate concentration reached 0.18 +/- 0.06 mmol/L during the last 20 minutes of the study. The relative fractional enrichment of 13C-4-glutamate labeling was 6.78 +/- 1.71%, whereas 13C-4-glutamine was 5.68 +/- 1.84%. Steady-state modeling of the 13C label distribution in glutamate and glutamine suggests that, under these conditions, the consumption of the beta-hydroxybutyrate is predominantly neuronal, used at a rate of 0.032 +/- 0.009 mmol. kg-1. min-1, and accounts for 6.4 +/- 1.6% of total acetyl coenzyme A oxidation. These results are consistent with minimal accumulation of cerebral ketones with rapid utilization, implying blood-brain barrier control of ketone oxidation in the nonfasted adult human brain. PMID:12142574

  16. Anthelmintic resistance in Swedish sheep flocks based on a comparison of the results from the faecal egg count reduction test and resistant allele frequencies of the beta-tubulin gene.

    Science.gov (United States)

    Höglund, Johan; Gustafsson, Katarina; Ljungström, Britt-Louise; Engström, Annie; Donnan, Alison; Skuce, Philip

    2009-04-01

    A faecal egg count reduction test (FECRT) survey was conducted during the grazing season 2006 and 2007 to provide an updated indication of the prevalence of anthelmintic resistance in sheep flocks in Sweden. A total of 1330 faecal samples from 90 flocks on 45 farms, with a minimum of 20 ewes each, was collected by local sheep veterinarians. Per treatment group, approximately 15 lambs were dewormed either with oral suspensions of ivermectin (Ivomec vet.) or albendazole (Valbazen vet.). The efficacy on each farm was investigated either in 2006 or 2007 by faecal egg counts collected on the day of treatment and in a new sample from the same animals 7-10 days later. Third-stage larvae (L3) were initially identified morphologically from pooled cultures. These were then used as the source of genomic DNA template for two molecular tests. The first was a PCR-based test for specific identification of Haemonchus contortus, and the second was a Pyrosequencing assay for the analysis of benzimidazole (BZ) resistance targeting the P200 mutation in the parasite's beta-tubulin gene. Larval cultures indicated that Teladorsagia and Trichostrongylus were the predominant genera, but Haemonchus was diagnosed in 37% of the flocks. The PCR results revealed an almost 100% agreement with those farms that had previously been shown to have Haemonchus present, even when the % prevalence was low (approximately 3%). Only two (4%) of the surveyed farms showed evidence of BZ-resistant worm populations, with H. contortus being the species implicated according to post-treatment larval culture results. The Pyrosequencing assay detected BZ resistant allele frequencies of >40% in the Haemonchus-positive farms and 100% resistant alleles in the clinically most resistant farms. These preliminary results suggest that the FECRT is less sensitive than the molecular test at detecting BZ resistance. However, both tests need to be interpreted carefully, bearing in mind the relative proportions of species

  17. Tubulin tyrosine ligase-like genes ttll3 and ttll6 maintain zebrafish cilia structure and motility.

    Science.gov (United States)

    Pathak, Narendra; Austin, Christina A; Drummond, Iain A

    2011-04-01

    Tubulin post-translational modifications generate microtubule heterogeneity and modulate microtubule function, and are catalyzed by tubulin tyrosine ligase-like (TTLL) proteins. Using antibodies specific to monoglycylated, polyglycylated, and glutamylated tubulin in whole mount immunostaining of zebrafish embryos, we observed distinct, tissue-specific patterns of tubulin modifications. Tubulin modification patterns in cilia correlated with the expression of ttll3 and ttll6 in ciliated cells. Expression screening of all zebrafish tubulin tyrosine ligase-like genes revealed additional tissue-specific expression of ttll1 in brain neurons, ttll4 in muscle, and ttll7 in otic placodes. Knockdown of ttll3 eliminated cilia tubulin glycylation but had surprisingly mild effects on cilia structure and motility. Similarly, knockdown of ttll6 strongly reduced cilia tubulin glutamylation but only partially affected cilia structure and motility. Combined loss of function of ttll3 and ttll6 caused near complete loss of cilia motility and induced a variety of axonemal ultrastructural defects similar to defects previously observed in zebrafish fleer mutants, which were shown to lack tubulin glutamylation. Consistently, we find that fleer mutants also lack tubulin glycylation. These results indicate that tubulin glycylation and glutamylation have overlapping functions in maintaining cilia structure and motility and that the fleer/dyf-1 TPR protein is required for both types of tubulin post-translational modification. PMID:21262966

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-01

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

  19. Theta, alpha and beta burst transcranial magnetic stimulation: brain modulation in tinnitus

    OpenAIRE

    Dirk De Ridder, Elsa van der Loo, Karolien Van der Kelen, Tomas Menovsky, Paul van de Heyning, Aage Moller

    2007-01-01

    Introduction: Some forms of tinnitus are considered to be auditory phantom phenomena related to reorganization and hyperactivity of the auditory central nervous system. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool capable of modulating human brain activity, using single pulse or burst stimuli. Burst rTMS has only been performed in the theta range, and has not been used clinically. The authors analyze whether burst TMS at theta (5 Hz), alpha (10 Hz) and beta (20 H...

  20. PET imaging of dopamine transporters in the human brain using [{sup 11}C]-{beta}-CPPIT, a cocaine derivative lacking the 2{beta}-ester function

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbaechler, Roland D.; Gucker, Pascale M.; Arigoni, Michele; Kneifel, Stefan; Vollenweider, Franz X.; Buck, Alfred; Burger, Cyrill; Berthold, Thomas; Bruehlmeier, Matthias; Schubiger, P. August; Ametamey, Simon M. E-mail: simon-mensah.ametamey@psi.ch

    2002-01-01

    The compound 3{beta}-(4'-chlorophenyl)-2{beta}-(3'-phenylisoxazol-5'-yl)tropane (CPPIT or RTI 177) is a 2{beta}-heterocyclic substituted cocaine congener with high in vitro selectivity and affinity for the dopamine transporter relative to serotonin and norepinephrine transporters. The aim of the present study was to evaluate the in vivo selectivity of [{sup 11}C]-{beta}-CPPIT and to determine whether [{sup 11}C]-{beta}-CPPIT may be a suitable alternative to existing DAT PET radioligands. [{sup 11}C]-{beta}-CPPIT was prepared by N-alkylation of the free amine with [{sup 11}C]methyl iodide. In mouse brain, the striatal binding of [{sup 11}C]-{beta}-CPPIT was reduced significantly by preinjecting the dopamine reuptake antagonist GBR 12909 (5 mg/kg). By contrast, radioactivity uptake in the brain was not affected significantly by the preinjection of citalopram (5 mg/kg) and desipramine (5 mg/kg), inhibitors for the serotonin and norepinephrine transporters, respectively. No effect was also observed by pretreatment with ketanserin (2.5 mg/kg) a compound with high affinity for the 5-HT{sub 2A}-receptor and the vesicular monoamine transporter. In a PET study with six healthy volunteers high striatal uptake was observed. The distribution pattern of [{sup 11}C]-{beta}-CPPIT was similar to the known distribution of the dopamine transporter in the human brain. Compared to {sup 123}I labeled {beta}-CIT, the rate of metabolic degradation of [{sup 11}C]-{beta}-CPPIT was almost twofold slower suggesting that bioisosteric heterocyclic substitution of the ester group at the 2{beta}-position of the tropane ring does have an influence on the rate of metabolism of [{sup 11}C]-{beta}-CPPIT. The rank order of the distribution volumes obtained via the one-tissue compartment model is also similar to the reported distribution of DAT. These preliminary results suggest that [{sup 11}C]-{beta}-CPPIT may be a useful PET radioligand for the visualization and quantification of

  1. 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.

  2. 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; Wang, W; Steffansen, B; Frokjaer, S; Borchardt, R 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 perm...

  3. Screening Anti-Cancer Drugs against Tubulin using Catch-and-Release Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Rezaei Darestani, Reza; Winter, Philip; Kitova, Elena N.; Tuszynski, Jack A.; Klassen, John S.

    2016-03-01

    Tubulin, which is the building block of microtubules, plays an important role in cell division. This critical role makes tubulin an attractive target for the development of chemotherapeutic drugs to treat cancer. Currently, there is no general binding assay for tubulin-drug interactions. The present work describes the application of the catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS) assay to investigate the binding of colchicinoid drugs to αβ-tubulin dimers extracted from porcine brain. Proof-of-concept experiments using positive (ligands with known affinities) and negative (non-binders) controls were performed to establish the reliability of the assay. The assay was then used to screen a library of seven colchicinoid analogues to test their binding to tubulin and to rank their affinities.

  4. Screening Anti-Cancer Drugs against Tubulin using Catch-and-Release Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Rezaei Darestani, Reza; Winter, Philip; Kitova, Elena N.; Tuszynski, Jack A.; Klassen, John S.

    2016-05-01

    Tubulin, which is the building block of microtubules, plays an important role in cell division. This critical role makes tubulin an attractive target for the development of chemotherapeutic drugs to treat cancer. Currently, there is no general binding assay for tubulin-drug interactions. The present work describes the application of the catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS) assay to investigate the binding of colchicinoid drugs to αβ-tubulin dimers extracted from porcine brain. Proof-of-concept experiments using positive (ligands with known affinities) and negative (non-binders) controls were performed to establish the reliability of the assay. The assay was then used to screen a library of seven colchicinoid analogues to test their binding to tubulin and to rank their affinities.

  5. Localization of betav tubulin in the cochlea and cultured cells with a novel monoclonal antibody.

    Science.gov (United States)

    Banerjee, Asok; Jensen-Smith, Heather; Lazzell, Anna; Prasad, Veena; Elguezabal, Gerardo; Hallworth, Richard; Ludueña, Richard F

    2008-06-01

    Tubulin, the dimeric structural protein of microtubules, is a heterodimer of alpha and beta subunits; both alpha and beta exist as numerous isotypes encoded by different genes. In vertebrates the sequence differences among the beta(I), beta(II), beta(III), beta(IV) and beta(V) isotypes are highly conserved in evolution, implying that the isotypes may have functional significance. Isotype-specific monoclonal antibodies have been useful in determining the cellular and sub-cellular distributions and possible functions of the beta(I), beta(II), beta(III), and beta(IV) isotypes; however, little is known about the beta(V) isotype. We here report the creation and purification of a monoclonal antibody (SHM.12G11) specific for beta(V). The antibody was designed to be specific for the C-terminal sequence EEEINE, which is unique to rodent and chicken beta(V). The antibody was found to bind specifically to the C-terminal peptide EEEINE, and does not cross-react with the carboxy-termini of either alpha-tubulin or the other beta-tubulin isotypes. However, the antibody also binds to the peptide EEEVNE, but not to the peptide EEEIDG, corresponding respectively to the C-terminal peptides of bovine and human beta(V). Immunofluorescence analysis indicates that beta(V) is found in microtubules of both the interphase network and the mitotic spindle. In gerbils, beta(V) also occurs in the cochlea where it is found largely in the specialized cells that are unique in containing bundled microtubules with 15 protofilaments. PMID:18412253

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

    Directory of Open Access Journals (Sweden)

    Zhuang Liying

    2012-12-01

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

  7. Preferential Transport Theory for Beta-Amyloid Clearance from the Brain

    Science.gov (United States)

    Coloma, Mikhail; Schaffer, David; Chiarot, Paul; Huang, Peter

    2015-11-01

    The failure to clear beta-amyloid from the aging brain leads to its accumulation within the walls of arteries and to Alzheimer's disease. However, the transport mechanism for beta-amyloid clearance is not well understood. In this study, we propose a preferential transport theory for flow within the vascular walls in the cerebral arterial basement membrane. The flow conduit within the arterial basement membrane is modeled as an annulus between deformable concentric cylinders filled with an incompressible, single-phase Newtonian fluid. The transport is driven by arterial lumen deformation induced by heart pulsations superimposed with reflected boundary waves. Our theory predicts that while the overall arterial wave propagation is in the same direction as the blood flow toward the capillaries, a reverse flow in the basement membrane can be preferentially induced toward larger arteries. This has been suggested as a potential clearance pathway for beta-amyloid. We estimate the magnitude of the reverse transport through a control volume analysis which is corroborated by numerical solutions of the Navier-Stokes equations. Bench-top experiments to validate our computational models are presented.

  8. 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 in...... 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...... support the notion for the existence of free CK2beta population and/or CK2beta in complex with other protein(s) present in brain and testicles. In all other mouse organs investigated, i.e. heart, lung, liver, kidney and spleen, no comparable amount of free CK2beta was observed. This is the first...

  9. Electrochemical Studies of Paclitaxel Interaction with Tubulin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A highly sensitive linear sweep voltammetric method was developed for the determination of paclitaxel and the mechanism of the binding of paclitaxel to tubulin was studied. Tubulin dimer formed with paclitaxel an electrochemically nonactive complex with a combination ratio of 2:2. Its stability constant was 2.85×1022. So the tubulin dimer had two binding sites for paclitaxel. The experiment showed that the binding sites of paclitaxel to tubulin dimer were different from that of Ca2+ to tubulin dimer.

  10. Effects of Beta-Alanine Supplementation on Brain Homocarnosine/Carnosine Signal and Cognitive Function: An Exploratory Study

    OpenAIRE

    Marina Yazigi Solis; Simon Cooper; Hobson, Ruth M; Artioli, Guilherme G.; Otaduy, Maria C.; Hamilton Roschel; Jacques Robertson; Daniel Martin; Vitor S Painelli; Harris, Roger C; Bruno Gualano; Craig Sale

    2015-01-01

    Objectives 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). Methods 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...

  11. Copper Exposure Perturbs Brain Inflammatory Responses and Impairs Clearance of Amyloid-Beta.

    Science.gov (United States)

    Kitazawa, Masashi; Hsu, Heng-Wei; Medeiros, Rodrigo

    2016-07-01

    Copper promotes a toxic buildup of amyloid-beta (Aβ) and neurofibrillary tangle pathology in the brain, and its exposure may increase the risk for Alzheimer's disease (AD). However, underlying molecular mechanisms by which copper triggers such pathological changes remain largely unknown. We hypothesized that the copper exposure perturbs brain inflammatory responses, leading to impairment of Aβ clearance from the brain parenchyma. Here, we investigated whether copper attenuated Aβ clearance by microglial phagocytosis or by low-density lipoprotein-related receptor protein-1 (LRP1) dependent transcytosis in both in vitro and in vivo When murine monocyte BV2 cells were exposed to copper, their phagocytic activation induced by fibrillar Aβ or LPS was significantly reduced, while the secretion of pro-inflammatory cytokines, such as IL-1β, TNF-α, and IL-6, were increased. Interestingly, not only copper itself but also IL-1β, IL-6, or TNF-α were capable of markedly reducing the expression of LRP1 in human microvascular endothelial cells (MVECs) in a concentration-dependent manner. While copper-mediated downregulation of LRP1 was proteasome-dependent, the cytokine-induced loss of LRP1 was proteasome- or lysosome-independent. In the mouse model, copper exposure also significantly elevated neuroinflammation and downregulated LRP1 in the brain, consistent with our in vitro results. Taken together, our findings support the pathological impact of copper on inflammatory responses and Aβ clearance in the brain, which could serve as key mechanisms to explain, in part, the copper exposure as an environmental risk factor for AD. PMID:27122238

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

    Directory of Open Access Journals (Sweden)

    Jun-jie JING

    2012-09-01

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

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

    OpenAIRE

    Das Lalita; Bhattacharya Bhabatarak; Basu Gautam

    2012-01-01

    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 ...

  14. The beta-neurexin-neuroligin link is essential for quantum brain dynamics

    CERN Document Server

    Georgiev, D D

    2002-01-01

    There are many blank areas in understanding the brain dynamics and especially how it gives rise to conscious experience. Quantum mechanics is believed to be capable of explaining the enigma of consciousness, however till now there is not good enough model considering both the data from clinical neurology and having some explanatory power! In this paper is presented a novel model in defense of macroscopic quantum events within and between neural cells. The beta-neurexin-neuroligin link is claimed to be not just the core of the central neural synapse, instead it is a device mediating entanglement between the cytoskeletons of the cortical neurons. The neurexin is also participating in the process of exocytosis through quantum tunneling. The gap junction tunneling supposed by Stuart Hameroff is shown to be incapable of sustaining quantum coherence between neurons for the needed 25 milliseconds. The possible role of DLBs, mitochondria and different types of glia in conscious experience is rationally criticized.

  15. Effects of beta radiation from organically bound tritium on cultured mouse embryonic mid brain cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bing [Univ. of Tokyo (Japan)]|[Toho Univ. School of Medicine, Tokyo (Japan); Watanabe, Keiko; Yamada, Takeshi [Toho Univ. School of Medicine, Tokyo (Japan); Shima, Akihiro [Univ. of Tokyo (Japan)

    1996-12-01

    Effects of beta radiation from four kinds of organically bound tritium compounds were investigated on cultured mouse embryonic mid brain cells, isolated form 11-d-old mouse embryos. The MBC showed a critical time when they were more radiosensitive. Although dose-dependent inhibition was found for both cellular proliferation and differentiation. the differential was more sensitive to radiation than proliferation when compared at ID50, the inhibitory dose that reduced assessment value by 50% of the control. Dose-dependent decrease of DNA and protein contents were also observed. The relative biological effectiveness values, ranging from 4.6 to 8.7, of beta ray from organically bound tritium compounds were obtained when compared with x irradiation at their ID50s on the inhibition of cell proliferation and differentiation, and on the decrease of DNA and protein contents of the cultures. Th mixed exposure to x ray and one kind of organically bound tritium compound or to any two kinds of organically bound tritium compound resulted in a more efficiently inhibitory effect on differentiation than the exposure to x ray or to any one kind of organically bound tritium compound d alone, especially when methyl-{sup 3}H-thymidine was used. Doses as low as 0.05 Gy (5 cGy) from a mixed exposure resulted in detectable inhibitory effects. 21 refs., 4 figs., 1 tab.

  16. Effects of beta radiation from organically bound tritium on cultured mouse embryonic mid brain cells

    International Nuclear Information System (INIS)

    Effects of beta radiation from four kinds of organically bound tritium compounds were investigated on cultured mouse embryonic mid brain cells, isolated form 11-d-old mouse embryos. The MBC showed a critical time when they were more radiosensitive. Although dose-dependent inhibition was found for both cellular proliferation and differentiation. the differential was more sensitive to radiation than proliferation when compared at ID50, the inhibitory dose that reduced assessment value by 50% of the control. Dose-dependent decrease of DNA and protein contents were also observed. The relative biological effectiveness values, ranging from 4.6 to 8.7, of beta ray from organically bound tritium compounds were obtained when compared with x irradiation at their ID50s on the inhibition of cell proliferation and differentiation, and on the decrease of DNA and protein contents of the cultures. Th mixed exposure to x ray and one kind of organically bound tritium compound or to any two kinds of organically bound tritium compound resulted in a more efficiently inhibitory effect on differentiation than the exposure to x ray or to any one kind of organically bound tritium compound d alone, especially when methyl-3H-thymidine was used. Doses as low as 0.05 Gy (5 cGy) from a mixed exposure resulted in detectable inhibitory effects. 21 refs., 4 figs., 1 tab

  17. Tyrosine phosphorylation of plant tubulin

    Czech Academy of Sciences Publication Activity Database

    Blume, Y. B.; Yemets, A.; Sulimenko, Vadym; Sulimenko, Tetyana; Chan, J.; Lloyd, C.; Dráber, Pavel

    2008-01-01

    Roč. 229, č. 1 (2008), s. 143-150. ISSN 0032-0935 R&D Projects: GA MŠk LC545; GA ČR GA204/05/2375 Grant ostatní: EU(XE) INTAS 03-51-6459 Institutional research plan: CEZ:AV0Z50520514 Keywords : plant microtubules * tubulin * post-translation modifications Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.088, year: 2008

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

    OpenAIRE

    Goichi Beck; Koei Shinzawa; Hideki Hayakawa; Kousuke Baba; Toru Yasuda; Hisae Sumi-Akamaru; Yoshihide Tsujimoto; Hideki Mochizuki

    2015-01-01

    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 hom...

  19. 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.

  20. Theta, alpha and beta burst transcranial magnetic stimulation: brain modulation in tinnitus

    Directory of Open Access Journals (Sweden)

    Dirk De Ridder, Elsa van der Loo, Karolien Van der Kelen, Tomas Menovsky, Paul van de Heyning, Aage Moller

    2007-01-01

    Full Text Available Introduction: Some forms of tinnitus are considered to be auditory phantom phenomena related to reorganization and hyperactivity of the auditory central nervous system. Repetitive transcranial magnetic stimulation (rTMS is a non-invasive tool capable of modulating human brain activity, using single pulse or burst stimuli. Burst rTMS has only been performed in the theta range, and has not been used clinically. The authors analyze whether burst TMS at theta (5 Hz, alpha (10 Hz and beta (20 Hz frequencies can temporarily suppress narrow band noise/white noise tinnitus, which has been demonstrated to be intractable to tonic stimulation. Methods: rTMS is performed both in tonic and burst mode in 46 patients contralateral to the tinnitus side, at 5, 10 and 20 Hz. Fourteen placebo negative rTMS responders are further analyzed. Results: In 5 patients, maximal tinnitus suppression is obtained with theta, in 2 with alpha and in 7 with beta burst stimulation. Burst rTMS suppresses narrow band/white tinnitus much better than tonic rTMS t(13=6.4, p<.000. Women experience greater suppression of their tinnitus with burst stimulation than men, t(12=2.9, p<.05. Furthermore left sided tinnitus is perceived as more distressing on the TQ than right sided tinnitus, t(12=3.2, p<.01. The lower the tinnitus pitch the more effectively rTMS suppresses tinnitus(r=-0.65, p<0.05. Discussion: Burst rTMS can be used clinically, not only theta burst, but also alpha and beta burst. Burst rTMS is capable of suppressing narrow band/white noise tinnitus very much better than tonic rTMS. This could be due the simple fact that burst neuromodulation is more powerful than tonic neuromodulation or to a differential effect of burst and tonic stimulation on the lemniscal and extralemniscal auditory system. In some patients only alpha or beta burst rTMS is capable of suppressing tinnitus, and theta burst not. Therefore in future rTMS studies it could be worthwhile not to limit burst

  1. Effect of visual experience on tubulin synthesis during a critical period of visual cortex development in the hooded rat.

    Science.gov (United States)

    Cronly-Dillon, J; Perry, G W

    1979-08-01

    1. In some species, restriction of visual experience in early life may affect normal functional development of visual cortical cells. The purpose of the present study was to determine if visual deprivation during post-natal development in the hooded rat also affects the production in brain cells of certain molecular components such as tubulin, that are needed for growth and maintenance of synapses and neurites. 2. Norwegian black hooded rats were reared under a variety of conditions of visual deprivation. At various stages of development the animals were killed and the rate of synthesis of tubulin in visual and motor cortex determined. Tritiated colchicine was used to assay tubulin and L-[14C]leucine injected into the brain ventricles 2 hr before death was used to measure rate of tubulin synthesis. 3. In rats reared in normal light there is a marked elevation in visual cortex tubulin synthesis that spans the period from eye-opening (13 days) until approximately 35 days. This elevation in tubulin synthesis is absent in animals reared in darkness from birth or deprived of pattern vision by eyelid suture. Also the effect of visual deprivation on tubulin synthesis was specifically confined to visual cortex and was not found for the motor cortex. Similarly, the incorporation of L-[14C]leucine into total protein in visual cortex was unaffected by dark rearing. Hence the stimulation of tubulin synthesis by visual experience in rat visual cortex is not attributable to a general non-specific stimulation of protein synthesis. 4. Rats that were dark-reared from birth and then exposed to a lighted environment for 24 hr during a certain critical period that extends from eye-opening (13 days) until approximately 35 days, displayed a significant increase in visual cortex tubulin rats that were brought into the light later than 35 days showed no significant increase in tubulin synthesis when compared with their continuously dark-rearer controls. 5. It is suggested that the number

  2. Phylogenetic analysis of Penicillium subgenus Penicillium using partial P-tubulin sequences

    DEFF Research Database (Denmark)

    Samson, R.A.; Seifert, K.A.; Kuijpers, A.F.A.; Houbraken, J.A.M.P.; Frisvad, Jens Christian

    2004-01-01

    Partial beta-tubulin sequences were determined for 180 strains representing all accepted species of Penicillium subgenus Penicillium. The overall phylogenctic structure of the subgenus was determined by a parsimony analysis with each species represented by its type (or other reliably identified) ...

  3. GDP-Tubulin Incorporation into Growing Microtubules Modulates Polymer Stability.

    OpenAIRE

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

    2010-01-01

    Microtubule growth proceeds through the endwise addition of nucleotide-bound tubulin dimers. The microtubule wall is composed of GDP-tubulin subunits, which are thought to come exclusively from the incorporation of GTP-tubulin complexes at microtubule ends followed by GTP hydrolysis within the polymer. The possibility of a direct GDP-tubulin incorporation into growing polymers is regarded as hardly compatible with recent structural data. Here, we have examined GTP-tubulin and GDP-tubulin inco...

  4. 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.

  5. GTP binding to the β-subunit of tubulin is greatly reduced in Alzheimers disease

    International Nuclear Information System (INIS)

    A decrease occurs (80-100%) in the [32P]8N3GTP photoinsertion into a cytosolic protein (55K M/sub r/) of Alzheimer's (AD) brain, tentatively identified as the β-subunit of tubulin (co-migration with purified tubulin, concentration dependence of interaction with GTP, ATP and their 8-azido photoprobes, and similar effects of Ca2+ and EDTA on photoinsertion). This agrees with prior observations of [32P]8N3GTP interactions with brain tubulin and a recent report on faulty microtubular assembly in AD brain. The decrease in [32P]8N3GTP 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 [32P]8N3GTP photoinsertion species in non-AD brain. Of 5 AD brains, the photoinsertion of [32P]8N3GTP 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 β-tubulin blocked/modified such that [32P]8N3GTP cannot interact normally with this site

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

    Science.gov (United States)

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

    2013-07-01

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

  7. Protective effects of beta glucan in brain tissues of post-menopausal rats: a histochemical and ultra-structural study.

    Science.gov (United States)

    Selli, Jale; Unal, Deniz; Mercantepe, Filiz; Akaras, Nurhan; Kabayel, Rabia; Unal, Bunyami; Atilay, Hilal

    2016-01-01

    Decline of estrogen during menopause has been associated with numerous significant changes that have been linked to many pathophysiological complications. In addition, ovarian hormone deficiency increases the production of reactive oxygen radicals which could result in oxidative stress and cell damage. While estrogen therapy is often considered to overcome the behavioral and physiological shortcomings, antioxidants are gaining popularity for their beneficial property. For this purpose, in the present study, utilizing the antioxidant properties of beta glucan has been examined in treatment of menopause induced oxidative stress in cerebral neurons. Four groups of female Wistar rats were used: control, ovariectomy, ovariectomy + estrogen treated and ovariectomy + beta glucan treated. We observed a significant increase in neural degeneration in ovariectomized rats as compared to controls. Moreover, increased oxidative stress in the brains of the ovariectomized rats has been detected by performing immunohistochemical analysis. A large number of immuno-positive cerebral neurons have been observed in ovariectomy group rat brains. Interestingly, providing beta glucan treatment to ovariectomized rats reduced the number of degenerated neurons. Our study is the first to examine light and electron microscopic examination and immunohistochemical and stereological analysis of estrogen depletion in rats and to test protective role of beta glucan in the experimental study. PMID:26486170

  8. Alzheimer's disease amyloid-beta links lens and brain pathology in Down syndrome.

    Directory of Open Access Journals (Sweden)

    Juliet A Moncaster

    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

  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. [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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-10

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

  12. Measurement of antibodies to tubulin by radioimmunoassay

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-15

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

  14. Tubulin dipole moment, dielectric constant and quantum behavior: computer simulations, experimental results and suggestions

    CERN Document Server

    Mershin, A; Schüssler, H A; Nanopoulos, Dimitri V; Mershin, Andreas; Kolomenski, Alexandre A.; Schuessler, Hans A.; Nanopoulos, Dimitri V.

    2004-01-01

    We used computer simulation to calculate the electric dipole moments of the alpha and beta tubulin monomers and dimer and found those to be |palpha|=552D, |pbeta|=1193D and |palpha-beta|=1740D respectively. Independent surface plasmon resonance (SPR) and refractometry measurements of the high-frequency dielectric constant and polarizability strongly corroborated our previous SPR-derived results giving delta-n/delta-c ~1.800x10^-3 ml/mg. The refractive index of tubulin was measured to be n_tub ~2.90 and the high frequency tubulin dielectric constant kappa_tub ~8.41 while the high-frequency polarizability was found to be alpha_tub ~ 2.1x10^-33 C m^2/V. Methods for the experimental determination of the low-frequency p are explored as well as ways to test the often conjectured quantum coherence and entanglement properties of tubulin. Biobits, bioqubits and other applications to bioelectronics are discussed.

  15. Seeded growth of beta-amyloid fibrils from Alzheimer's brain-derived fibrils produces a distinct fibril structure.

    Science.gov (United States)

    Paravastu, Anant K; Qahwash, Isam; Leapman, Richard D; Meredith, Stephen C; Tycko, Robert

    2009-05-01

    Studies by solid-state nuclear magnetic resonance (NMR) of amyloid fibrils prepared in vitro from synthetic 40-residue beta-amyloid (Abeta(1-40)) peptides have shown that the molecular structure of Abeta(1-40) fibrils is not uniquely determined by amino acid sequence. Instead, the fibril structure depends on the precise details of growth conditions. The molecular structures of beta-amyloid fibrils that develop in Alzheimer's disease (AD) are therefore uncertain. We demonstrate through thioflavin T fluorescence and electron microscopy that fibrils extracted from brain tissue of deceased AD patients can be used to seed the growth of synthetic Abeta(1-40) fibrils, allowing preparation of fibrils with isotopic labeling and in sufficient quantities for solid-state NMR and other measurements. Because amyloid structures propagate themselves in seeded growth, as shown in previous studies, the molecular structures of brain-seeded synthetic Abeta(1-40) fibrils most likely reflect structures that are present in AD brain. Solid-state (13)C NMR spectra of fibril samples seeded with brain material from two AD patients were found to be nearly identical, indicating the same molecular structures. Spectra of an unseeded control sample indicate greater structural heterogeneity. (13)C chemical shifts and other NMR data indicate that the predominant molecular structure in brain-seeded fibrils differs from the structures of purely synthetic Abeta(1-40) fibrils that have been characterized in detail previously. These results demonstrate a new approach to detailed structural characterization of amyloid fibrils that develop in human tissue, and to investigations of possible correlations between fibril structure and the degree of cognitive impairment and neurodegeneration in AD. PMID:19376973

  16. Beta-propeller protein-associated neurodegeneration: a new X-linked dominant disorder with brain iron accumulation

    Science.gov (United States)

    Hayflick, Susan J.; Kruer, Michael C.; Gregory, Allison; Haack, Tobias B.; Kurian, Manju A.; Houlden, Henry H.; Anderson, James; Boddaert, Nathalie; Sanford, Lynn; Harik, Sami I.; Dandu, Vasuki H.; Nardocci, Nardo; Zorzi, Giovanna; Dunaway, Todd; Tarnopolsky, Mark; Skinner, Steven; Holden, Kenton R.; Frucht, Steven; Hanspal, Era; Schrander-Stumpel, Connie; Mignot, Cyril; Héron, Delphine; Saunders, Dawn E.; Kaminska, Margaret; Lin, Jean-Pierre; Lascelles, Karine; Cuno, Stephan M.; Meyer, Esther; Garavaglia, Barbara; Bhatia, Kailash; de Silva, Rajith; Crisp, Sarah; Lunt, Peter; Carey, Martyn; Hardy, John; Meitinger, Thomas; Prokisch, Holger; Hogarth, Penelope

    2013-01-01

    Neurodegenerative disorders with high iron in the basal ganglia encompass an expanding collection of single gene disorders collectively known as neurodegeneration with brain iron accumulation. These disorders can largely be distinguished from one another by their associated clinical and neuroimaging features. The aim of this study was to define the phenotype that is associated with mutations in WDR45, a new causative gene for neurodegeneration with brain iron accumulation located on the X chromosome. The study subjects consisted of WDR45 mutation-positive individuals identified after screening a large international cohort of patients with idiopathic neurodegeneration with brain iron accumulation. Their records were reviewed, including longitudinal clinical, laboratory and imaging data. Twenty-three mutation-positive subjects were identified (20 females). The natural history of their disease was remarkably uniform: global developmental delay in childhood and further regression in early adulthood with progressive dystonia, parkinsonism and dementia. Common early comorbidities included seizures, spasticity and disordered sleep. The symptoms of parkinsonism improved with l-DOPA; however, nearly all patients experienced early motor fluctuations that quickly progressed to disabling dyskinesias, warranting discontinuation of l-DOPA. Brain magnetic resonance imaging showed iron in the substantia nigra and globus pallidus, with a ‘halo’ of T1 hyperintense signal in the substantia nigra. All patients harboured de novo mutations in WDR45, encoding a beta-propeller protein postulated to play a role in autophagy. Beta-propeller protein-associated neurodegeneration, the only X-linked disorder of neurodegeneration with brain iron accumulation, is associated with de novo mutations in WDR45 and is recognizable by a unique combination of clinical, natural history and neuroimaging features. PMID:23687123

  17. Modulation of. beta. -adrenergic response in rat brain astrocytes by serum and hormones

    Energy Technology Data Exchange (ETDEWEB)

    Wu, D.K.; Morrison, R.S.; de Vellis, J.

    1985-01-01

    Purified astrocyte cultures from neonatal rat cerebrum respond to isoproterenol, a ..beta..-adrenergic agonist, with a transient rise in cAMP production. This astroglial property was regulated by serum, a chemically defined medium (serum-free medium plus hydrocortisone, putrescine, prostaglandin F/sub 2/, insulin, and fibroblast growth factor) and epidermal growth factor. Compared to astrocytes grown in serum-supplemented medium, astrocytes grown in the chemically defined medium were nonresponsive to isoproterenol stimulation, and this difference did not appear to be due to selection of a subpopulation of cells by either medium. The data suggest that a decreased ..beta..-adrenergic receptor number and an increased degradation of cAMP may account for the reduced response to ..beta..-adrenergic stimulation. The nonresponsive state of astrocytes in the defined medium was reversible when the medium was replaced with serum-supplemented medium. An active substance(s) in serum was responsible for restoring the responsiveness of astrocytes. Each of the five components of the defined medium had little effect by itself; however, together they acted synergistically to desensitize astrocytes to ..beta..-adrenergic stimulation. On the other hand, epidermal growth factor, a potent mitogen for astrocytes, was very competent by itself in reducing the cAMP response of astrocytes to ..beta..-adrenergic stimulation. Thus purified astrocytes grown in the chemically defined medium appear to be a good model for the study of hormonal interactions and of serum factors which may modulate the ..beta..-adrenergic response.

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

    NARCIS (Netherlands)

    A. Copani; J.J.M. Hoozemans; F. Caraci; M. Calafiore; E.S. van Haastert; R. Veerhuis; A.J.M. Rozemuller; E. Aronica; M.A. Sortino; F. Nicoletti

    2006-01-01

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

  19. Differential expression of gamma-tubulin and class III beta-tubulin in meduloblastoma cell lines

    Czech Academy of Sciences Publication Activity Database

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

    2010-01-01

    Roč. 69, č. 5 (2010), s. 558-558. ISSN 0022-3069. [Annual Meeting of the American-Association-of-Neuropathologists /86./. 10.06.10-13.06.10, Phidadelphia] Institutional research plan: CEZ:AV0Z50520514

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-01-01

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

  1. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-02-01

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

  3. Drosophila E-cadherin and its binding partner Armadillo/ beta-catenin are required for axonal pathway choices in the developing larval brain.

    Science.gov (United States)

    Fung, Siaumin; Wang, Fay; Spindler, Shana R; Hartenstein, Volker

    2009-08-15

    The fly brain is formed by approximately hundred paired lineages of neurons, each lineage derived from one neuroblast. Embryonic neuroblasts undergo a small number of divisions and produce the primary neurons that form the functioning larval brain. In the larva, neuroblasts produce the secondary lineages that make up the bulk of the adult brain. Axons of a given secondary lineage fasciculate with each other and form a discrete bundle, the secondary axon tract (SAT). Secondary axon tracts prefigure the long axon connections of the adult brain, and therefore pathway choices of SATs made in the larva determine adult brain circuitry. Drosophila Shotgun/E-cadherin (DE-cad) and its binding partner Armadillo/beta-catenin (beta-cat) are expressed in newly born secondary neurons and their axons. The fact that the highly diverse, yet invariant pattern of secondary lineages and SATs has been recently mapped in the wild-type brain enabled us to investigate the role of DE-cad and beta-cat with the help of MARCM clones. Clones were validated by their absence of DE-cad immuno-reactivity. The most significant phenotype consists in the defasciculation and an increased amount of branching of SATs at the neuropile-cortex boundary, as well as subtle changes in the trajectory of SATs within the neuropile. In general, only a fraction of mutant clones in a given lineage showed structural abnormalities. Furthermore, although they all globally express DE-cad and beta-cat, lineages differ in their requirement for DE-cad function. Some lineages never showed morphological abnormalities in MARCM clones, whereas others reacted with abnormal branching and changes in SAT trajectory at a high frequency. We conclude that DE-cad/beta-cat form part of the mechanism that control branching and trajectory of axon tracts in the larval brain. PMID:19520071

  4. Excitotoxic brain damage in the rat induces interleukin-1beta protein in microglia and astrocytes: correlation with the progression of cell death.

    Science.gov (United States)

    Pearson, V L; Rothwell, N J; Toulmond, S

    1999-02-15

    Interleukin-1 beta (IL-1beta) has been proposed as a mediator of several forms of brain damage, including that induced by excitotoxins. In vitro studies suggest that glial cells are the effector cells of IL-1beta-mediated neurodegeneration. We have investigated the expression of IL-1beta protein by glial cells in vivo in response to NMDA receptor-mediated excitotoxicity in the rat parietal cortex and striatum. Expression of IL-1beta by glial cells was investigated using immunocytochemistry 30 min to 7 days after infusion of the NMDA agonist cis-2,4-methanoglutamate (MGlu; 10 nmol) into the cortex. Early expression (1-4 h) of IL-1beta by microglia was directly related to lesion development. Later expression by microglia (up to 24 h), and by astrocytes (2-7 days), was widespread compared to the area involved in excitotoxic cell death and co-localised with areas of reactive gliosis. Infusion of MGlu into the striatum induced a similar temporal pattern of IL-1beta expression by microglia and astrocytes. However, IL-1beta-expressing glial cells were localised strictly to the area of striatal cell death. Infusion of PBS or a subtoxic dose of MGlu into the cortex or striatum induced only limited neuronal death and negligible glial IL-1beta expression. These studies reveal that IL-1beta is expressed specifically by microglia during the early response to excitotoxicity in the adult rat cortex and striatum. However, the widespread and delayed IL-1beta expression by astrocytes suggests diverse roles for IL-1beta in response to excitotoxicity. PMID:10028914

  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. Structural requirements for galanin interaction with receptors from pancreatic beta cells and from brain tissue of the rat

    Energy Technology Data Exchange (ETDEWEB)

    Lagny-Pourmir, I.; Lorinet, A.M.; Yanaihara, N.; Laburthe, M. (Unite de Recherches sur la Differenciation et la Neuroendocrinologie de Cellules Digestives, Batiment INSERM, Villejuif (France))

    1989-07-01

    The binding activity of several galanin fragments and analogs was measured on specific receptors present in rat brain and the rat pancreatic beta cell line Rin m 5F. In both tissues it was observed that: (1) galanin(3-29), galanin(10-29) and (Ile2)-galanin were ineffective for inhibiting ({sup 125}I) galanin binding and (2) active peptides had the following rank order of potency: galanin(1-29) greater than (Ac-Trp2)-galanin(2-29) greater than galanin(2-29) greater than galanin(1-15) greater than (Phe2)-galanin greater than (Tyr2)-galanin. It was concluded that the N-terminal portion of galanin is very important for interaction with central or peripheral receptors. The aromatic amino acid in position 2 (Trp in native galanin) plays a crucial role.

  7. Disruption of estrogen receptor beta in mice brain results in pathological alterations resembling Alzheimer disease

    Institute of Scientific and Technical Information of China (English)

    Qing-hong ZHANG; Yan-hong HUANG; Yu-zhen HU; Geng-ze WEI; Xue-feng HAN; Shun-yan LU; Yu-feng ZHAO

    2004-01-01

    AIM: To study the pathological characteristics of the mice with estrogen receptor β (ERβ) disruption in brain.METHODS: Immunohistochemistry method was applied in the study. RESULTS: β-Amyloid peptide(Aβ42) and apolipoprotein E (ApoE) immunoreactive substances were accumulated notably in cortex and limbic structures such as the hippocampus and amygdala in brain, resembling the pathological changes of human Alzheimer disease (AD). Aβ formed cloudy-like deposits in parenchyma of brain, while apoE also deposited along or surrounding the blood vessels. CONCLUSIONS: ERβ is crucial to the development of neural degenerative disease, so modulation of Aβ metabolism via ERβ signal pathway might be beneficial for AD prevention or therapy.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-01

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

  9. Coupling between intrinsic prefrontal HbO2 and central EEG beta power oscillations in the resting brain.

    Directory of Open Access Journals (Sweden)

    Gert Pfurtscheller

    Full Text Available There is increasing interest in the intrinsic activity in the resting brain, especially that of ultraslow and slow oscillations. Using near-infrared spectroscopy (NIRS, electroencephalography (EEG, blood pressure (BP, respiration and heart rate recordings during 5 minutes of rest, combined with cross spectral and sliding cross correlation calculations, we identified a short-lasting coupling (duration [Formula: see text] s between prefrontal oxyhemoglobin (HbO2 in the frequency band between 0.07 and 0.13 Hz and central EEG alpha and/or beta power oscillations in 8 of the 9 subjects investigated. The HbO2 peaks preceded the EEG band power peaks by 3.7 s in 6 subjects, with moderate or no coupling between BP and HbO2 oscillations. HbO2 and EEG band power oscillations were approximately in phase with BP oscillations in the 2 subjects with an extremely high coupling (squared coherence [Formula: see text] between BP and HbO2 oscillation. No coupling was identified in one subject. These results indicate that slow precentral (deoxyhemoglobin concentration oscillations during awake rest can be temporarily coupled with EEG fluctuations in sensorimotor areas and modulate the excitability level in the brains' motor areas, respectively. Therefore, this provides support for the idea that resting state networks fluctuate with frequencies of between 0.01 and 0.1 Hz (Mantini et.al. PNAS 2007.

  10. Molecular insight of isotypes specific β-tubulin interaction of tubulin heterodimer with noscapinoids.

    Science.gov (United States)

    Santoshi, Seneha; Naik, Pradeep K

    2014-07-01

    Noscapine and its derivatives bind stoichiometrically to tubulin, alter its dynamic instability and thus effectively inhibit the cellular proliferation of a wide variety of cancer cells including many drug-resistant variants. The tubulin molecule is composed of α- and β-tubulin, which exist as various isotypes whose distribution and drug-binding properties are significantly different. Although the noscapinoids bind to a site overlapping with colchicine, their interaction is more biased towards β-tubulin. In fact, their precise interaction and binding affinity with specific isotypes of β-tubulin in the αβ-heterodimer has never been addressed. In this study, the binding affinity of a panel of noscapinoids with each type of tubulin was investigated computationally. We found that the binding score of a specific noscapinoid with each type of tubulin isotype is different. Specifically, amino-noscapine has the highest binding score of -6.4, -7.2, -7.4 and -7.3 kcal/mol with αβI, αβII, αβIII and αβIV isotypes, respectively. Similarly 10 showed higher binding affinity of -6.8 kcal/mol with αβV, whereas 8 had the highest binding affinity of -7.2, -7.1 and -7.2 kcal/mol, respectively with αβVI, αβVII and αβVIII isotypes. More importantly, both amino-noscapine and its clinical derivative, bromo-noscapine have the highest binding affinity of -46.2 and -38.1 kcal/mol against αβIII (overexpression of αβIII has been associated with resistance to a wide range of chemotherapeutic drugs for several human malignancies) as measured using MM-PBSA. Knowledge of the isotype specificity of the noscapinoids may allow for development of novel therapeutic agents based on this class of drugs. PMID:24916062

  11. 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.

  12. 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 < 0.05). By the end of the resident-intruder test (300 s), the dominant control gilts and barrows, and both dominant and subordinate RAC-fed gilts performed the greatest percentage of attacks (P < 0.05). Gilts had decreased norepinephrine and DOPAC concentrations in the amygdala and frontal cortex, and when fed RAC, gilts also had the least 5-HIAA concentration and

  13. A synchrotron X-ray scattering characterization of purified tubulin and of its expansion induced by mild detergent binding

    International Nuclear Information System (INIS)

    This report presents a synchrotron radiation X-ray scattering characterization of calf brain tubulin purified by the modified Weisenberg procedure. The results show that under nonassembly conditions these preparations consist of a uniform population of molecules with a radius of gyration of 3.1 ± 0.1 nm, which can be interpreted as arising from the native α-β heterodimer. The uniformity in the population persists even at unusually high concentrations of protein. Binding of colchicine or substitution of GTP by GDP does not induce, within the statistical accuracy and resolution range of our measurements, any significant structural modification in soluble tubulin. In assembly buffer, these preparations readily assemble into microtubules upon increasing the temperature from 4 to 37 degree C. Binding of nondenaturing amphiphiles to soluble tubulin provides a simplified model for tubulin-membrane interactions. The X-ray scattering data show that the radius of gyration of tubulin progressively increases upon binding of the mild detergent sodium deoxycholate, reaching a maximum value of 4.3 ± 0.1 nm at detergent saturation. The relative increase in the radius of gyration coincides within experimental error with the previously determined relative increase in the frictional coefficient. Analysis of these observations suggests that the effect of detergent binding is to induce an isotropic swelling of the protein structure

  14. Huperzine A protects isolated rat brain mitochondria against beta-amyloid peptide.

    Science.gov (United States)

    Gao, Xin; Zheng, Chun Yan; Yang, Ling; Tang, Xi Can; Zhang, Hai Yan

    2009-06-01

    Our previous work in cells and animals showed that mitochondria are involved in the neuroprotective effect of huperzine A (HupA). In this study, the effects of HupA on isolated rat brain mitochondria were investigated. In addition to inhibiting the Abeta(25-35) (40 microM)-induced decrease in mitochondrial respiration, adenosine 5'-triphosphate (ATP) synthesis, enzyme activity, and transmembrane potential, HupA (0.01 or 0.1 microM) effectively prevented Abeta-induced mitochondrial swelling, reactive oxygen species increase, and cytochrome c release. More interestingly, administration of HupA to isolated mitochondria promoted the rate of ATP production and blocked mitochondrial swelling caused by normal osmosis. These results indicate that HupA protects mitochondria against Abeta at least in part by preserving membrane integrity and improving energy metabolism. These direct effects on mitochondria further extend the noncholinergic functions of HupA. PMID:19272446

  15. Probing the origin of tubulin rigidity with molecular simulations

    OpenAIRE

    Dima, Ruxandra I.; Joshi, Harshad

    2008-01-01

    Tubulin heterodimers are the building blocks of microtubules, a major component of the cytoskeleton, whose mechanical properties are fundamental for the life of the cell. We uncover the microscopic origins of the mechanical response in microtubules by probing features of the energy landscape of the tubulin monomers and tubulin heterodimer. To elucidate the structures of the unfolding pathways and reveal the multiple unfolding routes, we performed simulations of a self-organized polymer (SOP) ...

  16. Brain

    Science.gov (United States)

    ... will return after updating. Resources Archived Modules Updates Brain Cerebrum The cerebrum is the part of the ... the outside of the brain and spinal cord. Brain Stem The brain stem is the part of ...

  17. Prion protein inhibits microtubule assembly by inducing tubulin oligomerization

    International Nuclear Information System (INIS)

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

  18. Drosophila Stathmins Bind Tubulin Heterodimers with High and Variable Stoichiometries*

    Science.gov (United States)

    Lachkar, Sylvie; Lebois, Marion; Steinmetz, Michel O.; Guichet, Antoine; Lal, Neha; Curmi, Patrick A.; Sobel, André; Ozon, Sylvie

    2010-01-01

    In vertebrates, stathmins form a family of proteins possessing two tubulin binding repeats (TBRs), which each binds one soluble tubulin heterodimer. The stathmins thus sequester two tubulins in a phosphorylation-dependent manner, providing a link between signal transduction and microtubule dynamics. In Drosophila, we show here that a single stathmin gene (stai) encodes a family of D-stathmin proteins. Two of the D-stathmins are maternally deposited and then restricted to germ cells, and the other two are detected in the nervous system during embryo development. Like in vertebrates, the nervous system-enriched stathmins contain an N-terminal domain involved in subcellular targeting. All the D-stathmins possess a domain containing three or four predicted TBRs, and we demonstrate here, using complementary biochemical and biophysical methods, that all four predicted TBR domains actually bind tubulin. D-stathmins can indeed bind up to four tubulins, the resulting complex being directly visualized by electron microscopy. Phylogenetic analysis shows that the presence of regulated multiple tubulin sites is a conserved characteristic of stathmins in invertebrates and allows us to predict key residues in stathmin for the binding of tubulin. Altogether, our results reveal that the single Drosophila stathmin gene codes for a stathmin family similar to the multigene vertebrate one, but with particular tubulin binding properties. PMID:20145240

  19. Drosophila stathmins bind tubulin heterodimers with high and variable stoichiometries.

    Science.gov (United States)

    Lachkar, Sylvie; Lebois, Marion; Steinmetz, Michel O; Guichet, Antoine; Lal, Neha; Curmi, Patrick A; Sobel, André; Ozon, Sylvie

    2010-04-01

    In vertebrates, stathmins form a family of proteins possessing two tubulin binding repeats (TBRs), which each binds one soluble tubulin heterodimer. The stathmins thus sequester two tubulins in a phosphorylation-dependent manner, providing a link between signal transduction and microtubule dynamics. In Drosophila, we show here that a single stathmin gene (stai) encodes a family of D-stathmin proteins. Two of the D-stathmins are maternally deposited and then restricted to germ cells, and the other two are detected in the nervous system during embryo development. Like in vertebrates, the nervous system-enriched stathmins contain an N-terminal domain involved in subcellular targeting. All the D-stathmins possess a domain containing three or four predicted TBRs, and we demonstrate here, using complementary biochemical and biophysical methods, that all four predicted TBR domains actually bind tubulin. D-stathmins can indeed bind up to four tubulins, the resulting complex being directly visualized by electron microscopy. Phylogenetic analysis shows that the presence of regulated multiple tubulin sites is a conserved characteristic of stathmins in invertebrates and allows us to predict key residues in stathmin for the binding of tubulin. Altogether, our results reveal that the single Drosophila stathmin gene codes for a stathmin family similar to the multigene vertebrate one, but with particular tubulin binding properties. PMID:20145240

  20. Pharmacophore Modeling, Atom based 3D-QSAR and Docking Studies of Chalcone derivatives as Tubulin inhibitors

    Directory of Open Access Journals (Sweden)

    Naresh Kandakatla

    2014-09-01

    Full Text Available Tubulin is attractive target for anticancer drug design and their inhibitors are useful in treatment of various cancers. Pharmacophore and Atom based QSAR studies were carried out for series of Chalcone derivatives. Pharmacophore model was developed using 38 compounds, having pIC50 ranging 4.003 to 6.552. The best Pharmacophoric hypothesis AHHRR.10 (one H-acceptor, two hydrophobic groups, two aromatic rings had survival score of 4.824. Atom based 3D QSAR was built for the best hypothesis with training set of 31 and test set of 7 compounds using PLS factor. The obtained QSAR model has excellent regression coefficient of R2 = 0.954, cross validated correlation coefficient q2 = 0.681, Pearson-R = 0.886 and Fisher ratio F = 136.9. The QSAR results explain electron withdrawing, positive, negative ionic and hydrophobic groups are crucial for tubulin inhibition. The docking studies of these inhibitors on the active site of the beta-tubulin shows crucial hydrogen bond interactions with the Gln11, Asn101, Thr145 amino acids. These findings provide designing of novel compounds with better tubulin inhibitory potential.

  1. Cembrene Diterpenoids: Conformational Studies and Molecular Docking to Tubulin

    Directory of Open Access Journals (Sweden)

    Heather E. Villanueva

    2010-04-01

    Full Text Available A conformational analysis of the cembrene diterpenoids cembrene, cembrene A, (3Z-cembrene A, isocembrene, casbene, and incensole, has been carried out using density functional theory at the B3LYP/6-31G* level of theory. A molecular docking analysis of these cembrenoids with tubulin has also been performed in order to assess the potential of tubulin binding of these cytotoxic agents. The macrocyclic cembrenoids are conformationally mobile and numerous low-energy conformations were found. Molecular docking reveals that the cembrenoids dock into the colchicine binding site of tubulin with comparable docking energies to colchicine.

  2. The role of gama tubulin in acentrosomal plant cells

    Czech Academy of Sciences Publication Activity Database

    Petrovská; Cenklová, Věra; Procházková, Jiřina; Doskočilová, Anna; Volc, Jindřich; Binarová, Pavla

    2007. s. 35. [Konference experimentální biologie rostlin, dny fyziologie rostlin /11./. 09.07.2007-12.07.2007, Olomouc] Keywords : gama tubulin * acentrosomal plant cells Subject RIV: EB - Genetics ; Molecular Biology

  3. Gama Tubulin and its role in Arabidopsis development

    Czech Academy of Sciences Publication Activity Database

    Cenklová, Věra; Doskočilová, Anna; Petrovská; Gallová, Barbora; Kofroňová, Olga; Benada, Oldřich; Binarová, Pavla

    2007. s. 79. [International Symposium on Plant Neurobiology/3./. 14.05.2007-18.05.2007, Štrbské Pleso] Keywords : gama tubulin * Arabidopsis development Subject RIV: EB - Genetics ; Molecular Biology

  4. Laser-Induced In-Source Decay Applied to the Determination of Amyloid-Beta in Alzheimer's Brains.

    Science.gov (United States)

    Kelley, Andrea R; Perry, George; Castellani, Rudolph J; Bach, Stephan B H

    2016-03-16

    A method for the analysis of amyloid-beta peptides in isolated plaques and intact tissue sections affected by Alzheimer's disease (AD) is presented. This method employs matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry and the inherent laser-induced in-source decay (ISD) that occurs coupled with imaging mass spectrometry (IMS) to investigate the composition of these samples eliminating the need for other confirmational MS/MS techniques. These results demonstrate this technique's usefulness for the identification of amyloid-beta peptides in tissue and isolated senile plaques from AD patients using the reproducible fragmentation pattern demonstrated via the laser-induced ISD of synthetic amyloid-beta peptide clips (1-40, 1-42). Clear differences between the hippocampal AD tissue and the control hippocampal tissue regarding the presence of amyloid-beta have been identified. These are based on laser-induced ISD of standard amyloid-beta clips as controls as well as the analysis of isolated senile plaques as a confirmation before tissue analysis. Using the resulting observed peptide clip masses from the control data, we present mass spectrometry based identification of the amyloid-beta peptides in both isolated plaques and hippocampal regions of those patients diagnosed with AD. PMID:26720297

  5. Mass spectrometry identifies multiple organophosphorylated sites on tubulin

    OpenAIRE

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

    2009-01-01

    Acute toxicity of organophosphorus poisons (OP) is explained by inhibition of acetylcholinesterase in nerve synapses. Low dose effects are hypothesized to result from modification of other proteins, whose identity is not yet established. The goal of the present work was to obtain information that would make it possible to identify tubulin as a target of OP exposure. Tubulin was selected for study because live mice injected with a nontoxic dose of a biotinylated organophosphorus agent appeared...

  6. Hypothiocyanous acid oxidation of tubulin cysteines inhibits microtubule polymerization

    OpenAIRE

    Clark, Hillary M; Hagedorn, Tara D.; Landino, Lisa M.

    2013-01-01

    Thiol oxidation is a probable outcome of cellular oxidative stress and is linked to degenerative disease progression. In addition, protein thiol redox reactions are increasingly identified as a mechanism to regulate protein structure and function. We assessed the effect of hypothiocyanous acid on the cytoskeletal protein tubulin. Total cysteine oxidation by hypothiocyanous and hypochlorous acids was monitored by labeling tubulin with 5-iodoacetamidofluorescein and by detecting higher molecula...

  7. Inhibition of tubulin polymerization by hypochlorous acid and chloramines

    OpenAIRE

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

    2011-01-01

    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-sele...

  8. Impaired dopaminergic neurotransmission in patients with traumatic brain injury: a SPET study using {sup 123}I-{beta}-CIT and {sup 123}I-IBZM

    Energy Technology Data Exchange (ETDEWEB)

    Donnemiller, E.; Riccabona, G. [Innsbruck Univ. (Austria). Dept. of Nuclear Medicine; Brenneis, C.; Wissel, J.; Scherfler, C.; Poewe, W.; Wenning, G.K. [Dept. of Neurology, Univ. of Innsbruck (Austria)

    2000-09-01

    Structural imaging suggests that traumatic brain injury (TBI) may be associated with disruption of neuronal networks, including the nigrostriatal dopaminergic pathway. However, to date deficits in pre- and/or postsynaptic dopaminergic neurotransmission have not been demonstrated in TBI using functional imaging. We therefore assessed dopaminergic function in ten TBI patients using [{sup 123}I]2-{beta}-carbomethoxy-3-{beta}-(4-iodophenyl)tropane ({beta}-CIT) and [{sup 123}I]iodobenzamide (IBZM) single-photon emission tomography (SPET). Average Glasgow Coma Scale score ({+-}SD) at the time of head trauma was 5.8{+-}4.2. SPET was performed on average 141 days (SD {+-}92) after TBI. The SPET images were compared with structural images using cranial computerised tomography (CCT) and magnetic resonance imaging (MRI). SPET was performed with an ADAC Vertex dual-head camera. The activity ratios of striatal to cerebellar uptake were used as a semiquantitative parameter of striatal dopamine transporter (DAT) and D2 receptor (D2R) binding. Compared with age-matched controls, patients with TBI had significantly lower striatal/cerebellar {beta}-CIT and IBZM binding ratios (P{<=}0.01). Overall, the DAT deficit was more marked than the D2R loss. CCT and MRI studies revealed varying cortical and subcortical lesions, with the frontal lobe being most frequently affected whereas the striatum appeared structurally normal in all but one patient. Our findings suggest that nigrostriatal dysfunction may be detected using SPET following TBI despite relative structural preservation of the striatum. Further investigations of possible clinical correlates and efficacy of dopaminergic therapy in patients with TBI seem justified. (orig.)

  9. Integrated proteomic platforms for the comparative characterization of medulloblastoma and pilocytic astrocytoma pediatric brain tumors: a preliminary study.

    Science.gov (United States)

    Martelli, Claudia; Iavarone, Federica; D'Angelo, Luca; Arba, Morena; Vincenzoni, Federica; Inserra, Ilaria; Delfino, Daniela; Rossetti, Diana Valeria; Caretto, Marta; Massimi, Luca; Tamburrini, Gianpiero; Di Rocco, Concezio; Caldarelli, Massimo; Messana, Irene; Castagnola, Massimo; Sanna, Maria Teresa; Desiderio, Claudia

    2015-06-01

    A top-down/bottom-up integrated proteomic approach based on LC-MS and 2-DE analysis was applied for comparative characterization of medulloblastoma and pilocytic astrocytoma posterior cranial fossa pediatric brain tumor tissues. Although rare, primary brain tumors are the most frequent solid tumors in the pediatric age. Among them the medulloblastoma is the prevalent malignant tumor in childhood while pilocytic astrocytoma is the most common, rarely showing a malignant progression. Due to the limited availability of this kind of sample, the study was applied to pooled tumor tissues for a preliminary investigation. The results showed different proteomic profiles of the two tumors and evidenced interesting differential expression of several proteins and peptides. Top-down proteomics of acid-soluble fractions of brain tumor homogenates ascribed a potential biomarker role of malignancy to β- and α-thymosins and their truncated proteoforms and to C-terminal truncated (des-GG) ubiquitin, resulting exclusively detected or over-expressed in the highly malignant medulloblastoma. The bottom-up proteomics of the acid-soluble fraction identified several proteins, some of them in common with 2-DE analysis of acid-insoluble pellets. Peroxiredoxin-1, peptidyl-prolyl cis-trans isomerase A, triosephosphate isomerase, pyruvate kinase PKM, tubulin beta and alpha chains, heat shock protein HSP-90-beta and different histones characterized the medulloblastoma while the Ig kappa chain C region, serotransferrin, tubulin beta 2A chain and vimentin the pilocytic astrocytoma. The two proteomic strategies, with their pros and cons, well complemented each other in characterizing the proteome of brain tumor tissues and in disclosing potential disease biomarkers to be validated in a future study on individual samples of both tumor histotypes. PMID:25909245

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

    International Nuclear Information System (INIS)

    Rationale: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity β2-containing nicotinic receptors (β2*nAChRs) are located. Objectives We intend to see which brain circuits are activated when nicotine is given in animals naive for nicotine and whether the β2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. Materials and methods: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and β2 knockout (KO) mice. Results: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, β2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via α7 nicotinic receptors. Conclusions: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on β2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice. (authors)

  11. 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. PMID:25575679

  12. Tubulin acetylation: responsible enzymes, biological functions and human diseases.

    Science.gov (United States)

    Li, Lin; Yang, Xiang-Jiao

    2015-11-01

    Microtubules have important functions ranging from maintenance of cell morphology to subcellular transport, cellular signaling, cell migration, and formation of cell polarity. At the organismal level, microtubules are crucial for various biological processes, such as viral entry, inflammation, immunity, learning and memory in mammals. Microtubules are subject to various covalent modifications. One such modification is tubulin acetylation, which is associated with stable microtubules and conserved from protists to humans. In the past three decades, this reversible modification has been studied extensively. In mammals, its level is mainly governed by opposing actions of α-tubulin acetyltransferase 1 (ATAT1) and histone deacetylase 6 (HDAC6). Knockout studies of the mouse enzymes have yielded new insights into biological functions of tubulin acetylation. Abnormal levels of this modification are linked to neurological disorders, cancer, heart diseases and other pathological conditions, thereby yielding important therapeutic implications. This review summarizes related studies and concludes that tubulin acetylation is important for regulating microtubule architecture and maintaining microtubule integrity. Together with detyrosination, glutamylation and other modifications, tubulin acetylation may form a unique 'language' to regulate microtubule structure and function. PMID:26227334

  13. Combretastatin A-4 and Derivatives: Potential Fungicides Targeting Fungal Tubulin.

    Science.gov (United States)

    Ma, Zhong-lin; Yan, Xiao-jing; Zhao, Lei; Zhou, Jiu-jiu; Pang, Wan; Kai, Zhen-peng; Wu, Fan-hong

    2016-02-01

    Combretastatin A-4, first isolated from the African willow tree Combretum caffrum, is a tubulin polymerization inhibitor in medicine. It was first postulated as a potential fungicide targeting fungal tubulin for plant disease control in this study. Combretastatin A-4 and its derivatives were synthesized and tested against Rhizoctonia solani and Pyricularia oryzae. Several compounds have EC50 values similar to or better than that of isoprothiolane, which is widely used for rice disease control. Structure-activity relationship study indicated the the cis configuration and hydroxyl group in combretastatin A-4 are crucial to the antifungal effect. Molecular modeling indicated the binding sites of combretastatin A-4 and carbendazim on fungal tubulin are totally different. The bioactivity of combretastatin A-4 and its derivatives against carbendazim-resistant strains was demonstrated in this study. The results provide a new approach for fungicide discovery and fungicide resistance management. PMID:26711170

  14. In vitro assembly of plant tubulin in the absence of microtubule-stabilizing reagents

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The assembly of microtubules is essential for physiological functions of microtubules. Addition of microtubule-stabilizing reagents or microtubule "seeds" is usually necessary for plant tubulin assembly in vitro, which hinders the investigation of plant microtubule dynamics. In the present note, highly purified plant tubulins have been obtained from lily pollen, a non-microtubule-stabilizing reagent or microtubule "seed" system for plant tubulin assembly has been established and the analysis of plant tubulin assembly performed. Experiment results showed that purified tubulin polymerized in vitro, and a typical microtubule structure was observed with electron microscopy. The kinetics curve of tubulin assembly exhibited typical "parabola". The presence of taxol significantly altered the character of plant tubulin assembly, including that abnormal microtubules were assembled and the critical concentration for plant tubulin assembly was decreased exceedingly from 3 mg/mL in the absence of taxol to 0.043 mg/mL in the presence of taxol.

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

    OpenAIRE

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

    2005-01-01

    http://www.pnas.org/content/102/22/7853.long International audience Tubulin is subject to a special cycle of detyrosination/tyrosination in which the C-terminal tyrosine of alpha-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 persist...

  16. 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.

  17. Curcumin inhibits beta-amyloid protein 40/42 expression in the brain in a concentration-and time-dependent manner

    Institute of Scientific and Technical Information of China (English)

    Xiong Zhang; Lu Si; Xiaodong Shi; Wenke Yin; Yu Li

    2010-01-01

    Several studies have demonstrated that the amount of beta-amyloid(Aβ)protein in the brain can be lowered by down-regulating Aβ production,promoting Aβ degradation,reducing Aβ oligomerization or deposition,thereby alleviating symptoms of Alzheimer's disease.Curcumin has been known to be a peroxisome proliferator activated receptor gamma(PPARy)agonist and can obviously inhibit Aβ production and oligomerization.This study investigated the effects of curcumin on the β-site APP cleaving enzyme 1(BACE1)activity and PPARy expression in human neuroblastoma SH-SY5Y cells,and validated the inhibitory effects of curcumin on Aβ40/42 expression in the brain.Results revealed that PPARy mRNA and protein expression in the human neuroblastoma SH-SY5Y cells significantly increased with increasing curcumin concentration and time course(P < 0.05);BACE1 mRNA and protein expression and Aβ40/42 production significantly decreased with increasing curcumin concentration and time course(P < 0.05).The changes in PPARY and BACE1expression during Aβ production could be reversed by the PPARy antagonist GW9662.These findings indicate that curcumin reduced Aβ production by activating PPARy expression and inhibiting BACE1 expression in a concentration-and time-dependent manner.

  18. A comparison of peripheral and central axotomy effects on neurofilament and tubulin gene expression in rat dorsal root ganglion neurons

    International Nuclear Information System (INIS)

    The expression of major cytoskeletal protein mRNAs was studied in adult rat dorsal root ganglion (DRG) neurons after crushing either their central or peripheral branch axons. mRNA levels in DRG neurons were examined by quantitative in situ hybridization with radiolabeled cDNA probes specific for the low-molecular-weight neurofilament protein (NF-L) and beta-tubulin. The large-sized (greater than 1000 microns 2) neurons which give rise to myelinated axons in lumbar ganglia (L4 and L5) were studied 1 d through 8 weeks after either dorsal root or sciatic nerve crush. NF-L and beta-tubulin mRNA levels in axotomized DRG neurons were compared to those in contralateral control DRG neurons, as well as to those in normal (completely untreated) DRG cells. In the case of NF-L mRNA, changes were observed after central as well as peripheral branch axotomy and the time course and magnitude of changes were similar after both types of axotomy. NF-L mRNA levels initially decreased (first 2 weeks after crush) and then began to return towards control levels at longer survival times. Similar, but less pronounced, changes in NF-L mRNA levels also occurred in contralateral DRG neurons (which were uninjured); the changes in contralateral neurons were not simply a result of surgical stress since no changes in NF-L mRNA levels were observed in sham-operated DRG neurons. In the case of tubulin mRNA, changes were observed after central as well as peripheral branch axotomy by in situ hybridization, but the time course and magnitude of changes were different after each type of axotomy

  19. 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

  20. Recent advances in the field of tubulin polymerization inhibitors.

    Science.gov (United States)

    Prinz, Helge

    2002-12-01

    In recent years, enormous progress has been made in the field of tubulin targeting agents. Several companies and academic laboratories have entered this field and competition has become very strong. Nevertheless, clinically promising compounds often face substantial limitations, such as high systemic toxicity, poor water solubility and bioavailability, as well as complex synthesis and isolation procedures. As a drawback of established drugs, like paclitaxel or the vinca alkaloids, the outcome of cancer chemotherapy is often affected by the emergence of the multidrug resistance phenotype. Among the recently disclosed tubulin polymerization inhibitors, there are several interesting low molecular weight compounds with improved oral bioavailability and demonstrated activity against multi-drug resistance positive phenotypes. As documented by the imidazole-based combretastatin analogs, to name just one example, chemical optimization of a lead structure resulted in compounds with potent in vitro and in vivo activity along with appropriate pharmacodynamic and pharmacokinetic requirements for a potential therapeutic candidate. Currently, several compounds are undergoing Phase I or Phase II clinical trials, among them orally bioavailable sulfonamides or dolastatin 10. Several other compounds are close to entering Phase I trials. The purpose of this review is to focus on the most recent advances in tubulin polymerization inhibitors from a survey of the published patent literature and related publications between late 1999 and April 2002. However, biological data, especially for the inhibition of tubulin polymerization, obtained from different laboratories cannot easily be compared. PMID:12503216

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

    Science.gov (United States)

    Gnanambal K, Mary Elizabeth; Lakshmipathy, Shailaja Vommi

    2016-03-01

    Tubulin/microtubule assembly and disassembly is characterized as one of the chief processes during cell growth and division. Hence drugs those perturb these process are considered to be effective in killing fast multiplying cancer cells. There is a collection of natural compounds which disturb microtubule/tubulin dis/assemblage and there have been a lot of efforts concerted in the marine realm too, to surveying such killer molecules. Close to half the natural compounds shooting out from marine invertebrates are generally with no traceable definite mechanisms of action though may be tough anti-cancerous hits at nanogram levels, hence fatefully those discoveries conclude therein without a capacity of translation from laboratory to pharmacy. Astoundingly at least 50% of natural compounds which have definite mechanisms of action causing disorders in tubulin/microtubule kinetics have an isolation history from sponges belonging to the Phylum: Porifera. Poriferans have always been a wonder worker to treat cancers with a choice of, yet precise targets on cancerous tissues. There is a specific order: Dictyoceratida within this Phylum which has contributed to yielding at least 50% of effective compounds possessing this unique mechanism of action mentioned above. However, not much notice is driven to Dictyoceratidans alongside the order: Demospongiae thus dictating the need to know its select microtubule/tubulin irritants since the unearthing of avarol in the year 1974 till date. Hence this review selectively pinpoints all the compounds, noteworthy derivatives and analogs stemming from order: Dictyoceratida focusing on the past, present and future. PMID:26874035

  2. 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.

  3. 音乐治疗对慢性应激大鼠脑内5-羟色胺及微管蛋白的影响%Effects of the music therapy on the serotonin and tubulin in brain tissue of chronic unpredictable mild stress rats

    Institute of Scientific and Technical Information of China (English)

    吴涵; 牟晓洁

    2014-01-01

    目的 探讨音乐治疗对慢性轻度不可预测性应激(CUMS)大鼠脑内前额叶、海马、下丘脑等脑区5-羟色胺及微管蛋白的水平及可能作用机制.方法 随机将24只SD雄性大鼠分为音乐治疗应激组(n=8)、应激组(n=8)和正常对照组(n=8).采用慢性轻度不可预测性应激(CUMS)模型连续刺激大鼠21 d,音乐治疗应激组在应激的同时给予音乐治疗.实验结束后对每组大鼠进行行为学观察,然后处死大鼠,检测下丘脑、海马和前额叶皮质中5-羟色胺(5-HT)及其代谢产物5-羟吲哚乙酸(5-HIAA)的含量和微管蛋白的表达.结果 旷场试验的中央格停留时间比较,应激组大鼠显著低于对照组(P<0.01),而音乐治疗应激组与对照组相比差异无统计学意义(P>0.05).与应激组相比,对照组和音乐治疗应激组的海马、前额叶中5-HT及5-HIAA含量均显著升高(P<0.01);但三组下丘脑中5-HT及5-HIAA含量差异无统计学意义(P>0.05).与应激组相比,对照组和音乐治疗应激组的海马中乙酰化微管蛋白表达均显著降低(P<0.01),酪氨酸化微管蛋白表达均显著升高(P<0.01);但三组的前额叶和下丘脑中乙酰化微管蛋白、酪氨酸化微管蛋白表达差异无统计学意义(P>0.05).结论 音乐治疗能改善应激所致的前额叶、海马5-羟色胺水平的低下和海马微管蛋白的降低.%Objective To study the effect of the music therapy on the serotonin and tubulin in frontal cortex,hippocampus and hypothalamus of chronic unpredictable mild stress (CUMS) rats,and to explore the neurobiology of the music therapy on stress disorders.Methods Twenty-four male Sprague-Dawley rats were randomly divided equally to music therapy stress group(n=8),stress group(n=8) and normal control group(n=8).Mild chronic unpredictable stress was used for 21 days in a continuous stimulation pattern to establish the CUMS model.The 5-HT,5-HIAA and tubulin levels in the the frontal cortex

  4. Increased expression of class III β-tubulin in castration-resistant human prostate cancer

    OpenAIRE

    Terry, S; Ploussard, G; Allory, Y; Nicolaiew, N; Boissière-Michot, F; Maillé, P; Kheuang, L; Coppolani, E; Ali, A.; Bibeau, F; Culine, S; Buttyan, R.; de la Taille, A; Vacherot, F

    2009-01-01

    Background: Class III β-tubulin (βIII-tubulin) is expressed in tissues of neuronal lineage and also in several human malignancies, including non-small-cell lung carcinoma, breast and ovarian cancer. Overexpression of βIII-tubulin in these tumours is associated with an unfavourable outcome and resistance to taxane-based therapies. At present, βIII-tubulin expression remains largely uncharacterised in prostate cancer. Methods: In this report, we evaluated the expression of βIII-tubulin in 138 d...

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

    OpenAIRE

    Landreth Gary E; Heneka Michael T; Breidert Tilo; Schmidt Stephen D; Mathews Paul M; Lacombe Pierre; Feinstein Douglas L; Galea Elena

    2004-01-01

    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...

  6. 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.

  7. 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

  8. Tubulin Tyrosine Ligase-like Genes ttll3 and ttll6 Maintain Zebrafish Cilia Structure and Motility*

    OpenAIRE

    Pathak, Narendra; Austin, Christina A.; Drummond, Iain A.

    2011-01-01

    Tubulin post-translational modifications generate microtubule heterogeneity and modulate microtubule function, and are catalyzed by tubulin tyrosine ligase-like (TTLL) proteins. Using antibodies specific to monoglycylated, polyglycylated, and glutamylated tubulin in whole mount immunostaining of zebrafish embryos, we observed distinct, tissue-specific patterns of tubulin modifications. Tubulin modification patterns in cilia correlated with the expression of ttll3 and ttll6 in ciliated cells. ...

  9. The solution structure of the N-terminal domain of human tubulin binding cofactor C reveals a platform for tubulin interaction.

    Directory of Open Access Journals (Sweden)

    Ma Flor Garcia-Mayoral

    Full Text Available Human Tubulin Binding Cofactor C (TBCC is a post-chaperonin involved in the folding and assembly of α- and β-tubulin monomers leading to the release of productive tubulin heterodimers ready to polymerize into microtubules. In this process it collaborates with other cofactors (TBC's A, B, D, and E and forms a supercomplex with TBCD, β-tubulin, TBCE and α-tubulin. Here, we demonstrate that TBCC depletion results in multipolar spindles and mitotic failure. Accordingly, TBCC is found at the centrosome and is implicated in bipolar spindle formation. We also determine by NMR the structure of the N-terminal domain of TBCC. The TBCC N-terminal domain adopts a spectrin-like fold topology composed of a left-handed 3-stranded α-helix bundle. Remarkably, the 30-residue N-terminal segment of the TBCC N-terminal domain is flexible and disordered in solution. This unstructured region is involved in the interaction with tubulin. Our data lead us to propose a testable model for TBCC N-terminal domain/tubulin recognition in which the highly charged N-terminus as well as residues from the three helices and the loops interact with the acidic hypervariable regions of tubulin monomers.

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

    Directory of Open Access Journals (Sweden)

    Jian Guan

    2015-06-01

    Full Text Available 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.

  11. Sequence divergence of Entamoeba histolytica tubulin is responsible for its altered tertiary structure

    International Nuclear Information System (INIS)

    Atypical microtubular structures of the protozoan parasite Entamoeba histolytica (Eh) have been attributed to amino acid sequence divergence of Eh tubulin. To investigate if this sequence divergence leads to significant differences in the tertiary structure of the Eh αβ-tubulin heterodimer, we have modeled αβ-tubulin heterodimer of Eh based on the crystal structure of mammalian tubulin. The predicted 3D homology model exhibits an overall resemblance with the known crystal structure of mammalian tubulin except for the 16 residue long carboxy terminal region of Eh β-tubulin. We propose that this C-terminal region may provide steric hindrance in the polymerization of Eh αβ-tubulin for microtubule formation. Using docking studies, we have identified the binding sites for different microtubule specific drugs on Eh β-tubulin. Our model provides a rational framework, both for understanding the contribution of Ehβ-tubulin C-terminal region to αβ-tubulin polymerization and design of new anti-protozoan drugs in order to control amoebiasis

  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...

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

    Directory of Open Access Journals (Sweden)

    Christian eHumpel

    2015-04-01

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

  14. Beta Thalassemia

    Science.gov (United States)

    ... South Asian (Indian, Pakistani, etc.), Southeast Asian and Chinese descent. 1 Beta Thalassemia ßß Normal beta globin ... then there is a 25% chance with each pregnancy that their child will inherit two abnormal beta ...

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

    Czech Academy of Sciences Publication Activity Database

    Katsetos, C.D.; Dráber, Pavel

    2012-01-01

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

  16. Structural interrogation of benzosuberene-based inhibitors of tubulin polymerization.

    Science.gov (United States)

    Herdman, Christine A; Devkota, Laxman; Lin, Chen-Ming; Niu, Haichan; Strecker, Tracy E; Lopez, Ramona; Liu, Li; George, Clinton S; Tanpure, Rajendra P; Hamel, Ernest; Chaplin, David J; Mason, Ralph P; Trawick, Mary Lynn; Pinney, Kevin G

    2015-12-15

    The discovery of 3-methoxy-9-(30,40,50-trimethoxyphenyl)-6,7-dihydro-5H-benzo[7]annulen-4-ol (a benzosuberene-based analogue referred to as KGP18) was originally inspired by the natural products colchicine and combretastatin A-4 (CA4). The relative structural simplicity and ease of synthesis of KGP18, coupled with its potent biological activity as an inhibitor of tubulin polymerization and its cytotoxicity (in vitro) against human cancer cell lines, has resulted in studies focused on new analogue design and synthesis. Our goal was to probe the relationship of structure to function in this class of anticancer agents. A series of twenty-two new benzosuberene-based analogues of KGP18 was designed and synthesized. These compounds vary in their methoxylation pattern and separately incorporate trifluoromethyl groups around the pendant aryl ring for the evaluation of the effect of functional group modifications on the fused six-membered aromatic ring. In addition, the 8,9-saturated congener of KGP18 has been synthesized to assess the necessity of unsaturation at the carbon atom bearing the pendant aryl ring. Six of the molecules from this benzosuberene-series of compounds were active (IC50 < 5 lM) as inhibitors of tubulin polymerization while four analogues were comparable (IC50 approximately 1 lM) in their tubulin inhibitory activity to CA4 and KGP18. The potency of a bis-trifluoromethyl analogue 74 and the unsaturated KGP18 derivative 73 as inhibitors of tubulin assembly along with their moderate cytotoxicity suggested the potential utility of these compounds as vascular disrupting agents (VDAs) to selectively target microvessels feeding tumors. Accordingly, water-soluble and DMSO-soluble phosphate prodrug salts of each were synthesized for preliminary in vivo studies to assess their potential efficacy as VDAs. PMID:26775540

  17. RNAi Depletion of Gamma -Tubulin as a Tool for Studying Gamma -Tubulin Role in Organization of Acentrosomal Cells

    Czech Academy of Sciences Publication Activity Database

    Doskočilová, Anna; Procházková, Jiřina; Cenklová, Věra; Binarová, Pavla

    San Diego : Springer, 2006, s. 137-137. [Annual Meeting of The American Society for Cell Biology /46./. San Diego (US), 09.12.2006-13.12.2006] R&D Projects: GA AV ČR IAA5020302; GA MŠk LC545; GA ČR GD204/05/H023 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50380511 Keywords : microtubules * gamma-tubulin * mitosis Subject RIV: EE - Microbiology, Virology

  18. Tubulin tyrosine ligase expression corresponds to changes in the tyrosination/detyrosination status of alpha tubulin in prostate cancer cells

    Czech Academy of Sciences Publication Activity Database

    Souček, Karel; Phung, A.D.; Bulinski, J.Ch.; Harper, R.W.; McManus, M.; Eiserich, J.P.

    2006-01-01

    Roč. 100, č. 5 (2006), s. 406-406. ISSN 0009-2770. [Mezioborové setkání mladých biologů, biochemiků a chemiků /6./. 14.06.2006-17.06.2006, Milovy] Institutional research plan: CEZ:AV0Z50040507 Keywords : prostate cancer * tubulin * tyrosination/detyrosination cycle Subject RIV: BO - Biophysics

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

    International Nuclear Information System (INIS)

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

  20. Novel Suicide Ligands of Tubulin Arrest Cancer Cells in S-Phase

    OpenAIRE

    Ashley Davis; Jian-Dong Jiang; Middleton, Kim M; Yue Wang; Imre Weisz; Yi-He Ling; J. George Bekesi

    1999-01-01

    It is presently accepted that the mechanism of action for all anti-tumor tubulin ligands involves the perturbation of microtubule dynamics during the G2/M phase of cell division and subsequent entry into apoptosis 1]. In this report, we challenge the established dogma by describing a unique mechanism of action caused by a novel series of tubulin ligands, halogenated derivatives of acetamido benzoyl ethyl ester. We have developed a suicide ligand for tubulin, which covalently attaches to the t...

  1. Novel Suicide Ligands of Tubulin Arrest Cancer Cells in S-Phase1

    OpenAIRE

    Davis, Ashley; Jiang, Jian-Dong; Middleton, Kim M; Wang, Yue; Weisz, Imre; Ling, Yi-He; Bekesi, J George

    1999-01-01

    It is presently accepted that the mechanism of action for all anti-tumor tubulin ligands involves the perturbation of microtubule dynamics during the G2/M phase of cell division and subsequent entry into apoptosis [1]. In this report, we challenge the established dogma by describing a unique mechanism of action caused by a novel series of tubulin ligands, halogenated derivatives of acetamido benzoyl ethyl ester. We have developed a suicide ligand for tubulin, which covalently attaches to the ...

  2. The 90-kDa Heat Shock Protein Hsp90 Protects Tubulin against Thermal Denaturation*

    OpenAIRE

    Weis, Felix; Moullintraffort, Laura; Heichette, Claire; Chrétien, Denis; Garnier, Cyrille

    2010-01-01

    Hsp90 and tubulin are among the most abundant proteins in the cytosol of eukaryotic cells. Although Hsp90 plays key roles in maintaining its client proteins in their active state, tubulin is essential for fundamental processes such as cell morphogenesis and division. Several studies have suggested a possible connection between Hsp90 and the microtubule cytoskeleton. Because tubulin is a labile protein in its soluble form, we investigated whether Hsp90 protects it against thermal denaturation....

  3. The carbonic anhydrase inhibitor methazolamide prevents amyloid beta-induced mitochondrial dysfunction and caspase activation protecting neuronal and glial cells in vitro and in the mouse brain.

    Science.gov (United States)

    Fossati, Silvia; Giannoni, Patrizia; Solesio, Maria E; Cocklin, Sarah L; Cabrera, Erwin; Ghiso, Jorge; Rostagno, Agueda

    2016-02-01

    Mitochondrial dysfunction has been recognized as an early event in Alzheimer's disease (AD) pathology, preceding and inducing neurodegeneration and memory loss. The presence of cytochrome c (CytC) released from the mitochondria into the cytoplasm is often detected after acute or chronic neurodegenerative insults, including AD. The carbonic anhydrase inhibitor (CAI) methazolamide (MTZ) was identified among a library of drugs as an inhibitor of CytC release and proved to be neuroprotective in Huntington's disease and stroke models. Here, using neuronal and glial cell cultures, in addition to an acute model of amyloid beta (Aβ) toxicity, which replicates by intra-hippocampal injection the consequences of interstitial and cellular accumulation of Aβ, we analyzed the effects of MTZ on neuronal and glial degeneration induced by the Alzheimer's amyloid. MTZ prevented DNA fragmentation, CytC release and activation of caspase 9 and caspase 3 induced by Aβ in neuronal and glial cells in culture through the inhibition of mitochondrial hydrogen peroxide production. Moreover, intraperitoneal administration of MTZ prevented neurodegeneration induced by intra-hippocampal Aβ injection in the mouse brain and was effective at reducing caspase 3 activation in neurons and microglia in the area surrounding the injection site. Our results, delineating the molecular mechanism of action of MTZ against Aβ-mediated mitochondrial dysfunction and caspase activation, and demonstrating its efficiency in a model of acute amyloid-mediated toxicity, provide the first combined in vitro and in vivo evidence supporting the potential of a new therapy employing FDA-approved CAIs in AD. PMID:26581638

  4. Dimethyl Sulfoxide Is Feasible for Plant Tubulin Assembly In vitro: A Comprehensive Analysis

    Institute of Scientific and Technical Information of China (English)

    Chun-Hua XU; Shan-Jin HUANG; Ming YUAN

    2005-01-01

    It is much more difficult for tubulin from plant sources to polymerize in vitro than tubulin from animal sources. Taxol, a most widely used reagent in microtubule studies, enhances plant microtubule assembly, but hinders microtubule dynamics. Dimethyl sulfoxide (DMSO), a widely used reagent in animal microtubule studies, is a good candidate for the investigation of plant microtubule assembly in vitro.However, proper investigation is lacking about the effects of DMSO on plant microtubule assembly in vitro.In the present study, DMSO was used to establish optimal conditions for the polymerization of plant tubulin. Tubulin, purified from lily pollen, polymerizes into microtubules at a critical concentration of 1.2mg/mL in the presence of 10% DMSO. The polymers appear to have a normal microtubule structure, as revealed by electron microscopy. In the presence of 10% DMSO, microtubule polymerization decreases when the pH of the medium is increased from 6.5 to 7.4. Both the polymerization rate and the mass of the polymers increase as temperature increases from 25 to 40 ℃. Tubulin polymerizes and depolymerizes along with cycling of temperature, from 37 to 4 ℃, or following the addition to or the removal of Ca2+ from the medium. When incubated with nuclei isolated from tobacco BY-2 suspension cells, tubulin assembles onto the nuclear surface in the presence of 10% DMSO. Labeling lily pollen tubulin with 5- (and 6-)carboxytetramethyl-rhodamine succinimidyl ester (NHS-rhodamine) was performed successfully in the presence of 10% DMSO. Labeled tubulin assembles into a radial structure on the surface of BY-2 nuclei. The polymerization of lily pollen tubulin is also enhanced by microtubule-associated proteins from animal sources in the presence of 10% DMSO. All the experimental results indicate that plant tubulin functions normally in the presence of DMSO. Therefore, DMSO is an appropriate reagent for plant tubulin polymerization and investigation of plant microtubules in

  5. 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.

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Mohamed Youssef Banora

    2011-12-01

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

  8. Unusual tubulin-clustering ability of specifically c7-modified colchicine analogues.

    Science.gov (United States)

    Zefirova, Olga N; Lemcke, Heiko; Lantow, Margareta; Nurieva, Evgeniya V; Wobith, Birgit; Onishchenko, Galina E; Hoenen, Antje; Griffiths, Gareth; Zefirov, Nikolay S; Kuznetsov, Sergei A

    2013-08-19

    Highly cytotoxic C7-modified colchicine analogues, exemplified by tubuloclustin, promote microtubule disassembly followed by the formation of very stable tubulin clusters, both in vitro and in cells. The proposed mechanism of action of tubuloclustin and its analogues, beyond that of colchicine, includes additional specific interactions with the α-tubulin subunit. PMID:23843347

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

    Science.gov (United States)

    Ohta, Shinya; Hamada, Mayako; Sato, Nobuko; Toramoto, Iyo

    2015-01-01

    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. PMID:26562023

  10. Plant polar growth in tobacco disturbed by y-tubulin gene silencing

    Institute of Scientific and Technical Information of China (English)

    Shuang Zhao; Kun Yang; Qian Ma; Qi Wang; Xiaodan Wang; Yanhong Li

    2009-01-01

    To further understand the functions of y-tubulin in plant cells, we conducted a study in which the y-tubulin gene was down-regulated in tobacco plants (obtained by the Agrobacterium-mediated method). This involved transforming the target fragments, in which the sense and antisense partial y-tubulin cDNA fragments were ligated together, into Nicotiana tabacum var. Samsun NN. The y-tubulin down-regulated transformants developed multiple meristems or branches with trumpet-shaped leaves; their root generation also appeared abnormal, with the taproots undeveloped, whereas lateral roots were developed. In addition, the content of indole-3-acetic acid (IAA) and expression of polarity transportation vector PGPI were aberrant. These results suggest that y-tubulin gene silencing disturbed the polar growth of tobacco plants, and that this phenomenon was probably correlated with the IAA content and the polar transpor-tation process.

  11. PSA NCAM and class III beta-tubulin expression in the developing inner ear in mice

    Czech Academy of Sciences Publication Activity Database

    Buckiová, Daniela; Syka, Josef

    Geneva : Federation of European Neurosciences Societies, 2008. s. 179.1. [FENS. Forum of European Neuroscience /6./. 12.07.2008-16.07.2008, Geneva] R&D Projects: GA MŠk(CZ) LC554; GA ČR GA309/04/1074 Institutional research plan: CEZ:AV0Z50390512 Keywords : Development * Sensory * Other sensory systems Subject RIV: FH - Neurology

  12. 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....... fischeri was identified as the closest known meiotic relative to the cosmopolitan species most often implicated in human aspergillosis, A. fumigatus....

  13. Molecular modeling reveals binding interface of γ-tubulin with GCP4 and interactions with noscapinoids.

    Science.gov (United States)

    Suri, Charu; Joshi, Harish C; Naik, Pradeep Kumar

    2015-05-01

    The initiation of microtubule assembly within cells is guided by a cone shaped multi-protein complex, γ-tubulin ring complex (γTuRC) containing γ-tubulin and atleast five other γ-tubulin-complex proteins (GCPs), i.e., GCP2, GCP3, GCP4, GCP5, and GCP6. The rim of γTuRC is a ring of γ-tubulin molecules that interacts, via one of its longitudinal interfaces, with GCP2, GCP3, or GCP4 and, via other interface, with α/β-tubulin dimers recruited for the microtubule lattice formation. These interactions however, are not well understood in the absence of crystal structure of functional reconstitution of γTuRC subunits. In this study, we elucidate the atomic interactions between γ-tubulin and GCP4 through computational techniques. We simulated two complexes of γ-tubulin-GCP4 complex (we called dimer1 and dimer2) for 25 ns to obtain a stable complex and calculated the ensemble average of binding free energies of -158.82 and -170.19 kcal/mol for dimer1 and -79.53 and -101.50 kcal/mol for dimer2 using MM-PBSA and MM-GBSA methods, respectively. These highly favourable binding free energy values points to very robust interactions between GCP4 and γ-tubulin. From the results of the free-energy decomposition and the computational alanine scanning calculation, we identified the amino acids crucial for the interaction of γ-tubulin with GCP4, called hotspots. Furthermore, in the endeavour to identify chemical leads that might interact at the interface of γ-tubulin-GCP4 complex; we found a class of compounds based on the plant alkaloid, noscapine that binds with high affinity in a cavity close to γ-tubulin-GCP4 interface compared with previously reported compounds. All noscapinoids displayed stable interaction throughout the simulation, however, most robust interaction was observed for bromo-noscapine followed by noscapine and amino-noscapine. This offers a novel chemical scaffold for γ-tubulin binding drugs near γ-tubulin-GCP4 interface. PMID:25662919

  14. The zebrafish fleer gene encodes an essential regulator of cilia tubulin polyglutamylation.

    Science.gov (United States)

    Pathak, Narendra; Obara, Tomoko; Mangos, Steve; Liu, Yan; Drummond, Iain A

    2007-11-01

    Cilia and basal bodies are essential organelles for a broad spectrum of functions, including the development of left-right asymmetry, kidney function, cerebrospinal fluid transport, generation of photoreceptor outer segments, and hedgehog signaling. Zebrafish fleer (flr) mutants exhibit kidney cysts, randomized left-right asymmetry, hydrocephalus, and rod outer segment defects, suggesting a pleiotropic defect in ciliogenesis. Positional cloning flr identified a tetratricopeptide repeat protein homologous to the Caenorhabditis elegans protein DYF1 that was highly expressed in ciliated cells. flr pronephric cilia were shortened and showed a reduced beat amplitude, and olfactory cilia were absent in mutants. flr cilia exhibited ultrastructural defects in microtubule B-tubules, similar to axonemes that lack tubulin posttranslational modifications (polyglutamylation or polyglycylation). flr cilia showed a dramatic reduction in cilia polyglutamylated tubulin, indicating that flr encodes a novel modulator of tubulin polyglutamylation. We also found that the C. elegans flr homologue, dyf-1, is also required for tubulin polyglutamylation in sensory neuron cilia. Knockdown of zebrafish Ttll6, a tubulin polyglutamylase, specifically eliminated tubulin polyglutamylation and cilia formation in olfactory placodes, similar to flr mutants. These results are the first in vivo evidence that tubulin polyglutamylation is required for vertebrate cilia motility and structure, and, when compromised, results in failed ciliogenesis. PMID:17761526

  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. 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

  17. Molecular simulations of Taxawallin I inside classical taxol binding site of β-tubulin.

    Science.gov (United States)

    Khan, Inamullah; Nisar, Muhammad; Ahmad, Manzoor; Shah, Hamidullah; Iqbal, Zafar; Saeed, Muhammad; Halimi, Syed Muhammad Ashhad; Kaleem, Waqar Ahmad; Qayum, Mughal; Aman, Akhter; Abdullah, Syed Muhammad

    2011-03-01

    A new taxoid Taxawallin I (1) along with two known taxoids (2-3) were isolated from methanolic bark extract of Taxus wallichiana Zucc. Structural characterization was confirmed by mass and NMR spectral techniques. Taxawallin I exhibited significant in-vitro anticancer activity against HepG2, A498, NCI-H226 and MDR 2780AD cancer lines. Tubulin binding assay was performed to assess its tubulin binding activity. Molecular docking analysis was performed to study the potential binding mode inside the taxol binding site of β-tubulin. PMID:20969934

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

    International Nuclear Information System (INIS)

    Highlights: •The effect of Cd2+ on Clathrina clathrus microtubule network was studied. •Cd2+ exposure increases acetylated and detyrosinated α-tubulin levels. •Microtubules enriched in acetylated/detyrosinated α-tubulin were resistant to cold. •Clathrina clathrus exposed to Cd2+ 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 CdCl2, 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 Cd2+-treated cells indicates that divalent Cd ions

  19. 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

  20. Exploration of the binding mode between (-)-zampanolide and tubulin using docking and molecular dynamics simulation.

    Science.gov (United States)

    Liao, Si-Yan; Mo, Guang-Quan; Chen, Jin-Can; Zheng, Kang-Cheng

    2014-02-01

    The binding mode of (-)-zampanolide (ZMP) to tubulin was investigated using docking, molecular dynamics (MD) simulation, and binding free-energy calculations. The docking studies validated the experimental results indicating that the paclitaxel site is the binding site for (-)-ZMP. The 18 ns MD simulation shows the docking mode has changed a lot, whereas it offers more reliable binding data. MM-PBSA binding free-energy calculations further confirmed the results of the MD simulation. The study revealed that hydrophobic interactions play an important role in stabilizing the binding, and the strong hydrogen bond formed with Asp224 enhances the affinity for tubulin. Meanwhile, the results support the assumption that (-)-ZMP can be attacked by His227, leading to a nucleophilic reaction and covalent binding. These theoretical results lead to a greater understanding of the mechanism of action of binding to tubulin, and will therefore aid the design of new compounds with higher affinities for tubulin. PMID:24478043

  1. Zampanolide and Dactylolide: Cytotoxic Tubulin-Assembly Agents and Promising Anticancer Leads

    OpenAIRE

    Chen, Qiao-Hong; Kingston, David G. I.

    2014-01-01

    Zampanolide is a marine natural macrolide and a recent addition to the family of microtubule-stabilizing cytotoxic agents. Zampanolide exhibits unique effects on tubulin assembly and is more potent than paclitaxel against several multi-drug resistant cancer cell lines. A high-resolution crystal structure of xB-tubulin in complex with zampanolide explains how taxane-site microtubule-stabilizing agents promote microtubule assemble and stability. This review provides an overview of current devel...

  2. Zampanolide and dactylolide: cytotoxic tubulin-assembly agents and promising anticancer leads

    OpenAIRE

    Chen, Qiao-Hong; Kingston, David G. I.

    2014-01-01

    Covering: through January 2014 Zampanolide is a marine natural macrolide and a recent addition to the family of microtubule-stabilizing cytotoxic agents. Zampanolide exhibits unique effects on tubulin assembly and is more potent than paclitaxel against several multi-drug resistant cancer cell lines. A high-resolution crystal structure of αβ-tubulin in complex with zampanolide explains how taxane-site microtubule-stabilizing agents promote microtubule assemble and stability. This review provid...

  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. PMID:10580715

  4. Neurogenic Responses to Amyloid-Beta Plaques in the Brain of Alzheimer's Disease-Like Transgenic (pPDGF-APPSw,Ind) Mice

    OpenAIRE

    Gan, Li; Qiao, Shuhong; Lan, Xun; Chi, Liying; Luo, Chun; Lien, Lindsey; Liu, Qing Yan; Liu, Rugao

    2007-01-01

    Formation and accumulation of amyloid-beta (Aβ) plaques are associated with declined memory and other neurocognitive function in Alzheimer's Disease (AD) patients. However, the effects of Aβ plaques on neural progenitor cells (NPCs) and neurogenesis from NPCs remain largely unknown. The existing data on neurogenesis in AD patients and AD-like animal models remain controversial. For this reason, we utilized the nestin second-intron enhancer controlled LacZ (pNes-LacZ) reporter transgenic mice ...

  5. Messenger RNA-based therapeutics for brain diseases: An animal study for augmenting clearance of beta-amyloid by intracerebral administration of neprilysin mRNA loaded in polyplex nanomicelles.

    Science.gov (United States)

    Lin, Chin-Yu; Perche, Federico; Ikegami, Masaru; Uchida, Satoshi; Kataoka, Kazunori; Itaka, Keiji

    2016-08-10

    Alzheimer's disease (AD) pathogenesis is considered to be the metabolic imbalance between anabolism and clearance of amyloid-beta (Aβ), and the strategy of breaking the equilibrium between soluble and insoluble forms of Aβ is likely to help prevent the progression of AD. Neprilysin (NEP) plays a major role in the clearance of Aβ in the brain, and its supplementation using viral vectors has shown to decrease Aβ deposition and prevent pathogenic changes in the brain. In this study, we developed a new therapeutic strategy by mRNA-based gene introduction. mRNA has the advantages of negligible risk of random integration into genome and not needing to be transcribed precludes the need for nuclear entry. This allows efficient protein expression in slowly-dividing or non-dividing cells, such as neural cells. We constructed mRNA encoding the mouse NEP protein and evaluated its ability degrade Aβ. In vitro transfection of NEP mRNA to primary neurons exhibited Amyloid Precursor Protein (APP) degradation activity superior to that of NEP encoding plasmid DNA. We then evaluated the in vivo activity of NEP mRNA by intracerebroventricular (i.c.v.) infusion using a cationic polymer-based PEGylated nanocarrier to form polyplex nanomicelles, which have been shown to have a high potential to deliver mRNA to various target tissues and organs. Nanomicelles carrying a GFP-NEP fusion mRNA produced efficient protein expression in a diffuse manner surrounding the ventricular space. An ELISA evaluation revealed that the mRNA infusion significantly augmented NEP level and effectively reduced the concentration of Aβ that had been supplemented in the mouse brain. To the best of our knowledge, this is the first study to demonstrate the therapeutic potential of introducing exogenous mRNA for the treatment of brain diseases, opening the new era of mRNA-based therapeutics. PMID:27282413

  6. Tubulin tyrosine ligase expression corresponds to changes in the tyrosination/detyrosination status of alpha-tubulin in prostate cancer cells

    Czech Academy of Sciences Publication Activity Database

    Souček, Karel; Phung, A.D.; Bulinski, J.C.; Harper, R.W.; McManus, M.T.; Eserich, J.P.

    Quebec City: ISAC, 2006 - (Robinson, J.). s. 134-134 [ISAC XXIII International Congress. 20.05.2006-24.05.2006, Québec City] Institutional research plan: CEZ:AV0Z50040507 Keywords : prostate cancer * tubulin * tyrosination/detyrosination cycle Subject RIV: BO - Biophysics

  7. 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.

  8. Genetic variations in tau-tubulin kinase-1 are linked to Alzheimer's disease in a Spanish case-control cohort.

    Science.gov (United States)

    Vázquez-Higuera, José Luis; Martínez-García, Ana; Sánchez-Juan, Pascual; Rodríguez-Rodríguez, Eloy; Mateo, Ignacio; Pozueta, Ana; Frank, Ana; Valdivieso, Fernando; Berciano, José; Bullido, María J; Combarros, Onofre

    2011-03-01

    Neurofibrillary tangles, one of the characteristic neuropathological lesions found in Alzheimer's disease (AD) brains, are composed of abnormally hyperphosphorylated tau protein. Tau-tubulin kinase-1 (TTBK1) is a brain-specific protein kinase involved in tau phosphorylation at AD-related sites. We examined genetic variations of TTBK1 by genotyping nine haplotype tagging SNPs (htSNPs) (rs2104142, rs2651206, rs10807287, rs7764257, rs3800294, rs1995300, rs2756173, rs6936397, and rs6458330) in a group of 645 Spanish late-onset AD patients and 738 healthy controls. Using a recessive genetic model, minor allele homozygotes for rs2651206 in intron 1 (OR=0.50, p=0.0003), rs10807287 in intron 5 (OR=0.49, p=0.0002), and rs7764257 in intron 9 (OR=0.57, p=0.023), which are in strong linkage disequilibrium, had a lower risk of developing AD than subjects homozygotes and heterozygotes for the major allele. TTBK1 is a promising new candidate tau phosphorylation-related gene for AD risk. PMID:20096481

  9. Elevation of neuron specific enolase and brain iron deposition on susceptibility-weighted imaging as diagnostic clues for beta-propeller protein-associated neurodegeneration in early childhood: Additional case report and review of the literature.

    Science.gov (United States)

    Takano, Kyoko; Shiba, Naoko; Wakui, Keiko; Yamaguchi, Tomomi; Aida, Noriko; Inaba, Yuji; Fukushima, Yoshimitsu; Kosho, Tomoki

    2016-02-01

    Beta-propeller protein-associated neurodegeneration (BPAN), also known as static encephalopathy of childhood with neurodegeneration in adulthood (SENDA), is a subtype of neurodegeneration with brain iron accumulation (NBIA). BPAN is caused by mutations in an X-linked gene WDR45 that is involved in autophagy. BPAN is characterized by developmental delay or intellectual disability until adolescence or early adulthood, followed by severe dystonia, parkinsonism, and progressive dementia. Brain magnetic resonance imaging (MRI) shows iron deposition in the bilateral globus pallidus (GP) and substantia nigra (SN). Clinical manifestations and laboratory findings in early childhood are limited. We report a 3-year-old girl with BPAN who presented with severe developmental delay and characteristic facial features. In addition to chronic elevation of serum aspartate transaminase, lactate dehydrogenase, creatine kinase, and soluble interleukin-2 receptor, she had persistent elevation of neuron specific enolase (NSE) in serum and cerebrospinal fluid. MRI using susceptibility-weighted imaging (SWI) demonstrated iron accumulation in the GP and SN bilaterally. Targeted next-generation sequencing identified a de novo splice-site mutation, c.831-1G>C in WDR45, which resulted in aberrant splicing evidenced by reverse transcriptase-PCR. Persistent elevation of NSE and iron deposition on SWI may provide clues for diagnosis of BPAN in early childhood. PMID:26481852

  10. New potential peptide therapeutics perturbing CK1δ/α-tubulin interaction.

    Science.gov (United States)

    Krüger, Marc; Kalbacher, Hubert; Kastritis, Panagiotis L; Bischof, Joachim; Barth, Holger; Henne-Bruns, Doris; Vorgias, Constantinos; Sarno, Stefania; Pinna, Lorenzo A; Knippschild, Uwe

    2016-06-01

    Members of the CK1 family are highly conserved serine/threonine specific kinases being expressed in all eukaryotes. They are involved in many cellular processes and therefore tightly regulated. A central mechanism to modulate CK1 activity is via interaction with cellular proteins. CK1δ interacts with α-/β-tubulin and is involved in the regulation of microtubule dynamics. Therefore, it is important to identify the structural elements responsible for the interaction between these proteins. Using a peptide library covering the human CK1δ amino acid sequence in SPR and ELISA analyses, we identified peptide 39 (P39), encompassing aa361-aa375 of CK1δ, as a prominent binding partner of α-tubulin. P39 decreases α-tubulin phosphorylation by CK1δ and reduces the thermodynamic stability of α-tubulin in fluorescence thermal shift assays. Furthermore, P39 induces an inhibition of mitotic progression and a disruption of cells entering mitosis in CV-1 cells. Taken together our data provide valuable information regarding the interaction of CK1δ and α-tubulin and a novel approach for the development of pharmacological tools to inhibit proliferation of cancer cells. PMID:26996302

  11. FtsZ Protofilament Curvature Is the Opposite of Tubulin Rings.

    Science.gov (United States)

    Housman, Max; Milam, Sara L; Moore, Desmond A; Osawa, Masaki; Erickson, Harold P

    2016-07-26

    FtsZ protofilaments (pfs) form the bacterial cytokinetic Z ring. Previous work suggested that a conformational change from straight to curved pfs generated the constriction force. In the simplest model, the C-terminal membrane tether is on the outside of the curved pf, facing the membrane. Tubulin, a homologue of FtsZ, also forms pfs with a curved conformation. However, it is well-established that tubulin rings have the C terminus on the inside of the ring. Could FtsZ and tubulin rings have the opposite curvature? In this study, we explored the FtsZ curvature direction by fusing large protein tags to the FtsZ termini. Thin section electron microscopy showed that the C-terminal tag was on the outside, consistent with the bending pf model. This has interesting implications for the evolution of tubulin. Tubulin likely began with the curvature of FtsZ, but evolution managed to reverse direction to produce outward-curving rings, which are useful for pulling chromosomes. PMID:27368355

  12. Sequencing of the β-tubulin genes in the ascarid nematodes Parascaris equorum and Ascaridia galli.

    Science.gov (United States)

    Tydén, E; Engström, A; Morrison, D A; Höglund, J

    2013-07-01

    Benzimidazoles (BZ) are used to control infections of the equine roundworm Parascaris equorum and the poultry roundworm Ascaridia galli. There are still no reports of anthelmintic resistance (AR) to BZ in these two nematodes, although AR to BZ is widespread in several other veterinary parasites. Several single nucleotide polymorphisms (SNP) in the β-tubulin genes have been associated with BZ-resistance. In the present study we have sequenced β-tubulin genes: isotype 1 and isotype 2 of P. equorum and isotype 1 of A. galli. Phylogenetic analysis of all currently known isotypes showed that the Nematoda has more diversity among the β-tubulin genes than the Vertebrata. In addition, this diversity is arranged in a more complex pattern of isotypes. Phylogenetically, the A. galli sequence and one of the P. equorum sequences clustered with the known Ascaridoidea isotype 1 sequences, while the other P. equorum sequence did not cluster with any other β-tubulin sequences. We therefore conclude that this is a previously unreported isotype 2. The β-tubulin gene sequences were used to develop a PCR for genotyping SNP in codons 167, 198 and 200. No SNP was observed despite sequencing 95 and 100 individual adult worms of P. equorum and A. galli, respectively. Given the diversity of isotype patterns among nematodes, it is likely that associations of genetic data with BZ-resistance cannot be generalised from one taxonomic group to another. PMID:23685342

  13. Novel Suicide Ligands of Tubulin Arrest Cancer Cells in S-Phase

    Directory of Open Access Journals (Sweden)

    Ashley Davis

    1999-12-01

    Full Text Available It is presently accepted that the mechanism of action for all anti-tumor tubulin ligands involves the perturbation of microtubule dynamics during the G2/M phase of cell division and subsequent entry into apoptosis 1]. In this report, we challenge the established dogma by describing a unique mechanism of action caused by a novel series of tubulin ligands, halogenated derivatives of acetamido benzoyl ethyl ester. We have developed a suicide ligand for tubulin, which covalently attaches to the target and shows potent cancericidal activity in tissue culture assays and in animal tumor models. These compounds target early S-phase at the G1/S transition rather than the G2/M phase and mitotic arrest. Bcl-2 phosphorylation, a marker of mitotic microtubule inhibition by other tubulin ligands was dramatically altered, phosphorylation was rapid and biphasic rather than a slow linear event. The halogenated ethyl ester series of derivatives thus constitute a unique set of tubulin ligands which induce a novel mechanism of apoptosis.

  14. 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.

  15. Biochemical characterization and molecular dynamic simulation of β-sitosterol as a tubulin-binding anticancer agent.

    Science.gov (United States)

    Mahaddalkar, Tejashree; Suri, Charu; Naik, Pradeep Kumar; Lopus, Manu

    2015-08-01

    Βeta-sitosterol (β-SITO), a phytosterol present in pomegranate, peanut, corn oil, almond, and avocado, has been recognized to offer health benefits and potential clinical uses. β-SITO is orally bioavailable and, as a constituent of edible natural products, is considered to have no undesired side effects. It has also been considered as a potent anticancer agent. However, the molecular mechanism of action of β-SITO as a tubulin-binding anticancer agent and its binding site on tubulin are poorly understood. Using a combination of biochemical analyses and molecular dynamic simulation, we investigated the molecular details of the binding interactions of β-SITO with tubulin. A polymer mass assay comparing the effects of β-SITO and of taxol and vinblastine on tubulin assembly showed that this phytosterol stabilized microtubule assembly in a manner similar to taxol. An 8-anilino-1-naphthalenesulfonic acid assay confirmed the direct interaction of β-SITO with tubulin. Although β-SITO did not show direct binding to the colchicine site on tubulin, it stabilized the colchicine binding. Interestingly, no sulfhydryl groups of tubulin were involved in the binding interaction of β-SITO with tubulin. Based on the results from the biochemical assays, we computationally modeled the binding of β-SITO with tubulin. Using molecular docking followed by molecular dynamic simulations, we found that β-SITO binds tubulin at a novel site (which we call the 'SITO site') adjacent to the colchicine and noscapine sites. Our data suggest that β-SITO is a potent anticancer compound that interferes with microtubule assembly dynamics by binding to a novel site on tubulin. PMID:25912799

  16. The effect of physical therapy on beta-endorphin levels.

    Science.gov (United States)

    Bender, Tamás; Nagy, György; Barna, István; Tefner, Ildikó; Kádas, Eva; Géher, Pál

    2007-07-01

    Beta-endorphin (betaE) is an important reliever of pain. Various stressors and certain modalities of physiotherapy are potent inducers of the release of endogenous betaE to the blood stream. Most forms of exercise also increase blood betaE level, especially when exercise intensity involves reaching the anaerobic threshold and is associated with the elevation of serum lactate level. Age, gender, and mental activity during exercise also may influence betaE levels. Publications on the potential stimulating effect of manual therapy and massage on betaE release are controversial. Sauna, mud bath, and thermal water increase betaE levels through conveying heat to the tissues. The majority of the techniques for electrical stimulation have a similar effect, which is exerted both centrally and--to a lesser extent--peripherally. However, the parameters of electrotherapy have not yet been standardised. The efficacy of analgesia and the improvement of general well-being do not necessarily correlate with betaE level. Although in addition to blood, increased brain and cerebrospinal fluid betaE levels are also associated with pain, the majority of studies have concerned blood betaE levels. In general, various modalities of physical therapy might influence endorphin levels in the serum or in the cerebrospinal fluid--this is usually manifested by elevation with potential mitigation of pain. However, a causal relationship between the elevation of blood, cerebrospinal fluid or brain betaE levels and the onset of the analgesic action cannot be demonstrated with certainty. PMID:17483960

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

    International Nuclear Information System (INIS)

    Tubulin-folding cofactor A from A. thaliana has been crystallized and preliminarily analyzed using X-ray diffraction. Tubulin-folding cofactor A (TFC A) is a molecular post-chaperonin that is involved in the β-tubulin-folding pathway. It has been identified in many organisms including yeasts, humans and plants. In this work, Arabidopsis thaliana TFC A was expressed in Escherichia coli and purified to homogeneity. After thrombin cleavage, a well diffracting crystal was obtained by the sitting-drop vapour-diffusion method at 289 K. The crystal diffracted to 1.6 Å resolution using synchrotron radiation and belonged to space group I41, with unit-cell parameters a = 55.0, b = 55.0, c = 67.4 Å

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

    Institute of Scientific and Technical Information of China (English)

    Yuxia Gao; Yun Niu; Xiumin Ding; Yong Yu

    2008-01-01

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

  19. Hyper-beta-alaninemia associated with beta-aminoaciduria and gamma-aminobutyricaciduaia, somnolence and seizures.

    Science.gov (United States)

    Scriver, C R; Pueschel, S; Davies, E

    1966-03-24

    Hyper-beta-alaninemia was found in a somnolent, convulsing infant. Hyper-beta-aminoaciduria (beta-ala, betaAIB and taurine) was also observed, varying directly with plasma beta-alanine concentration. The beta-aminoaciduria is explained by the interaction between beta-alanine and a specific cellular-transport system with preference for beta-amino compounds. Gamma-aminobutyricaciduria was also observed, its excretion being independent of beta-alanine levels. Dietary modifications, pyridoxine, pantothenic acid and antibiotic therapy were not beneficial. Post-mortem tissues had elevated levels of beta-alanine and carnosine; GABA levels in brain were probably elevated for the age of the patient. A proposed block in beta-alanine-alpha-ketoglutarate transaminase would expand the free beta-alanine pool, thus increasing tissue carnosine. beta-Alanine is a central-nervous-system depressant. Associated inhibition of GABA transaminase and displacement of GABA from central-nervous-system binding sites would produce GABAuria and convulsions. PMID:17926374

  20. Synthesis of triazoloquinazolinone based compounds as tubulin polymerization inhibitors and vascular disrupting agents.

    Science.gov (United States)

    Driowya, Mohsine; Leclercq, Julien; Verones, Valerie; Barczyk, Amélie; Lecoeur, Marie; Renault, Nicolas; Flouquet, Nathalie; Ghinet, Alina; Berthelot, Pascal; Lebegue, Nicolas

    2016-06-10

    A series of 1-phenyl-[1,2,4]triazolo[4,3-a]quinazolin-5-ones designed as conformationally restricted CA-4 analogues, were tested for their tubulin polymerization and growth inhibitory activities. The 3-hydroxy-4-methoxy derivatives 11d and 12d are potent inhibitors of tubulin assembly but only the N-methylated amid counterpart 12d possesses potent anticancer activity in a large panel of cancer cell lines. Upon treatment with compound 12d, remarkable cell shape changes as cell migration and tube formation were elicited in HUVECs, consistent with vasculature damaging activity. PMID:27031215

  1. Molecular Modeling of the Axial and Circumferential Elastic Moduli of Tubulin

    OpenAIRE

    Zeiger, A. S.; Layton, B. E.

    2008-01-01

    Microtubules play a number of important mechanical roles in almost all cell types in nearly all major phylogenetic trees. We have used a molecular mechanics approach to perform tensile tests on individual tubulin monomers and determined values for the axial and circumferential moduli for all currently known complete sequences. The axial elastic moduli, in vacuo, were found to be 1.25 GPa and 1.34 GPa for α- and β-bovine tubulin monomers. In the circumferential direction, these moduli were 378...

  2. 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.

  3. (-)-Rhazinilam and the diphenylpyridazinone NSC 613241: Two compounds inducing the formation of morphologically similar tubulin spirals but binding apparently to two distinct sites on tubulin.

    Science.gov (United States)

    Bai, Ruoli; Hamel, Ernest

    2016-08-15

    The most potent microtubule assembly inhibitor of newer diphenylpyridazinone derivatives examined was NSC 613241. Because NSC 613241 and (-)-rhazinilam also induce the formation of similar 2-filament spirals, these aberrant reactions were compared. Spiral formation with both compounds was enhanced by GTP and inhibited by GDP and by 15 other inhibitors of microtubule assembly. Similarly, microtubule assembly induced by paclitaxel or laulimalide is enhanced by GTP and inhibited by GDP and assembly inhibitors, but neither [(3)H]NSC 613241 nor [(3)H](-)-rhazinilam bound to microtubules or inhibited the binding of [(3)H]paclitaxel or [(3)H]peloruside A to microtubules. Differences in the pitch of aberrant polymers were found: NSC 613241-induced and (-)-rhazinilam-induced spirals had average repeats of 85 and 79-80 nm, respectively. We found no binding of [(3)H]NSC 613241 or [(3)H](-)-rhazinilam to αβ-tubulin dimer, but both compounds were incorporated into the polymers they induced in substoichiometric reactions, with as little as 0.1-0.2 mol compound/mol of tubulin, and no cross-inhibition by NSC 613241 or (-)-rhazinilam into spirals occurred. Under reaction conditions where neither compound induced spiral formation, both compounds together synergistically induced substantial spiral formation. We conclude that (-)-rhazinilam and NSC 613241 bind to different sites on tubulin that differ from binding sites for other antitubulin agents. PMID:27311615

  4. Kinesin-1 translocation: Surprising differences between bovine brain and MCF7-derived microtubules.

    Science.gov (United States)

    Feizabadi, Mitra Shojania; Jun, Yonggun

    2014-10-30

    While there have been many single-molecule studies of kinesin-1, most have been done along microtubules purified from bovine or porcine brain, and relatively little is known about how variations in tubulin might alter motor function. Of particular interest is transport along microtubules polymerized from tubulin purified from MCF7 breast cancer cells, both because these cells are a heavily studied model system to help understand breast cancer, and also because the microtubules are already established to have interesting polymerization/stability differences from bovine tubulin, suggesting that perhaps transport along them is also different. Thus, we carried out paired experiments to allow direct comparison of in vitro kinesin-1 translocation along microtubules polymerized from either human breast cancer cells (MCF7) or microtubules from bovine brain. We found surprising differences: on MCF7 microtubules, kinesin-1's processivity is significantly reduced, although its velocity is only slightly altered. PMID:25450690

  5. Analysis of the binding mode of laulimalide to microtubules: Establishing a laulimalide-tubulin pharmacophore.

    Science.gov (United States)

    Churchill, Cassandra D M; Klobukowski, Mariusz; Tuszynski, Jack A

    2016-07-01

    Laulimalide (LA) is a microtubule-stabilizing agent, currently in preclinical studies. However, studying the binding of this species and successfully synthesizing potent analogues have been challenging. The LA binding site is located between tubulin protofilaments, and therefore LA is in contact with two adjacent [Formula: see text]-tubulin units. Here, an improved model of the binding mode of LA in microtubules is presented, using the newly available crystal structure pose and an extended tubulin heterodimer complex, as well as molecular dynamics simulations. With this model, a series of LA analogues developed by Mooberry and coworkers are also analyzed in order to establish important pharmacophores in LA binding and cytotoxicity. In the side chain, [Formula: see text]-[Formula: see text] interactions are important contributors to LA binding, as are water-mediated hydrogen bonds. An intramolecular hydrogen bond is correlated with high cytotoxicity, and is dependent on macrocycle conformation. Therefore, while the epoxide and olefin groups in the macrocycle do not engage in specific interactions with the protein, they are essential contributions to an active macrocycle conformation, and therefore potency. Calculations reveal that a balance in binding affinity is important for LA activity, where the more potent compounds have larger interactions with the adjacent tubulin unit than the less-active analogs. Several modifications are suggested for the rational design of LA analogues that should not disrupt the active macrocycle conformation. PMID:26230757

  6. Recovery of tubulin functions after freeze-drying in the presence of trehalose

    Czech Academy of Sciences Publication Activity Database

    Sulimenko, Vadym

    Praha: ÚMG AV ČR, Československá biologická společnost, 2010. [Cytoskeletal Club /18./. 05.05.10-07.05.10, Vranovská ves] Institutional research plan: CEZ:AV0Z50520514 Keywords : tubulin * freeze - drying * stability Subject RIV: EB - Genetics ; Molecular Biology

  7. Recovery of tubulin functions after freeze-dying in the presence of trehalose

    Czech Academy of Sciences Publication Activity Database

    Dráberová, Eduarda; Sulimenko, Vadym; Sulimenko, Tetyana; Böhm, K. J.; Dráber, Pavel

    2010-01-01

    Roč. 397, č. 1 (2010), s. 67-72. ISSN 0003-2697 R&D Projects: GA AV ČR KAN200520701; GA MŠk LC545 Institutional research plan: CEZ:AV0Z50520514 Keywords : Tubulin * Freeze - drying * Stability Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.236, year: 2010

  8. Evidence for the presence of gamma-tubulin in the nucleolus

    Czech Academy of Sciences Publication Activity Database

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

    San Francisko : The American Society for Cell Biology, 2008. ---. [The American Society for Cell Biology, Annual Meeting/48/. 13.12.2088-17.12.2008, San Francisko] R&D Projects: GA AV ČR KAN200520701; GA MŠk LC545 Institutional research plan: CEZ:AV0Z50520514 Keywords : gamma-tubulin * nucleolus Subject RIV: EB - Genetics ; Molecular Biology

  9. Unprecedented inhibition of tubulin polymerization directed by gold nanoparticles inducing cell cycle arrest and apoptosis

    Science.gov (United States)

    Choudhury, Diptiman; Xavier, Paulrajpillai Lourdu; Chaudhari, Kamalesh; John, Robin; Dasgupta, Anjan Kumar; Pradeep, Thalappil; Chakrabarti, Gopal

    2013-05-01

    The effect of gold nanoparticles (AuNPs) on the polymerization of tubulin has not been examined till now. We report that interaction of weakly protected AuNPs with microtubules (MTs) could cause inhibition of polymerization and aggregation in the cell free system. We estimate that single citrate capped AuNPs could cause aggregation of ~105 tubulin heterodimers. Investigation of the nature of inhibition of polymerization and aggregation by Raman and Fourier transform-infrared (FTIR) spectroscopies indicated partial conformational changes of tubulin and microtubules, thus revealing that AuNP-induced conformational change is the driving force behind the observed phenomenon. Cell culture experiments were carried out to check whether this can happen inside a cell. Dark field microscopy (DFM) combined with hyperspectral imaging (HSI) along with flow cytometric (FC) and confocal laser scanning microscopic (CLSM) analyses suggested that AuNPs entered the cell, caused aggregation of the MTs of A549 cells, leading to cell cycle arrest at the G0/G1 phase and concomitant apoptosis. Further, Western blot analysis indicated the upregulation of mitochondrial apoptosis proteins such as Bax and p53, down regulation of Bcl-2 and cleavage of poly(ADP-ribose) polymerase (PARP) confirming mitochondrial apoptosis. Western blot run after cold-depolymerization revealed an increase in the aggregated insoluble intracellular tubulin while the control and actin did not aggregate, suggesting microtubule damage induced cell cycle arrest and apoptosis. The observed polymerization inhibition and cytotoxic effects were dependent on the size and concentration of the AuNPs used and also on the incubation time. As microtubules are important cellular structures and target for anti-cancer drugs, this first observation of nanoparticles-induced protein's conformational change-based aggregation of the tubulin-MT system is of high importance, and would be useful in the understanding of cancer therapeutics

  10. A new method for fibrous protein analysis illustrated by application to tubulin microtubule polymerisation and depolymerisation.

    Science.gov (United States)

    Marrington, Rachel; Seymour, Mark; Rodger, Alison

    2006-09-01

    A thermostatted micro volume Couette cell has been designed to enable linear dichroism (LD) data to be collected at a range of temperatures. The cell is a development of the traditional Couette flow LD cell and includes the recent development of micro-volume LD (20-40 microL) coupled with the addition of a heating element, temperature probe and controller. This new micro volume Couette LD cell opens the way not only to the LD analysis of systems where sample volume is critical, but also for the LD analysis of temperature sensitive samples. The polymerization of the microtubule protein tubulin has been followed in a range of different conditions using the thermostatted micro volume Couette LD cell. The focusing lenses on the cell, which are required for the microvolume cell, have the side benefit of significantly reducing the light-scattering artifacts caused by the large size of tubulin microtubules. It is now possible to monitor real-time polymerization and depolymerization kinetics, and any structural rearrangements of chromophores within the polymer. In the case of tubulin, the LD spectra revealed a greater change in the orientation of tryptophan residues at approximately 290 nm during polymerization compared to other contributing chromophores-guanine, phenylalanine, and tyrosine. The improvements in instrumental design have also allowed LD spectra of tubulin to be collected down to approximately 230 nm (previous data have only been available from the near UV region), which means that some indication of protein backbone-orientation changes are now available. It was observed during this work that apparent LD intensity maxima are in fact artifacts when the high-tension voltage is high. The onset of such artifacts has been observed at much lower voltages with light-scattering fibrous proteins (including tubulin) than with nonscattering samples. Therefore, caution must be used when interpreting LD data collected with medium to high photomultiplier tube voltages

  11. 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.

  12. Biphasic regulation by dibutyryl cyclic AMP of tubulin and actin mRNA levels in neuroblastoma cells.

    OpenAIRE

    Ginzburg, I.; Rybak, S.; Kimhi, Y; Littauer, U. Z.

    1983-01-01

    Blot hybridization analysis that used labeled tubulin cDNA probes revealed that N6,O2'-dibutyryladenosine 3',5'-cyclic monophosphate [dibutyryl cyclic AMP (Bt2cAMP)] initially increases and later decreases the level of tubulin mRNA in a neuroblastoma-glioma hybrid cell line as well as in the parent cells. A significant increase in tubulin mRNA sequences is already evident 1 hr after the addition of Bt2cAMP to the neuroblastoma cells, and a maximal induction of 2-fold is seen after 12 hr. Cont...

  13. 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.

  14. RASSF1A Suppresses Cell Migration through Inactivation of HDAC6 and Increase of Acetylated α-Tubulin

    OpenAIRE

    Jung, Hae-Yun; Jung, Jun Seok; Whang, Young Mi; Kim, Yeul Hong

    2013-01-01

    Purpose The RAS association domain family protein 1 (RASSF1) has been implicated in a tumor-suppressive function through the induction of acetylated α-tubulin and modulation of cell migration. However, the mechanisms of how RASSF1A is associated with acetylation of α-tubulin for controlling cell migration have not yet been elucidated. In this study, we found that RASSF1A regulated cell migration through the regulation of histon deacetylase 6 (HDAC6), which functions as a tubulin deacetylase. ...

  15. Partial Unfolding of Tubulin Heterodimers Induced by Two-Photon Excitation of Bound meso-Tetrakis(sulfonatophenyl)porphyrin.

    Science.gov (United States)

    McMicken, Brady; Thomas, Robert J; Brancaleon, Lorenzo

    2016-04-21

    The water-soluble porphyrin meso-tetrakis(p-sulfonatophenyl)porphyrin (TSPP) can be noncovalently bound to tubulin and used as a photosensitizer, which upon irradiation triggers photochemical reactions that lead to conformational changes of the protein. These conformational changes in turn inhibit tubulin's primary function of polymerizing into microtubules. We explored the possibility of using two-photon excitation of the bound porphyrin to induce photosensitized protein unfolding. Although TSPP has a relatively low cross section (∼30 GM) our results did find that two-photon excitation of the ligand causes partial unfolding of the tubulin host and the inhibition of the in vitro formation of microtubules. Conversely, irradiating tubulin alone caused no such effects despite the large irradiance per pulse (97-190 GW/cm(2)). The conformational changes were characterized using spectroscopic studies and provide a promising protocol for the future application of non-native photosensitization of proteins. PMID:27035156

  16. 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

  17. 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. PMID:25313010

  18. Surface plasmon resonance study of the actin-myosin sarcomeric complex and tubulin dimers

    CERN Document Server

    Schüssler, H A; Kolomenskij, A A; Nanopoulos, Dimitri V; Schuessler, Hans A.; Mershin, Andreas; Kolomenskii, Alexander A.

    2003-01-01

    Biosensors based on the principle of surface plasmon resonance (SPR) detection were used to measure biomolecular interactions in sarcomeres and changes of the dielectric constant of tubulin samples with varying concentration. At SPR, photons of laser light efficiently excite surface plasmons propagating along a metal (gold) film. This resonance manifests itself as a sharp minimum in the reflection of the incident laser light and occurs at a characteristic angle. The dependence of the SPR angle on the dielectric permittivity of the sample medium adjacent to the gold film allows the monitoring of molecular interactions at the surface. We present results of measurements of cross-bridge attachment/detachment within intact mouse heart muscle sarcomeres and measurements on bovine tubulin molecules pertinent to cytoskeletal signal transduction models.

  19. On the Nature and Shape of Tubulin Trails: Implications on Microtubule Self-Organization

    CERN Document Server

    Glade, Nicolas

    2012-01-01

    Microtubules, major elements of the cell skeleton are, most of the time, well organized in vivo, but they can also show self-organizing behaviors in time and/or space in purified solutions in vitro. Theoretical studies and models based on the concepts of collective dynamics in complex systems, reaction-diffusion processes and emergent phenomena were proposed to explain some of these behaviors. In the particular case of microtubule spatial self-organization, it has been advanced that microtubules could behave like ants, self-organizing by 'talking to each other' by way of hypothetic (because never observed) concentrated chemical trails of tubulin that are expected to be released by their disassembling ends. Deterministic models based on this idea yielded indeed like-looking spatio-temporal self-organizing behaviors. Nevertheless the question remains of whether microscopic tubulin trails produced by individual or bundles of several microtubules are intense enough to allow microtubule self-organization at a macr...

  20. The Tubulin Binding Mode of Microtubule Stabilizing Agents Studied by Electron Crystallography

    Science.gov (United States)

    Nettles, James H.; Downing, Kenneth H.

    Since tubulin was discovered in 1967, drug probes have been used to manipulate mechanisms of microtubule polymerization and disassembly. In parallel, advances in optical imagery, electron microscopy, along with both electron and X-ray diffraction have provided ability to "see" the molecular underpinning of these machines. Nanoscale mapping of different tubulin polymers formed in the presence of different drugs and cofactors provide a context for examining the dynamic features relevant to their biological activity. Models built from EM maps have been used to understand the binding of stabilizing drugs such as taxanes and epothilones, to predict more effective molecules, and to explain mutation based resistance. Here, we discuss drug binding in the context of different polymeric forms and propose a trigger mechanism associated with microtubules' dynamic instability.

  1. Defective tubulin organization and proplatelet formation in murine megakaryocytes lacking Rac1 and Cdc42

    DEFF Research Database (Denmark)

    Pleines, Irina; Dütting, Sebastian; Cherpokova, Deya; Eckly, Anita; Meyer, Imke; Morowski, Martina; Krohne, Georg; Schulze, Harald; Gachet, Christian; Debili, Najet; Brakebusch, Cord Herbert; Nieswandt, Bernhard

    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...

  2. Tubulin-Targeting Chemotherapy Impairs Androgen Receptor Activity in Prostate Cancer

    OpenAIRE

    Zhu, Meng-Lei; Horbinski, Craig; Garzotto, Mark; Qian, David Z.; Beer, Tomasz M.; Kyprianou, Natasha

    2010-01-01

    Recent insights into the regulation of the androgen receptor (AR) activity led to novel therapeutic targeting of AR function in prostate cancer patients. Docetaxel is an approved chemotherapy for treatment of castration-resistant-prostate cancer (CRPC), but the mechanism underlying the action of this tubulin-targeting drug is not fully understood. This study investigates the contribution of microtubules and the cytoskeleton to androgen-mediated signaling, and the consequences of their inhibit...

  3. 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

  4. C239S Mutation in the β-Tubulin of Phytophthora sojae Confers Resistance to Zoxamide

    Science.gov (United States)

    Cai, Meng; Miao, Jianqiang; Song, Xi; Lin, Dong; Bi, Yang; Chen, Lei; Liu, Xili; Tyler, Brett M.

    2016-01-01

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

  5. Recovery of tubulin functions after freeze-drying in the presence of trehalose

    Czech Academy of Sciences Publication Activity Database

    Sulimenko, Vadym; Dráberová, Eduarda; Sulimenko, Tetyana; Böhm, K. J.; Dráber, Pavel

    San Diego: The American Society for Cell Biology, 2009. s. 32-32. [The American Society for Cell Biology, 49th Annual Meeting. 05.12.2009-09.12.2009, San Diego] R&D Projects: GA AV ČR KAN200520701; GA MŠk LC545 Institutional research plan: CEZ:AV0Z50520514 Keywords : tubulin * freeze - drying * cytoskleteon * stability Subject RIV: EB - Genetics ; Molecular Biology

  6. Selective Expression of β Tubulin Isotypes in Gerbil Vestibular Sensory Epithelia and Neurons

    OpenAIRE

    Perry, Brian; Jensen–Smith, Heather C.; Ludueña, Richard F.; Hallworth, Richard

    2003-01-01

    The seven mammalian isotypes of β tubulin are strikingly similar in amino acid sequence. The differences in isotypic sequence, although small, are nonetheless conserved in evolution, which suggests that they may confer distinct functional roles. If so, such roles should be reflected in the selective expression of isotypes by cell type, or even in the sorting of isotypes to within-cell pools. Hair cells of the vestibular sensory epithelia each possess a kinocilium, a microtubule-based organell...

  7. Arsenite-induced mitotic death involves stress response and is independent of tubulin polymerization

    International Nuclear Information System (INIS)

    Arsenite, a known mitotic disruptor, causes cell cycle arrest and cell death at anaphase. The mechanism causing mitotic arrest is highly disputed. We compared arsenite to the spindle poisons nocodazole and paclitaxel. Immunofluorescence analysis of α-tubulin in interphase cells demonstrated that, while nocodazole and paclitaxel disrupt microtubule polymerization through destabilization and hyperpolymerization, respectively, microtubules in arsenite-treated cells remain comparable to untreated cells even at supra-therapeutic concentrations. Immunofluorescence analysis of α-tubulin in mitotic cells showed spindle formation in arsenite- and paclitaxel-treated cells but not in nocodazole-treated cells. Spindle formation in arsenite-treated cells appeared irregular and multi-polar. γ-tubulin staining showed that cells treated with nocodazole and therapeutic concentrations of paclitaxel contained two centrosomes. In contrast, most arsenite-treated mitotic cells contained more than two centrosomes, similar to centrosome abnormalities induced by heat shock. Of the three drugs tested, only arsenite treatment increased expression of the inducible isoform of heat shock protein 70 (HSP70i). HSP70 and HSP90 proteins are intimately involved in centrosome regulation and mitotic spindle formation. HSP90 inhibitor 17-DMAG sensitized cells to arsenite treatment and increased arsenite-induced centrosome abnormalities. Combined treatment of 17-DMAG and arsenite resulted in a supra-additive effect on viability, mitotic arrest, and centrosome abnormalities. Thus, arsenite-induced abnormal centrosome amplification and subsequent mitotic arrest is independent of effects on tubulin polymerization and may be due to specific stresses that are protected against by HSP90 and HSP70

  8. Design, synthesis, and bioactivity of putative tubulin ligands with adamantane core.

    Science.gov (United States)

    Zefirova, Olga N; Nurieva, Evgeniya V; Lemcke, Heiko; Ivanov, Andrei A; Shishov, Dmitrii V; Weiss, Dieter G; Kuznetsov, Sergei A; Zefirov, Nikolay S

    2008-09-15

    Several adamantane-based taxol mimetics were synthesized and found to be cytotoxic at micromolar concentrations and to cause tubulin aggregation. The extent of the aggregation is maximal for N-benzoyl-(2R,3S)-phenylisoseryloxyadamantane (5) and is very sensitive to the structural modifications. A hybrid compound (15), combining adamantane-based taxol mimetic with colchicine was synthesized and found to possess both microtubule depolymerizing and microtubule bundling activities in A549 human lung carcinoma cells. PMID:18715782

  9. Gamma-Tubulin In chicken Erythrocytes: Changes in Locakalization During Cell Differentiation of Cytoplasmic Complexes

    Czech Academy of Sciences Publication Activity Database

    Linhartová, Irena; Novotná, Božena; Sulimenko, Vadym; Dráberová, Eduarda; Dráber, Pavel

    2002-01-01

    Roč. 223, - (2002), s. 229-240. ISSN 1058-8388 R&D Projects: GA AV ČR IAA5052701; GA ČR GA304/00/0553; GA MŠk LN00A026 Institutional research plan: CEZ:AV0Z5039906; CEZ:AV0Z5052915 Keywords : chick embryo * marginal band * gamma-tubulin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.804, year: 2002

  10. M233I Mutation in the β-Tubulin of Botrytis cinerea Confers Resistance to Zoxamide.

    Science.gov (United States)

    Cai, Meng; Lin, Dong; Chen, Lei; Bi, Yang; Xiao, Lu; Liu, Xi-li

    2015-01-01

    Three phenotypes were detected in 161 Botrytis cinerea field isolates, including Zox(S)Car(S) (sensitive to zoxamide and carbendazim), Zox(S)Car(R) (sensitive to zoxamide and resistant to carbendazim), and Zox(R)Car(R) (resistant to zoxamide and carbendazim), but not Zox(R)Car(S) (resistant to zoxamide and sensitive to carbendazim). The baseline sensitivity to zoxamide was determined with a mean EC50 of 0.76 μg/ml. Two stable Zox(R)Car(S) isolates were obtained with a resistance factor of 13.28 and 20.43; there was a fitness penalty in mycelial growth rate, sporulation, virulence and sclerotium production. The results suggest that the resistance risk of B. cinerea to zoxamide is low where benzimidazoles have not been used. E198V, E198K and M233I, were detected in the β-tubulin of Zox(S)Car(R), Zox(R)Car(R), Zox(R)Car(S), respectively. Molecular docking indicated that position 198 in β-tubulin were targets for both zoxamide and carbendazim. The mutations at 198 prevented formation of hydrogen bonds between β-tubulin and carbendazim (E198V/K), and changed the conformation of the binding pocket of zoxamide (E198K). M233I had no effect on the binding of carbendazim but resulted in loss of a hydrogen bond between zoxamide and F200. M233 is suggested to be a unique target site for zoxamide and be very important in the function of β tubulin. PMID:26596626

  11. Colchicine-induced polyploidization depends on tubulin polymerization in c-metaphase cells.

    Science.gov (United States)

    Caperta, A D; Delgado, M; Ressurreição, F; Meister, A; Jones, R N; Viegas, W; Houben, A

    2006-05-01

    The microtubule cytoskeleton plays a crucial role in the cell cycle and in mitosis. Colchicine is a microtubule-depolymerizing agent that has long been used to induce chromosome individualization in cells arrested at metaphase and also in the induction of polyploid plants. Although attempts have been made to explain the processes and mechanisms underlying polyploidy induction, the role of the cytoskeleton still remains largely unknown. Through immunodetection of alpha-tubulin, different concentrations (0.5 or 5 mM) of colchicine were found to produce opposite effects in the organization of the cytoskeleton in rye (Secale cereale L.). A low concentration (0.5 mM) induced depolymerization of the microtubular cytoskeleton in all phases of the cell cycle. In contrast, a high concentration (5 mM) was found to induce the polymerization of new tubulin-containing structures in c-metaphase cells. Furthermore, both treatments also showed contrasting effects in the induction of polyploid cells. Flow cytometric analysis and quantitative assessments of nucleolus-organizing regions revealed that only the high-concentration colchicine treatment was effective in the formation of polyploid cells. Our studies indicate that spindle disruption alone is insufficient for the induction of polyploid cells. The absence of any tubulin structures in plants treated with colchicine at the low concentration induced cell anomalies, such as the occurrence of nuclei with irregular shape and/or (additional) micronuclei, 12 h after recovery, pointing to a direct effect on cell viability. In contrast, the almost insignificant level of cell anomalies in the high-concentration treatment suggests that the presence of new tubulin-containing structures allows the reconstitution of 4C nuclei and their progression into the cell cycle. PMID:16520877

  12. Surface plasmon resonance study of the actin-myosin sarcomeric complex and tubulin dimers

    OpenAIRE

    Schuessler, Hans A.; Kolomenskii, Alexander A.; Mershin, Andreas; Nanopoulos, D. V.

    2003-01-01

    Biosensors based on the principle of surface plasmon resonance (SPR) detection were used to measure biomolecular interactions in sarcomeres and changes of the dielectric constant of tubulin samples with varying concentration. At SPR, photons of laser light efficiently excite surface plasmons propagating along a metal (gold) film. This resonance manifests itself as a sharp minimum in the reflection of the incident laser light and occurs at a characteristic angle. The dependence of the SPR angl...

  13. Theoretical studies on QSAR and mechanism of 2-indolinone derivatives as tubulin inhibitors

    Science.gov (United States)

    Liao, Si Yan; Qian, Li; Miao, Ti Fang; Lu, Hai Liang; Zheng, Kang Cheng

    The theoretical studies on three-dimensional quantitative structure activity relationship (3D-QSAR) and action mechanism of a series of 2-indolinone derivatives as tubulin inhibitors against human breast cancer cell line MDA-MB-231 have been carried out. The established 3D-QSAR model from the comparative molecular field analysis (CoMFA) shows not only significant statistical quality but also predictive ability, with high correlation coefficient (R2 = 0.986) and cross-validation coefficient (q2 = 0.683). In particular, the appropriate binding orientations and conformations of these 2-indolinone derivatives interacting with tubulin are located by docking study, and it is very interesting to find that the plot of the energy scores of these compounds in DOCK versus the corresponding experimental pIC50 values exhibits a considerable linear correlation. Therefore, the inhibition mechanism that 2-indolinone derivatives were regarded as tubulin inhibitors can be theoretically confirmed. Based on such an inhibition mechanism along with 3D-QSAR results, some important factors improving the activities of these compounds were discussed in detail. These factors can be summarized as follows: the H atom adopted as substituent R1, the substituent R2 with higher electropositivity and smaller bulk, the substituents R4-R6 (on the phenyl ring) with higher electropositivity and larger bulk, and so on. These results can offer useful theoretical references for understanding the action mechanism, designing more potent inhibitors, and predicting their activities prior to synthesis.

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

    Science.gov (United States)

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

    2015-10-28

    Microtubule targeting based therapies have revolutionized cancer treatment; however, resistance and side effects remain a major limitation. Therefore, novel strategies that can overcome these limitations are urgently needed. We made a novel discovery that fisetin, a hydroxyflavone, is a microtubule stabilizing agent. Fisetin binds to tubulin and stabilizes microtubules with binding characteristics far superior than paclitaxel. Surface plasmon resonance and computational docking studies suggested that fisetin binds to β-tubulin with superior affinity compared to paclitaxel. Fisetin treatment of human prostate cancer cells resulted in robust up-regulation of microtubule associated proteins (MAP)-2 and -4. In addition, fisetin treated cells were enriched in α-tubulin acetylation, an indication of stabilization of microtubules. Fisetin significantly inhibited PCa cell proliferation, migration, and invasion. Nudc, a protein associated with microtubule motor dynein/dynactin complex that regulates microtubule dynamics, was inhibited with fisetin treatment. Further, fisetin treatment of a P-glycoprotein overexpressing multidrug-resistant cancer cell line NCI/ADR-RES inhibited the viability and colony formation. Our results offer in vitro proof-of-concept for fisetin as a microtubule targeting agent. We suggest that fisetin could be developed as an adjuvant for treatment of prostate and other cancer types. PMID:26235140

  15. BETA-S, Multi-Group Beta-Ray Spectra

    International Nuclear Information System (INIS)

    1 - Description of program or function: BETA-S calculates beta-decay source terms and energy spectra in multigroup format for time-dependent radionuclide inventories of actinides, fission products, and activation products. Multigroup spectra may be calculated in any arbitrary energy-group structure. The code also calculates the total beta energy release rate from the sum of the average beta-ray energies as determined from the spectral distributions. BETA-S also provides users with an option to determine principal beta-decaying radionuclides contributing to each energy group. The CCC-545/SCALE 4.3 (or SCALE4.2) code system must be installed on the computer before installing BETA-S, which requires the SCALE subroutine library and nuclide-inventory generation from the ORIGEN-S code. 2 - Methods:Well-established models for beta-energy distributions are used to explicitly represent allowed, and 1., 2. - and 3. -forbidden transition types. Forbidden non-unique transitions are assumed to have a spectral shape of allowed transitions. The multigroup energy spectra are calculated by numerically integrating the energy distribution functions using an adaptive Simpson's Rule algorithm. Nuclide inventories are obtained from a binary interface produced by the ORIGEN-S code. BETA-S calculates the spectra for all isotopes on the binary interface that have associated beta-decay transition data in the ENSDF-95 library, developed for the BETA-S code. This library was generated from ENSDF data and contains 715 materials, representing approximately 8500 individual beta transition branches. 3 - Restrictions on the complexity of the problem: The algorithms do not treat positron decay transitions or internal conversion electrons. The neglect of positron transitions in inconsequential for most applications involving aggregate fission products, since most of the decay modes are via electrons. The neglect of internal conversion electrons may impact on the accuracy of the spectrum in the low

  16. No significant role for beta tubulin mutations and mismatch repair defects in ovarian cancer resistance to paclitaxel/cisplatin

    International Nuclear Information System (INIS)

    The mechanisms of chemoresistance in ovarian cancer patients remain largely to be elucidated. Paclitaxel/cisplatin combination is the standard chemotherapeutic treatment for this disease, although some patients do not respond to therapy. Our goals were to investigate whether TUBB mutations and mismatch repair defects underlie paclitaxel and cisplatin resistance. Thirty-four patients with primary ovarian carcinomas (26 serous and eight clear cell carcinomas) treated with paclitaxel/cisplatin were analysed. TUBB exon 4 was analysed by nested PCR after a first round PCR using intronic primers. Microsatellite analysis was performed with the quasimonomorphic markers BAT 26 and BAT 34. Twenty-two of the 34 ovarian cancers (64.7%) presented residual tumour after surgery, seven of which (7/22; 31.8%) were shown to be chemoresistant (five serous and two clear cell tumours). Sequence analysis did not find any mutation in TUBB exon 4. Microsatellite instability was not detected in any of the ovarian carcinomas. We conclude that TUBB exon 4 mutations and mismatch repair defects do not play a significant role in paclitaxel/cisplatin resistance

  17. β-tubulin mutations in ovarian cancer using single strand conformation analysis – risk of false positive results from paraffin embedded tissues

    OpenAIRE

    Green, Henrik; Rosenberg, Per; Söderkvist, Peter; Horvath, György; Peterson, Curt

    2006-01-01

    Mutations in the β-tubulin gene have been proposed as a resistance mechanism to paclitaxel. We therefore investigated the presence of mutations in the β-tubulin M40 gene in 40 ovarian tumours (16 paraffin-embedded and 24 freshly frozen) selected for good or poor response to chemotherapy with paclitaxel or non-tubulin-affecting regimens. The presence of mutations was investigated using single strand conformation analysis followed by sequencing of the products with altered mobility. No sequence...

  18. Class III β-tubulin overexpression within the tumor microenvironment is a prognostic biomarker for poor overall survival in ovarian cancer patients treated with neoadjuvant carboplatin/paclitaxel

    OpenAIRE

    Roque, Dana M; Buza, Natalia; Glasgow, Michelle; Bellone, Stefania; Bortolomai, Ileana; Gasparrini, Sara; Cocco, Emiliano; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Rutherford, Thomas J.; Schwartz, Peter E.; Alessandro D Santin

    2013-01-01

    Critics have suggested that neoadjuvant chemotherapy (NACT) followed by interval debulking may select for resistant clones or cancer stem cells when compared to primary cytoreduction. β-tubulins are chemotherapeutic targets of taxanes and epothilones. Class III β-tubulin overexpression has been linked to chemoresistance and hypoxia. Herein, we describe changes in class III β-tubulin in patients with advanced ovarian carcinoma in response to NACT, in relationship to clinical outcome, and betwe...

  19. Combined molecular dynamics and continuum solvent approaches (MM-PBSA/GBSA) to predict noscapinoid binding to γ-tubulin dimer.

    Science.gov (United States)

    Suri, C; Naik, P K

    2015-06-01

    γ-tubulin plays crucial role in the nucleation and organization of microtubules during cell division. Recent studies have also indicated its role in the regulation of microtubule dynamics at the plus end of the microtubules. Moreover, γ-tubulin has been found to be over-expressed in many cancer types, such as carcinomas of the breast and glioblastoma multiforme. These studies have led to immense interest in the identification of chemical leads that might interact with γ-tubulin and disrupt its function in order to explore γ-tubulin as potential chemotherapeutic target. Recently a colchicine-interacting cavity was identified at the interface of γ-tubulin dimer that might also interact with other similar compounds. In the same direction we theoretically investigated binding of a class of compounds, noscapinoids (noscapine and its derivatives) at the interface of the γ-tubulin dimer. Molecular interaction of noscapine and two of its derivatives, amino-noscapine and bromo-noscapine, was investigated by molecular docking, molecular dynamics simulation and binding free energy calculation. All noscapinoids displayed stable interaction throughout simulation of 25 ns. The predictive binding free energy (ΔGbind) indicates that noscapinoids bind strongly with the γ-tubulin dimer. However, bromo-noscapine showed the best binding affinity (ΔGbind = -37.6 kcal/mol) followed by noscapine (ΔGbind = -29.85 kcal/mol) and amino-noscapine (ΔGbind = -23.99 kcal/mol) using the MM-PBSA method. Similarly using the MM-GBSA method, bromo-noscapine showed highest binding affinity (ΔGbind = -43.64 kcal/mol) followed by amino-noscapine (ΔGbind = -37.56 kcal/mol) and noscapine (ΔGbind = -34.57 kcal/mol). The results thus generate compelling evidence that these noscapinoids may hold great potential for preclinical and clinical evaluation. PMID:26274780

  20. 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. PMID:26306046

  1. Inside the Brain: Unraveling the Mystery of Alzheimer's Disease

    Medline Plus

    Full Text Available ... is important for the brain to function well. Alzheimer's disease disrupts this intricate interplay. By compromising the ability ... of the brain changes that take place in Alzheimer's disease. Abnormal structures called beta amyloid plaques and neurofibrillary ...

  2. Inside the Brain: Unraveling the Mystery of Alzheimer's Disease

    Medline Plus

    Full Text Available ... is important for the brain to function well. Alzheimer's disease disrupts this intricate interplay. By compromising the ... of the brain changes that take place in Alzheimer's disease. Abnormal structures called beta amyloid plaques and ...

  3. Effect of treatment with interferon beta-1a on changes in voxel-wise magnetization transfer ratio in normal appearing brain tissue and lesions of patients with relapsing-remitting multiple sclerosis: a 24-week, controlled pilot study.

    Directory of Open Access Journals (Sweden)

    Robert Zivadinov

    Full Text Available This pilot study investigated changes in remyelinating and demyelinating activity in normal appearing brain tissue (NABT and lesions, by using voxel-wise magnetization transfer ratio (VW-MTR, in patients with relapsing-remitting multiple sclerosis (RRMS receiving interferon beta-1a 44 mcg subcutaneously (IFN β-1a SC three times weekly versus healthy controls (HCs (NCT01085318.Increasing (suggestive of remyelination and decreasing (suggestive of demyelination VW-MTR changes in NABT and in T2, T1 and gadolinium (Gd-enhancing lesion volume were measured over 24 weeks in 23 patients treated with IFN β-1a SC and in 15 HCs (where applicable. VW-MTR changes were tested using the Wilcoxon signed-rank or Wilcoxon rank-sum test.A trend for greater volume of NABT with increasing VW-MTR at 24 weeks was observed for patients versus HCs (median [range] 1206 [0-15278]; 342 [0-951] mm3; p = 0.061. NABT volume with increasing VW-MTR at 12 weeks was significantly greater in patients than in HCs (852 [6-11577]; 360 [0-1755] mm3; p = 0.028. Similar findings were detected for lesion volumes. Two patients with notably high numbers of Gd-enhancing lesions at baseline had a markedly greater volume of tissue with increasing VW-MTR compared with other patients. Volume of NABT tissue with decreasing VW-MTR was significantly greater in patients versus HCs at 24 weeks (942 [0-6141]; 297 [0-852] mm3; p<0.001.The significant change in NABT volume with increasing VW-MTR at 12 weeks suggests that active remyelination in patients with RRMS may occur during treatment with IFN β-1a SC. Findings from two patients with the highest number of Gd-enhancing lesions at baseline suggest that extensive remyelination in NABT may occur in patients with high disease activity. Tissue volume with decreasing VW-MTR was greater in patients than in HCs, despite treatment, validating the sensitivity of this technique for detecting MS disease activity.ClinicalTrials.gov NCT01085318.

  4. 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.

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

    NARCIS (Netherlands)

    Harkany, T; Hortobagyi, T; Sasvari, M; Konya, C; Penke, B; Luiten, PGM; Nyakas, C

    1999-01-01

    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 prot

  6. Synthesis and biological evaluation of quinoline analogues of flavones as potential anticancer agents and tubulin polymerization inhibitors.

    Science.gov (United States)

    Shobeiri, Nikta; Rashedi, Maryam; Mosaffa, Fatemeh; Zarghi, Afshin; Ghandadi, Morteza; Ghasemi, Ali; Ghodsi, Razieh

    2016-05-23

    A new series of 2-aryl-trimethoxyquinoline analogues was designed and synthesized as tubulin inhibitors using methoxylated flavones as the lead compounds. The cytotoxic activity of the synthesized compounds was evaluated against four human cancer cell lines including MCF-7, MCF-7/MX, A-2780, and A-2780/RCIS. All the alcoholic derivatives (6a-6e) showed significant cytotoxic activity with IC50 in the range of 7.98-60 μM. The flow cytometry analysis of the four human cancer cell lines treated with 6e and 5b showed that 6e induced cell cycle arrest at G2/M phase and apoptosis as well. The effect of quinolines on tubulin polymerization was also evaluated. Compound 6e that demonstrated the best antiproliferative activity in the series was identified as the most potent inhibitor of tubulin polymerization as well. Molecular docking studies of 6e into the colchicine-binding site of tubulin displayed possible mode of interaction between this compound and tubulin. PMID:26974371

  7. Discovery of a Series of Acridinones as Mechanism-Based Tubulin Assembly Inhibitors with Anticancer Activity

    Science.gov (United States)

    Magalhaes, Luma G.; Marques, Fernando B.; da Fonseca, Marina B.; Rogério, Kamilla R.; Graebin, Cedric S.; Andricopulo, Adriano D.

    2016-01-01

    Microtubules play critical roles in vital cell processes, including cell growth, division, and migration. Microtubule-targeting small molecules are chemotherapeutic agents that are widely used in the treatment of cancer. Many of these compounds are structurally complex natural products (e.g., paclitaxel, vinblastine, and vincristine) with multiple stereogenic centers. Because of the scarcity of their natural sources and the difficulty of their partial or total synthesis, as well as problems related to their bioavailability, toxicity, and resistance, there is an urgent need for novel microtubule binding agents that are effective for treating cancer but do not have these disadvantages. In the present work, our lead discovery effort toward less structurally complex synthetic compounds led to the discovery of a series of acridinones inspired by the structure of podophyllotoxin, a natural product with important microtubule assembly inhibitory activity, as novel mechanism-based tubulin assembly inhibitors with potent anticancer properties and low toxicity. The compounds were evaluated in vitro by wound healing assays employing the metastatic and triple negative breast cancer cell line MDA-MB-231. Four compounds with IC50 values between 0.294 and 1.7 μM were identified. These compounds showed selective cytotoxicity against MDA-MB-231 and DU-145 cancer cell lines and promoted cell cycle arrest in G2/M phase and apoptosis. Consistent with molecular modeling results, the acridinones inhibited tubulin assembly in in vitro polymerization assays with IC50 values between 0.9 and 13 μM. Their binding to the colchicine-binding site of tubulin was confirmed through competitive assays. PMID:27508497

  8. Antitumour potential of BPT: a dual inhibitor of cdk4 and tubulin polymerization.

    Science.gov (United States)

    Mahale, S; Bharate, S B; Manda, S; Joshi, P; Jenkins, P R; Vishwakarma, R A; Chaudhuri, B

    2015-01-01

    The marine natural product fascaplysin (1) is a potent Cdk4 (cyclin-dependent kinase 4)-specific inhibitor, but is toxic to all cell types possibly because of its DNA-intercalating properties. Through the design and synthesis of numerous fascaplysin analogues, we intended to identify inhibitors of cancer cell growth with good therapeutic window with respect to normal cells. Among various non-planar tryptoline analogues prepared, N-(biphenyl-2-yl) tryptoline (BPT, 6) was identified as a potent inhibitor of cancer cell growth and free from DNA-binding properties owing to its non-planar structure. This compound was tested in over 60 protein kinase assays. It displayed inhibition of Cdk4-cyclin D1 enzyme in vitro far more potently than many other kinases including Cdk family members. Although it blocks growth of cancer cells deficient in the mitotic-spindle checkpoint at the G0/G1 phase of the cell cycle, the block occurs primarily at the G2/M phase. BPT inhibits tubulin polymerization in vitro and acts as an enhancer of tubulin depolymerization of paclitaxel-stabilized tubulin in live cells. Western blot analyses indicated that, in p53-positive cells, BPT upregulates the expression of p53, p21 and p27 proteins, whereas it downregulates the expression of cyclin B1 and Cdk1. BPT selectively kills SV40-transformed mouse embryonic hepatic cells and human fibroblasts rather than untransformed cells. BPT inhibited the growth of several human cancer cells with an IC50anticancer agent than fascaplysin with an unusual ability to block two overlapping yet crucial phases of the cell cycle, mitosis and G0/G1. Its ability to effectively halt tumour growth in human tumour-bearing mice would suggest that BPT has the potential to be a candidate for further clinical development. PMID:25950473

  9. Discovery of a Series of Acridinones as Mechanism-Based Tubulin Assembly Inhibitors with Anticancer Activity.

    Science.gov (United States)

    Magalhaes, Luma G; Marques, Fernando B; da Fonseca, Marina B; Rogério, Kamilla R; Graebin, Cedric S; Andricopulo, Adriano D

    2016-01-01

    Microtubules play critical roles in vital cell processes, including cell growth, division, and migration. Microtubule-targeting small molecules are chemotherapeutic agents that are widely used in the treatment of cancer. Many of these compounds are structurally complex natural products (e.g., paclitaxel, vinblastine, and vincristine) with multiple stereogenic centers. Because of the scarcity of their natural sources and the difficulty of their partial or total synthesis, as well as problems related to their bioavailability, toxicity, and resistance, there is an urgent need for novel microtubule binding agents that are effective for treating cancer but do not have these disadvantages. In the present work, our lead discovery effort toward less structurally complex synthetic compounds led to the discovery of a series of acridinones inspired by the structure of podophyllotoxin, a natural product with important microtubule assembly inhibitory activity, as novel mechanism-based tubulin assembly inhibitors with potent anticancer properties and low toxicity. The compounds were evaluated in vitro by wound healing assays employing the metastatic and triple negative breast cancer cell line MDA-MB-231. Four compounds with IC50 values between 0.294 and 1.7 μM were identified. These compounds showed selective cytotoxicity against MDA-MB-231 and DU-145 cancer cell lines and promoted cell cycle arrest in G2/M phase and apoptosis. Consistent with molecular modeling results, the acridinones inhibited tubulin assembly in in vitro polymerization assays with IC50 values between 0.9 and 13 μM. Their binding to the colchicine-binding site of tubulin was confirmed through competitive assays. PMID:27508497

  10. 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. PMID:27023063

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

    Directory of Open Access Journals (Sweden)

    Puspendu Sardar

    Full Text Available BACKGROUND: 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. METHODOLOGY AND PRINCIPAL FINDINGS: 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. CONCLUSIONS AND SIGNIFICANCE: 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

  12. 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

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

    Czech Academy of Sciences Publication Activity Database

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

    2012-01-01

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

  14. γ-Tubulin 2 nucleates microtubules and is downregulated in mouse early embryogenesis

    Czech Academy of Sciences Publication Activity Database

    Vinopal, Stanislav; Černohorská, Markéta; Sulimenko, Vadym; Sulimenko, Tetyana; Vosecká, Věra; Flemr, Matyáš; Dráberová, Eduarda; Dráber, Pavel

    2012-01-01

    Roč. 7, č. 1 (2012), e29919. E-ISSN 1932-6203 R&D Projects: GA MŠk LC545; GA MŠk 1M0506; GA ČR(CZ) GD204/09/H084; GA ČR GA204/09/1777; GA AV ČR KAN200520701; GA ČR GAP302/10/1701 Institutional research plan: CEZ:AV0Z50520514 Keywords : γ-tubulin 2 * nucleation * embryogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.730, year: 2012

  15. 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

    Variations in the S100beta gene may be instrumental in producing a continuum from mild cognitive decline to overt dementia. After screening 25 single nucleotide polymorphisms (SNPs) in S100beta, we observed association of the rs2300403 intron 2 SNP with poorer cognitive function in three...... 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...

  16. 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

  17. New imidazoquinoxaline derivatives: Synthesis, biological evaluation on melanoma, effect on tubulin polymerization and structure-activity relationships.

    Science.gov (United States)

    Zghaib, Zahraa; Guichou, Jean-François; Vappiani, Johanna; Bec, Nicole; Hadj-Kaddour, Kamel; Vincent, Laure-Anaïs; Paniagua-Gayraud, Stéphanie; Larroque, Christian; Moarbess, Georges; Cuq, Pierre; Kassab, Issam; Deleuze-Masquéfa, Carine; Diab-Assaf, Mona; Bonnet, Pierre-Antoine

    2016-06-01

    Microtubules are considered as important targets of anticancer therapy. EAPB0503 and its structural imidazo[1,2-a]quinoxaline derivatives are major microtubule-interfering agents with potent anticancer activity. In this study, the synthesis of several new derivatives of EAPB0503 is described, and the anticancer efficacy of 13 novel derivatives on A375 human melanoma cell line is reported. All new compounds show significant antiproliferative activity with IC50 in the range of 0.077-122μM against human melanoma cell line (A375). Direct inhibition of tubulin polymerization assay in vitro is also assessed. Results show that compounds 6b, 6e, 6g, and EAPB0503 highly inhibit tubulin polymerization with percentages of inhibition of 99%, 98%, 90%, and 84% respectively. Structure-activity relationship studies within the series are also discussed in line with molecular docking studies into the colchicine-binding site of tubulin. PMID:27094151

  18. Brain Basics

    Medline Plus

    Full Text Available ... News 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 ...

  19. Brain Basics

    Science.gov (United States)

    ... News 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 ...

  20. 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 ...

  1. 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.

  2. Functional Role of Tia1/Pub1 and Sup35 Prion Domains: Directing Protein Synthesis Machinery to the Tubulin Cytoskeleton

    OpenAIRE

    Li, Xiang; Joseph B. Rayman; Kandel, Eric R.; Derkatch, Irina L.

    2014-01-01

    Tia1/Pub1 is a stress granule component carrying a Q/N-rich prion domain. We provide direct evidence that Tia1 forms a prion in yeast. Moreover, Tia1/Pub1 acts co-operatively with release factor Sup35/eRF3 to establish a two-protein self-propagating state. This two-protein prion driven by the Q/N-rich prion domains of Sup35 and Tia1/Pub1 can be visualized as distinctive line structures along tubulin cytoskeleton. Furthermore, we find that tubulin-associated complex containing Pub1 and Sup35 o...

  3. 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 ostatní: 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: 3.797, year: 2014

  4. Levered and unlevered Beta

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

  5. Chloroplast FtsZ assembles into a contractible ring via tubulin-like heteropolymerization.

    Science.gov (United States)

    Yoshida, Yamato; Mogi, Yuko; TerBush, Allan D; Osteryoung, Katherine W

    2016-01-01

    Chloroplast division is driven by a ring containing FtsZ1 and FtsZ2 proteins, which originated from bacterial FtsZ, a tubulin-like protein; however, mechanistic details of the chloroplast FtsZ ring remain unclear. Here, we report that FtsZ1 and FtsZ2 can heteropolymerize into a contractible ring ex vivo. Fluorescently labelled FtsZ1 and/or FtsZ2 formed single rings in cells of the yeast Pichia pastoris. Photobleaching experiments indicated that co-assembly of FtsZ1 and FtsZ2 imparts polarity to polymerization. Assembly of FtsZ chimaeras revealed that the protofilaments assemble via heteropolymerization of FtsZ2 and FtsZ1. Contraction of the ring was accompanied by an increase in the filament turnover rate. Our findings suggest that the evolutionary duplication of FtsZ in plants may have increased the mobility and kinetics of FtsZ ring dynamics in chloroplast division. Thus, the gene duplication and heteropolymerization of chloroplast FtsZs may represent convergent evolution with eukaryotic tubulin. PMID:27322658

  6. Specific expression of a β-tubulin gene (GhTub1) in developing cotton fibers

    Institute of Scientific and Technical Information of China (English)

    李园莉; 孙杰; 李春红; 朱勇清; 夏桂先

    2003-01-01

    A cDNA library was constructed using poly (A)+ RNA isolated from -1-15 DPA fibers of upland cotton (Gossypium hirsutum). The cDNA encoding a β-tubulin isoform (designated as GhTub1) was identified through EST search. Northern blot analysis using 3′-UTR of the cDNA as a gene-specific probe was performed to investigate the expression levels of GhTub1 in various organs and in the developing fibers. The results showed that GhTub1 gene was specifically expressed in cotton fiber cells. During fiber development, GhTub1 transcripts accumulated highlyat the stage of cell rapid elongation with the highest expression appearing at the time when fiber expansion reaches the peak rate. To probe the in vivo function of GhTub1, its cDNA was cloned in the yeast expression vector pREP1 and transformed into the fission yeast Schizosaccharomyces pombe. Overexpression of GhTub1 in yeast cells caused severe changes in the cell morphology. These results suggest that GhTub1 may play a role in the polar elongation of cotton fibers. To our knowledge, this is the first report on the fiber-specific transcript accumulation of a cotton β-tubulin gene.

  7. Expression, purification and crystallization of a human tau-tubulin kinase 2 that phosphorylates tau protein

    International Nuclear Information System (INIS)

    The kinase domain (residues 1–331) of human tau-tubulin kinase 2 was expressed in insect cells, purified and crystallized. Diffraction data have been collected to 2.9 Å resolution. Tau-tubulin kinase 2 (TTBK2) is a Ser/Thr kinase that putatively phosphorylates residues Ser208 and Ser210 (numbered according to a 441-residue human tau isoform) in tau protein. Functional analyses revealed that a recombinant kinase domain (residues 1–331) of human TTBK2 expressed in insect cells with a baculovirus overexpression system retains kinase activity for tau protein. The kinase domain of TTBK2 was crystallized using the hanging-drop vapour-diffusion method. The crystals belong to space group P212121, with unit-cell parameters a = 55.6, b = 113.7, c = 117.3 Å, α = β = γ = 90.0°. Diffraction data were collected to 2.9 Å resolution using synchrotron radiation at BL24XU of SPring-8

  8. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    .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...

  9. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward-...

  10. 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

  11. Class III β-tubulin overexpression within the tumor microenvironment is a prognostic biomarker for poor overall survival in ovarian cancer patients treated with neoadjuvant carboplatin/paclitaxel.

    Science.gov (United States)

    Roque, Dana M; Buza, Natalia; Glasgow, Michelle; Bellone, Stefania; Bortolomai, Ileana; Gasparrini, Sara; Cocco, Emiliano; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Rutherford, Thomas J; Schwartz, Peter E; Santin, Alessandro D

    2014-01-01

    Critics have suggested that neoadjuvant chemotherapy (NACT) followed by interval debulking may select for resistant clones or cancer stem cells when compared to primary cytoreduction. β-tubulins are chemotherapeutic targets of taxanes and epothilones. Class III β-tubulin overexpression has been linked to chemoresistance and hypoxia. Herein, we describe changes in class III β-tubulin in patients with advanced ovarian carcinoma in response to NACT, in relationship to clinical outcome, and between patients who underwent NACT versus primary debulking; we characterize in vitro chemosensitivity to paclitaxel/patupilone of cell lines established from this patient population, and class III β-tubulin expression following repeated exposure to paclitaxel. Using immunohistochemistry, we observed among 22 paired specimens obtained before/after NACT decreased expression of class III β-tubulin following therapy within stroma (p=0.07), but not tumor (p=0.63). Poor median overall survival was predicted by high levels of class III β-tubulin in both tumor (HR 3.66 [1.11,12.05], p=0.03) and stroma (HR 4.53 [1.28,16.1], p=0.02). Class III β-tubulin expression by quantitative-real-time-polymerase-chain-reaction was higher among patients who received NACT (n=12) compared to primary cytoreduction (n=14) (mean±SD fold-change: 491.2±115.9 vs. 224.1±55.66, p=0.037). In vitro subculture with paclitaxel resulted in class III β-tubulin upregulation, however, cell lines that overexpressed class III β-tubulin remained sensitive to patupilone. Overexpression of class III β-tubulin in patients dispositioned to NACT may thus identify an intrinsically aggressive phenotype, and predict poor overall survival and paclitaxel resistance. Decreases in stromal expression may represent normalization of the tumor microenvironment following therapy. Epothilones warrant study for patients who have received neoadjuvant carboplatin and paclitaxel. PMID:24005572

  12. 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 ...

  13. 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...

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

    Czech Academy of Sciences Publication Activity Database

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

    2006-01-01

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

  15. Brain Basics

    Medline Plus

    Full Text Available ... Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take pictures of the brain's structure, studies show that brain growth in children with autism ...

  16. X-ray fiber diffraction analysis shows dynamic changes in axial tubulin repeats in native microtubules depending on paclitaxel content, temperature and GTP-hydrolysis.

    Science.gov (United States)

    Kamimura, Shinji; Fujita, Yosuke; Wada, Yuuko; Yagi, Toshiki; Iwamoto, Hiroyuki

    2016-03-01

    Microtubules are key components of the cytoskeleton in eukaryotic cells. The dynamics between assembled microtubules and free tubulin dimers in the cytoplasm is closely related to the active shape changes of microtubule networks. One of the most fundamental questions is the association of microtubule dynamics with the molecular conformation of tubulin within microtubules. To address this issue, we applied a new technique for the rapid shear-flow alignment of biological filaments, enabling us to acquire the structural periodicity data of microtubules by X-ray fiber diffraction under various physiological conditions. We classified microtubules into three main groups on the basis of distinct axial tubulin periodicities and mean microtubule diameters that varied depending on GTP hydrolysis and the content of paclitaxel, a microtubule stabilizer. Paclitaxel induced rapid changes in tubulin axial repeats in a cooperative manner. This is the first demonstration of dynamic changes of axial tubulin repeats within native microtubules without fixation. We also found extraordinary features of negative thermal expansion of axial tubulin repeats in both paclitaxel-stabilized and GMPCPP-containing microtubules. Our results suggest that even in assembled microtubules, both GTP- and GDP-tubulin dimers can undergo dynamic conversion between at least two different states: short and long configurations. © 2016 Wiley Periodicals, Inc. PMID:26873786

  17. 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. PMID:1681420

  18. 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.

  19. 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...

  20. Combretastatin dinitrogen-substituted stilbene analogues as tubulin-binding and vascular-disrupting agents.

    Science.gov (United States)

    Siles, Rogelio; Ackley, J Freeland; Hadimani, Mallinath B; Hall, John J; Mugabe, Benon E; Guddneppanavar, Rajsekhar; Monk, Keith A; Chapuis, Jean-Charles; Pettit, George R; Chaplin, David J; Edvardsen, Klaus; Trawick, Mary Lynn; Garner, Charles M; Pinney, Kevin G

    2008-03-01

    Several stilbenoid compounds having structural similarity to the combretastatin group of natural products and characterized by the incorporation of two nitrogen-bearing groups (amine, nitro, serinamide) have been prepared by chemical synthesis and evaluated in terms of biochemical and biological activity. The 2',3'-diamino B-ring analogue 17 demonstrated remarkable cytotoxicity against selected human cancer cell lines in vitro (average GI 50 = 13.9 nM) and also showed good activity in regard to inhibition of tubulin assembly (IC 50 = 2.8 microM). In addition, a single dose (10 mg/kg) of compound 17 caused a 40% tumor-selective blood flow shutdown in tumor-bearing SCID mice at 24 h, thus suggesting the potential value of this compound and its corresponding salt formulations as new vascular-disrupting agents. PMID:18303849

  1. Tubulin and actin interplay at the T cell and Antigen-presenting cell interface

    Directory of Open Access Journals (Sweden)

    Noa B Martín-Cófreces

    2011-07-01

    Full Text Available T cells reorganize their actin and tubulin-based cytoskeletons to provide a physical basis to the immune synapse. However, growing evidence shows that their roles on T cell activation are more dynamic than merely serving as tracks or scaffold for different molecules. The cross-talk between both skeletons may be important for the formation and movement of the lamella at the IS by increasing the adhesion of the T cell to the APC, thus favoring the transport of components towards the plasma membrane and in turn regulating the T-APC intercellular communication. Microtubules and F-actin appear to be essential for the transport of the different signaling microclusters along the membrane, therefore facilitating the propagation of the signal. Finally, they can also be important for regulating the endocytosis, recycling and degradation of the TCR signaling machinery, thus helping both to sustain the activated state and to switch it off.

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

    Science.gov (United States)

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

    2016-03-01

    The effects of hexavalent chromium [Cr(VI)] on the cortical microtubules (MTs) of five species of the Fabaceae family (Vicia faba, Pisum sativum, Vigna sinensis, Vigna angularis, and Medicago sativa) were investigated by confocal laser scanning microscopy after immunolocalization of total tubulin with conventional immunofluorescence techniques and of acetylated α-tubulin with the specific 6-11B-1 monoclonal antibody. Moreover, total α-tubulin and acetylated α-tubulin were quantified by Western immunoblotting and scanning densitometry. Results showed the universality of Cr(VI) detrimental effects to cortical MTs, which proved to be a sensitive and reliable subcellular marker for monitoring Cr(VI) toxicity in plant cells. However, a species-specific response was recorded, and a correlation of MT disturbance with the acetylation status of α-tubulin was demonstrated. In V. faba, MTs were depolymerized at the gain of cytoplasmic tubulin background and displayed low α-tubulin acetylation, while in P. sativum, V. sinensis, V. angularis, and M. sativa, MTs became bundled and changed orientation from perpendicular to oblique or longitudinal. Bundled MTs were highly acetylated as determined by both immunofluorescence and Western immunoblotting. Tubulin acetylation in P. sativum and M. sativa preceded MT bundling; in V. sinensis it followed MT derangement, while in V. angularis the two phenomena coincided. Total α-tubulin remained constant in all treatments. Should acetylation be an indicator of MT stabilization, it is deduced that bundled MTs became stabilized, lost their dynamic properties, and were rendered inactive. Results of this report allow the conclusion that Cr(VI) toxicity disrupts MTs and deranges the MT-mediated functions either by depolymerizing or stabilizing them. PMID:26015161

  3. The adverse outcome pathway (AOP) for chemical binding to tubulin in oocytes leading to aneuploid offspring.

    Science.gov (United States)

    Marchetti, Francesco; Massarotti, Alberto; Yauk, Carole L; Pacchierotti, Francesca; Russo, Antonella

    2016-03-01

    The Organisation for Economic Co-operation and Development (OECD) has launched the Adverse Outcome Pathway (AOP) Programme to advance knowledge of pathways of toxicity and improve the use of mechanistic information in risk assessment. An AOP links a molecular initiating event (MIE) to an adverse outcome (AO) through intermediate key events (KE). Here, we present the scientific evidence in support of an AOP whereby chemicals that bind to tubulin cause microtubule depolymerization resulting in spindle disorganization followed by altered chromosome alignment and segregation and the generation of aneuploidy in female germ cells, ultimately leading to aneuploidy in the offspring. Aneuploidy, an abnormal number of chromosomes that is not an exact multiple of the haploid number, is a well-known cause of human disease and represents a major cause of infertility, pregnancy failure, and serious genetic disorders in the offspring. Among chemicals that induce aneuploidy in female germ cells, a large majority impairs microtubule dynamics and spindle function. Colchicine, a prototypical chemical that binds to tubulin and causes microtubule depolymerization, is used here to illustrate the AOP. This AOP is specific to female germ cells exposed during the periovulation period. Although the majority of the data come from rodent studies, the available evidence suggests that the MIE and KEs are conserved across species and would occur in human oocytes. The development of AOPs related to mutagenicity in germ cells is expected to aid the identification of potential hazards to germ cell genomic integrity and support regulatory efforts to protect population health. Environ. Mol. Mutagen. 57:87-113, 2016. © 2015 Her Majesty the Queen in Right of Canada. PMID:26581746

  4. Regulation of apoptosis and cell cycle in irradiated mouse brain

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Won Yong; Song, Mi Hee; Hung, Eun Ji; Seong, Jin Sil; Suh, Chang Ok [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2001-06-01

    To investigate the regulation of apoptosis and cell cycle in mouse brain irradiation. 8-week old male mice, C57B 1/6J were given whole body {gamma} -radiation with a single dose of 25 Gy using Cobalt 60 irradiator. At different times 1, 2, 4, 8 and 24hr after irradiation, mice were killed and brain tissues were collected. Apoptotic cells were scored by TUNEL assay. Expression of p53, Bcl-2, and Bax and cell cycle regulating molecules; cyclins BI, D1, E and cdk2, cdk4, p34{sup cdc2} were analysed by Western blotting. Cell cycle was analysed by flow cytometry. The peak of radiation induced apoptosis is shown at 8 hour after radiation. With a single 25 Gy irradiation, the peak of apoptotic index in C57B1/6J is 24.0{+-}0.25 (p<0.05) at 8 hour after radiation. Radiation upregulated the expression of p53/tubulin, Bax/tubulin, and Bcl-2/tubulin with 1.3, 1.1 and 1.45 fold increase, respectively were shown at the peak level at 8 hour after radiation. The levels of cell cycle regulating molecules after radiation are not changed significantly except cyclin D1 with 1.3 fold increase. Fractions of Go-G 1, G2-M and S phase in the cell cycle does not specific changes by time. In mouse brain tissue, radiation induced apoptosis is particularly shown in a specific area, subependyma. These results and lack of radiation induced changes in cell cycle offer better understanding of radiation response of normal brain tissue.

  5. Regulation of apoptosis and cell cycle in irradiated mouse brain

    International Nuclear Information System (INIS)

    To investigate the regulation of apoptosis and cell cycle in mouse brain irradiation. 8-week old male mice, C57B 1/6J were given whole body γ -radiation with a single dose of 25 Gy using Cobalt 60 irradiator. At different times 1, 2, 4, 8 and 24hr after irradiation, mice were killed and brain tissues were collected. Apoptotic cells were scored by TUNEL assay. Expression of p53, Bcl-2, and Bax and cell cycle regulating molecules; cyclins BI, D1, E and cdk2, cdk4, p34cdc2 were analysed by Western blotting. Cell cycle was analysed by flow cytometry. The peak of radiation induced apoptosis is shown at 8 hour after radiation. With a single 25 Gy irradiation, the peak of apoptotic index in C57B1/6J is 24.0±0.25 (p<0.05) at 8 hour after radiation. Radiation upregulated the expression of p53/tubulin, Bax/tubulin, and Bcl-2/tubulin with 1.3, 1.1 and 1.45 fold increase, respectively were shown at the peak level at 8 hour after radiation. The levels of cell cycle regulating molecules after radiation are not changed significantly except cyclin D1 with 1.3 fold increase. Fractions of Go-G 1, G2-M and S phase in the cell cycle does not specific changes by time. In mouse brain tissue, radiation induced apoptosis is particularly shown in a specific area, subependyma. These results and lack of radiation induced changes in cell cycle offer better understanding of radiation response of normal brain tissue

  6. 670 nm laser light and EGCG complementarily reduce amyloid-{beta} aggregates in human neuroblastoma cells: basis for treatment of Alzheimer's disease?

    OpenAIRE

    Sommer, A.P.; Bieschke, J.; Friedrich, R.P.; Zhu, D.; Wanker, E. E.; Fecht, H.J.; Mereles, D; Hunstein, W

    2012-01-01

    Objective: The aim of the present study is to present the results of in vitro experiments with possible relevance in the treatment of Alzheimer's disease (AD). Background Data: Despite intensive research efforts, there is no treatment for AD. One root cause of AD is the extra- and intracellular deposition of amyloid-beta (A{beta}) fibrils in the brain. Recently, it was shown that extracellular A{beta} can enter brain cells, resulting in neurotoxicity. Methods: After internalization of A{beta}...

  7. Koedam {beta} factors revisited

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, J.E. [Physics Department, University of Wisconsin, Madison, WI (United States); Doughty, D.A. [Perkin-Elmer Optoelectronics, Santa Clara, CA (United States); Lister, G.G. [OSRAM SYLVANIA Inc., Beverly, MA (United States)

    2002-07-21

    A Koedam {beta} factor makes it possible to compute the total output power in line radiation from a positive column discharge using a single radiance measurement normal to an aperture in the wall. The results of analytic derivations of {beta} factors are presented for columns with uniform ({beta}=1.0) and parabolic ({beta}=0.75) excitation rates per unit volume and with negligible opacity. A Monte Carlo code for simulating radiation trapping with a spatially uniform density of absorbing atoms is then used to determine {beta} factors as a function of opacity. The code includes partial frequency redistribution and a Voigt line shape with radiative broadening, resonance collisional broadening, and Doppler broadening. The resulting {beta} factors are found to be nearly independent of opacity over a wide range of column radii for spectral line shapes dominated by Doppler broadening or by resonance collisional broadening. Additional Monte Carlo simulations are used to study {beta} factors as a function of a non-uniform density of absorbing atoms from radial cataphoresis with line shapes dominated by Doppler broadening, foreign gas broadening, and resonance collisional broadening. Radial cataphoresis is found to increase {beta} factors in all cases. Geometrical effects, refraction, and imperfect transmission at the glass wall are studied and found to decrease {beta} factors. (author)

  8. Beta-energy averaging and beta spectra

    International Nuclear Information System (INIS)

    A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

  9. DFP initiated early alterations of PKA/p-CREB pathway and differential persistence of β-tubulin subtypes in the CNS of hens contributes to OPIDN

    International Nuclear Information System (INIS)

    changes in pCREB at time points studied. Similarly another set of animals were treated with DFP and perfused using standard protocols and immunohistochemistry for p-CREB in the brain and spinal cord confirmed the overall protein expression pattern identified by western analysis. Expression of β-tubulin subtypes (1, 2, 3, and 4), studied by Northern blotting showed complex and differential pattern, while immunohistochemistry of the anti-β-tubulin for the entire period of OPIDN developmental stages showed early induction and persistence even in the disintegrating axonal and non-neuronal structures of the CNS. These data thus strongly suggest that early cytoskeletal damage at molecular level mediated by PKA/p-CREB pathways leads to the culmination of gross (microscopically observable) level cytoskeletal changes in various components of central nervous system (CNS), consistent with our earlier findings. Thus, the differential protein expression of PKA, CREB, p-CREB and β-tubulin subtypes appear to contribute to the initiation, progression and development of OPIDN, probably by recruiting other molecular pathways specific to various components of nervous system.

  10. Alcohol-related brain damage in humans.

    Directory of Open Access Journals (Sweden)

    Amaia M Erdozain

    Full Text Available Chronic excessive alcohol intoxications evoke cumulative damage to tissues and organs. We examined prefrontal cortex (Brodmann's area (BA 9 from 20 human alcoholics and 20 age, gender, and postmortem delay matched control subjects. H & E staining and light microscopy of prefrontal cortex tissue revealed a reduction in the levels of cytoskeleton surrounding the nuclei of cortical and subcortical neurons, and a disruption of subcortical neuron patterning in alcoholic subjects. BA 9 tissue homogenisation and one dimensional polyacrylamide gel electrophoresis (PAGE proteomics of cytosolic proteins identified dramatic reductions in the protein levels of spectrin β II, and α- and β-tubulins in alcoholics, and these were validated and quantitated by Western blotting. We detected a significant increase in α-tubulin acetylation in alcoholics, a non-significant increase in isoaspartate protein damage, but a significant increase in protein isoaspartyl methyltransferase protein levels, the enzyme that triggers isoaspartate damage repair in vivo. There was also a significant reduction in proteasome activity in alcoholics. One dimensional PAGE of membrane-enriched fractions detected a reduction in β-spectrin protein levels, and a significant increase in transmembranous α3 (catalytic subunit of the Na+,K+-ATPase in alcoholic subjects. However, control subjects retained stable oligomeric forms of α-subunit that were diminished in alcoholics. In alcoholics, significant loss of cytosolic α- and β-tubulins were also seen in caudate nucleus, hippocampus and cerebellum, but to different levels, indicative of brain regional susceptibility to alcohol-related damage. Collectively, these protein changes provide a molecular basis for some of the neuronal and behavioural abnormalities attributed to alcoholics.

  11. Double beta decay experiments

    OpenAIRE

    Barabash, A. S.

    2011-01-01

    The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.

  12. Negative Beta Encoder

    CERN Document Server

    Kohda, Tohru; Aihara, Kazuyuki

    2008-01-01

    A new class of analog-digital (A/D), digital-analog (D/A) converters as an alternative to conventional ones, called $\\beta$-encoder, has been shown to have exponential accuracy in the bit rates while possessing self-correction property for fluctuations of amplifier factor $\\beta$ and quantizer threshold $\

  13. 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...

  14. 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.

  15. The level and distribution pattern of HP1 beta in the embryonic brain correspond to those of H3K9me1/me2 but not of H3K9me3

    Czech Academy of Sciences Publication Activity Database

    Bártová, Eva; Veceřa, J.; Krejčí, Jana; Legartová, Soňa; Pacherník, J.; Kozubek, Stanislav

    2016-01-01

    Roč. 145, č. 4 (2016), s. 447-461. ISSN 0948-6143 R&D Projects: GA ČR GA13-07822S; GA MŠk 7F14369 Institutional support: RVO:68081707 Keywords : Brain sections * Epigenetics * Histones Subject RIV: BO - Biophysics

  16. 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, or ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are metastatic, ...

  17. Brain Basics

    Medline Plus

    Full Text Available ... Basics will introduce you to some of this science, such as: How the brain develops How genes and the environment affect the brain The basic structure of the brain How different parts of the brain communicate and work with each other How changes in the brain ...

  18. 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 ...

  19. Brain Fingerprinting

    Directory of Open Access Journals (Sweden)

    ravi kumar

    2012-12-01

    Full Text Available Brain Fingerprinting is a scientific technique to determine whether or not specific information is stored in an individual's brain by measuring a electrical brain wave response to Word, phrases, or picture that are presented on computer screen. Brain Fingerprinting is a controversial forensic science technique that uses electroencephalograph y (EEG to determine whether specific information is stored in a subject's brain

  20. Rapid synthesis of beta zeolites

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Evaluation of the Tubulin-Bound Paclitaxel Conformation: Synthesis, Biology and SAR Studies of C-4 to C-3′ Bridged Paclitaxel Analogs

    OpenAIRE

    Ganesh, Thota; Yang, Chao; Norris, Andrew,; Glass, Tom; Bane, Susan; Ravindra, Rudravajhala; Banerjee, Abhijit; Metaferia, Belhu; Thomas, Shala L.; Giannakakou, Paraskevi; Alcaraz, Ana A.; Lakdawala, Ami S.; Snyder, James P.; Kingston, David G I

    2007-01-01

    The important anticancer drug paclitaxel binds to the β-subunit of the αβ-tubulin dimer in the microtubule in a stoichiometric ratio, promoting microtubule polymerization and stability. The conformation of microtubule-bound drug has been the subject of intense study, and various suggestions have been made for it. In previous work we presented experimental and theoretical evidence that paclitaxel adopts a T-shaped conformation when it is bound to tubulin. In this study we report additional exp...

  2. Design, synthesis, and biological evaluation of combretastatin nitrogen-containing derivatives as inhibitors of tubulin assembly and vascular disrupting agents.

    Science.gov (United States)

    Monk, Keith A; Siles, Rogelio; Hadimani, Mallinath B; Mugabe, Benon E; Ackley, J Freeland; Studerus, Scott W; Edvardsen, Klaus; Trawick, Mary Lynn; Garner, Charles M; Rhodes, Monte R; Pettit, George R; Pinney, Kevin G

    2006-05-01

    A series of analogs with nitro or serinamide substituents at the C-2'-, C-5'-, or C-6'-position of the combretastatin A-4 (CA4) B-ring was synthesized and evaluated for cytotoxic effects against heart endothelioma cells, blood flow reduction to tumors in SCID mice, and as inhibitors of tubulin polymerization. The synthesis of these analogs typically featured a Wittig reaction between a suitably functionalized arylaldehyde and an arylphosphonium salt followed by separation of the resultant E- and Z-isomers. Several of these nitrogen-modified CA4 derivatives (both amino and nitro) demonstrate significant inhibition of tubulin assembly as well as cytotoxicity and in vivo blood flow reduction. 2'-Aminostilbenoid 7 and 2'-amino-3'-hydroxystilbenoid 29 proved to be the most active in this series. Both compounds, 7 and 29, have the potential for further pro-drug modification and development as vascular disrupting agents for treatment of solid tumor cancers and certain ophthalmological diseases. PMID:16442292

  3. Microtubule-Destabilizing Agents: Structural and Mechanistic Insights from the Interaction of Colchicine and Vinblastine with Tubulin

    Science.gov (United States)

    Gigant, B.; Cormier, A.; Dorléans, A.; Ravelli, R. B. G.; Knossow, M.

    Microtubules (MTs) are dynamic structures of the eukaryotic cytoskeleton that, during cell division, form the mitotic spindle. Perturbing them leads to mitotic arrest and ultimately to cell death. Consistently, MTs and their building block, αβ tubulin, are one of the best characterized targets in anti-cancer chemotherapy. Drugs that interfere with MTs either stabilize or destabilize them. The latter class is the subject of this review. These ligands bind to the colchicine site or to the vinca domain, two distinct sites located at a distance from each other on tubulin. Nevertheless the effects of both classes of ligands share a common theme, they prevent the formation of MT specific contacts, therefore triggering their disassembly.

  4. Ferrocenyl 2,5-Piperazinediones as Tubulin-Binding Organometallic ABCB1 and ABCG2 Inhibitors Active against MDR Cells.

    Science.gov (United States)

    Wieczorek, Anna; Błauż, Andrzej; Zakrzewski, Janusz; Rychlik, Błażej; Plażuk, Damian

    2016-06-01

    The tubulin-microtubule system is a common target of many anticancer drugs. However, the use of chemotherapeutics frequently leads to the development of a clinically relevant phenomenon of multidrug resistance (MDR). One of the basic mechanisms involved in MDR involves elevated expression and/or activity of several ATP-binding cassette superfamily members (ABC transporters) which are normally responsible for the efflux of xenobiotics or secondary metabolites outside the cell. Here we present the synthesis and biological characteristics of ferrocenyl analogues of plinabulin, i.e. one of the so-called "spindle poisons". We found that replacement of the phenyl group of plinabulin by the ferrocenyl moiety turns this compound into a potent inhibitor of ABCB1 and ABCG2, thus making it possible to overcome the multidrug resistance phenomenon. We also demonstrated that the alkyl group attached to the imidazole moiety of ferrocenyl analogues of plinabulin strongly affects their potency to inhibit tubulin polymerization. PMID:27326336

  5. Pironetin Binds Covalently to αCys316 and Perturbs a Major Loop and Helix of α-Tubulin to Inhibit Microtubule Formation.

    Science.gov (United States)

    Prota, Andrea E; Setter, Jocelyn; Waight, Andrew B; Bargsten, Katja; Murga, Juan; Diaz, José Fernando; Steinmetz, Michel O

    2016-07-31

    Microtubule-targeting agents are among the most powerful drugs used in chemotherapy to treat cancer patients. Pironetin is a natural product that displays promising anticancer properties by binding to and potently inhibiting tubulin assembly into microtubules; however, its molecular mechanism of action remained obscure. Here, we solved the crystal structure of the tubulin-pironetin complex and found that the compound covalently binds to Cys316 of α-tubulin. The structure further revealed that pironetin perturbs the T7 loop and helix H8 of α-tubulin. Since both these elements are essential for establishing longitudinal tubulin contacts in microtubules, this result explains how pironetin inhibits the formation of microtubules. Together, our data define the molecular details of the pironetin binding site on α-tubulin and thus offer a promising basis for the rational design of pironetin variants with improved activity profiles. They further extend our knowledge on strategies evolved by natural products to target and perturb the microtubule cytoskeleton. PMID:27395016

  6. Distinct cerebrospinal fluid amyloid beta peptide signatures in sporadic and PSEN1 A431E-associated familial Alzheimer's disease

    OpenAIRE

    Portelius, Erik; Andreasson, Ulf; Ringman, John M.; Buerger, Katharina; Daborg, Jonny; Buchhave, Peder; Hansson, Oskar; Harmsen, Andreas; Gustavsson, Mikael K; Hanse, Eric; Galasko, Douglas; Hampel, Harald; Blennow, Kaj; Zetterberg, Henrik

    2010-01-01

    Background: Alzheimer's disease (AD) is associated with deposition of amyloid beta (A beta) in the brain, which is reflected by low concentration of the A beta 1-42 peptide in the cerebrospinal fluid (CSF). There are at least 15 additional A beta peptides in human CSF and their relative abundance pattern is thought to reflect the production and degradation of A beta. Here, we test the hypothesis that AD is characterized by a specific CSF A beta isoform pattern that is distinct when comparing ...

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

    Czech Academy of Sciences Publication Activity Database

    Kukharskyy, Vitaliy; Sulimenko, Vadym; Macůrek, Libor; Sulimenko, Tetyana; Dráberová, Eduarda; Dráber, Pavel

    2004-01-01

    Roč. 298, - (2004), s. 218-228. ISSN 0014-4827 R&D Projects: GA AV ČR IAA5052004; GA ČR GA304/00/0553; GA ČR GA304/04/1273; GA MŠk LN00A026 Keywords : gamma-tubulin * P19 cells * Fyn and Src kinase Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.007, year: 2004

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

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

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

  9. Assessing Whether Alpha-Tubulin Sequences Are Suitable for Phylogenetic Reconstruction of Ciliophora with Insights into Its Evolution in Euplotids

    OpenAIRE

    Yi, Zhenzhen; Katz, Laura A.; Song, Weibo

    2012-01-01

    The current understanding of ciliate phylogeny is mainly based on analyses of a single gene, the small subunit ribosomal RNA (SSU-rDNA). However, phylogenetic trees based on single gene sequence are not reliable estimators of species trees, and SSU-rDNA genealogies are not useful for resolution of some branches within Ciliophora. Since congruence between multiple loci is the best tool to determine evolutionary history, we assessed the usefulness of alpha-tubulin gene, a protein-coding gene th...

  10. Brain Basics

    Medline Plus

    Full Text Available ... The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are the basic working unit of the ... distant nerve cells (via axons) to form brain circuits. These circuits control specific body functions such as ...

  11. Brain Basics

    Medline Plus

    Full Text Available ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take pictures of the brain's structure, studies ...

  12. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... others live with symptoms of mental illness every day. They can be moderate, or serious and cause ...

  13. Brain Basics

    Medline Plus

    Full Text Available ... helps Sarah to better cope with her feelings. Brain Research Modern research tools and techniques are giving scientists ... the treatment for a person's specific conditions. Such brain research help increase the understanding of how the brain ...

  14. Brain Basics

    Medline Plus

    Full Text Available ... little dopamine or problems using dopamine in the thinking and feeling regions of the brain may play ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ...

  15. 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 ...

  16. 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, ...

  17. 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 ...

  18. Brain Basics

    Medline Plus

    Full Text Available ... Basics will introduce you to some of this science, such as: How the brain develops How genes and the environment affect the brain The basic structure of the brain How different parts of ...

  19. Brain Basics

    Medline Plus

    Full Text Available ... understanding of the brain than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take pictures ...

  20. 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 ...

  1. 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 ...

  2. The novel tubulin polymerization inhibitor MHPT exhibits selective anti-tumor activity against rhabdomyosarcoma in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Yan Mu

    Full Text Available The dose-limiting toxicity caused by standard chemotherapy has become a major roadblock to successful rhabdomyosarcoma chemotherapy. By screening a thiazolidinone library including 372 compounds, a novel synthetic compound, 2-((4-hydroxyphenylimino-5-(3-methoxybenzylidenethiazolidin-4-one (MHPT, was identified as a potent and selective anti-rhabdomyosarcoma agent. MHPT inhibited 50% of the growth of the rhabdomyosarcoma cell lines RD and SJ-RH30 at 0.44 μM and 1.35 μM, respectively, while displaying no obvious toxicity against normal human fibroblast cells at 100 μM. Further investigation revealed that MHPT suppressed the polymerization of tubulin, leading to rhabdomyosarcoma cell growth arrest at the G2/M phase followed by apoptosis. In vivo, MHPT inhibited tumor growth by 48.6% relative to the vehicle control after 5 intraperitoneal injections of 40 mg/kg without appreciable toxicity to normal tissues and systems in an RD xenograft mouse model, while vincristine caused lethal toxicity when similar growth inhibition was achieved. As a moderate tubulin polymerization inhibitor compared with vincristine, MHPT requires a more dynamic tubulin to exert its cytotoxicity, which is a situation that only exists in cancer cells. This attribute may account for the low toxicity of MHPT in normal cells. Our data suggest that MHPT has the potential to be further developed into a selective anti-rhabdomyosarcoma drug with low toxicity.

  3. Heat-shock protein 90 promotes nuclear transport of herpes simplex virus 1 capsid protein by interacting with acetylated tubulin.

    Science.gov (United States)

    Zhong, Meigong; Zheng, Kai; Chen, Maoyun; Xiang, Yangfei; Jin, Fujun; Ma, Kaiqi; Qiu, Xianxiu; Wang, Qiaoli; Peng, Tao; Kitazato, Kaio; Wang, Yifei

    2014-01-01

    Although it is known that inhibitors of heat shock protein 90 (Hsp90) can inhibit herpes simplex virus type 1 (HSV-1) infection, the role of Hsp90 in HSV-1 entry and the antiviral mechanisms of Hsp90 inhibitors remain unclear. In this study, we found that Hsp90 inhibitors have potent antiviral activity against standard or drug-resistant HSV-1 strains and viral gene and protein synthesis are inhibited in an early phase. More detailed studies demonstrated that Hsp90 is upregulated by virus entry and it interacts with virus. Hsp90 knockdown by siRNA or treatment with Hsp90 inhibitors significantly inhibited the nuclear transport of viral capsid protein (ICP5) at the early stage of HSV-1 infection. In contrast, overexpression of Hsp90 restored the nuclear transport that was prevented by the Hsp90 inhibitors, suggesting that Hsp90 is required for nuclear transport of viral capsid protein. Furthermore, HSV-1 infection enhanced acetylation of α-tubulin and Hsp90 interacted with the acetylated α-tubulin, which is suppressed by Hsp90 inhibition. These results demonstrate that Hsp90, by interacting with acetylated α-tubulin, plays a crucial role in viral capsid protein nuclear transport and may provide novel insight into the role of Hsp90 in HSV-1 infection and offer a promising strategy to overcome drug-resistance. PMID:24901434

  4. Functional Role of Tia1/Pub1 and Sup35 Prion Domains: Directing Protein Synthesis Machinery to the Tubulin Cytoskeleton

    Science.gov (United States)

    Li, Xiang; Rayman, Joseph B.; Kandel, Eric R; Derkatch, Irina L.

    2014-01-01

    SUMMARY Tia1/Pub1 is a stress granule component carrying a Q/N-rich prion domain. We provide direct evidence that Tia1 forms a prion in yeast. Moreover, Tia1/Pub1 acts co-operatively with release factor Sup35/eRF3 to establish a two-protein self-propagating state. This two-protein prion driven by the Q/N-rich prion domains of Sup35 and Tia1/Pub1 can be visualized as distinctive line structures along tubulin cytoskeleton. Furthermore, we find that tubulin-associated complex containing Pub1 and Sup35 oligomers normally exists in yeast, and its assembly depends on prion domains of Pub1 and Sup35. This Sup35/Pub1 complex, which also contains TUB1 mRNA and components of translation machinery, is important for the integrity of the tubulin cytoskeleton: PUB1 disruption and Sup35 depletion from the complex lead to cytoskeletal defects. We propose that the complex is implicated in protein synthesis at the site of microtubule assembly. Thus our study identifies the role for prion domains in the assembly of multi-protein complexes. PMID:24981173

  5. Synthesis and SAR requirements of adamantane-colchicine conjugates with both microtubule depolymerizing and tubulin clustering activities.

    Science.gov (United States)

    Zefirova, Olga N; Nurieva, Evgeniya V; Shishov, Dmitrii V; Baskin, Igor I; Fuchs, Fabian; Lemcke, Heiko; Schröder, Fabian; Weiss, Dieter G; Zefirov, Nikolay S; Kuznetsov, Sergei A

    2011-09-15

    A series of analogues of conjugate 1, combining an adamantane-based paclitaxel (taxol) mimetic with colchicine was synthesized and tested for cytotoxicity in a cell-based assay with the human lung carcinoma cell line A549. The most active compounds (10 EC(50) 2 ± 1.0 nM, 23 EC(50) 6 ± 1.4 nM, 26 EC(50) 5 ± 1.8 nM, 28 EC(50) 11 ± 1.7 nM, 30 EC(50) 4.8 ± 0.5 nM) were found to interfere with the microtubule dynamics in an interesting manner. Treatment of the cells with these compounds promoted disassembly of microtubules followed by the formation of stable tubulin clusters. Structure-activity relationships for the analogues of 23 revealed the sensitivity of both cytotoxicity and tubulin clustering ability to the linker length. The presence of adamantane (or another bulky hydrophobic and non-aromatic moiety) in 23 was found to play an important role in the formation of tubulin clusters. Structural requirements for optimal activity have been partially explained by molecular modeling. PMID:21873068

  6. C1, a highly potent novel curcumin derivative, binds to tubulin, disrupts microtubule network and induces apoptosis

    Science.gov (United States)

    Srivastava, Shalini; Mishra, Satyendra; Surolia, Avadhesha; Panda, Dulal

    2016-01-01

    We have synthesized a curcumin derivative, 4-{5-(4-hydroxy-3-methoxy-phenyl)-2-[3-(4-hydroxy-3-methoxy-phenyl)-acryloyl]-3-oxo-penta-1,4-dienyl}-piperidine-1-carboxylic acid tert-butyl ester (C1) that displays much stronger antiproliferative activity against various types of cancer cells including multidrug resistance cells than curcumin. C1 depolymerized both interphase and mitotic microtubules in MCF-7 cells and also inhibited the reassembly of microtubules in these cells. C1 inhibited the polymerization of purified tubulin, disrupted the lattice structure of microtubules and suppressed their GTPase activity in vitro. The compound bound to tubulin with a dissociation constant of 2.8±1 μM and perturbed the secondary structures of tubulin. Further, C1 treatment reduced the expression of Bcl2, increased the expression of Bax and down regulated the level of a key regulator of p53, murine double minute 2 (Mdm2) (S166), in MCF-7 cells. C1 appeared to induce p53 mediated apoptosis in MCF-7 cells. Interestingly, C1 showed more stability in aqueous buffer than curcumin. The results together showed that C1 perturbed microtubule network and inhibited cancer cells proliferation more efficiently than curcumin. The strong antiproliferative activity and improved stability of C1 indicated that the compound may have a potential as an anticancer agent. PMID:26980197

  7. Brain mapping

    OpenAIRE

    Blaž Koritnik

    2004-01-01

    Cartography of the brain ("brain mapping") aims to represent the complexities of the working brain in an understandable and usable way. There are four crucial steps in brain mapping: (1) acquiring data about brain structure and function, (2) transformation of data into a common reference, (3) visualization and interpretation of results, and (4) databasing and archiving. Electrophysiological and functional imaging methods provide information about function of the human brain. A prere...

  8. 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

    OpenAIRE

    Tucsek, Zsuzsanna; Toth, Peter; Sosnowska, Danuta; Gautam, Tripti; Mitschelen, Matthew; Koller, Akos; Szalai, Gabor; Sonntag, William E.; Ungvari, Zoltan; Csiszar, Anna

    2013-01-01

    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 inflamma...

  9. 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…

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

    International Nuclear Information System (INIS)

    Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-β endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I125 h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables

  11. Tubulin cofactor B regulates microtubule densities during microglia transition to the reactive states

    International Nuclear Information System (INIS)

    Microglia are highly dynamic cells of the CNS that continuously survey the welfare of the neural parenchyma and play key roles modulating neurogenesis and neuronal cell death. In response to injury or pathogen invasion parenchymal microglia transforms into a more active cell that proliferates, migrates and behaves as a macrophage. The acquisition of these extra skills implicates enormous modifications of the microtubule and actin cytoskeletons. Here we show that tubulin cofactor B (TBCB), which has been found to contribute to various aspects of microtubule dynamics in vivo, is also implicated in microglial cytoskeletal changes. We find that TBCB is upregulated in post-lesion reactive parenchymal microglia/macrophages, in interferon treated BV-2 microglial cells, and in neonate amoeboid microglia where the microtubule densities are remarkably low. Our data demonstrate that upon TBCB downregulation both, after microglia differentiation to the ramified phenotype in vivo and in vitro, or after TBCB gene silencing, microtubule densities are restored in these cells. Taken together these observations support the view that TBCB functions as a microtubule density regulator in microglia during activation, and provide an insight into the understanding of the complex mechanisms controlling microtubule reorganization during microglial transition between the amoeboid, ramified, and reactive phenotypes

  12. Beta-carotene

    Science.gov (United States)

    ... and deterioration of the lining of the mouth (oral mucositis). Taking beta-carotene by mouth doesn’t appear to prevent the development of oral mucositis during radiation therapy or chemotherapy. Pancreatic cancer. Taking ...

  13. Neutrinoless double beta decay

    International Nuclear Information System (INIS)

    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. (author)

  14. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    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.

  15. [High beta tokamak research

    International Nuclear Information System (INIS)

    Our activities on High Beta Tokamak Research during the past 20 months of the present grant period can be divided into six areas: reconstruction and modeling of high beta equilibria in HBT; measurement and analysis of MHD instabilities observed in HBT; measurements of impurity transport; diagnostic development on HBT; numerical parameterization of the second stability regime; and conceptual design and assembly of HBT-EP. Each of these is described in some detail in the sections of this progress report

  16. High beta multipoles

    International Nuclear Information System (INIS)

    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

  17. Autoregressive conditional beta

    OpenAIRE

    Yunmi Kim

    2012-01-01

    The capital asset pricing model provides various predictions about equilibrium expected returns on risky assets. One key prediction is that the risk premium on a risky asset is proportional to the nondiversifiable market risk measured by the asset's beta coefficient. This paper proposes a new method for estimating and drawing inferences from a time-varying capital asset pricing model. The proposed method, which can be considered a vector autoregressive model for multiple beta coefficients, is...

  18. Lactate fuels the human brain during exercise

    DEFF Research Database (Denmark)

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

    2008-01-01

    The human brain releases a small amount of lactate at rest, and even an increase in arterial blood lactate during anesthesia does not provoke a net cerebral lactate uptake. However, during cerebral activation associated with exercise involving a marked increase in plasma lactate, the brain takes up...... suggests that lactate may partially replace glucose as a substrate for oxidation. Thus, the notion of the human brain as an obligatory glucose consumer is not without exceptions....... 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...

  19. 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…

  20. Brain Basics

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    Full Text Available ... in Real Life Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video ... early brain development, and may also assist in learning and memory. ... rise to disabilities or diseases. neural circuit —A network of neurons ...

  1. Brain Basics

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    Full Text Available ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take pictures of the brain's structure, studies show that brain growth in children with autism appears to peak early. And as ...

  2. Brain Basics

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    Full Text Available ... Research Modern research tools and techniques are giving scientists a more detailed understanding of the brain than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take pictures of the brain's structure, studies ...

  3. Brain Basics

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    Full Text Available ... Welcome. Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... highly developed area at the front of the brain that, in humans, plays a role in executive functions such as ...

  4. A Single Amino-Acid Substitution at Lysine 40 of an Arabidopsis thaliana α-tubulin Causes Extensive Cell Proliferation and Expansion Defects

    Institute of Scientific and Technical Information of China (English)

    Xue Xiong; Deyang Xu; Zhongnan Yang; HaiHuang; Xiaofeng Cui

    2013-01-01

    Microtubules are highly dynamic cytoskeletal polymers of α/β-tubulin heterodimers that undergo multiple post-translational modifications essential for various cellular functions in eukaryotes.The lysine 40 (K40) is largely conserved in α-tubulins in many eukaryote species,and the post-translational modification by acetylation at K40 is critical for neuronal development in vertebrates.However,the biological function of K40 of α-tubulins in plants remains unexplored.In this study,we show in Arabidopsis thaliana that constitutive expression of mutated forms of α-tubulin6 (TUA6) at K40 (TUA6κ40A or TUA6κ40Q),in which K40 is replaced by alanine or glutamine,result in severely reduced plant size.Phenotypic characterization of the 35S:TUA6κ40A transgenic plants revealed that both cell proliferation and cell expansion were affected.Cytological and biochemical analyses showed that the accumulation ofα-and β-tubulin proteins was significantly reduced in the transgenic plants,and the cortical microtubule arrays were severely disrupted,indicating that K40 of the plant α-tubulin is critical in maintaining microtubule stability.We also constructed 35S:TUA6κ40R transgenic plants in which K40 of the engineered TUA6 protein is replaced by an arginine,and found that the 35S:TUA6K40R plants were phenotypically indistinguishable from the wild-type.Since lysine and arginine are similar in biochemical nature but arginine cannot be acetylated,these results suggest a structural importance for K40 of α-tubulins in cell division and expansion.

  5. Brain mapping

    Directory of Open Access Journals (Sweden)

    Blaž Koritnik

    2004-08-01

    Full Text Available Cartography of the brain ("brain mapping" aims to represent the complexities of the working brain in an understandable and usable way. There are four crucial steps in brain mapping: (1 acquiring data about brain structure and function, (2 transformation of data into a common reference, (3 visualization and interpretation of results, and (4 databasing and archiving. Electrophysiological and functional imaging methods provide information about function of the human brain. A prerequisite for multisubject, multidimensional and multimodal mapping is transformation of individual images to match a standard brain template. To produce brain maps, color, contours, and other visual cues are used to differentiate metabolic rates, electrical field potentials, receptor densities, and other attributes of structure or function. Databases are used to organize and archive data records. By relating the maps to cognitive functions and psychological models, brain mapping offers a prerequisite for the understanding of organizational principles of the human brain.

  6. Bone Marrow Stromal Cells Express Neural Phenotypes in vitro and Migrate in Brain After Transplantation in vivo

    Institute of Scientific and Technical Information of China (English)

    LI-YE YANG; TIAN-HUA HUANG; LIAN MA

    2006-01-01

    Objective To investigate the differentiation of bone marrow stromal cells (BMSC) into neuron-like cells and to explore their potential use for neural transplantation. Methods BMSC from rats and adult humans were cultured in serum-containing media. Salvia miltiorrhiza was used to induce human BMSC (hBMSC) to differentiate. BMSC were identified with immunocytochemistry. Semi-quantitative RT-PCR was used to examine mRNA expression of neurofilamentl (NF1), nestin and neuron-specific enolase (NSE) in rat BMSC (rBMSC). Rat BMSC labelled by Hoschst33258 were transplanted into striatum of rats to trace migration and distribution. Results BMSC expressed NSE, NF1 and nestin mRNA, and NF1 mRNA and expression was increased with induction of Salvia miltiorrhiza. A small number of hBMSC were stained by anti-nestin, anti-GFAP and anti-S100. Salvia miltiorrhiza could induce hBMSC to differentiate into neuron-like cells.Some differentiated neuron-like cells, that expressed NSE, beta-tubulin and NF-200, showed typical neuron morphology, but some neuron-like cells also expressed alpha smooth muscle protein, making their neuron identification complicated. rBMSC could migrate and adapted in the host brains after being transplanted. Conclusion Bone marrow stromal cells could express phenotypes of neurons, and Salvia miltiorrhiza could induce hBMSC to differentiate into neuron-like cells. If BMSC could be converted into neurons instead of mesenchymal derivatives, they would be an abundant and accessible cellular source to treat a variety of neurological diseases.

  7. Inside the Brain: Unraveling the Mystery of Alzheimer's Disease

    Medline Plus

    Full Text Available ... changes that take place in Alzheimer's disease. Abnormal structures called beta amyloid plaques and neurofibrillary tangles are ... is modified. In normal brain cells, tau stabilizes structures critical to the cell's internal transport system. Nutrients ...

  8. Dynamic and Static Water Molecules Complement the TN16 Conformational Heterogeneity inside the Tubulin Cavity.

    Science.gov (United States)

    Majumdar, Sarmistha; Maiti, Satyabrata; Ghosh Dastidar, Shubhra

    2016-01-19

    TN16 is one of the most promising inhibitors of α, β dimer of tubulin that occupies the cavity in the β-subunit located at the dimeric interface, known as the colchicine binding site. The experimentally determined structure of the complex (Protein Data Bank entry 3HKD) presents the conformation and position of the ligand based on the "best fit", keeping the controversy of other significant binding modes open for further investigation. Computation has already revealed that TN16 experiences fluctuations within the binding pocket, but the insight from that previous report was limited by the shorter windows of sampling and by the approximations on the surrounding environment by implicit solvation. This article reports that in most of the cases straightforward MMGBSA calculations of binding energy revealed a gradual loss of stabilization that was inconsistent with the structural observations, and thus, it indicated the lack of consideration of stabilizing factors with appropriate weightage. Consideration of the structurally packed water molecules in the space between the ligand and receptor successfully eliminated such discrepancies between the structure and stability, serving as the "litmus test" of the importance of explicit consideration of such structurally packed water in the calculations. Such consideration has further evidenced a quasi-degenerate character of the different binding modes of TN16 that has rationalized the observed intrinsic fluctuations of TN16 within the pocket, which is likely to be the most critical insight into its entropy-dominated binding. Quantum mechanical calculations have revealed a relay of electron density from TN16 to the protein via a water molecule in a concerted manner. PMID:26666704

  9. Interleukin-1 beta induced transient diabetes mellitus in rats. A model of the initial events in the pathogenesis of insulin-dependent diabetes mellitus?

    DEFF Research Database (Denmark)

    Reimers, J I

    1998-01-01

    initial events (Nerup et al 1994) (Fig. 1). In vitro rat experiments demonstrated that rhIL-1 beta inhibits beta cell function and induces beta cell death both in isolated islets of Langerhans and in the isolated perfused pancreatic gland. With the long term goal of identifying new modalities capable of...... induction of PGE2 in the brain or in peripheral tissues thereafter passing the blood-brain barrier. Nitric oxide produced by cNOS seems to be a molecular mediator of IL-1 beta induced fever but not of anorexia. Fever and anorexia are well described effects of IL-1 beta in rats, and are as such usefull...

  10. Expression of α-tubulin and β-tubulin at different stages in the course of breast carcinoma and its significance%α、β-微管蛋白在乳腺癌变不同阶段的表达及意义

    Institute of Scientific and Technical Information of China (English)

    应荣彪; 冯俊; 李建军; 瞿海江; 姚俊

    2011-01-01

    Background and purpose: Taxanes is one of the most important chemotherapeutic drugs in treating breast cancer. By promoting tubulin polymerization, it encourages apoptosis of breast tumor cells. However, resistance to taxanes makes it difficult for disease control. Therefore, it is important to reveal the expression level changes of α, β-tubulin in the breast cancer process. We studied the expression of α-tubulin and β-tubulin in breast atypical ductal hyperplasia(ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma(IDC) and its relationship in the development of breast cancer. Methods: Immunohistochemistry was used to examine the expression of α-tubulin and P-tubulin in 3 groups including ADH, DCIS and IDC with 30 cases in each group; 30 cases of normal breast tissues were selected as a control group. Results: a-tubulin and β-tubulin expression in normal breast tissues, ADH, DCIS and IDC showed a gradual increasing trend where the difference was statistically significant (P0.05), the differences of the vestige groups were statistically significant (P0.05),其余各组间差异均有统计学意义(P

  11. Double beta decay experiments

    International Nuclear Information System (INIS)

    The great sensitivity of double beta decay to neutrino mass and right handed currents has motivated many new and exciting attempts to observe this elusive nuclear phenomenon directly. Experiments in operation and other coming on line in the next one or two years are expected to result in order-of-magnitude improvements in detectable half lives for both the two-neutrino and no-neutrino modes. A brief history of double beta decay experiments is presented together with a discussion of current experimental efforts, including a gas filled time projection chamber being used to study selenium-82. (author)

  12. Plasma beta HCG determination

    International Nuclear Information System (INIS)

    There are three important indications for the early diagnosis of pregnancy through the determination of the beta sub-unit of chorionic gonadotrophin using radioimmunoassay: 1) some patient's or doctor's anxiety to discover the problem; 2) when it will be necessary to employ diagnostic or treatment procedures susceptible to affect the ovum; and 3) in the differential diagnosis of amenorrhoea, uterine hemorrhage and abdominal tumors. Other user's are the diagnosis of missed absortion, and the diagnosis and follow-up of chrorioncarcinoma. The AA. studied 200 determinations of plasma beta-HCG, considering the main difficulties occuring in the clinical use of this relevant laboratory tool in actual Obstetrics. (author)

  13. 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 that the...

  14. Genotypic analysis of β-tubulin in Onchocerca volvulus from communities and individuals showing poor parasitological response to ivermectin treatment.

    Science.gov (United States)

    Osei-Atweneboana, Mike Y; Boakye, Daniel A; Awadzi, Kwablah; Gyapong, John O; Prichard, Roger K

    2012-12-01

    Ivermectin (IVM) has been in operational use for the control of onchocerciasis for two decades and remains the only drug of choice. To investigate the parasitological responses and genetic profile of Onchocerca volvulus, we carried out a 21 month epidemiological study to determine the response of the parasite to IVM in 10 Ghanaian endemic communities. Onchocerca nodules were surgically removed from patients in three IVM response categories (good, intermediate and poor) and one IVM naïve community. DNA from adult worms was analyzed to determine any association between genotype and IVM response phenotypic. Embryogramme analysis showed significantly higher reproductive activity in worms from poor response communities, which had up to 41% of females with live stretched microfilaria (mf) in utero, despite IVM treatment, compared with good response communities, which had no intra-uterine stretched mf. β-tubulin isotype 1 gene has been shown to be linked to IVM selection in O. volvulus and also known to be associated with IVM resistance in veterinary nematodes. We have genotyped the full length genomic DNA sequence of the β-tubulin gene from 127 adult worms obtained from the four community categories. We found SNPs at 24 sites over the entire 3696 bp. Eight of the SNPs occurred at significantly higher (p < 0.05) frequencies in the poor response communities compared with the good response communities and the IVM naïve community. Phenotypic and genotypic analyses show that IVM resistance has been selected and the genotype (1183GG/1188CC/1308TT/1545GG) was strongly associated with the resistance phenotype. Since the region in the β-tubulin gene where these four SNPs occur is within 362 bp, it is feasible to develop a genetic marker for the early detection of IVM resistance. PMID:24533268

  15. Cardiac glycosides induce resistance to tubulin-dependent anticancer drugs in androgen-independent human prostate cancer.

    Science.gov (United States)

    Huang, Dong-Ming; Guh, Jih-Hwa; Huang, Yao-Ting; Chueh, Shih-Chieh; Wang, Hui-Po; Teng, Che-Ming

    2002-01-01

    Due to high prevalence and mortality and the lack of effective therapies, prostate cancer is one of the most crucial health problems in men. Drug resistance aggravates the situation, not only in human prostate cancer but also in other cancers. In this study, we report for the first time that cardiac glycosides (e.g. ouabain and digitoxin) induced resistance of human prostate cancer cells (PC-3) in vitro to tubulin-binding anticancer drugs, such as paclitaxel, colchicine, vincristine and vinblastine. Cardiac glycosides exhibited amazing ability to reverse the G2/M arrest of the cell cycle and cell apoptosis induced by tubulin-binding agents. However, neither ionomycin (a Ca(2+) ionophore) nor veratridine (a Na(+) ionophore) mimicked the preventive action of cardiac glycosides, indicating that elevation of the intracellular Ca(2+) concentration and Na(+) accumulation were not involved in the cardiac glycoside action. Furthermore, cardiac glycosides showed little influence on the effects induced by actinomycin D, anisomycin and doxorubicin, suggesting selectivity for microtubule-targeted anticancer drugs. Using in situ immunofluorescent detection of mitotic spindles, our data showed that cardiac glycosides diminished paclitaxel-induced accumulation of microtubule spindles; however, in a non-cell assay system, cardiac glycosides had little influence on colchicine- and paclitaxel-induced microtubule dynamics. Using an isotope-labeled assay method, we found that ouabain modestly but significantly inhibited the transport of [(14)C]paclitaxel from the cytosol into the nucleus. It is suggested that cardiac glycosides inhibit the G2/M arrest induced by tubulin-binding anticancer drugs via an indirect blockade on microtubule function. The decline in transport of these drugs into the nucleus may partly explain the action of cardiac glycosides. PMID:12218360

  16. Quantification of alpha-tubulin isotypes by sandwich ELISA with signal amplification through biotinyl-tyramide or immuno-PCR

    Czech Academy of Sciences Publication Activity Database

    Dráberová, Eduarda; Stegurová, Lucie; Sulimenko, Vadym; Hájková, Zuzana; Dráber, Petr; Dráber, Pavel

    2013-01-01

    Roč. 395, 1-2 (2013), s. 63-70. ISSN 0022-1759 R&D Projects: GA AV ČR KAN200520701; GA ČR GAP302/12/1673; GA ČR GPP302/11/P709; GA ČR GAP302/10/1759; GA ČR GA301/09/1826; GA MŠk(CZ) LD13015; GA MŠk LD12073 Institutional support: RVO:68378050 Keywords : alpha-tubulin isotypes * biotinyl-tyramide * ELISA * immuno-PCR * mast cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.005, year: 2013

  17. Positional Scanning Synthesis of a Peptoid Library Yields New Inducers of Apoptosis that Target Karyopherins and Tubulin.

    Science.gov (United States)

    Vendrell-Navarro, Glòria; Rúa, Federico; Bujons, Jordi; Brockmeyer, Andreas; Janning, Petra; Ziegler, Slava; Messeguer, Angel; Waldmann, Herbert

    2015-07-27

    We describe the synthesis of a library of 11, 638 N-alkylglycine peptoid trimers in a positional scanning format with adjustment of reaction conditions to account for different reactivities of the monomer building blocks. Evaluation of the library by high-content phenotypic screening for modulators of the cytoskeleton and mitosis resulted in the identification of two apoptosis-inducing peptoids, which, despite their structural similarity, target different proteins and cellular mechanisms. Whereas one peptoid binds to karyopherins, which mediate nuclear transport, the other N-alkylglycine trimer binds tubulin at the vinca alkaloid binding site. PMID:26010161

  18. Complexes of membrane-associated gamma-tubulin with Fyn kinase and phosphoinositide 3-kinase in differentiating cells

    Czech Academy of Sciences Publication Activity Database

    Sulimenko, Vadym; Macůrek, Libor; Dráberová, Eduarda; Richterová, Věra; Sulimenko, Tetyana; Dráberová, Lubica; Marková, Vladimíra; Dráber, Pavel

    2009-01-01

    Roč. 276, č. 1 (2009), s. 253-253. ISSN 1742-464X. [FEBS Congress /34/. 04.07.2009-09.07.2009, Praha] R&D Projects: GA MŠk 1M0506; GA MŠk LC545; GA ČR GA204/05/2375; GA ČR GA304/04/1273 Institutional research plan: CEZ:AV0Z50520514 Keywords : detergent-resistant membrane * Fyn * PI3K gamma-tubulin Subject RIV: EB - Genetics ; Molecular Biology

  19. Pharmacophore Modeling, Atom based 3D-QSAR and Docking Studies of Chalcone derivatives as Tubulin inhibitors

    OpenAIRE

    Naresh Kandakatla; Geetha Ramakrishnan; J. Karthikeyan; Rajasekhar Chekkara

    2014-01-01

    Tubulin is attractive target for anticancer drug design and their inhibitors are useful in treatment of various cancers. Pharmacophore and Atom based QSAR studies were carried out for series of Chalcone derivatives. Pharmacophore model was developed using 38 compounds, having pIC50 ranging 4.003 to 6.552. The best Pharmacophoric hypothesis AHHRR.10 (one H-acceptor, two hydrophobic groups, two aromatic rings) had survival score of 4.824. Atom based 3D QSAR was built for the best hypothesis w...

  20. Nano-ZnO leads to tubulin macrotube assembly and actin bundling, triggering cytoskeletal catastrophe and cell necrosis

    Science.gov (United States)

    García-Hevia, Lorena; Valiente, Rafael; Martín-Rodríguez, Rosa; Renero-Lecuna, Carlos; González, Jesús; Rodríguez-Fernández, Lidia; Aguado, Fernando; Villegas, Juan C.; Fanarraga, Mónica L.

    2016-05-01

    Zinc is a crucial element in biology that plays chief catalytic, structural and protein regulatory roles. Excess cytoplasmic zinc is toxic to cells so there are cell-entry and intracellular buffering mechanisms that control intracellular zinc availability. Tubulin and actin are two zinc-scavenging proteins that are essential components of the cellular cytoskeleton implicated in cell division, migration and cellular architecture maintenance. Here we demonstrate how exposure to different ZnO nanostructures, namely ZnO commercial nanoparticles and custom-made ZnO nanowires, produce acute cytotoxic effects in human keratinocytes (HaCat) and epithelial cells (HeLa) triggering a dose-dependent cell retraction and collapse. We show how engulfed ZnO nanoparticles dissolve intracellularly, triggering actin filament bundling and structural changes in microtubules, transforming these highly dynamic 25 nm diameter polymers into rigid macrotubes of tubulin, severely affecting cell proliferation and survival. Our results demonstrate that nano-ZnO causes acute cytoskeletal collapse that triggers necrosis, followed by a late reactive oxygen species (ROS)-dependent apoptotic process.Zinc is a crucial element in biology that plays chief catalytic, structural and protein regulatory roles. Excess cytoplasmic zinc is toxic to cells so there are cell-entry and intracellular buffering mechanisms that control intracellular zinc availability. Tubulin and actin are two zinc-scavenging proteins that are essential components of the cellular cytoskeleton implicated in cell division, migration and cellular architecture maintenance. Here we demonstrate how exposure to different ZnO nanostructures, namely ZnO commercial nanoparticles and custom-made ZnO nanowires, produce acute cytotoxic effects in human keratinocytes (HaCat) and epithelial cells (HeLa) triggering a dose-dependent cell retraction and collapse. We show how engulfed ZnO nanoparticles dissolve intracellularly, triggering actin

  1. Evaluation of neutrino masses from $m_{\\beta\\beta}$ values

    CERN Document Server

    Khrushchov, V V

    2008-01-01

    A neutrino mass matrix is considered under conditions of the CP invariance and the negligible reactor mixing $\\theta_{13}$ angle. Absolute mass values for three neutrinos are evaluated in normal and inverted hierarchy spectra on the ground of data for oscillation mixing neutrino parameters and effective neutrino mass entering into a probability of neutrinoless two beta decay $m_{\\beta\\beta}$ values.

  2. Brain Basics

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    Full Text Available ... the anatomy, physiology, and chemistry of the nervous system. When the brain cannot effectively coordinate the billions ... basic working unit of the brain and nervous system. These cells are highly specialized for the function ...

  3. Brain Basics

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    Full Text Available ... the brain cannot effectively coordinate the billions of cells in the body, the results can affect many ... unit of the brain and nervous system. These cells are highly specialized for the function of conducting ...

  4. Brain Basics

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    Full Text Available ... Neurons & Neural Circuits Neurons are the basic working unit of the brain and nervous system. These cells ... A nerve cell that is the basic, working unit of the brain and nervous system, which processes ...

  5. Brain Basics

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    Full Text Available ... Trials — Participants Statistics Help for Mental Illnesses Outreach Research Priorities Funding Labs at NIMH News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The ...

  6. Brain Basics

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    Full Text Available ... brain may play a role in disorders like schizophrenia or attention deficit hyperactivity disorder (ADHD) . Glutamate —the ... mental disorders, including autism , obsessive compulsive disorder (OCD) , schizophrenia , and depression . Brain Regions Just as many neurons ...

  7. Brain Basics

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    Full Text Available ... medical professionals who can diagnose mental disorders are psychologists or clinical social workers. The psychiatrist asked Sarah ... important research tool in understanding how the brain functions. Another type of brain scan called magnetoencephalography, or ...

  8. Brain Basics

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    Full Text Available ... normal brain development and function can go awry, leading to mental illnesses. Brain Basics will introduce you ... of DNA. Sometimes this copying process is imperfect, leading to a gene mutation that causes the gene ...

  9. Brain Basics

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    Full Text Available ... and epigenetic changes can be passed on to future generations. Further understanding of genes and epigenetics may ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ...

  10. Brain Basics

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    Full Text Available ... works in healthy people, and how normal brain development and function can go awry, leading to mental ... and are working to compare that with brain development in people mental disorders. Genes and environmental cues ...

  11. Brain Basics

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    Full Text Available ... 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 ...

  12. Brain Basics

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    Full Text Available ... problems using dopamine in the thinking and feeling regions of the brain may play a role in ... obsessive compulsive disorder (OCD) , schizophrenia , and depression . Brain Regions Just as many neurons working together form a ...

  13. Brain Basics

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    Full Text Available ... medications could reduce the amount of trial and error and frustration that many people with depression experience ... early brain development, and may also assist in learning and memory. hippocampus —A portion of the brain ...

  14. Brain Basics

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    Full Text Available ... Brain Basics will introduce you to some of this science, such as: How the brain develops How ... cell, and responds to signals from the environment; this all helps the cell maintain its balance with ...

  15. Brain Basics

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    Full Text Available ... Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle- ... However, recent research points to a possible new class of antidepressants that can relieve symptoms of the ...

  16. Brain Basics

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    Full Text Available ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ... depression experience when starting treatment. Gene Studies Advanced technologies are also making it faster, easier, and more ...

  17. Brain Basics

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    Full Text Available ... have been linked to many mental disorders, including autism , obsessive compulsive disorder (OCD) , schizophrenia , and depression . Brain ... studies show that brain growth in children with autism appears to peak early. And as they grow ...

  18. Brain Basics

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    Full Text Available ... 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 ...

  19. Brain Diseases

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    The brain is the control center of the body. It controls thoughts, memory, speech, and movement. It regulates the function of many organs. When the brain is healthy, it works quickly and automatically. However, ...

  20. Brain Basics

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    Full Text Available ... working unit of the brain and nervous system. These cells are highly specialized for the function of ... nerve cells (via axons) to form brain circuits. These circuits control specific body functions such as sleep ...

  1. Brain Basics

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    Full Text Available ... mainly involved in controlling movement and aiding the flow of information to the front of the brain, ... the neuron will fire. This enhances the electrical flow among brain cells required for normal function and ...

  2. Brain Basics

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    Full Text Available ... speech. The brain continues maturing well into a person's early 20s. Knowing how the brain is wired ... in Parkinson's disease, a disorder that affects a person's ability to move as they want to, resulting ...

  3. Brain Basics

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    Full Text Available ... of brain scan called magnetoencephalography, or MEG, can capture split-second changes in the brain. Using MEG, ... The study of how environmental factors like diet, stress and post-natal care can change gene expression ( ...

  4. Brain Basics

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    Full Text Available ... neurons, the most highly specialized cells of all, conduct messages. Every cell in our bodies contains a ... brain's structure, studies show that brain growth in children with autism appears to peak early. And as ...

  5. Brain Basics

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    Full Text Available ... can be related to changes in the anatomy, physiology, and chemistry of the nervous system. When the ... healthy people, and how normal brain development and function can go awry, leading to mental illnesses. Brain ...

  6. Brain Basics

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    Full Text Available ... Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a ... volunteers PubMed Central: An archive of life sciences journals NIH Research Fact Sheets NIH Office of Science ...

  7. Brain Basics

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    Full Text Available ... How the brain develops How genes and the environment affect the brain The basic structure of the ... inside contents of the cell from its surrounding environment and controls what enters and leaves the cell, ...

  8. Brain Basics

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    Full Text Available ... how the brain works, how mental illnesses are disorders of the brain, and ongoing research that helps us better understand and treat disorders. Mental disorders are common. You may have a ...

  9. Brain Basics

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    Full Text Available ... affect many aspects of life. Scientists are continually learning more about how the brain grows and works ... early brain development. It may also assist in learning and memory. Problems in making or using glutamate ...

  10. Brain Basics

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    Full Text Available ... all. She was happily married and successful in business. Then, after a serious setback at work, she ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ...

  11. Brain Basics

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    Full Text Available ... and the environment affect the brain The basic structure of the brain How different parts of the ... for the cell to work properly including small structures called cell organelles. Dendrites branch off from the ...

  12. Brain Basics

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    Full Text Available ... may help improve treatments for anxiety disorders like phobias or post-traumatic stress disorder (PTSD) . Prefrontal cortex ( ... brain's structure, studies show that brain growth in children with autism appears to peak early. And as ...

  13. Brain Basics

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    Full Text Available ... Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a ... blues" from time to time. In contrast, major depression is a serious disorder that lasts for weeks. ...

  14. Low-beta structures

    OpenAIRE

    M. Vretenar(CERN, Geneva, Switzerland)

    2012-01-01

    'Low-beta' radio-frequency accelerating structures are used in the sections of a linear accelerator where the velocity of the particle beam increases with energy. The requirement for space periodicity to match the increasing particle velocity led to the development of a large variety of structures, both normal and superconducting, which are described in this lecture.

  15. Applied Beta Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements.

  16. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross-section...

  17. Neutrinoless Double Beta Decay

    CERN Document Server

    Päs, Heinrich

    2015-01-01

    We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.

  18. Applied Beta Dosimetry

    International Nuclear Information System (INIS)

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements

  19. The progression and topographic distribution of interleukin-1beta expression after permanent middle cerebral artery occlusion in the rat.

    Science.gov (United States)

    Davies, C A; Loddick, S A; Toulmond, S; Stroemer, R P; Hunt, J; Rothwell, N J

    1999-01-01

    The cytokine interleukin-1 (IL-1) has been implicated in the exacerbation of ischemic damage in the brains of rodents. This study has ascertained the cellular localization and chronologic and topographic distribution of pro/mature interleukin-1beta (IL-1beta) protein 0.5, 1, 2, 6, 24, and 48 hours after ischemia by subjecting rats to permanent unilateral occlusion of the middle cerebral artery. Interleukin-1beta was localized immunocytochemically in vibratome sections of perfusion-fixed brains. The cells that expressed IL-1beta had the morphologic features of microglia and macrophages. Interleukin-1beta was first detected 1 hour after occlusion in ipsilateral meningeal macrophage-like cells. By 6 hours, pro/mature IL-1beta-immunoreactive (IL-1(beta)ir) putative microglia were present in the ischemic cerebral cortex, corpus callosum, caudoputamen, and surrounding tissue. By 24 and 48 hours after ischemia, the number and spread of IL-1(beta)ir cells increased greatly, including those resembling activated microglia and macrophages, as the core of the infarct became infiltrated. Interleukin-1(beta)ir cells also were present in apparently undamaged tissue, adjacent to the lesion ipsilaterally, and contralaterally in the cerebral cortex, dorsal corpus callosum, dorsal caudoputamen, and hippocampus. These results support the functional role of IL-1 in ischemic brain damage and reveal a distinct temporal and spatial expression of IL-1beta protein in cells believed to be microglia and macrophages. PMID:9886359

  20. Interferon Beta-1b Injection

    Science.gov (United States)

    Interferon beta-1b injection is used to reduce episodes of symptoms in patients with relapsing-remitting (course ... and problems with vision, speech, and bladder control). Interferon beta-1b is in a class of medications ...

  1. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... for Disease Control and Prevention Centre for Genetics Education (Australia) Cold Spring Harbor Laboratory: Your Genes Your Health Disease InfoSearch: Beta Thalassemia Genomics Education Programme (UK) MalaCards: dominant beta-thalassemia Merck Manual ...

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

    International Nuclear Information System (INIS)

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

  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 ... having trouble coping with the stresses in her life. She began to think of suicide because she ...

  4. Brain Basics

    Medline Plus

    Full Text Available ... Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle-aged woman ... new memories. hypothalmic-pituitary-adrenal (HPA) axis —A brain-body ... stress. impulse —An electrical communication signal sent between neurons ...

  5. Brain Aneurysm

    Science.gov (United States)

    A brain aneurysm is an abnormal bulge or "ballooning" in the wall of an artery in the brain. They are sometimes called berry aneurysms because they ... often the size of a small berry. Most brain aneurysms produce no symptoms until they become large, ...

  6. Brain Basics

    Medline Plus

    Full Text Available ... other cells guide neurons in forming various brain structures. Neighboring neurons make connections with each other and with distant nerve cells (via axons) to form brain circuits. These circuits control specific body functions such as sleep and speech. The brain continues ...

  7. 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

    animals such as mice and rats. In addition, we have recently shown that BACE1 protein is expressed by reactive astrocytes in close proximity to beta-amyloid plaques in the brains of aged transgenic Tg2576 mice that overexpress human amyloid precursor protein carrying the double mutation K670N-M671L. To...... address the question whether astrocytic BACE1 expression is an event specifically triggered by beta-amyloid plaques or whether glial cell activation by other mechanisms also induces BACE1 expression, we used six different experimental strategies to activate brain glial cells acutely or chronically. Brain...... 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....

  8. Survivin counteracts the therapeutic effect of microtubule de-stabilizers by stabilizing tubulin polymers

    Directory of Open Access Journals (Sweden)

    Hsieh Hsing-Pang

    2009-07-01

    stability of microtubules, but not with caspases inhibition. Over-expression of survivin counteracts the therapeutic effect of microtubule de-stabilizer BPR0L075 probably by stabilizing tubulin polymers, instead of the inhibition of caspase activity in cancer cells. Besides microtubule-related caspase-dependent cell death, caspase-independent mitotic cell death could be initiated in survivin/BPR0L075 combination treatments. We suggest that combining microtubule de-stabilizers with a survivin inhibitor may attribute to a better clinical outcome than the use of anti-mitotic monotherapy in clinical situations.

  9. Beta gets better with age

    OpenAIRE

    Tomunen, Tuomas

    2015-01-01

    The objective of my thesis is to study the cause for the low beta anomaly, which is an observation that the high beta stocks perform poorly relative to the low beta stocks. Based on earlier findings, I hypothesize that if a stock has high investor attention, its price overreacts to market-wide shocks, which results in a positive measurement error in its beta. Simultaneously, high attention causes overpricing, because the stock overreacts more often to positive shocks than to negat...

  10. Maintained activity of glycogen synthase kinase-3{beta} despite of its phosphorylation at serine-9 in okadaic acid-induced neurodegenerative model

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Yong-Whan [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Yoon, Seung-Yong, E-mail: ysy@amc.seoul.kr [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Choi, Jung-Eun [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Kim, Sang-Min [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Lee, Hui-Sun; Choe, Han [Department of Physiology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Lee, Seung-Chul [CrystalGenomics, Seoul (Korea, Republic of); Kim, Dong-Hou, E-mail: dhkim@amc.seoul.kr [Department of Anatomy and Cell Biology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute for Biomacromolecules, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2010-04-30

    Glycogen synthase kinase-3{beta} (GSK3{beta}) is recognized as one of major kinases to phosphorylate tau in Alzheimer's disease (AD), thus lots of AD drug discoveries target GSK3{beta}. However, the inactive form of GSK3{beta} which is phosphorylated at serine-9 is increased in AD brains. This is also inconsistent with phosphorylation status of other GSK3{beta} substrates, such as {beta}-catenin and collapsin response mediator protein-2 (CRMP2) since their phosphorylation is all increased in AD brains. Thus, we addressed this paradoxical condition of AD in rat neurons treated with okadaic acid (OA) which inhibits protein phosphatase-2A (PP2A) and induces tau hyperphosphorylation and cell death. Interestingly, OA also induces phosphorylation of GSK3{beta} at serine-9 and other substrates including tau, {beta}-catenin and CRMP2 like in AD brains. In this context, we observed that GSK3{beta} inhibitors such as lithium chloride and 6-bromoindirubin-3'-monoxime (6-BIO) reversed those phosphorylation events and protected neurons. These data suggest that GSK3{beta} may still have its kinase activity despite increase of its phosphorylation at serine-9 in AD brains at least in PP2A-compromised conditions and that GSK3{beta} inhibitors could be a valuable drug candidate in AD.

  11. Left Brain. Right Brain. Whole Brain

    Science.gov (United States)

    Farmer, Lesley S. J.

    2004-01-01

    As the United States student population is becoming more diverse, library media specialists need to find ways to address these distinctive needs. However, some of these differences transcend culture, touching on variations in the brain itself. Most people have a dominant side of the brain, which can affect their personality and learning style.…

  12. Misleading Betas: An Educational Example

    Science.gov (United States)

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  13. α-Lipoic acid promotes α-tubulin hyperacetylation and blocks the turnover of mitochondria through mitophagy.

    Science.gov (United States)

    Stoner, Michael W; Thapa, Dharendra; Zhang, Manling; Gibson, Gregory A; Calderon, Michael J; St Croix, Claudette M; Scott, Iain

    2016-06-15

    Lysine acetylation is tightly coupled to the nutritional status of the cell, as the availability of its cofactor, acetyl-CoA, fluctuates with changing metabolic conditions. Recent studies have demonstrated that acetyl-CoA levels act as an indicator of cellular nourishment, and increased abundance of this metabolite can block the induction of cellular recycling programmes. In the present study we investigated the cross-talk between mitochondrial metabolic pathways, acetylation and autophagy, using chemical inducers of mitochondrial acetyl-CoA production. Treatment of cells with α-lipoic acid (αLA), a cofactor of the pyruvate dehydrogenase complex, led to the unexpected hyperacetylation of α-tubulin in the cytosol. This acetylation was blocked by pharmacological inhibition of mitochondrial citrate export (a source for mitochondria-derived acetyl-CoA in the cytosol), was dependent on the α-tubulin acetyltransferase (αTAT) and was coupled to a loss in function of the cytosolic histone deacetylase, HDAC6. We further demonstrate that αLA slows the flux of substrates through autophagy-related pathways, and severely limits the ability of cells to remove depolarized mitochondria through PTEN-associated kinase 1 (PINK1)-mediated mitophagy. PMID:27099338

  14. Tracking the Biogenesis and Inheritance of Subpellicular Microtubule in Trypanosoma brucei with Inducible YFP-α-Tubulin

    Directory of Open Access Journals (Sweden)

    Omar Sheriff

    2014-01-01

    Full Text Available The microtubule cytoskeleton forms the most prominent structural system in Trypanosoma brucei, undergoing extensive modifications during the cell cycle. Visualization of tyrosinated microtubules leads to a semiconservative mode of inheritance, whereas recent studies employing microtubule plus end tracking proteins have hinted at an asymmetric pattern of cytoskeletal inheritance. To further the knowledge of microtubule synthesis and inheritance during T. brucei cell cycle, the dynamics of the microtubule cytoskeleton was visualized by inducible YFP-α-tubulin expression. During new flagellum/flagellum attachment zone (FAZ biogenesis and cell growth, YFP-α-tubulin was incorporated mainly between the old and new flagellum/FAZ complexes. Cytoskeletal modifications at the posterior end of the cells were observed with EB1, a microtubule plus end binding protein, particularly during mitosis. Additionally, the newly formed microtubules segregated asymmetrically, with the daughter cell inheriting the new flagellum/FAZ complex retaining most of the new microtubules. Together, our results suggest an intimate connection between new microtubule formation and new FAZ assembly, consequently leading to asymmetric microtubule inheritance and cell division.

  15. Characterization of tub4P287L, a b-tubulin mutant, revealed new aspects of microtubule regulation in shade

    Institute of Scientific and Technical Information of China (English)

    Jie Yu; Hong Qiu; Xin Liu; Meiling Wang; Yongli Gao; Joanne Chory; Yi Tao

    2015-01-01

    When sun plants, such as Arabidopsis thaliana, are under canopy shade, elongation of stems/petioles will be induced as one of the most prominent responses. Plant hormones mediate the elongation growth. However, how environmental and hormonal signals are translated into cell expansion activity that leads to the elongation growth remains elusive. Through forward genetic study, we identi-fied shade avoidance2 (sav2) mutant, which contains a P287L mutation in b-TUBULIN 4. Cortical microtubules (cMTs) play a key role in anisotropic cell growth. Hypocotyls of sav2 are wild type-like in white light, but are short and highly swollen in shade and dark. We showed that shade not only induces cMT rearrangement, but also affects cMT stability and dynamics of plus ends. Even though auxin and brassinosteroids are required for shade-induced hypocotyl elongation, they had little effect on shade-induced rearrangement of cMTs. Blocking auxin transport suppressed dark phenotypes of sav2, while overexpressing EB1b-GFP, a microtubule plus-end binding protein, rescued sav2 in both shade and dark, suggesting that tub4P287L represents a unique type of tubulin mutation that does not affect cMT function in supporting cell elongation, but may affect the ability of cMTs to respond properly to growth promoting stimuli.

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

    Directory of Open Access Journals (Sweden)

    CB Toaldo

    2001-01-01

    Full Text Available The molecular karyotype of nine Trypanosoma rangeli strains was analyzed by contour-clamped homogeneous electric field electrophoresis, followed by the chromosomal localization of ß-tubulin, cysteine proteinase, 70 kDa heat shock protein (hsp 70 and actin genes. The T. rangeli strains were isolated from either insects or mammals from El Salvador, Honduras, Venezuela, Colombia, Panama and southern Brazil. Also, T. cruzi CL-Brener clone was included for comparison. Despite the great similarity observed among strains from Brazil, the molecular karyotype of all T. rangeli strains analyzed revealed extensive chromosome polymorphism. In addition, it was possible to distinguish T. rangeli from T. cruzi by the chromosomal DNA electrophoresis pattern. The localization of ß-tubulin genes revealed differences among T. rangeli strains and confirmed the similarity between the isolates from Brazil. Hybridization assays using probes directed to the cysteine proteinase, hsp 70 and actin genes discriminated T. rangeli from T. cruzi, proving that these genes are useful molecular markers for the differential diagnosis between these two species. Numerical analysis based on the molecular karyotype data revealed a high degree of polymorphism among T. rangeli strains isolated from southern Brazil and strains isolated from Central and the northern South America. The T. cruzi reference strain was not clustered with any T. rangeli strain.

  17. Stable and predictive functional domain selection with application to brain images

    OpenAIRE

    Park, Ah Yeon; Aston, John A. D.; Ferraty, Frederic

    2016-01-01

    Motivated by increasing trends of relating brain images to a clinical outcome of interest, we propose a functional domain selection (FuDoS) method that effectively selects subregions of the brain associated with the outcome. View each individual's brain as a 3D functional object, the statistical aim is to distinguish the region where a regression coefficient $\\beta(t)=0$ from $\\beta(t)\

  18. Molecular biology of the mammalian brain

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Ji Dar-Der

    2008-06-01

    Full Text Available Abstract Background Because the outcomes and sequelae after different types of brain injury (BI are variable and difficult to predict, investigations on whether enhanced expressions of BI-associated biomarkers (BIABs, including transforming growth factor β1 (TGF-β1, S100B, glial fibrillary acidic protein (GFAP, neurofilament light chain (NF-L, tissue transglutaminases (tTGs, β-amyloid precursor proteins (AβPP, and tau are present as well as whether impairment of the ubiquitin-proteasome system (UPS is present have been widely used to help delineate pathophysiological mechanisms in various BIs. Larvae of Toxocara canis can invade the brain and cause BI in humans and mice, leading to cerebral toxocariasis (CT. Because the parasitic burden is light in CT, it may be too cryptic to be detected in humans, making it difficult to clearly understand the pathogenesis of subtle BI in CT. Since the pathogenesis of murine toxocariasis is very similar to that in humans, it appears appropriate to use a murine model to investigate the pathogenesis of CT. Methods BIAB expressions and UPS function in the brains of mice inoculated with a single dose of 250 T. canis embryonated eggs was investigated from 3 days (dpi to 8 weeks post-infection (wpi by Western blotting and RT-PCR. Results Results revealed that at 4 and 8 wpi, T. canis larvae were found to have invaded areas around the choroid plexus but without eliciting leukocyte infiltration in brains of infected mice; nevertheless, astrogliosis, an indicator of BI, with 78.9~142.0-fold increases in GFAP expression was present. Meanwhile, markedly increased levels of other BIAB proteins including TGF-β1, S100B, NF-L, tTG, AβPP, and tau, with increases ranging 2.0~12.0-fold were found, although their corresponding mRNA expressions were not found to be present at 8 wpi. Concomitantly, UPS impairment was evidenced by the overexpression of conjugated ubiquitin and ubiquitin in the brain. Conclusion Further studies

  20. Immunohistochemical demonstration of specific antigens in the human brain fixed in zinc-ethanol-formaldehyde.

    Science.gov (United States)

    Korzhevskii, D E; Sukhorukova, E G; Kirik, O V; Grigorev, I P

    2015-01-01

    Tissue fixation is critical for immunohistochemistry. Recently, we developed a zinc-ethanol-formalin fixative (ZEF), and the present study was aimed to assess the applicability of the ZEF for the human brain histology and immunohistochemistry and to evaluate the detectability of different antigens in the human brain fixed with ZEF. In total, 11 antigens were tested, including NeuN, neuron-specific enolase, GFAP, Iba-1, calbindin, calretinin, choline acetyltransferase, glutamic acid decarboxylase (GAD65), tyrosine hydroxylase, synaptophysin, and α-tubulin. The obtained data show that: i) the ZEF has potential for use in general histological practice, where detailed characterization of human brain morphology is needed; ii) the antigens tested are well-preserved in the human brain specimens fixed in the ZEF. PMID:26428887

  1. Immunohistochemical demonstration of specific antigens in the human brain fixed in zinc-ethanol-formaldehyde

    Directory of Open Access Journals (Sweden)

    D.E. Korzhevskii

    2015-08-01

    Full Text Available Tissue fixation is critical for immunohistochemistry. Recently, we developed a zinc-ethanol-formalin fixative (ZEF, and the present study was aimed to assess the applicability of the ZEF for the human brain histology and immunohistochemistry and to evaluate the detectability of different antigens in the human brain fixed with ZEF. In total, 11 antigens were tested, including NeuN, neuron-specific enolase, GFAP, Iba-1, calbindin, calretinin, choline acetyltransferase, glutamic acid decarboxylase (GAD65, tyrosine hydroxylase, synaptophysin, and α-tubulin. The obtained data show that: i the ZEF has potential for use in general histological practice, where detailed characterization of human brain morphology is needed; ii the antigens tested are well-preserved in the human brain specimens fixed in the ZEF.

  2. 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

  3. Beta and muon decays

    International Nuclear Information System (INIS)

    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)

  4. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

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

    2004-01-01

    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...... 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 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...

  5. 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....

  6. Beta decay for pedestrians

    CERN Document Server

    Lipkin, Harry Jeannot

    1962-01-01

    The ""pedestrian approach"" was developed to describe some essentially simple experimental results and their theoretical implications in plain language. In this graduate-level text, Harry J. Lipkin presents simply, but without oversimplification, the aspects of beta decay that can be understood without reference to the formal theory; that is, the reactions that follow directly from conservation laws and elementary quantum mechanics.The pedestrian treatment is neither a substitute for a complete treatment nor a watered-down version.

  7. Specific recognition of the C-terminal end of A beta 42 by a high affinity monoclonal antibody

    DEFF Research Database (Denmark)

    Axelsen, T.V.; Holm, A.; Birkelund, S.;

    2009-01-01

    The neurotoxic peptide A beta(42) is derived from the amyloid precursor protein by proteolytic cleavage and is deposited in the brain of patients suffering from Alzheimer's disease (AD). In this study we generate a high affinity monoclonal antibody that targets the C-terminal end of A beta(42) with...

  8. Analysis of Claviceps africana and C. sorghi from India using AFLPs, EF-1alfa gene intron 4, and Beta-tubulin gene intron 3

    Czech Academy of Sciences Publication Activity Database

    Tooley, P. W.; Bandyopadhyay, R.; Carras, M. M.; Pažoutová, Sylvie

    2006-01-01

    Roč. 101, č. 4 (2006), s. 441-451. ISSN 0953-7562 Institutional research plan: CEZ:AV0Z50200510 Keywords : clavicipitaceae * coevolution * ergot Subject RIV: EE - Microbiology, Virology Impact factor: 1.860, year: 2006

  9. Beta-tubulin paralogue tubC is frequently misidentified as the benA gene in Aspergillus section Nigri taxonomy: primer specificity testing ad taxonomic consequences

    Czech Academy of Sciences Publication Activity Database

    Hubka, Vít; Kolařík, Miroslav

    2012-01-01

    Roč. 29, DEC 2012 (2012), s. 1-10. ISSN 0031-5850 Institutional research plan: CEZ:AV0Z50200510 Keywords : biseriate black aspergilli * codon usage * gene duplication Subject RIV: EE - Microbiology, Virology Impact factor: 3.486, year: 2012

  10. Peptide hormone exendin-4 stimulates subventricular zone neurogenesis in the adult rodent brain and induces recovery in an animal model of Parkinson's disease.

    Science.gov (United States)

    Bertilsson, Göran; Patrone, Cesare; Zachrisson, Olof; Andersson, Annica; Dannaeus, Karin; Heidrich, Jessica; Kortesmaa, Jarkko; Mercer, Alex; Nielsen, Elisabet; Rönnholm, Harriet; Wikström, Lilian

    2008-02-01

    We investigated the effects of exendin-4 on neural stem/progenitor cells in the subventricular zone of the adult rodent brain and its functional effects in an animal model of Parkinson's disease. Our results showed expression of GLP-1 receptor mRNA or protein in the subventricular zone and cultured neural stem/progenitor cells isolated from this region. In vitro, exendin-4 increased the number of neural stem/progenitor cells, and the number of cells expressing the neuronal markers microtubule-associated protein 2, beta-III-tubulin, and neuron-specific enolase. When exendin-4 was given intraperitoneally to naïve rodents together with bromodeoxyuridine, a marker for DNA synthesis, both the number of bromodeoxyuridine-positive cells and the number of neuronal precursor cells expressing doublecortin were increased. Exendin-4 was tested in the 6-hydroxydopamine model of Parkinson's disease to investigate its possible functional effects in an animal model with neuronal loss. After unilateral lesion and a 5-week stabilization period, the rats were treated for 3 weeks with exendin-4. We found a reduction of amphetamine-induced rotations in animals receiving exendin-4 that persisted for several weeks after drug administration had been terminated. Histological analysis showed that exendin-4 significantly increased the number of both tyrosine hydroxylase- and vesicular monoamine transporter 2-positive neurons in the substantia nigra. In conclusion, our results show that exendin-4 is able to promote adult neurogenesis in vitro and in vivo, normalize dopamine imbalance, and increase the number of cells positive for markers of dopaminergic neurons in the substantia nigra in a model of Parkinson's disease. PMID:17803225

  11. 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.

  12. Brain glycogen

    DEFF Research Database (Denmark)

    Obel, Linea Lykke Frimodt; Müller, Margit S; Walls, Anne B;

    2012-01-01

    Glycogen is a complex glucose polymer found in a variety of tissues, including brain, where it is localized primarily in astrocytes. The small quantity found in brain compared to e.g., liver has led to the understanding that brain glycogen is merely used during hypoglycemia or ischemia....... In this review evidence is brought forward highlighting what has been an emerging understanding in brain energy metabolism: that glycogen is more than just a convenient way to store energy for use in emergencies-it is a highly dynamic molecule with versatile implications in brain function, i.e., synaptic...... activity and memory formation. In line with the great spatiotemporal complexity of the brain and thereof derived focus on the basis for ensuring the availability of the right amount of energy at the right time and place, we here encourage a closer look into the molecular and subcellular mechanisms...

  13. The alpha-tubulin gene AmTuba1: a marker for rapid mycelial growth in the ectomycorrhizal basidiomycete Amanita muscaria.

    Science.gov (United States)

    Tarkka, Mika T; Schrey, Silvia; Nehls, Uwe

    2006-05-01

    The apical extension of hyphae is of central importance for extensive spread of fungal mycelium in forest soils and for effective ectomycorrhiza development. Since the tubulin cytoskeleton is known to be important for fungal tip growth, we have investigated the expression of an alpha-tubulin gene from the ectomycorrhizal basidiomycete Amanita muscaria (AmTuba1). The phylogenetic analysis of protein sequences revealed the existence of two subgroups of alpha-tubulins in homobasidiomycetes, clearly distinguishable by defined amino acids. AmTuba1 belongs to subgroup1. The AmTuba1 transcript level is related to mycelial growth rate. Growth induction of carbohydrate starved (non-growing) hyphae resulted in an enhanced AmTuba1 expression as soon as hyphal growth started, reaching a maximum at highest mycelial growth rate. Bacterium-induced hyphal elongation also leads to increased AmTuba1 transcript levels. In mature A. muscaria/P. abies ectomycorrhizas, where fungal hyphae are highly branched, and slowly growing, AmTuba1 expression were even lower than in carbohydrate-starved mycelium, indicating a further down-regulation of gene expression in symbiosis. In conclusion, our analyses show that the AmTuba1 gene can be used as a marker for active apical extension in fly agaric, and that alpha-tubulin proteins are promising tools for the classification of fungi. PMID:16447071

  14. Ex vivo evaluation of N-(3-[{sup 18}F]fluoropropyl)-2{beta}-carbomethoxy-3{beta}-(4-fluorophenyl)nortrop ane in rats

    Energy Technology Data Exchange (ETDEWEB)

    Koivula, Teija [Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki (Finland); Marjamaeki, Paeivi; Haaparanta, Merja; Fagerholm, Veronica; Groenroos, Tove [MediCity PET Laboratory, Turku PET Centre, Tykistoekatu 6 A, FI-20520 Turku (Finland); Lipponen, Tiina; Perhola, Outi [Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki (Finland); Vepsaelaeinen, Jouko [Department of Chemistry, University of Kuopio, P.O. Box 1627, FI-70210 Kuopio (Finland); Solin, Olof [Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki (Finland); MediCity PET Laboratory, Turku PET Centre, Tykistoekatu 6 A, FI-20520 Turku (Finland)], E-mail: olof.solin@abo.fi

    2008-02-15

    Introduction: The dopamine transporter (DAT) ligand N-(3-fluoropropyl)-2{beta}-carbomethoxy-3{beta}-(4-fluorophenyl)nortropane ({beta}-CFT-FP) was labeled with fluorine-18, and its biodistribution was evaluated in rats ex vivo. Methods: The distribution of {sup 18}F radioactivity in the brain and peripheral organs and tissues was determined at several time points 5-120 min after intravenous injection of [{sup 18}F]{beta}-CFT-FP. Results: The highest brain uptake of [{sup 18}F]{beta}-CFT-FP was localized in the striatum; limbic structures also exhibited high uptake. Low uptake was found in the cerebellum. The highest ratio of striatum-to-cerebellum uptake, already reached within 5 min, was 3.1. Pretreatment with the selective DAT inhibitor GBR12909 significantly decreased [{sup 18}F]{beta}-CFT-FP uptake in the striatum. In most peripheral tissues, the highest uptake was found at 5 min, indicating fast washout of the radioligand. Some accumulation of {sup 18}F radioactivity was seen in bone as a function of time, reflecting defluorination of the radioligand. Conclusion: The results indicate that [{sup 18}F]{beta}-CFT-FP is a potential radioligand for studying DAT in vivo with positron emission tomography.

  15. Two novel series of allocolchicinoids with modified seven membered B-rings: design, synthesis, inhibition of tubulin assembly and cytotoxicity.

    Science.gov (United States)

    Büttner, Frank; Bergemann, Silke; Guénard, Daniel; Gust, Ronald; Seitz, Gunther; Thoret, Sylviane

    2005-05-16

    Two new attractive series of allocolchicinoids were designed as inhibitors of tubulin assembly using the potent ketone 4 and the tetracyclic, pyrazole annulated NCME variant 7 (NCME = N-acetyl colchinol-O-methylether (2)) as lead structures. The first group of inhibitors of type 6 with novel oxepine and azepine B-ring structures belongs to the NCME-series and was synthesized via a multistep total synthesis starting from simple and cheap 3-methoxybenzaldehyde (12) and 3,4,5-trimethoxybenzaldehyde (13). Biaryl-coupling of the starting materials 12 and 13 was accomplished via Ziegler-Ullmann-reaction to furnish the biphenyl 11 equipped with two carbaldehyde functions. The subsequent Cannizzaro reaction of this dicarbaldehyde 11 proceeded with high regioselectivity to yield almost exclusively the key compound, the hydroxymethyl carboxylic acid 9. Ring closure to the o,o'-bridged biphenyls was accomplished by two routes: on the one hand, treatment of 9 with aqueous hydrochloric acid yielded the lactone 15. On the other hand, a four step sequence starting from the isomeric mixture 9/10 furnished the constitutionally isomeric lactams 23 and 24; these could be converted to the corresponding thiolactams 25 and 26 and to the tetrazole annulated NCME-type derivatives 27 and 28. The second series of bioactive compounds are congeners of allocolchicine (3). The well known desacetyl allocolchicine (29) was easily oxidized to the oxime 30, which was further transformed to the corresponding ketone 31. This served as key precursor for the syntheses of various tetracyclic allocolchicine modifications 33-36 annulated with a pyrazole, isoxazole, pyrimidine or 2-aminopyrimidine heterocycle, respectively. Unexpectedly, all the NCME-variants with a substituent in position 7 like in NCME (2) inhibited the tubulin assembly only moderately. In contrast, the new series of allocolchicine modifications proved to be highly potent antimicrotubule agents. Inhibition of tubulin assembly occurred at

  16. Generalized epilepsy with febrile seizures plus-associated sodium channel beta1 subunit mutations severely reduce beta subunit-mediated modulation of sodium channel function.

    Science.gov (United States)

    Xu, R; Thomas, E A; Gazina, E V; Richards, K L; Quick, M; Wallace, R H; Harkin, L A; Heron, S E; Berkovic, S F; Scheffer, I E; Mulley, J C; Petrou, S

    2007-08-10

    Two novel mutations (R85C and R85H) on the extracellular immunoglobulin-like domain of the sodium channel beta1 subunit have been identified in individuals from two families with generalized epilepsy with febrile seizures plus (GEFS+). The functional consequences of these two mutations were determined by co-expression of the human brain NaV1.2 alpha subunit with wild type or mutant beta1 subunits in human embryonic kidney (HEK)-293T cells. Patch clamp studies confirmed the regulatory role of beta1 in that relative to NaV1.2 alone the NaV1.2+beta1 currents had right-shifted voltage dependence of activation, fast and slow inactivation and reduced use dependence. In addition, the NaV1.2+beta1 current entered fast inactivation slightly faster than NaV1.2 channels alone. The beta1(R85C) subunit appears to be a complete loss of function in that none of the modulating effects of the wild type beta1 were observed when it was co-expressed with NaV1.2. Interestingly, the beta1(R85H) subunit also failed to modulate fast kinetics, however, it shifted the voltage dependence of steady state slow inactivation in the same way as the wild type beta1 subunit. Immunohistochemical studies revealed cell surface expression of the wild type beta1 subunit and undetectable levels of cell surface expression for both mutants. The functional studies suggest association of the beta1(R85H) subunit with the alpha subunit where its influence is limited to modulating steady state slow inactivation. In summary, the mutant beta1 subunits essentially fail to modulate alpha subunits which could increase neuronal excitability and underlie GEFS+ pathogenesis. PMID:17629415

  17. SIAH-1 interacts with alpha-tubulin and degrades the kinesin Kid by the proteasome pathway during mitosis.

    Science.gov (United States)

    Germani, A; Bruzzoni-Giovanelli, H; Fellous, A; Gisselbrecht, S; Varin-Blank, N; Calvo, F

    2000-12-01

    SIAH-1, a human homologue of the Drosophila seven in absentia (Sina), has been implicated in ubiquitin-mediated proteolysis of different target proteins through its N-terminal RING finger domain. SIAH-1 is also induced during p53-mediated apoptosis. Furthermore, SIAH-1-transfected breast cancer cell line MCF-7 exhibits an altered mitotic process resulting in multinucleated giant cells. Now, using the two-hybrid system, we identified two new SIAH interacting proteins: Kid (kinesin like DNA binding protein) and alpha-tubulin. We demonstrate that SIAH is involved in the degradation of Kid via the ubiquitin-proteasome pathway. Our results suggest that SIAH-1 but not its N-terminal deletion mutant, affects the mitosis by an enhanced reduction of kinesin levels. Our results imply, for the first time, SIAH-1 in regulating the degradation of proteins directly implicated in the mitotic process. PMID:11146551

  18. Xeroradiography in. beta. -thalassaemia

    Energy Technology Data Exchange (ETDEWEB)

    Scutellari, P.N.; Orzincolo, C.; Tamarozzi, R.

    1985-01-01

    Xeroradiographic investigations of the skull, hand, and elbow were performed on 27 patients with homozygous ..beta..-thalassaemia. The results were compared with plain radiographic examinations. Xeroradiography, because of its technical properties (i.e. edge contrast enhancement and wide latitude), was shown to demonstrate cortical thinning of long bones, swelling of the diploic space in the skull, and reticulated patterns in the elbow better than standard radiography. Moreover, the use of 'positive' mode imaging was shown to have advantages in the study of the skull and extremities.

  19. Realized Beta GARCH

    DEFF Research Database (Denmark)

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

    2014-01-01

    particularly useful for modeling financial returns during periods of rapid changes in the underlying covariance structure. When applied to market returns in conjunction with returns on an individual asset, the model yields a dynamic model specification of the conditional regression coefficient that is known as...... conditional beta series during the financial crises.......We introduce a multivariate generalized autoregressive conditional heteroskedasticity (GARCH) model that incorporates realized measures of variances and covariances. Realized measures extract information about the current levels of volatilities and correlations from high-frequency data, which is...

  20. Regulation of bolting and identification of the α-tubulin gene family in Brassica rapa L. ssp pekinensis.

    Science.gov (United States)

    Zhang, Y W; Jin, D; Xu, C; Zhang, L; Guo, M H; Fang, Z Y

    2016-01-01

    Microtubules are important components of eukaryotic cells, and they play vital roles in cell morphogenesis, carrying of signaling molecules, transport of materials, and establishing the cell polarity. During bolting of biennial plants, cell division and elongation are involved, and cell elongation inevitably involves the microtubules arrangement and expression of related genes. So we deduce that it is of great significance to figure out the mechanism of bolting and flowering in which TUA genes are involved. In the present study, bioinformatic methods were used to predict and identify the α-tubulin gene family (BrTUAs) in Brassica rapa L. ssp pekinensis (Chinese cabbage) through the alignment of AtTUA gene sequence from Arabidopsis thaliana with the B. rapa genome database (http://brassicadb.org/brad/) using the basic local alignment search tool. The change in the structure and functions of BrTUAs during the process of evolution, cis-acting elements in the promoter sequences of BrTUAs, and the expression of the identified genes was also analyzed. Twelve members of the α-tubulin gene family were identified from Chinese cabbage. The gene length, intron, exon, and promoter regions were determined to have changed significantly during the genome evolution. Only five of the 12 members were encoded completely and were observed to differ in their spatial and temporal expression. The five BrTUA promoter sequences contained different numbers of cis-elements responsive to light and low-temperature response, cis-elements responsive among which hormonal responses were significantly different. We also report that the BrTUAs were involved in the regulation of the bolting in Chinese cabbage, and propose that this process could be controlled by regulating the expression of BrTUAs. PMID:26909938

  1. Brain Basics

    Medline Plus

    Full Text Available ... as they grow there are differences in brain development in children who develop bipolar disorder than children who do not. Studies comparing such children to those with normal brain development may help scientists to pinpoint when and where ...

  2. Brain Basics

    Medline Plus

    Full Text Available ... PTSD) . Prefrontal cortex (PFC) —Seat of the brain's executive functions, such as judgment, decision making, and problem solving. ... brain that, in humans, plays a role in executive functions such as judgment, decision making and problem solving, ...

  3. Brain Basics

    Medline Plus

    Full Text Available ... Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take ... to slow or stop them from progressing. Functional magnetic resonance imaging (fMRI) is another important research tool in ...

  4. Brain Basics

    Medline Plus

    Full Text Available ... in brain development in children who develop bipolar disorder than children who do not. Studies comparing such children to those with normal brain development may help scientists to pinpoint when and where mental disorders begin and perhaps how to slow or stop ...

  5. Brain Basics

    Medline Plus

    Full Text Available ... and are working to compare that with brain development in people mental disorders. Genes and environmental cues both help to direct ... as they grow there are differences in brain development in children who develop bipolar disorder than children who do not. Studies comparing such ...

  6. Brain Basics

    Medline Plus

    Full Text Available ... her symptoms were not caused by a stroke, brain tumor, or similar conditions, Sarah's doctor referred her to a psychiatrist, a type of medical doctor who is an expert on mental ... of serotonin in the brain and help reduce symptoms of depression. Sarah also ...

  7. Brain Basics

    Medline Plus

    Full Text Available ... the brain, which is linked to thought and emotion. It is also linked to reward systems in the brain. Problems in producing dopamine can result in Parkinson's disease, a disorder that affects a person's ability to move as they want to, resulting ...

  8. Brain imaging

    International Nuclear Information System (INIS)

    The techniques of brain imaging and results in perfusion studies and delayed images are outlined. An analysis of the advantages and disadvantages of the brain scan in a variety of common problems is discussed, especially as compared with other available procedures. Both nonneoplastic and neoplastic lesions are considered. (Auth/C.F.)

  9. Brain Basics

    Medline Plus

    Full Text Available ... will fire. This enhances the electrical flow among brain cells required for normal function and plays an important ... of neurons and their interconnections. neuron —A nerve cell that is the basic, working unit of the brain and nervous system, which processes and transmits information. ...

  10. Brain surgery

    Science.gov (United States)

    ... piece of tumor for a biopsy Remove abnormal brain tissue Drain blood or an infection Free a nerve The bone flap is usually replaced after surgery, using small metal ... or if the brain was swollen. (This is called a craniectomy.) The ...

  11. Brain Basics

    Medline Plus

    Full Text Available ... little dopamine or problems using dopamine in the thinking and feeling regions of the brain may play ... axis —A brain-body circuit which plays a critical role in the body's response to stress. impulse — ...

  12. Brain Basics

    Medline Plus

    Full Text Available ... Basics in Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle-aged woman who seemed to have it all. She was happily married and successful in business. Then, after a serious setback at work, she lost interest ...

  13. Brain Basics

    Medline Plus

    Full Text Available ... Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses magnetic fields to take pictures of ... to slow or stop them from progressing. Functional magnetic resonance imaging (fMRI) is another important research tool in understanding ...

  14. Brain Basics

    Medline Plus

    Full Text Available ... Basics in Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a ... medical history. Epigenetic changes from stress or early-life experiences ... In contrast, major depression is a serious disorder that lasts for weeks. ...

  15. Brain Basics

    Medline Plus

    Full Text Available ... her feelings. Brain Research Modern research tools and techniques are giving scientists a more detailed understanding of the brain than ... a person responds to a certain medication. This information may someday ... is allowing scientists to make important discoveries that could change the ...

  16. Brain Diseases

    Science.gov (United States)

    ... know what causes some brain diseases, such as Alzheimer's disease. The symptoms of brain diseases vary widely depending on the specific problem. In some cases, damage is permanent. In other cases, treatments such as surgery, medicines, or physical therapy can correct the source of the problem or ...

  17. Double beta decay: present status

    OpenAIRE

    Barabash, A. S.

    2008-01-01

    The present status of double beta decay experiments (including the search for $2\\beta^{+}$, EC$\\beta^{+}$ and ECEC processes) are reviewed. The results of the most sensitive experiments are discussed. Average and recommended half-life values for two-neutrino double beta decay are presented. Conservative upper limits on effective Majorana neutrino mass and the coupling constant of the Majoron to the neutrino are established as $ < 0.75$ eV and $ < 1.9 \\cdot 10^{-4}$, respectively. Proposals fo...

  18. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  19. Scintillator based beta batteries

    Science.gov (United States)

    Rensing, Noa M.; Tiernan, Timothy C.; Shirwadkar, Urmila; O'Dougherty, Patrick; Freed, Sara; Hawrami, Rastgo; Squillante, Michael R.

    2013-05-01

    Some long-term, remote applications do not have access to conventional harvestable energy in the form of solar radiation (or other ambient light), wind, environmental vibration, or wave motion. Radiation Monitoring Devices, Inc. (RMD) is carrying out research to address the most challenging applications that need power for many months or years and which have undependable or no access to environmental energy. Radioisotopes are an attractive candidate for this energy source, as they can offer a very high energy density combined with a long lifetime. Both large scale nuclear power plants and radiothermal generators are based on converting nuclear energy to heat, but do not scale well to small sizes. Furthermore, thermo-mechanical power plants depend on moving parts, and RTG's suffer from low efficiency. To address the need for compact nuclear power devices, RMD is developing a novel beta battery, in which the beta emissions from a radioisotope are converted to visible light in a scintillator and then the visible light is converted to electrical power in a photodiode. By incorporating 90Sr into the scintillator SrI2 and coupling the material to a wavelength-matched solar cell, we will create a scalable, compact power source capable of supplying milliwatts to several watts of power over a period of up to 30 years. We will present the latest results of radiation damage studies and materials processing development efforts, and discuss how these factors interact to set the operating life and energy density of the device.

  20. Oligosaccharides derived by endo-beta-galactosidase digestion of bovine corneal keratan sulphate--characterisation of tetrasaccharides with incomplete sulphation and containing unsulphated N-acetylglucosamine residues.

    Science.gov (United States)

    Huckerby, T N; Tai, G H; Nieduszynski, I A

    1998-04-15

    Bovine corneal keratan sulphate has been fragmented using the enzyme endo-beta)-galactosidase and 1H-NMR chemical shift data are reported for five newly isolated tetrasaccharides which derived from the repeat region. They have the structures: GlcNAc(beta1-3)Gal(beta1-4)GlcNAc6S(beta1-3)Gal-ol, GlcNAc6S(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal-ol, GlcNAc(beta1-3)Gal6S(beta1-4)GlcNAc6S(beta1-3)Gal-ol, GlcNAc6S(beta1-3)Gal6S(beta1-4)GlcNAc(beta1-3)Gal-ol, and GlcNAc6S(beta1-3)Gal(beta1-4)GlcNAc6S(beta1-3)Gal-ol. Structures for two trisaccharides formed by a peeling reaction are also given. These are GlcNAc(beta1-3)Gal6S(beta1-4)GlcNAc-ol and GlcNAc6S(beta1-3)Gal(beta1-4)GlcNAc6S-ol where GlcNAc6S-ol represents N-acetylglucosaminitol 6-O-sulphate. Characterisation of such structures and their spectral assignments will be of considerable value for the studies of both selectin ligands and undersulphated keratan sulphates such as those occurring on cell surfaces and in brain tissue. PMID:9654103

  1. Influence of edaravone on expressions of beta amyloids and Tau protein in brain tissue of vascular dementia rats%依达拉奉对血管性痴呆大鼠脑组织β淀粉样蛋白、Tau蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    林森; 赵颖; 王建华; 晋光荣; 赵连东

    2011-01-01

    Objective It is to study the influence of edaravone on the expressions of beta amyloid ( Aβ ) and Tau protein in brain tissue of vascular dementia ( VD ) rats.Methods Sixty-four male SD rats were sieved with Morris water maze and randomly divided into normal group, sham operation group, control group and treatment group.After operation for 7 , 14 and 28 d, the loss information of space learning memory ability of those rats were tested with Morris water maze, and the frozen sections of brain tissue were taken to detect the expression information of Aβ and Tau protein.Results The increases of the positive expression cell numbers of Aβ and Tau protein in nerve cells of control group were obvious after cerebral ischemia reperfusion for one week ( both P < 0.01 ) and those were more obvious after cerebral ischemia reperfusion for four weeks ( both P <0.001 ).The positive expression cell numbers of Aβ and Tau protein in nerve cells of treatment group after ischemia reperfusion for one week were ohviously fewer than that in control group ( both P < 0.01 ) and that was more obvious after ischemia reperfusion for two weeks ( both P < 0.001 ).Conclusion Edaravone can restrain the expressions of Aβ and Tau protein in brain tissue after cerebral ischemia reperfusion.%目的 研究依达拉奉对血管性痴呆(VD)大鼠脑组织β淀粉样蛋白(Aβ)、Tau蛋白表达的影响.方法 通过Morris水迷宫筛选出雄性SD大鼠64只,随机分为正常组、假手术组、对照组、治疗组,术后7,14,28d分别用Morris水迷宫测试大鼠空间学习记忆能力缺失情况,并取脑组织冰冻切片检测Aβ、Tau蛋白表达情况.结果 对照组脑缺血再灌注后1周,神经细胞中Aβ、Tau蛋白的表达阳性细胞数均明显增多(P均<0.01),缺血再灌注4周后更明显(P均<0.001).治疗组缺血再灌注1周后神经细胞中Aβ、Tau蛋白的表达阳性细胞数均明显少于对照组(P均<0.01),缺血再灌注2

  2. 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.

  3. Brain tumor

    International Nuclear Information System (INIS)

    BNCT in the past was not widely accepted because of poor usability of a nuclear reactor as a neutron source. Recently, technical advancements in the accelerator field have made accelerator-based BNCT feasible. Consequently, clinical trials of intractable brain tumors have started using it since 2012. In this review, our clinical results obtained from conventional reactor-based BNCT for treatment of brain tumors are introduced. It is strong hope that accelerator-based BNCT becomes a standard therapy for current intractable brain tumors. (author)

  4. 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.

  5. BETA SPECTRA. I. Negatrons spectra

    International Nuclear Information System (INIS)

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  6. The best-beta CAPM

    NARCIS (Netherlands)

    L. Zou

    2006-01-01

    The issue of 'best-beta' arises as soon as potential errors in the Sharpe-Lintner-Black capital asset pricing model (CAPM) are acknowledged. By incorporating a target variable into the investor preferences, this study derives a best-beta CAPM (BCAPM) that maintains the CAPM's theoretical appeal and

  7. 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.

  8. RAVEN Beta Release

    International Nuclear Information System (INIS)

    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.

  9. Brain and Addiction

    Science.gov (United States)

    ... Teens / Drug Facts / Brain and Addiction Brain and Addiction Print Your Brain Your brain is who you ... is taken over and over. What Is Drug Addiction? Addiction is a chronic brain disease that causes ...

  10. Brain tumor - primary - adults

    Science.gov (United States)

    ... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

  11. 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.

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

    Czech Academy of Sciences Publication Activity Database

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

    2002-01-01

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

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