bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Barley Stripe Mosaic Virus Strains
Authors: Hafez Elsayed E. , Aleem Engy E. Abdel , Fattouh Faiza A.
Published: February 2015

BSMV (barley stripe mosaic virus) particles were obtained in a pure state from infected host plant tissues of Hordeum vulgare. The three genomic parities (α, β and γ) were amplified by PCR using specific primers for each particle; each was cloned. Partial sequence of the α, β and γ segments was determined for the Egyptian isolate of barley stripe mosaic virus (BSMV AE1). Alignment of nucleotide sequences with that of other known strains of the virus, BSMV type strains (CV17, ND18 and China), and the generation of phylogenetic trees was performed. A low level of homology was detected comparing 467 bp of the α and 643 bp of the segments to that of the other strains, and thus BSMV α and β segments were in separate clusters. However, 1154 bp of the γ segments of BSMV AE1 showed a high level of homology especially to strain BSMV ND18, as they both formed a distinct cluster. Northern blotting of pure BSMV AE1 virus and H. vulgare-infected tissue were compared using an α ND18 specific probe. Western blotting using antibodies specific for the coat protein (CP) and the triple gene block 1 (TGB1) protein, which are both encoded by the β ND18 segment, still indicated a high level of similarity between proteins produced by BSMV ND18 and AE1. We suggest that the BSMV AE1 isolate is a distinct strain of BSMV which reflects the genetic evolutionary divergence among BSMV strains and members of the Hordeivirus group
Lipase-Catalyzed Biodiesel Production with Methyl Acetate as Acyl Acceptor
Authors: Huang Ying , Yan Yunjun
Published: February 2015

Biodiesel is an alternative diesel fuel made from renewable biological resources. During the process of biodiesel production, lipase-catalyzed transesterification is a crucial step. However, current techniques using methanol as acyl acceptor have lower enzymatic activity; this limits the application of such techniques in large-scale biodiesel production. Furthermore, the lipid feedstock of currently available techniques is limited. In this paper, the technique of lipase-catalyzed transesterification of five different oils for biodiesel production with methyl acetate as acyl acceptor was investigated, and the transesterification reaction conditions were optimized. The operation stability of lipase under the obtained optimal conditions was further examined. The results showed that under optimal transesterification conditions, both plant oils and animal fats led to high yields of methyl ester: cotton-seed oil, 98%; rapeseed oil, 95%; soybean oil, 91%; tea-seed oil, 92%; and lard, 95%. Crude and refined cottonseed oil or lard made no significant difference in yields of methyl ester. No loss of enzymatic activity was detected for lipase after being repeatedly used for 40 cycles (ca. 800 h), which indicates that the operational stability of lipase was fairly good under these conditions. Our results suggest that cotton-seed oil, rape-seed oil and lard might substitute soybean oil as suitable lipid feedstock for biodiesel production. Our results also show that our technique is fit for various lipid feedstocks both from plants and animals, and presents a very promising way for the large-scale biodiesel production
Analysis of Interactions between Carbohydrates and Proteins Using Fluorescent Labeling and SDS-PAGE
Authors: Huang Gang L. , Wong Kongliang
Published: February 2015

A rapid method for the analysis of carbohydrateprotein interactions by using fluorescent labeling and SDS-PAGE was developed. The N-acetyl-β-d-glucosamine- WGA complex and α-d-mannose-Con A complex were labeled with 8-aminonaphthalene-1,3,6-trisulfonate (ANTS). The protein band displaying fluorescence with ultraviolet illumination was seen after SDS-PAGE
Antimicrobial Activity of Kaurane Diterpenes against Oral Pathogens
Authors: Ambrosio Sergio R. , Furtado Niege A. J. C. , de Oliveira Dionéia C. R. , da Costa Fernando B. , Martins Carlos H. G. , de Carvalho Tatiane C. , Porto Thiago S. , Veneziani Rodrigo C. S.
Published: February 2015

Two kaurane diterpenes, ent-kaur-16(17)-en-19-oic acid (KA) and 15-β-isovaleryloxy-entkaur- 16(17)-en-19-oic acid (KA-Ival), isolated from Aspilia foliacea, and the methyl ester derivative of KA (KA-Me) were evaluated against oral pathogens. KA was the most active compound, with MIC values of 10 μg mL-1 against the following microorganisms: Streptococcus sobrinus, Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, and Lactobacillus casei. However, KA did not show significant activity against Streptococcus salivarius and Enterococcus faecalis, with MIC values equal to 100 and 200 μg mL-1, respectively. Our results show that KA has potential to be used as a prototype for the discovery of new effective anti-infection agents against microorganisms responsible for caries and periodontal diseases. Moreover, these results allow to conclude that minor structural differences among these diterpenes significantly influence their antimicrobial activity, bringing new perspectives to studies on the structure-activity relationship of this type of metabolites with respect to caries and periodontal diseases.
In vitro Cytotoxic Activity of Salsola oppositifolia Desf. (Amaranthaceae) in a Panel of Tumour Cell Lines
Authors: Tundis Rosa , Loizzo Monica R. , Bonesi Marco , Menichini Federica , Statti Giancarlo A. , Menichini Francesco
Published: February 2015

The aim of the present study was to evaluate for the first time the in vitro cytotoxic activity of fractions and isolated flavonols from Salsola oppositifolia Desf. (Amaranthaceae). The nhexane fraction demonstrated an effective cytotoxic activity on the large lung carcinoma and amelanotic melanoma cell lines with IC50 values of 19.1 μg/ml and 24.4 μg/ml, respectively. Also the dichloromethane fraction exhibited cytotoxic activity against COR-L23 (IC50 30.4 μg/ml) and C32 (IC50 33.2 μg/ml) cells, while the EtOAc fraction demonstrated a selective cytotoxic activity against MCF-7 cells (IC50 67.9 μg/ml). The major active constituents of this fraction were isorhamnetin-3-O-glucoside (1) and isorhamnetin-3-O-rutinoside (2), which showed an interesting activity against the cell line MCF-7 with IC50 values of 18.2 and 25.2 μg/ml, respectively. Compound 2 exhibited a strong activity against the hormonedependent prostate carcinoma LNCaP cell line with an IC50 of 20.5 μg/ml. Constituents of S. oppositifolia were identified by GC-MS and NMR analyses.
Taxodione, a DNA-Binding Compound from Taxodium distichum L. (Rich.)
Authors: Zaghloul Ahmed M. , Gohar Ahmed A. , Naiem Zein Al-Abdin M. , Bar Fatma M. Abdel
Published: February 2015

8-β-Hydroxypimar-15-en-19-oic acid (1), taxodione (2), 6,7-dehydro-8-hydrotaxodone (3), quercetin-3-O-β-d-glucopyranoside (4), and shikimic acid (5) were isolated from the leaves of Taxodium distichum L. (Rich.) for the first time. Previously reported compounds [β-sitosterol (6), isorhamnetin (7), quercetin (8), isorhamnetin-3-O-α-arabinofuranoside (9), quercetin- 3-O-α-arabinofuranoside (10)] have also been isolated. The activity of taxodione as an inhibitor for hepatic stellate cells was determined. The antitumour activity of 2, 3, and 5 using a DNA affinity probe was examined.
Enzymatic Inhibitory Activity and Trypanocidal Effects of Extracts and Compounds from Siphoneugena densiflora O. Berg and Vitex polygama Cham.
Authors: Gallo Margareth B. C. , Marques Anna Sylvia F. , Vieira Paulo C. , da Silva Maria Fátima das G. F. , Fernandes João B. , Silva Márcio , Guido Rafael V. , Oliva Glaucius , Thiemann Otávio H. , Albuquerque Sérgio , Fairlamb Alan H.
Published: February 2015

Hexanic, methanolic, and hydroalcoholic extracts, and 34 isolated compounds from Vitex polygama Cham. (Lamiaceae, formely Verbenaceae) and Siphoneugena densiflora O. Berg (Myrtaceae) were screened for their trypanocidal effects on bloodstream forms of Trypanosoma cruzi and T. brucei, as well as for their enzymatic inhibitory activities on glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) and trypanothione reductase (TR) enzymes from T. cruzi and adeninephosphoribosyl transferase (APRT) enzyme from Leishmania tarentolae. In general, polar extracts displayed strong effects and some of the tested compounds have shown good results in comparison to positive controls of the bioassays.
Chemical Basis for the Phytotoxicity of N-Aryl Hydroxamic Acids and Acetanilide Analogues
Authors: Bravo Héctor R. , Villarroel Elisa , Copaja Sylvia V. , Argandoña Victor H.
Published: February 2015

Germination inhibition activity of N-aryl hydroxamic acids and acetanilide analogues was measured on lettuce seeds (Lactuca sativa). Lipophilicity of the compounds was determined by HPLC. A correlation between lipophilicity values and percentage of germination inhibition was established. A model mechanism of action for auxin was used for analyzing the effect of the substituent at the alpha carbon atom (Cα) on the polarization of hydroxamic and amide functions in relation to the germination inhibition activity observed. Results suggest that the lipophilic and acidic properties play an important role in the phytotoxicity of the compounds. A test with the microalga Chlorella vulgaris was used to evaluate the potential herbicide activity of the hydroxamic acids and acetanilides.
Production of Glycyrrhizin in Callus Cultures of Licorice
Authors: Wongwicha Winida , Tanaka Hiroyuki , Shoyama Yukihiro , Tuvshintogtokh Indree , Putalun Waraporn
Published: February 2015

Licorice plants, Glycyrrhiza glabra, G. uralensis, and G. inflata, were investigated for callus induction using Murashige and Skoog (MS) medium combined with auxins and cytokinins. After 4 weeks of culture, 33-100% of leaf or stem explants formed calli. Maximum of shoot induction from callus cultures was achieved by G. inflata stem explants cultured on MS medium supplemented with 1 mg/l α-naphthaleneacetic acid (NAA) and 0.5 mg/l 6-benzyladenine (BA) (67%) which also gave maximum shoot formation per explant (two shoots per explant). These results indicated that all three Glycyrrhiza species regenerated shoots from callus cultures on MS medium combined with NAA and BA or only thidiazuron (TDZ; 0.1 and 0.5 mg/l). Glycyrrhizin contents of G. uralensis calli induced using MS medium in combination with NAA and BA [(27.60 ± 8.47) μg/g DW] or TDZ alone [(36.52 ± 2.45) μg/ g DW] were higher than those found in other combinations.
Antileishmanial, Antimalarial and Antimicrobial Activities of the Extract and Isolated Compounds from Austroplenckia populnea (Celastraceae)
Authors: Andrade Sérgio F. , Silva Filho Ademar A. da , Cunha Wilson R. , Nanayakkara N. P. Dhammika , Bastos Jairo Kenupp
Published: February 2015

Austroplenckia populnea (Celastraceae), known as “marmelinho do campo”, is used in Brazilian folk medicine as antimicrobial, anti-inflammatory, and antitumoural agent. The aim of the present work was to evaluate the antimicrobial, antileishmanial and antimalarial activities of the crude hydroalcoholic extract of A. populnea (CHE) and some of its isolated compounds. The phytochemical study of the CHE was carried out affording the isolation of methyl populnoate (1), populnoic acid (2), and stigmast-5-en-3-O-β-(d-glucopyranoside) (3). This is the first time that the presence of compound 3 in A. populnea is reported. The results showed that the CHE presents antifungal and antibacterial activities, especially against Candida glabrata and Candida albicans, for which the CHE showed IC50 values of 0.7 μg mL-1 and 5.5 μg mL-1, respectively, while amphotericin B showed an IC50 value of 0.1 μg mL-1 against both microorganisms. Compounds 1D3 were inactive against all tested microorganisms. In the antileishmanial activity test against Leishmania donovani, the CHE showed an IC50 value of 52 μg mL-1, while compounds 2 and 3 displayed an IC50 value of 18 μg mL-1. In the antimalarial assay against Plasmodium falciparum (D6 and W2 clones), it was observed that all evaluated samples were inactive. In order to compare the effect on the parasites with the toxicity to mammalian cells, the cytotoxicity activity of the isolated compounds was evaluated against Vero cells, showing that all evaluated samples exhibited no cytotoxicity at the maximum dose tested.
Antineoplastic 31-Norcycloartanones from Solanum cernuum Vell
Authors: Grando Rogério , Antônio Marcia A. , Araújo Carlos E. P. , Soares Catarina , Medeiros Maria A. , Carvalho João E. de , Lourenço Ana M. , Lopes Luciane C.
Published: February 2015

Triterpenoids with 31-norcycloartanone structure were isolated for the first time from the Solanum genus. Cycloeucalenone and 24-oxo-31-norcycloartanone were the main constituents of the dichloromethane extract of Solanum cernuum Vell. leaves [7% (w/w) and 1.47% (w/w)]. Both triterpenoids were tested against human tumour cell lines, and 24-oxo-31-norcycloartanone was significantly active and selective against the lung tumour cell line NCI-H460 with total growth inhibition at 1.10 μg/mL, growth inhibition 50 at 0.19 μg/mL and lethal concentration 50 at 8.43 μg/mL, while cycloeucalenone showed poor activity. A homologous series of alkanes (C25-C34), β-sitosterol, and the xanthophyll lutein were also identified. The antiulcer activity was assayed for the dichloromethane extract. In the gastric ulcer model induced by 95% ethanol, administration of 500, 1000 and 2000 mg/kg/po dichloromethane extract gave ulcer lesion indices of, respectively, 38.2, 61.0 and 81.9%, while carbenoxolone inhibited 88.9% at 200 mg/kg. In the gastric ulcer model induced by indomethacin the dichloromethane extract showed a small percentage of lesion inhibition. The ethanol extract was also analyzed and was mainly composed of glycoalkaloids, peptides and disaccharides.
Evaluation of Lipoxygenase Inhibitory Activity of Anacardic Acids
Authors: Kubo Isao , Ha Kazuo , Tsujimoto Kazuo , Tocoli Felismino E. , Green Ivan R.
Published: February 2015

6-Alkylsalicylic acids inhibit the linoleic acid peroxidation catalyzed by soybean lipoxygenase- 1 (EC 1.13.11.12, type 1) competitively and without pro-oxidant effects. This activity is largely dependent on the nature of their alkyl side chains. Inhibitory activities of anacardic acids, viz. 6-pentadec(en)ylsalicylic acids, isolated from the cashew Anacardium occidentale, were initially used for comparison because their aromatic head portions are the same. Consequently, the data should be interpreted to mean that changes in the hydrophobic side chain tail portions of the molecules evaluated correlate with the specific activity determined.
Biotransformation of Glabratephrin, a Rare Type of Isoprenylated Flavonoids, by Aspergillus niger
Authors: Mohamed Abou-El-Hamd H , Khalafallah Ali K. , Yousof Afifi H.
Published: February 2015

Microbial transformation of glabratephrin, the major isolated compound from Tephrosia purpurea, afforded pseudosemiglabrin. The formation of the transformed compound seems to be performed via ring opening-closure of a five-membered ring causing transformation from a spiro into a fused system. The structure of the transformed compound was determined by comprehensive NMR studies, including DEPT, COSY, HMQC, NOE and MS.
Biosynthetic Origin of Graphenone in Cultured Lichen Mycobionts of Graphis handelii
Authors: Takenaka Yukiko , Hamada Nobuo , Tanahashi Takao
Published: February 2015

The biosynthetic origins of the carbon skeleton in graphenone were verified by feeding the culture of spore-derived mycobionts of the lichen Graphis handelii with sodium [1-13C]- acetate, sodium [1,2-13C2]-acetate, sodium [2-13C]-pyruvate, [1,2,3-13C]-glycerol, [13CH3]- methionine and sodium [1,4-13C2]-succinate.
Decreased DNA Repair Capacity of UV-Irradiated Cells Following Interferon Treatment
Authors: Tsoncheva Vania L. , Todorova Kristina A. , Maximova Vera A.
Published: February 2015

The aim of this study was to examine the effect of interferons (IFNs) on the recovery of UV-damaged cells by means of measuring cell viability rates. The influence of the recombinant human interferons IFN-α, IFN-βand IFN-γ on the repair capacity of the UV-irradiated human cell lines WISH and HeLa was studied. The ability of cells to repair UV-induced damage was determined by the comet assay and both short- and long-term survival assays in proliferating cell cultures. We found that INFs negatively regulated DNA repair in cells damaged by UV light. One day after treatment, in both cell lines tested, IFN-α had a stronger inhibitory effect than IFN-γ. Combined treatment with different IFNs exhibited a stronger inhibitory effect on cell recovery than treatment with each of them. The protein kinase inhibitor wortmanin further aggravated the effect of IFNs on cell survival.
Diterpenoid Production in Hairy Root Culture of Salvia sclarea L.
Authors: Kuzma Łukasz , Bruchajze Elzbieta , Wysokińska Halina
Published: February 2015

Growth and diterpenoid accumulation (salvipisone, ferruginol, aethiopinone and 1-oxoaethiopinone) during the growth cycle of a Salvia sclarea hairy root culture are described. The roots transformed by Agrobacterium rhizogenes (LBA 9402) were cultured in half-strength B5 liquid medium supplemented with 30 g L-1 sucrose under light (16 h/8 h light/dark). A culture period of 30 days was optimal for both biomass and diterpenoid production. The total content of four diterpenoids in the hairy roots [(27.3 ± 0.6) mg g-1 dry weight] was higher than that of roots of field-grown S. sclarea plants [(3.15 ± 0.15) mg g-1 dry weight]. In transformed roots, aethiopinone was the main diterpenoid, whereas the principal diterpenoid of natural roots was salvipisone.
Phytotoxicity of Major Constituents of the Volatile Oil from Leaves of Artemisia scoparia Waldst. & Kit.
Authors: Pal Singh Harminder , Kaur Shalinder , Mittal Sunil , Batish Daizy R. , Kohli Ravinder K.
Published: February 2015

The phytotoxicity of the three major monoterpene constituents of the essential oil from leaves of Artemisia scoparia Waldst. & Kit. (redstem wormwood) was investigated. GC/GCMS analysis revealed that the essential oil (yield 0.84%) is a complex mixture containing 19 monoterpenes, 7 sesquiterpenes and 15 other compounds - aliphatic alcohols, ketones, aromatic hydrocarbons and esters. The three major monoterpenes were β-myrcene (30.2%), p-cymene (12.8%) and dl-limonene (12.4%). The essential oil and the three monoterpenes exhibited phytotoxicity and reduced germination, seedling growth, chlorophyll content and percent respiration of Avena sativa and Triticum aestivum in a dose-response manner. The inhibitory effect of monoterpenes was comparatively smaller than of the crude essential oil and β-myrcene was most toxic followed by p-cymene, whereas limonene was least toxic. The study suggests that A. scoparia oil and β-myrcene can be explored for phytotoxicity against weeds.
Yangambin Cytotoxicity: A Pharmacologically Active Lignan Obtained from Ocotea duckei Vattimo (Lauraceae)
Authors: Monte Neto Rubens L. , Sousa M. A. , Dias Celidarque S. , Barbosa Filho José M. , Oliveira Márcia R.
Published: February 2015

The in vitro cytotoxic potential of yangambin was evaluated. Yangambin is a pharmacologically active furofuran lignan obtained from the leaves of Ocotea duckei. It is the major compound from the lignoids fraction. Yangambin presented low cytotoxicity in all in vitro models analyzed. Its cytotoxicity to murine macrophages was measured by the Trypan blue dye exclusion test and MTT reduction assay, resulting in high CC50 values of 187.0 μg/mL (383.3 μm) and 246.7 μg/mL (504.3 μm), respectively. The difference obtained in the inhibitory concentrations aforementioned can be explained, at least in part, by the different principles of the methods. While the MTT reduction assay evaluates the ability of yangambin to inhibit the activity of the mitochondrial enzyme succinate dehydrogenase, the Trypan blue dye exclusion test evaluates possible damages to the integrity of the cytoplasmic membrane which result in cell death. The capacity of yangambin to inhibit the sea urchin embryonic development showed that it has low antimitotic and teratogenic potential, once continued exposure of embryos to concentrations up to 500 μg/mL (1.025 μm) did not result in an inhibitory effect on the first egg cleavages. Such low in vitro cytotoxicity is correlated with the low acute toxicity previously studied. All these data, together with the various therapeutic properties of yangambin, make this lignan a promising one for a new drug.
Flow Cytometry and Phytochemical Analysis of a Sunflower Cell Suspension Culture in a 5-L Bioreactor
Authors: Haas Christiane , Weber Jost , Ludwig-Müller Jutta , Deponte Sandra , Bley Thomas , Georgiev Milen
Published: February 2015

A cell suspension culture of sunflower (Helianthus annuus), a producer of immunologically active polysaccharides, was cultivated in a 5-L stirred tank bioreactor, operated in batch mode. After some changes in the internal bioreactor design a stable growth of Helianthus cells was achieved and the accumulated biomass reached 15.2 g/L (only ~5% lower compared to the accumulated biomass in shake-flasks). Flow cytometry used for measuring the cell cycle parameters of suspended Helianthus cells did not reveal significant differences between shake-flasks and bioreactor cultivation modes. For both cultivation methods significant enhancement of the percentage of S-phase cells was observed at the beginning of the cultivation process. Concerning the metabolite production the maximum in exopolysaccharides was reached at day 9 of the cultivation period (1.9 g/L), while the highest amounts of α-tocopherol were accumulated at the beginning of the cultivation process (day 2 of the cultivation). These finding were related to the respective stress levels caused by the inoculation procedure. The kinetic parameters of growth and polysaccharide production as well as the time course of carbon source utilization were monitored and discussed.
Genetic Stability of Micropropagated Ginger Derived from Axillary Bud through Cytophotometric and RAPD Analysis
Authors: Mohanty Sujata , Panda Manoj K. , Subudhi Enketeswara , Acharya Laxmikanta , Nayak Sanghamitra
Published: February 2015

A protocol was developed for the in vitro propagation of ginger (Zingiber officinale) cv. Suprava using dormant axillary buds from unsprouted rhizomes. The dormant axillary buds embedded in the rhizome nodes were induced to sprout when cultured on MS medium supplemented with 6-benzyladenine (BA) alone (1 - 6 mg/l) or with a combination of BA (1 - 6 mg/l) and indole-3-acetic acid (IAA) (0.5, 1 mg/l). In vitro sprouted buds were transferred to the multiplication medium containing various combinations of auxins and cytokinins. MS basal medium supplemented with BA (1 mg/l), IAA (1 mg/l) and adenine sulfate (100 mg/l) was found optimum for the in vitro multiplication of shoots producing (8.2 ± 0.2) shoots from a single explant within 30 days of culture. The multiplication rate remained unchanged in subsequent subcultures. Rooting of shoots occurred in the same multiplication media. Upon transfer of the in vitro culture to ex vitro in pots, 96% of plants survived and established successfully under natural conditions. Tissue culture-raised plantlets of ginger could be conserved in vitro through subculturing at an interval of 4 months. The genetic stability of micropropagated clones was evaluated at regular intervals of 6 months up to 24 months in culture using cytophotometric estimation of 4C nuclear DNA content and random amplified polymorphic DNA (RAPD) analysis. Cytophotometric analysis revealed a unimodal distribution of the DNA content with a peak corresponding to the 4C value (23.1 pg), and RAPD analysis revealed monomorphic bands showing the absence of polymorphism in all fifty regenerants analyzed, thus confirming the genetic uniformity among in vitro grown somaclones of Z. officinale. This study is of commercial significance as axillary bud explants are available throughout the year for initiating a fresh culture of the elite ginger cv. Suprava to be used as a source of true-to-type disease-free planting material thereby minimizing the adverse effect of repeated subculturing from the same explant source.
Development of an Attractant-Baited Trap for Oxythyrea funesta Poda (Coleoptera: Scarabaeidae, Cetoniinae)
Authors: Vuts József , Imrei Zoltän , Tóth Miklós
Published: February 2015

In electroantennographic tests isosafrol, methyl salicylate, (±)-lavandulol, geraniol, (E)-anethol, and β-ionone evoked the largest responses from antennae of female or male Oxythyrea funesta (Coleoptera: Scarabaeidae, Cetoniinae) adult beetles. In field trapping tests in Hungary the 1: 1 blend of (±)-lavandulol and 2-phenylethanol attracted significantly more adult O. funesta than the single compounds. The addition of (E)-anethol, a previously described attractant for the species, was without effect. There was no difference in the responses of male or female beetles. The binary 2-phenylethanol/(±)-lavandulol bait described in this study is recommended for the use in traps of O. funesta for agricultural purposes.
Detection of Cytochrome P450-2A6, -3A5 and -4B1 with Real-Time Polymerase Chain Reaction in Prostate Tissue
Authors: Zencir Sevil , Alptekin Davut , Celiktas Medih , Canturk Pakize , Colak Deniz , Caner Vildan , Luleyap Umit H. , Topcu Zeki
Published: February 2015

Cytochrome P450 (CYP) is a heme-containing enzyme superfamily metabolizing a wide variety of xenobiotics, including drugs and carcinogens. The majority of CYP genes are expressed in the liver, however, some CYP isoforms are also reported for a number of extra hepatic tissues. We analyzed Cytochrome P450-2A6, -3A5 and -4B1 mRNAs using realtime reverse-transcriptase polymerase chain reaction (RT-PCR) in a total of 21 homogenized prostate tissues with or without malignancy. We detected a consistent expression of CYP2A6 and CYP3A5 in all, and of CYP4B1 in some (11/21) of the samples at mRNA level. Neither the histopathological status nor the smoking habit of the individuals affected CYP4B1 expression. Our results reflect possible roles for these particular CYPs in therapy and protection of prostate tissue.
Linking Cell Surface Receptors to Microtubules: Tubulin Folding Cofactor D Mediates Dscam Functions during Neuronal Morphogenesis
Authors: Okumura Misako , Sakuma Chisako , Miura Masayuki , Chihara Takahiro
Published: February 2015

Formation of functional neural networks requires the coordination of cell surface receptors and downstream signaling cascades, which eventually leads to dynamic remodeling of the cytoskeleton. Although a number of guidance receptors affecting actin cytoskeleton remodeling have been identified, it is relatively unknown how microtubule dynamics are regulated by guidance receptors. We usedDrosophilaolfactory projection neurons to study the molecular mechanisms of neuronal morphogenesis. Dendrites of each projection neuron target a single glomerulus of ∼50 glomeruli in the antennal lobe, and the axons show stereotypical pattern of terminal arborization. In the course of genetic analysis of thedachsousmutant allele (dsUAO71), we identified a mutation in thetubulin folding cofactor Dgene (TBCD) as a background mutation. TBCD is one of five tubulin-folding cofactors required for the formation of α- and β-tubulin heterodimers. Single-cell clones of projection neurons homozygous for theTBCDmutation displayed disruption of microtubules, resulting in ectopic arborization of dendrites, and axon degeneration. Interestingly, overexpression of TBCD also resulted in microtubule disruption and ectopic dendrite arborization, suggesting that an optimum level of TBCD is crucial forin vivoneuronal morphogenesis. We further found that TBCD physically interacts with the intracellular domain of Down syndrome cell adhesion molecule (Dscam), which is important for neural development and has been implicated in Down syndrome. Genetic analyses revealed that TBCD cooperates with Dscamin vivo. Our study may offer new insights into the molecular mechanism underlying the altered neural networks in cognitive disabilities of Down syndrome.
Learning to Integrate versus Inhibiting Information Is Modulated by Age
Authors: Cappelletti Marinella , Pikkat Helen , Upstill Emily , Speekenbrink Maarten , Walsh Vincent
Published: February 2015

Cognitive training aiming at improving learning is often successful, but what exactly underlies the observed improvements and how these differ across the age spectrum are currently unknown. Here we asked whether learning in young and older people may reflect enhanced ability to integrate information required to perform a cognitive task or whether it may instead reflect the ability to inhibit task-irrelevant information for successful task performance. We trained 30 young and 30 aging human participants on a numerosity discrimination task known to engage the parietal cortex and in which cue-integration and inhibitory abilities can be distinguished. We coupled training with parietal, motor, or sham transcranial random noise stimulation, known for modulating neural activity. Numerosity discrimination improved after training and was maintained long term, especially in the training + parietal stimulation group, regardless of age. Despite the quantitatively similar improvement in the two age groups, the content of learning differed remarkably: aging participants improved more in inhibitory abilities, whereas younger subjects improved in cue-integration abilities. Moreover, differences in the content of learning were reflected in different transfer effects to untrained but related abilities: in the younger group, improvements in cue integration paralleled improvements in continuous quantity (time and space), whereas in the elderly group, improvements in numerosity-based inhibitory abilities generalized to other measures of inhibition and corresponded to a decline in space discrimination, possibly because conflicting learning resources are used in numerosity and continuous quantity processing. These results indicate that training can enhance different, age-dependent cognitive processes and highlight the importance of identifying the exact processes underlying learning for effective training programs.
Attention Drives Synchronization of Alpha and Beta Rhythms between Right Inferior Frontal and Primary Sensory Neocortex
Authors: Sacchet Matthew D. , LaPlante Roan A. , Wan Qian , Pritchett Dominique L. , Lee Adrian K.C. , Hämäläinen Matti , Moore Christopher I. , Kerr Catherine E. , Jones Stephanie R.
Published: February 2015

The right inferior frontal cortex (rIFC) is specifically associated with attentional control via the inhibition of behaviorally irrelevant stimuli and motor responses. Similarly, recent evidence has shown that alpha (7–14 Hz) and beta (15–29 Hz) oscillations in primary sensory neocortical areas are enhanced in the representation of non-attended stimuli, leading to the hypothesis that allocation of these rhythms plays an active role in optimal inattention. Here, we tested the hypothesis that selective synchronization betweenrIFCand primary sensory neocortex occurs in these frequency bands during inattention. We used magnetoencephalography to investigate phase synchrony between primary somatosensory (SI) andrIFCregions during a cued-attention tactile detection task that required suppression of response to uncertain distractor stimuli. Attentional modulation of synchrony between SI andrIFCwas found in both the alpha and beta frequency bands. This synchrony manifested as an increase in the alpha-band early after cue between non-attended SI representations and rIFC, and as a subsequent increase in beta-band synchrony closer to stimulus processing. Differences in phase synchrony were not found in several proximal control regions. These results are the first to reveal distinct interactions between primary sensory cortex andrIFCin humans and suggest that synchrony betweenrIFCand primary sensory representations plays a role in the inhibition of irrelevant sensory stimuli and motor responses.
Large Intercalated Neurons of Amygdala Relay Noxious Sensory Information
Authors: Bienvenu Thomas C.M. , Busti Daniela , Micklem Benjamin R. , Mansouri Mahnaz , Magill Peter J. , Ferraguti Francesco , Capogna Marco
Published: February 2015

Various GABAergic neuron types of the amygdala cooperate to control principal cell firing during fear-related and other behaviors, and understanding their specialized roles is important. Among GABAergic neurons, the so-called intercalated cells (ITCcs) are critically involved in the expression and extinction of fear memory. Tightly clustered small-sized spiny neurons constitute the majority of ITCcs, but they are surrounded by sparse, larger neurons (L-ITCcs) for which very little information is known. We report here a detailed neurochemical, structural and physiological characterization of rat L-ITCcs, as identified with juxtacellular recording/labelingin vivo. We supplement these data with anatomical and neurochemical analyses of nonrecorded L-ITCcs. We demonstrate that L-ITCcs are GABAergic, and strongly express metabotropic glutamate receptor 1α and GABAAreceptor α1 subunit, together with moderate levels of parvalbumin. Furthermore, L-ITCcs are innervated by fibers enriched with metabotropic glutamate receptors 7a and/or 8a. In contrast to small-sized spiny ITCcs, L-ITCcs possess thick, aspiny dendrites, have highly branched, long-range axonal projections, and innervate interneurons in the basolateral amygdaloid complex. The axons of L-ITCcs also project to distant brain areas, such as the perirhinal, entorhinal, and endopiriform cortices.In vivorecorded L-ITCcs are strongly activated by noxious stimuli, such as hindpaw pinches or electrical footshocks. Consistent with this, we observed synaptic contacts on L-ITCc dendrites from nociceptive intralaminar thalamic nuclei. We propose that, during salient sensory stimulation, L-ITCcs disinhibit local and distant principal neurons, acting as “hub cells,” to orchestrate the activity of a distributed network.
Not GABA But Glycine Mediates Segmental, Propriospinal, and Bulbospinal Postsynaptic Inhibition in Adult Mouse Spinal Forelimb Motor Neurons
Authors: Jiang Juan , Alstermark Bror
Published: February 2015

The general view is that both glycine (Eccles, 1964) and GABA (Curtis and Felix, 1971) evoke postsynaptic inhibition in spinal motor neurons. In newborn or juvenile animals, there are conflicting results showing postsynaptic inhibition in motor neurons by corelease of GABA and glycine (Jonas et al., 1998) or by glycine alone (Bhumbra et al., 2012). To resolve the relative contributions of GABA and glycine to postsynaptic inhibition, we performedin vivointracellular recordings from forelimb motor neurons in adult mice. Postsynaptic potentials evoked from segmental, propriospinal, and bulbospinal systems in motor neurons were compared across four different conditions: control, after gabazine, gabazine followed by strychnine, and strychnine alone. No significant differences were observed in the proportion of IPSPs and EPSPs between control and gabazine conditions. In contrast, EPSPs but not IPSPs were recorded after adding strychnine with gabazine or administering strychnine alone, suggesting an exclusive role for glycine in postsynaptic inhibition. To test whether the injected (intraperitoneal) dose of gabazine blocked GABAergic inhibitory transmission, we evoked GABAAreceptor-mediated monosynaptic IPSPs in deep cerebellar nuclei neurons by stimulation of Purkinje cell fibers. No monosynaptic IPSPs could be recorded in the presence of gabazine, showing the efficacy of gabazine treatment. Our results demonstrate that, in the intact adult mouse, the postsynaptic inhibitory effects in spinal motor neurons exerted by three different systems, intrasegmental and intersegmental as well as supraspinal, are exclusively glycinergic. These findings emphasize the importance of glycinergic postsynaptic inhibition in motor neurons and challenge the view that GABA also contributes.
Activity-Dependent Rapid Local RhoA Synthesis Is Required for Hippocampal Synaptic Plasticity
Authors: Briz Victor , Zhu Guoqi , Wang Yubin , Liu Yan , Avetisyan Mariam , Bi Xiaoning , Baudry Michel
Published: February 2015

Dendritic protein synthesis and actin cytoskeleton reorganization are important events required for the consolidation of hippocampal LTP and memory. However, the temporal and spatial relationships between these two processes remain unclear. Here, we report that treatment of adult rat hippocampal slices with BDNF or with tetraethylammonium (TEA), which induces a chemical form of LTP, produces a rapid and transient increase in RhoA protein levels. Changes in RhoA were restricted to dendritic spines of CA3 and CA1 and requirede novoprotein synthesis regulated by mammalian target of rapamycin (mTOR). BDNF-mediated stimulation of RhoA activity, cofilin phosphorylation, and actin polymerization were completely suppressed by protein synthesis inhibitors. Furthermore, intrahippocampal injections of RhoA antisense oligodeoxynucleotides inhibited theta burst stimulation (TBS)-induced RhoA upregulation in dendritic spines and prevented LTP consolidation. Addition of calpain inhibitors after BDNF or TEA treatment maintained RhoA levels elevated and prolonged the effects of BDNF and TEA on actin polymerization. Finally, the use of isoform-selective calpain inhibitors revealed that calpain-2 was involved in RhoA synthesis, whereas calpain-1 mediated RhoA degradation. Overall, this mechanism provides a novel link between dendritic protein synthesis and reorganization of the actin cytoskeleton in hippocampal dendritic spines during LTP consolidation.
A Central Neural Pathway Controlling Odor Tracking inDrosophila
Authors: Slater Gemma , Levy Peter , Chan K.L. Andrew , Larsen Camilla
Published: February 2015

Chemotaxis is important for the survival of most animals. How the brain translates sensory input into motor output beyond higher olfactory processing centers is largely unknown. We describe a group of excitatory neurons, termed Odd neurons, which are important forDrosophilalarval chemotaxis. Odd neurons receive synaptic input from projection neurons in the calyx of the mushroom body and project axons to the central brain. Functional imaging shows that some of the Odd neurons respond to odor. Larvae in which Odd neurons are silenced are less efficient at odor tracking than controls and sample the odor space more frequently. Larvae in which the excitability of Odd neurons is increased are better at odor intensity discrimination and odor tracking. Thus, the Odd neurons represent a distinct pathway that regulates the sensitivity of the olfactory system to odor concentrations, demonstrating that efficient chemotaxis depends on processing of odor strength downstream of higher olfactory centers.
Interhemispheric Interactions of the Human Thalamic Reticular Nucleus
Authors: Viviano Joseph D. , Schneider Keith A.
Published: February 2015

The thalamic reticular nucleus is an important structure governing the recurrent interactions between the thalamus and cortex that may provide a substrate for unified perception. Despite the importance of the TRN, its activity has been scarcely investigatedin vivoin animal models, and never in humans. Here we anatomically identify the human TRN using multiple registered and averaged proton density-weighted structural MRI scans and drive its functional activity with a dual phase-encoded stimulus. We characterize the retinotopic and temporal response properties in the visual sector of the TRN and measured an inhibitory relationship with the contralateral LGN. These observations provide a basis for further gross characterizations of the role of the TRN in human behavior.
Vasoactive Intestinal Polypeptide (VIP)-Expressing Neurons in the Suprachiasmatic Nucleus Provide Sparse GABAergic Outputs to Local Neurons with Circadian Regulation Occurring Distal to the Opening of Postsynaptic GABAAIonotropic Receptors
Authors: Fan Junmei , Zeng Hongkui , Olson David P. , Huber Kimberly M. , Gibson Jay R. , Takahashi Joseph S.
Published: February 2015

GABAergic synaptic transmission plays an important role in resetting and synchronizing circadian rhythms in the suprachiasmatic nucleus (SCN). Although the circadian modulation of intrinsic membrane currents and biochemical signaling have been examined in the SCN, the modulation of specific synaptic pathways within the SCN is unexplored. In addition, little is known about the functional properties of these pathways, including which ones involve GABAAreceptors (GABAA-Rs). In brain slices obtained from mice, we examined synaptic responses originating from the SCN neurons expressing vasoactive intestinal peptide (VIP+ neurons). Focusing on the local projection within the ventromedial SCN, we found that VIP+ afferents provided input onto 49% of neurons with a preference for VIP-negative (VIP−) neurons. Responses were mediated by GABAA-Rs. The projection was sparsely connected and preferentially targeted a subset of SCN neurons unrelated to postsynaptic VIP expression. For most aspects of VIP+ network output, there was no circadian regulation. Excitability and spontaneous firing of the presynaptic VIP+ neurons were unchanged between day and night, and their network connectivity and synaptic function up through the evoked synaptic conductance were also unchanged. On the other hand, VIP+ input onto VIP− neurons became less inhibitory at night suggesting a postsynaptic alteration in the coupling of GABAA-R conductances to action potential firing. These data suggest that components of the VIP network and its synaptic output up through GABAA-R opening are invariant during the circadian cycle, but the effect on action potential firing is modulated by postsynaptic processes occurring after GABAA-R channel opening.
Ca2+Channel to Synaptic Vesicle Distance Accounts for the Readily Releasable Pool Kinetics at a Functionally Mature Auditory Synapse
Authors: Chen Zuxin , Das Brati , Nakamura Yukihiro , DiGregorio David A. , Young Samuel M.
Published: February 2015

Precise regulation of synaptic vesicle (SV) release at the calyx of Held is critical for auditory processing. At the prehearing calyx of Held, synchronous and asynchronous release is mediated by fast and slow releasing SVs within the readily releasable pool (RRP). However, the posthearing calyx has dramatically different release properties. Whether developmental alterations in RRP properties contribute to the accelerated release time course found in posthearing calyces is not known. To study these questions, we performed paired patch-clamp recordings, deconvolution analysis, and numerical simulations of buffered Ca2+diffusion and SV release in postnatal day (P) 16–19 mouse calyces, as their release properties resemble mature calyces of Held. We found the P16–P19 calyx RRP consists of two pools: a fast pool (τ ≤ 0.9 ms) and slow pool (τ ∼4 ms), in which release kinetics and relative composition of the two pools were unaffected by 5 mmEGTA. Simulations of SV release from the RRP revealed that two populations of SVs were necessary to reproduce the experimental release rates: (1) SVs located close (∼5–25 nm) and (2) more distal (25–100 nm) to VGCC clusters. This positional coupling was confirmed by experiments showing 20 mmEGTA preferentially blocked distally coupled SVs. Lowering external [Ca2+] toin vivolevels reduced only the fraction SVs released from the fast pool. Therefore, we conclude that a dominant parameter regulating the mature calyx RRP release kinetics is the distance between SVs and VGCC clusters.
Activation of BK and SK Channels by Efferent Synapses on Outer Hair Cells in High-Frequency Regions of the Rodent Cochlea
Authors: Rohmann Kevin N. , Wersinger Eric , Braude Jeremy P. , Pyott Sonja J. , Fuchs Paul Albert
Published: February 2015

Cholinergic neurons of the brainstem olivary complex project to and inhibit outer hair cells (OHCs), refining acoustic sensitivity of the mammalian cochlea. In all vertebrate hair cells studied to date, cholinergic inhibition results from the combined action of ionotropic acetylcholine receptors and associated calcium-activated potassium channels. Although inhibition was thought to involve exclusively small conductance (SK potassium channels), recent findings have shown that BK channels also contribute to inhibition in basal, high-frequency OHCs after the onset of hearing. Here we show that the waveform of randomly timed IPSCs (evoked by high extracellular potassium) in high-frequency OHCs is altered by blockade of either SK or BK channels, with BK channels supporting faster synaptic waveforms and SK channels supporting slower synaptic waveforms. Consistent with these findings, IPSCs recorded from high-frequency OHCs that express BK channels are briefer than IPSCs recorded from low-frequency (apical) OHCs that do not express BK channels and from immature high-frequency OHCs before the developmental onset of BK channel expression. Likewise, OHCs of BKα−/−mice lacking the pore-forming α-subunit of BK channels have longer IPSCs than do the OHCs of BKα+/+littermates. Furthermore, serial reconstruction of electron micrographs showed that postsynaptic cisterns of BKα−/−OHCs were smaller than those of BKα+/+OHCs, and immunofluorescent quantification showed that efferent presynaptic terminals of BKα−/−OHCs were smaller than those of BKα+/+OHCs. Together, these findings indicate that BK channels contribute to postsynaptic function, and influence the structural maturation of efferent-OHC synapses.
Developmental Tightening of Cerebellar Cortical Synaptic Influx-Release Coupling
Authors: Baur David , Bornschein Grit , Althof Daniel , Watanabe Masahiko , Kulik Akos , Eilers Jens , Schmidt Hartmut
Published: February 2015

Tight coupling between Ca2+channels and the sensor for vesicular transmitter release at the presynaptic active zone (AZ) is crucial for high-fidelity synaptic transmission. It has been hypothesized that a switch from a loosely coupled to a tightly coupled transmission mode is a common step in the maturation of CNS synapses. However, this hypothesis has never been tested at cortical synapses. We addressed this hypothesis at a representative small cortical synapse: the synapse connecting mouse cerebellar cortical parallel fibers to Purkinje neurons. We found that the slow Ca2+chelator EGTA affected release significantly stronger at immature than at mature synapses, while the fast chelator BAPTA was similarly effective in both groups. Analysis of paired-pulse ratios and quantification of release probability (pr) with multiple-probability fluctuation analysis revealed increased facilitation at immature synapses accompanied by reducedpr. Cav2.1 Ca2+channel immunoreactivity, assessed by quantitative high-resolution immuno-electron microscopy, was scattered over immature boutons but confined to putative AZs at mature boutons. Presynaptic Ca2+signals were quantified with two-photon microscopy and found to be similar between maturation stages. Models adjusted to fit EGTA dose–response curves as well as differential effects of the Ca2+channel blocker Cd2+indicate looser and less homogenous coupling at immature terminals compared with mature ones. These results demonstrate functionally relevant developmental tightening of influx-release coupling at a single AZ cortical synapse and corroborate developmental tightening of coupling as a prevalent phenomenon in the mammalian brain.