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1.
Nat Commun ; 11(1): 1509, 2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32198346

RESUMO

Nonsense mutations cause about 10% of genetic disease cases, and no treatments are available. Nonsense mutations can be corrected by molecules with nonsense mutation readthrough activity. An extract of the mushroom Lepista inversa has recently shown high-efficiency correction of UGA and UAA nonsense mutations. One active constituent of this extract is 2,6-diaminopurine (DAP). In Calu-6 cancer cells, in which TP53 gene has a UGA nonsense mutation, DAP treatment increases p53 level. It also decreases the growth of tumors arising from Calu-6 cells injected into immunodeficient nude mice. DAP acts by interfering with the activity of a tRNA-specific 2'-O-methyltransferase (FTSJ1) responsible for cytosine 34 modification in tRNATrp. Low-toxicity and high-efficiency UGA nonsense mutation correction make DAP a good candidate for the development of treatments for genetic diseases caused by nonsense mutations.


Assuntos
2-Aminopurina/análogos & derivados , 2-Aminopurina/farmacologia , Códon sem Sentido/efeitos dos fármacos , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Mutação/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genes p53/genética , Células HEK293 , Células HeLa , Humanos , Lepisma/química , Camundongos , Camundongos Nus , RNA de Transferência/genética , tRNA Metiltransferases/metabolismo
2.
PLoS One ; 14(2): e0212505, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30817757

RESUMO

The digestive system of selected phytophagous insects has been examined as a potential prospecting resource for identification of novel cellulolytic enzymes with potential industrial applications. In contrast to other model species, however, limited detailed information is available that characterizes cellulolytic activity and systems in basal hexapod groups. As part of a screening effort to identify insects with highly active cellulolytic systems, we have for the first time, identified species of Zygentoma that displayed the highest relative cellulase activity levels when compared to all other tested insect groups under the experimental conditions, including model species for cellulolytic systems such as termite and cockroach species in Rhinotermitidae (formerly Isoptera) and Cryptocercidae (formerly Blattodea). The goal of the present study was to provide a morphohistological characterization of cellulose digestion and to identify highly active cellulase enzymes present in digestive fluids of Zygentoma species. Morphohistological characterization supported no relevant differences in the digestive system of firebrat (Thermobia domestica) and the gray silverfish (Ctenolepisma longicaudata). Quantitative and qualitative cellulase assays identified the foregut as the region with the highest levels of cellulase activity in both T. domestica and C. longicaudata. However, T. domestica was found to have higher endoglucanase, xylanase and pectinase activities compared to C. longicaudata. Using nano liquid chromatography coupled to tandem mass spectrometry (nanoLC/MS/MS) and a custom gut transcriptome we identified cellulolytic enzymes from digestive fluids of T. domestica. Among the identified enzymes we report putative endoglucanases matching to insect or arthropod enzymes and glucan endo-1,6-ß-glucosidases matching bacterial enzymes. These findings support combined activities of endogenous and symbiont-derived plant cell wall degrading enzymes in lignocellulose digestion in Zygentoma and advance our understanding of cellulose digestion in a primitive insect group.


Assuntos
Celulase/metabolismo , Proteínas de Insetos/metabolismo , Insetos/enzimologia , Animais , Celulase/genética , Baratas/enzimologia , Baratas/genética , Baratas/microbiologia , Sistema Digestório/anatomia & histologia , Sistema Digestório/enzimologia , Sistema Digestório/microbiologia , Endo-1,4-beta-Xilanases/metabolismo , Proteínas de Insetos/genética , Insetos/genética , Insetos/microbiologia , Isópteros/enzimologia , Isópteros/genética , Isópteros/microbiologia , Lepisma/enzimologia , Lepisma/genética , Lepisma/microbiologia , Modelos Biológicos , Poligalacturonase/metabolismo , Especificidade da Espécie , Transcriptoma
3.
Sci Rep ; 8(1): 17856, 2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30552350

RESUMO

The Antarctic silverfish (Pleuragramma antarctica) is a critically important forage species with a circumpolar distribution and is unique among other notothenioid species for its wholly pelagic life cycle. Previous studies have provided mixed evidence of population structure over regional and circumpolar scales. The aim of the present study was to test the recent population hypothesis for Antarctic silverfish, which emphasizes the interplay between life history and hydrography in shaping connectivity. A total of 1067 individuals were collected over 25 years from different locations on a circumpolar scale. Samples were genotyped at fifteen microsatellites to assess population differentiation and genetic structuring using clustering methods, F-statistics, and hierarchical analysis of variance. A lack of differentiation was found between locations connected by the Antarctic Slope Front Current (ASF), indicative of high levels of gene flow. However, gene flow was significantly reduced at the South Orkney Islands and the western Antarctic Peninsula where the ASF is absent. This pattern of gene flow emphasized the relevance of large-scale circulation as a mechanism for circumpolar connectivity. Chaotic genetic patchiness characterized population structure over time, with varying patterns of differentiation observed between years, accompanied by heterogeneous standard length distributions. The present study supports a more nuanced version of the genetic panmixia hypothesis that reflects physical-biological interactions over the life history.


Assuntos
Fluxo Gênico , Genética Populacional , Genótipo , Lepisma/genética , Animais , Regiões Antárticas , Análise por Conglomerados , Técnicas de Genotipagem , Repetições de Microssatélites
4.
Zootaxa ; 4504(3): 447-450, 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30486022

RESUMO

With the discovery of Ctenolepisma longicaudata by Goddard et al. (2016) and the record of Ctenolepisma lineata as a possible introduced pest by Notton (2018), as well as the changes to the higher classification reported by Barnard (2011), the current number of UK Lepismatidae (silverfish and firebrats) that an entomologist might encounter has doubled. Therefore, the most recent checklist (Kloet Hicks 1964) is in need of revision. This paper aims to provide an updated check list, guide to keys that can be used to Identify UK Lepismatidae as well as to provide an overview of UK species.


Assuntos
Insetos , Lepisma , Animais , Reino Unido
5.
Carbohydr Polym ; 197: 540-547, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30007645

RESUMO

The present study examined the role of a polysaccharide (LSP, 25 and 100 µg/ml) from the fruiting bodies of Lepista sordid on the immunosuppressive enzyme indoleamine 2, 3-dioxygenase (IDO) in HepG2 cells, and the possible mechanism of action. IDO expression and kynurenine production from LSP-treated HepG2 cells following IFN-γ stimulation were dramatically inhibited by LSP treatment. In line with this, the medium of HepG2 cells pretreated with LSP improved the survival rate of primary CD4+ and CD8+ T cells as compared with IFN-γ-treated control cells. Moreover, tyrosine 701 and serine 727 phosphorylation of STAT1 were dramatically reduced by LSP pretreatment in IFN-γ-stimulated HepG2 cells. Furthermore phosphorylation of JAK-1 and JAK-2 was also inhibited by LSP. Additionally, two IDO promoters (GAS and ISRE) were inhibited in cells pretreated with LSP prior to IFN-γ exposure. These findings suggest that LSP exerts antitumor effects on HepG2 cells by inhibiting IDO via JAK-PKC-δ-STAT1 signaling pathway.


Assuntos
Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Janus Quinase 1/antagonistas & inibidores , Polissacarídeos/farmacologia , Proteína Quinase C-delta/antagonistas & inibidores , Fator de Transcrição STAT1/antagonistas & inibidores , Animais , Relação Dose-Resposta a Droga , Descoberta de Drogas , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Carpóforos/química , Células Hep G2 , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Janus Quinase 1/metabolismo , Lepisma/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Proteína Quinase C-delta/metabolismo , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade
7.
Arq. Inst. Biol ; 81(2): 140-144, abr.-jun. 2014. tab
Artigo em Português | ID: biblio-1004998

RESUMO

A traça Tuta absoluta (Meyrick) é o inseto-praga que mais compromete a produção do tomateiro. Basear o seu controle no uso de inseticidas sintéticos pode comprometer a cultura em termos econômicos e ambientais. Como alternativa de controle, o óleo de nim foi aplicado em folhas de tomateiro, avaliando os efeitos inseticida e antialimentar por ação sistêmica e translaminar. No ensaio para avaliar a ação translaminar, o óleo diluído em água foi aplicado na superfície adaxial dos folíolos, em concentrações de 0,5, 1, 5 e 10%. A mortalidade observada variou entre 49 e 100%, e o tamanho médio das minas, entre 1,62 e 0,34 cm. Nos tratamentos representados por água e água + emulsificante (5%), a mortalidade não ultrapassou 20%, com tamanho médio das minas de 1,63 cm. O estudo da ação sistêmica foi realizado ao aplicar o óleo de nim na superfície adaxial e abaxial de todas as folhas das plantas, à exceção daquelas em que as lagartas foram infestadas. Neste ensaio, o óleo foi aplicado nas concentrações de 1, 2,5 e 5%, diluídos em água e emulsificante. Observou-se que a mortalidade foi maior que 90% quando o óleo foi aplicado nas concentrações de 2,5 e 5%, sendo o tamanho médio das minas inferior a 1,0 cm. Não ocorreu mortalidade nos tratamentos controle, mas o tamanho das minas foi, em média, de 1,96 cm. Desta maneira ficou evidenciado que o óleo de nim apresenta efeito inseticida e antialimentar sobre lagartas de T. absoluta, com a propriedade de ser incorporado e translocado através das folhas de tomateiro.(AU)


The leaf miner Tuta absoluta (Meyrick) is the pest that mostly jeopardizes tomato production. The use of synthetic pesticides for its control can affect the crop economically and environmentally. As an alternative form of control, neem oil was applied on tomato leaves in order to assess antifeedant and insecticidal effects by systemic and translaminar action. In experiment for translaminar action, oil diluted in water was applied to the adaxial surface of leaflets at concentrations of 0.5, 1, 5 and 10%. The mortality rate ranged between 49 and 100%, and the average size of the mines, between 1.62 and 0.34 cm. In treatments represented by water and water + emulsifier (5%), mortality did not surpass 20%, with the average size of mines reaching 1.63 cm. The study of systemic action was performed by applying neem oil to the adaxial and abaxial surfaces of all leaves, except those that were infested by caterpillars. In this assay, the oil was applied at concentrations of 1, 2.5 and 5%, being diluted in water and emulsifiers. We observed that the mortality rate exceeded 90% when the oil was applied at concentrations of 2.5 and 5%, and the average size of mines was smaller than 1.0 cm. There was no mortality in the control treatments, but the mine size was on average 1.96 cm. Therefore, it is clear that the neem oil has an insecticidal and anti-food effect on T. absoluta caterpillars, and is possible to be incorporated and applied on tomato leaves.(AU)


Assuntos
Lycopersicon esculentum , Azadirachta , Lepisma , Inseticidas , Controle de Pragas , Insetos
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