Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Dev Cell ; 56(6): 842-859.e8, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33756122

RESUMO

Extracellular vesicles (EVs) are classified as large EVs (l-EVs, or microvesicles) and small EVs (s-EVs, or exosomes). S-EVs are thought to be generated from endosomes through a process that mainly depends on the ESCRT protein complex, including ALG-2 interacting protein X (ALIX). However, the mechanisms of l-EV generation from the plasma membrane have not been identified. Membrane curvatures are generated by the bin-amphiphysin-rvs (BAR) family proteins, among which the inverse BAR (I-BAR) proteins are involved in filopodial protrusions. Here, we show that the I-BAR proteins, including missing in metastasis (MIM), generate l-EVs by scission of filopodia. Interestingly, MIM-containing l-EV production was promoted by in vivo equivalent external forces and by the suppression of ALIX, suggesting an alternative mechanism of vesicle formation to s-EVs. The MIM-dependent l-EVs contained lysophospholipids and proteins, including IRS4 and Rac1, which stimulated the migration of recipient cells through lamellipodia formation. Thus, these filopodia-dependent l-EVs, which we named as filopodia-derived vesicles (FDVs), modify cellular behavior.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ciclo Celular/metabolismo , Movimento Celular , Endocitose , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Exossomos/metabolismo , Vesículas Extracelulares/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteínas de Neoplasias/metabolismo , Pseudópodes/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ciclo Celular/genética , Membrana Celular/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Células HEK293 , Humanos , Proteínas dos Microfilamentos/genética , Proteínas de Neoplasias/genética
2.
Lipids ; 55(2): 89-99, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31867745

RESUMO

Ricinoleic acid (RA) is the main fatty acid component of castor oil and was found to inhibit Ca2+ -signal transduction pathway-mediated cell cycle regulation in a yeast-based drug screening assay. RA is expected to have antidiabetic, antiallergy, and/or anticancer properties but its target molecule is unknown. To identify a novel pharmacological effect of RA, we investigated its target molecule in the Ca2+ -signal transduction pathway. RA inhibition of calcineurin (CN) was examined in a yeast-based CN inhibitor screening assay using the rsp5A401E mutant and in a phosphatase assay using recombinant human CN. RA showed growth-restoration activity at 5 µg/spot in the CN inhibitor screening assay with the rsp5A401E yeast strain. Furthermore, it directly inhibited CN without immunophilins at Ki = 33.7 µM in a substrate-competitive manner. The effects of RA on CN in mammalian cells were further evaluated by measuring ß-hexosaminidase (ß-HEX) release in RBL-2H3 cells. RA at 50 µM suppressed the release of ß-HEX from RBL-2H3 cells. Moreover, this compound was found to inhibit glycogen synthase kinase-3ß (GSK-3ß), as determined by a kinase assay using recombinant human GSK-3ß. RA inhibited GSK-3ß at Ki = 1.43 µM in a peptide substrate-competitive manner. The inhibition of GSK-3ß by this molecule was further assessed in mammalian cells by measuring the inhibition of glucose production in H4IIE rat hepatoma cells. RA at 25 µM suppressed glucose production in these cells. These findings indicate that RA and/or castor oil could be a useful functional fatty acid to treat allergy or type 2 diabetes.


Assuntos
Inibidores de Calcineurina/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Óleo de Rícino/química , Ácidos Ricinoleicos/farmacologia , Animais , Calcineurina/metabolismo , Avaliação Pré-Clínica de Medicamentos , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Fosforilação , Ratos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , beta-N-Acetil-Hexosaminidases/metabolismo
3.
Biosci Biotechnol Biochem ; 79(9): 1556-66, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25943373

RESUMO

Simultaneous extraction of plant organelle (mitochondria and plastid) genes during the DNA extraction step is major limitation in investigating the community structures of plant-associated bacteria. Although locked nucleic acid (LNA) oligonucleotides was designed to selectively amplify the bacterial small subunit rRNA genes by applying the PCR clamping technique, those for plastids were applicable only for particular plants, while those for mitochondria were available throughout most plants. To widen the applicable range, new LNA oligonucleotides specific for plastids were designed, and the efficacy was investigated. PCR without LNA oligonucleotides predominantly amplified the organelle genes, while bacterial genes were predominantly observed in having applied the LNA oligonucleotides. Denaturing gradient gel electrophoresis (DGGE) analysis displayed additional bacterial DGGE bands, the amplicons of which were prepared using the LNA oligonucleotides. Thus, new designed LNA oligonucleotides specific for plastids were effective and have widened the scope in investigating the community structures of plant-associated bacteria.


Assuntos
Proteínas de Bactérias/genética , Oligonucleotídeos/genética , Plastídeos/genética , Reação em Cadeia da Polimerase/métodos , Bactérias/genética , Bactérias/isolamento & purificação , Proteínas de Bactérias/isolamento & purificação , Eletroforese em Gel de Gradiente Desnaturante , Genes de RNAr , Mitocôndrias/genética , Plantas/genética , Plantas/microbiologia
4.
Evid Based Complement Alternat Med ; 5(4): 463-74, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18955217

RESUMO

'Oketsu' is a pathophysiologic concept in Japanese traditional (Kampo) medicine, primarily denoting blood stasis/stagnant syndrome. Here we have explored plasma protein biomarkers and/or diagnostic algorithms for 'Oketsu'. Sixteen rheumatoid arthritis (RA) patients were treated with keishibukuryogan (KBG), a representative Kampo medicine for improving 'Oketsu'. Plasma samples were diagnosed as either having an 'Oketsu' (n = 19) or 'non-Oketsu' (n = 29) state according to Terasawa's 'Oketsu' scoring system. Protein profiles were obtained by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) and hierarchical clustering and decision tree analyses were performed. KBG treatment for 4 or 12 weeks decreased the 'Oketsu' scores significantly. SELDI protein profiles gave 266 protein peaks, whose expression was significantly different between the 'Oketsu' and 'non-Oketsu' states. Hierarchical clustering gave three major clusters (I, II, III). The majority (68.4%) of 'Oketsu' samples were clustered into one cluster as the principal component of cluster I. The remaining 'Oketsu' profiles constituted a minor component of cluster II and were all derived from patients cured of the 'Oketsu' state at 12 weeks. Construction of the decision tree addressed the possibility of developing a diagnostic algorithm for 'Oketsu'. A reduction in measurement/pre-processing conditions (from 55 to 16) gave a similar outcome in the clustering and decision tree analyses. The present study suggests that the pathophysiologic concept of Kampo medicine 'Oketsu' has a physical basis in terms of the profile of blood proteins. It may be possible to establish a set of objective criteria for diagnosing 'Oketsu' using a combination of proteomic and bioinformatics-based classification methods.

5.
Clin Biochem ; 40(15): 1113-21, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17673196

RESUMO

OBJECTIVES: Kampo (Japanese traditional herbal) medicines are now ethically used in Japan as pharmaceutical grade prescription drugs. However, there are distinct groups of responders and non-responders to Kampo medicines. We searched for biomarker candidates to discriminate responders from non-responders to keishibukuryogan (KBG); one of the most frequently used Kampo medicines. DESIGN AND METHODS: A combination of SELDI technology and a decision tree analysis with proprietary developed bioinformatics tools was applied to 41 (32 for tree construction and 9 for validation test) plasma samples obtained from rheumatoid arthritis (RA) patients. A candidate biomarker protein was identified using LC-MS/MS. RESULTS: The constructed tree with measurable reliability contained only a single peak which was identified as haptoglobin alpha 1 chain (Hpalpha1). CONCLUSION: Hpalpha1 is a biomarker candidate for discriminating responders from non-responders to KBG treatment for RA. The present results may open the way to the establishment of "evidence-based" complementary and alternative medicine.


Assuntos
Artrite Reumatoide/diagnóstico , Artrite Reumatoide/tratamento farmacológico , Biomarcadores/análise , Medicamentos de Ervas Chinesas/uso terapêutico , Medicina Tradicional Chinesa , Medicina Kampo , Adulto , Idoso , Sequência de Aminoácidos , Medicamentos de Ervas Chinesas/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Dados de Sequência Molecular , Fitoterapia , Prognóstico , Análise Serial de Proteínas , Sensibilidade e Especificidade , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...