RESUMO
It was discovered recently that infection by a protozoan parasite, Azumiobodo hoyamushi, is the most probable cause for soft tunic syndrome in an edible ascidian, Halocynthia roretzi (Drasche). In an attempt to develop measures to eradicate the causative parasite, various drugs were tested for efficacy in vitro and in vivo. Of the 20 antiprotozoal drugs having different action mechanisms, five were found potent (24-h EC50 < 10 mg L(-1) ) in their parasite-killing effects: formalin, H2 O2 , bithionol, ClO2 and bronopol. Moderately potent drugs (10 < 24-h EC50 < 100 mg L(-1) ) were quinine, fumagillin, amphotericin B, ketoconazole, povidone-iodine, chloramine-T and benzalkonium chloride. Seven compounds, metronidazole, albendazole, paromomycin, nalidixic acid, sulfamonomethoxine, KMnO4 , potassium monopersulphate and citric acid, exhibited EC50 > 100 mg L(-1) . When ascidians were artificially infected with A. hoyamushi, treated using 40 mg L(-1) formalin, bronopol, ClO2 , or H2 O2 for 1 h and then monitored for 24 h, very low mortality was observed. However, the number of surviving parasite cells in the ascidian tunic tissues was significantly reduced by treating with 40 mg L(-1) formalin or ClO2 for 1 h. The data suggest that we might be able to develop a disinfection measure using a treatment regimen involving commonly available drugs.
Assuntos
Antiprotozoários/farmacologia , Kinetoplastida/efeitos dos fármacos , Urocordados/parasitologia , Animais , Aquicultura , Desinfetantes/farmacologia , Kinetoplastida/fisiologiaRESUMO
The aim of this study was to determine the dual effect of Maillard reaction and fermentation on the preventive cardiovascular effects of milk proteins. Maillard reaction products (MRP) were prepared from the reaction between milk proteins, such as whey protein concentrates (WPC) and sodium caseinate (SC), and lactose. The hydrolysates of MRP were obtained from fermentation by lactic acid bacteria (LAB; i.e., Lactobacillus gasseri H10, L. gasseri H11, Lactobacillus fermentum H4, and L. fermentum H9, where human-isolated strains were designated H1 to H15), which had excellent proteolytic and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities (>20%). The antioxidant activity of MRP was greater than that of intact proteins in assays of the reaction with 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and trivalent ferric ions; moreover, the effect of MRP was synergistically improved by fermentation. The Maillard reaction dramatically increased the level of antithrombotic activity and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) inhibitory effect of milk proteins, but did not change the level of activity for micellar cholesterol solubility. Furthermore, specific biological properties were enhanced by fermentation. Lactobacillus gasseri H11 demonstrated the greatest activity for thrombin and HMGR inhibition in Maillard-reacted WPC, by 42 and 33%, respectively, whereas hydrolysates of Maillard-reacted SC fermented by L. fermentum H9 demonstrated the highest reduction rate for micellar cholesterol solubility, at 52%. In addition, the small compounds that were likely released by fermentation of MRP were identified by size-exclusion chromatography. Therefore, MRP and hydrolysates of fermented MRP could be used to reduce cardiovascular risks.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Lactobacillus/metabolismo , Proteínas do Leite/uso terapêutico , Proteínas do Soro do Leite/uso terapêutico , Antioxidantes/metabolismo , Caseínas/química , Fermentação , Humanos , Lactose/química , Reação de Maillard , Proteínas do Leite/química , Proteínas do Soro do Leite/químicaRESUMO
The purpose of this study was to investigate the dietary effects of persimmon peel (PP) and PP ethanol extract (PPE) on egg production, egg quality, and liver lipids in the late stage of egg production in laying hens. One hundred and twenty 50-wk-old Hy-Line Brown layers (n = 120) were fed different diets. Four replicate groups of 6 hens each were randomly assigned to 5 dietary treatments. The 5 dietary treatments were as follows: i) CON, basal diet; ii) PP 0.15, CON+0.15% PP (0.035% tannin); iii) PP 0.5, CON +0.5% PP (0.117% tannin); iv) PPE 0.075, CON+0.075% PPE (0.03% tannin); and v) PPE 0.25, CON+0.25% PPE (0.11% tannin). The total tannin concentration of PPE was higher (p<0.05) than that of PP. Egg production in the PP 0.5 group was higher than in the other groups. Egg production and mass of hens in the PPE 0.25 group showed a greater decrease than that in the other groups (p<0.05). Eggshell color in the PP 0.15, PP 0.5, and PPE 0.075 groups was lighter than that of the control group (p<0.05). The Haugh unit for the groups that were fed PP and PPE were significantly higher than that in the other groups after 7 d of storage (p<0.05). Therefore, PP seems an effective feed additive for improving the production performance and egg quality in late stage laying hens.
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BACKGROUND: CD151 is a member of the tetraspanin family, which interacts with laminin-binding integrins and other tetraspanins. This protein is implicated in motility, invasion, and metastasis of cancer cells, but the prevalence of CD151 expression in subtypes of breast cancers and its influence on clinical outcome remains to be evaluated. METHODS AND RESULTS: The immunohistochemistry-based tissue microarray analysis showed that 127 (14.3%) cases overexpressed CD151 among 886 breast cancer patients. CD151 overexpression was found to be significantly associated with larger tumour size, higher nodal stage, advanced stage, absence of oestrogen receptor and progesterone receptor, and human epidermal growth factor receptor 2 overexpression. CD151 overexpression resulted in poorer overall survival (OS) (P<0.001) and disease-free survival (P=0.02), and stage II and III patients with CD151 overexpression demonstrated substantially poorer OS (P=0.0474 and 0.0169). In the five subtypes analyses, CD151 overexpression retained its adverse impact on OS in the Luminal A (P=0.0105) and quintuple-negative breast cancer (QNBC) subtypes, one subgroup of triple-negative breast cancer (P=0.0170). Multivariate analysis that included stage, subtype, and adjuvant chemotherapy showed that CD151 overexpression was independently associated with poor OS in invasive breast cancer. CONCLUSION: CD151 overexpression may be a potential molecular therapeutic target for breast cancer, especially in QNBC subtype and more advanced stages of breast cancer.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Invasividade Neoplásica , Tetraspanina 24/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/biossíntese , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Prognóstico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/biossíntese , Receptores de Progesterona/metabolismo , Análise Serial de TecidosRESUMO
BACKGROUND AND PURPOSE: The pathogenesis of rapid eye movement (REM) sleep behavior disorder (RBD) is not clear despite its frequent association with Parkinson's disease (PD). We investigated whether the nigrostriatal dopaminergic system is involved in the development of idiopathic RBD. METHODS: Fourteen patients with RBD, 14 patients with PD and 12 normal controls were included in the study. The diagnosis of RBD was confirmed on polysomnography. All the participants performed single-photon emission computed tomography imaging 3 h after injection of [(123)I]FP-CIT. During REM sleep of the RBD patients, each 30-s epoch was rated as 'tonic' when there was at least 50% of tonically maintained chin electromyography (EMG) activity in the epoch. Phasic EMG activities were calculated as the percentage of 3-s mini-epoch containing phasic EMG events (leg and chin, separately). RESULTS: The RBD patients showed a trend of lower binding in the striatum than the normal controls (P = 0.07), and the significance was revealed in the putamen (P = 0.02). However, in 11 individual cases of the 14 RBD patients, the dopamine transporter (DAT) densities in the putamen still remained within the normal range. In the RBD patients, there was no correlation between EMG activities and DAT densities. CONCLUSIONS: Nigrostriatal dopaminergic degeneration could be a part of the pathogenesis of RBD, but not essential for the development of RBD. The lack of correlation between RBD severity and DAT densities suggests that another pathogenic process not related to nigrostriatal dopaminergic transmission may be implicated in RBD.
Assuntos
Corpo Estriado/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Transtorno do Comportamento do Sono REM/fisiopatologia , Idoso , Ácido Ascórbico , Núcleo Caudado/diagnóstico por imagem , Núcleo Caudado/metabolismo , Queixo/fisiopatologia , Colecalciferol , Corpo Estriado/diagnóstico por imagem , Desidroepiandrosterona/análogos & derivados , Dopamina/metabolismo , Eletromiografia , Músculos Faciais/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Degeneração Neural/diagnóstico por imagem , Degeneração Neural/metabolismo , Ácidos Nicotínicos , Extratos Vegetais , Polissonografia , Putamen/diagnóstico por imagem , Putamen/metabolismo , Transtorno do Comportamento do Sono REM/diagnóstico , Transtorno do Comportamento do Sono REM/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , TropanosRESUMO
Vesicle budding and fusion underlies many essential biochemical deliveries in eukaryotic cells, and its core fusion machinery is thought to be built on one protein family named soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE). Recent technical advances based on site-directed fluorescence labelling and nano-scale detection down to the single-molecule level rapidly unveiled the protein and the lipid intermediates along the fusion pathway as well as the molecular actions of fusion effectors. Here we summarize these new exciting findings in context with a new mechanistic model that reconciles two existing fusion models: the proteinaceous pore model and the hemifusion model. Further, we attempt to locate the points of action for the fusion effectors along the fusion pathway and to delineate the energetic interplay between the SNARE complexes and the fusion effectors.
Assuntos
Neurônios/fisiologia , Proteínas SNARE/metabolismo , Animais , Membrana Celular/metabolismo , Fusão de Membrana/fisiologia , Modelos Moleculares , Proteínas SNARE/química , Proteínas SNARE/genética , Sinaptotagmina I/metabolismoRESUMO
Comparative analysis of proteomes using 5-fluorouracil (5-FU)-resistant human colon cancer cell line revealed that decreased galectin-3 expression was significantly associated with retarded proliferation. However, in the presence of 5-FU proliferation rate of cells with suppressed galectin-3 expression did not differ from that of cells with normal galectin-3 expression, even galectin-3 suppression augmented apoptosis. Mechanism by which galectin-3 regulates cancer cell proliferation has been identified in immunoprecipitates of the anti-galectin-3 antibody. Heterogeneous nuclear ribonucleoprotein Q (hnRNP Q) was identified as a protein interacting with galectin-3. Interestingly, while galectin-3 protein was not affected by the hnRNP Q level, its suppression was accompanied by a decrease in hnRNP Q expression. The present study demonstrates that galectin-3 stabilizes hnRNP Q via complex formation, and reduction in the hnRNP Q level leads to slow proliferation and less susceptibility to 5-FU.
Assuntos
Proliferação de Células , Neoplasias do Colo/metabolismo , Galectina 3/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Isoformas de Proteínas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Antimetabólitos/metabolismo , Apoptose/fisiologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Regulação para Baixo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fluoruracila/metabolismo , Galectina 3/genética , Ribonucleoproteínas Nucleares Heterogêneas/genética , Humanos , Dados de Sequência Molecular , Fosfoproteínas/metabolismo , Isoformas de Proteínas/genética , Proteínas Quinases/metabolismo , Proteoma/análise , Proteínas Quinases S6 Ribossômicas/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TORRESUMO
To investigate the mechanism of interaction of the toxin colicin E1 with membranes, three cysteine substitution mutants and the wild type of the channel-forming fragment were spin labeled at the unique thiol. Time-resolved interaction of these labeled proteins with phospholipid vesicles was investigated with stopped-flow electron paramagnetic resonance spectroscopy. The fragment interacts with neutral bilayers at low pH, indicating that the interaction is hydrophobic rather than electrostatic. The interaction occurs in at least two distinct steps: (i) rapid adsorption to the surface; and (ii) slow, rate-limiting insertion of the hydrophobic central helices into the membrane interior.
Assuntos
Membrana Celular/metabolismo , Colicinas/metabolismo , Mutagênese , Marcadores de Spin , Adsorção , Sítios de Ligação , Colicinas/química , Colicinas/genética , Cisteína/genética , Espectroscopia de Ressonância de Spin Eletrônica , Concentração de Íons de Hidrogênio , Cinética , Bicamadas Lipídicas/metabolismo , Fragmentos de Peptídeos/metabolismo , Estrutura Secundária de ProteínaRESUMO
The trimeric protein hemagglutinin (HA) of the influenza viral envelope is essential for cell entry. To investigate the interaction of HA with membranes, two 40-residue, cysteine-substituted peptides comprising the loop region and the first part of the coiled-coil stem were synthesized and modified with a nitroxide spin label. Electron paramagnetic resonance analysis revealed that the peptide inserts reversibly into phospholipid vesicles under endosomal pH conditions. This result suggests that some or all of the long coiled-coil trimer of HA may insert into membranes, which could bring the viral and cell membranes closer together and facilitate fusion.
Assuntos
Hemaglutininas Virais/metabolismo , Bicamadas Lipídicas/metabolismo , Fusão de Membrana , Proteínas do Envelope Viral/metabolismo , Sequência de Aminoácidos , Espectroscopia de Ressonância de Spin Eletrônica , Endocitose , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Hemaglutininas Virais/química , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Orthomyxoviridae/fisiologia , Conformação Proteica , Estrutura Secundária de Proteína , Temperatura , Proteínas do Envelope Viral/químicaRESUMO
To characterize the mechanism by which receptors propagate conformational changes across membranes, nitroxide spin labels were attached at strategic positions in the bacterial aspartate receptor. By collecting the electron paramagnetic resonance spectra of these labeled receptors in the presence and absence of the ligand aspartate, ligand binding was shown to generate an approximately 1 angstrom intrasubunit piston-type movement of one transmembrane helix downward relative to the other transmembrane helix. The receptor-associated phosphorylation cascade proteins CheA and CheW did not alter the ligand-induced movement. Because the piston movement is very small, the ability of receptors to produce large outcomes in response to stimuli is caused by the ability of the receptor-coupled enzymes to detect small changes in the conformation of the receptor.
Assuntos
Ácido Aspártico/metabolismo , Membrana Celular/metabolismo , Proteínas de Escherichia coli , Modelos Biológicos , Receptores de Aminoácido/química , Receptores de Aminoácido/metabolismo , Transdução de Sinais , Proteínas de Bactérias/metabolismo , Quimiotaxia , Dimerização , Espectroscopia de Ressonância de Spin Eletrônica , Escherichia coli/metabolismo , Análise de Fourier , Histidina Quinase , Ligantes , Bicamadas Lipídicas , Proteínas de Membrana/metabolismo , Proteínas Quimiotáticas Aceptoras de Metil , Metilação , Mutagênese , Fosforilação , Conformação Proteica , Proteínas Quinases/metabolismo , Estrutura Secundária de Proteína , Receptores de Aminoácido/genética , Marcadores de SpinRESUMO
Apicidin is a fungal metabolite shown to exhibit anti-proliferative, anti-invasive, and anti-inflammatory properties by the inhibition of histone deacetylase (HDAC). However, the effects of apicidin on the maturation and immunostimulatory function of dendritic cells (DCs) remain unknown. In this study, we investigated whether apicidin modulates surface molecule expression, cytokine production, endocytosis capacity, and underlying signaling pathways in murine bone marrow-derived DCs. We observed that apicidin significantly attenuated surface molecule expression in LPS-stimulated DCs, suppressed production of interleukin (IL)-12 and proinflammatory cytokines (IL-6 and TNF-alpha) by DCs, and reduced IFN-gama production by T cells. The apicidin-treated DCs were found to be highly efficient in antigen capture via mannose receptor-mediated endocytosis. Apicidin also inhibited LPS-induced MAPK activation and NF-kB nuclear translocation in DCs. Moreover, the apicidin-treated DCs were incapable of inducing Th1 responses and normal cell-mediated immune responses. These novel findings not only provide new insights into the immunopharmacological role of apicidin in terms of its effects on DCs, but also broaden current perspectives of the immunopharmacological functions of apicidin, and have implications for the development of therapeutic adjuvants for the treatment of DC-related acute and chronic diseases.
Assuntos
Adjuvantes Imunológicos/farmacologia , Células da Medula Óssea/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Inibidores de Histona Desacetilases , Peptídeos Cíclicos/farmacologia , Células Th1/imunologia , Transporte Ativo do Núcleo Celular , Animais , Células da Medula Óssea/enzimologia , Células da Medula Óssea/imunologia , Células Cultivadas , Células Dendríticas/enzimologia , Células Dendríticas/imunologia , Relação Dose-Resposta a Droga , Endocitose/efeitos dos fármacos , Histona Desacetilases/metabolismo , Interferon gama/metabolismo , Interleucinas/metabolismo , Lectinas Tipo C/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Receptor de Manose , Lectinas de Ligação a Manose/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Fosforilação , Receptores de Superfície Celular/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Since publication of the original article, the authors have noticed that there were errors in the labelling of Figures 6D and 6E. The correct figure and its legend are reproduced here. The authors wish to apologise for any inconvenience caused.
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BACKGROUND: Narcolepsy typically begins between adolescence and early adulthood causing severe neuropsychiatric impairments, but few prevalence studies are available on adolescent narcoleptics. In the present study, we investigated the prevalence of narcolepsy-cataplexy in adolescents. METHODS: In total 20,407 students, aged 14-19 years, participated in this study. Ullanlinna Narcolepsy Scale (UNS) was applied to all subjects and those with a UNS score of > or =14 were contacted by phone for semi-structured interview. Subjects then suspected of having narcolepsy participated in a laboratory investigation, which included polysomnography and HLA typing, or were interviewed in detail by telephone. RESULTS: Three subjects were finally diagnosed as narcolepsy with cataplexy and seven subjects might be diagnosed as narcolepsy without cataplexy. Among three narcoleptics with cataplexy, two subjects were HLA-DQB1*0602 and DRB1*1501 positive, but one subject had no test of HLA typing. The prevalence of narcolepsy with cataplexy in Korean adolescence was thus determined to be 0.015% (95% confidence interval = 0.0-0.0313%). CONCLUSION: This epidemiologic study is the first of its type on adolescent narcolepsy to use the International Classification of Sleep Disorders, 2nd edition (ICSD-2) diagnostic criteria. Considering those cases with an onset after adolescence were not included, the prevalence of narcolepsy with cataplexy determined in the present study is comparable with that of other studies in adults.
Assuntos
Narcolepsia/diagnóstico , Narcolepsia/epidemiologia , Adolescente , Adulto , Idade de Início , Povo Asiático , Diagnóstico Diferencial , Feminino , Genótipo , Antígenos HLA/genética , Humanos , Entrevistas como Assunto , Coreia (Geográfico)/epidemiologia , Masculino , Narcolepsia/fisiopatologia , Polissonografia , Valor Preditivo dos Testes , Prevalência , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: The Epstein-Barr virus transforms resting B cells into proliferating lymphoblastoid cells, the origin of cell lines. METHOD AND RESULTS: Our cDNA microarray analyses led to the identification of 232 up-regulated and 112 down-regulated genes with more than a 3-fold difference in lymphoblastoid cell lines compared to resting B cells. The functional classification of these genes exhibited the distinct expression signature for cell proliferation, cell cycle and an immune response. Among them, we verified the differential expression of several oncogenes such as stathmin 1 (STMN1), RAB27A, RAB9A, BACH1 and BACH2 using quantitative real-time reverse transcriptase-polymerase chain reactions or Western blot analysis. Expression of STMN1 (which is involved in regulation of the microtubule filament system, cell growth and S-phase of cell cycle) was increased in lymphoblastoid cell line as well as in 7-day post-Epstein-Barr virus infection B cells, compared to resting B cells. CONCLUSION: Thus, this study suggests that Epstein-Barr virus infection induces STMN1 expression, which play a role in cell cycle progression and proliferation in the human B lymphocyte.
Assuntos
Linfócitos B/metabolismo , Linfócitos B/virologia , Regulação da Expressão Gênica , Herpesvirus Humano 4/fisiologia , Estatmina/genética , Estatmina/metabolismo , Ciclo Celular , Processos de Crescimento Celular , Linhagem Celular , Transformação Celular Viral , Regulação para Baixo , Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4/genética , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos TestesRESUMO
This corrects the article DOI: 10.1038/oncsis.2017.87.
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Epithelial splicing regulatory protein 1 (ESRP1) and 2 (ESRP2), epithelial cell-specific regulators of alternative splicing, are downregulated during the epithelial-mesenchymal transition (EMT). These factors have roles in tumor progression and metastasis in some cancers; however, their expression and function in ovarian cancer (OC) remain unclear. We found that ESRP1 and ESRP2 mRNAs were expressed at higher levels in OC cells than in immortalized ovarian surface epithelial (IOSE) cells, and confirmed their overexpression in OC tissues at the protein level. The Cancer Genome Atlas (TCGA) data analysis revealed frequent gene amplification of ESRP1 in OC tissues; however, we detected no significant correlation between ESRP1 gene copy number and gene expression in OC cells. Importantly, expression of ESRP1 and ESRP2 was inversely correlated with DNA methylation in OC cells, and ESRP2 overexpression in OC tissues was significantly associated with DNA hypomethylation. Notably, survival analysis using TCGA data from 541 OC tissues revealed that high ESRP1 expression was significantly associated with shorter 5-year survival of patients. Ectopic ESRP1 expression in mesenchymal OC cells promoted cell proliferation but suppressed cell migration. Furthermore, we found that ESRP1 drives a switch from mesenchymal to epithelial phenotype characterized by reduced cell migration in association with induction of epithelial cell-specific variant of CD44 and ENAH. Taken together, our findings suggest that an epigenetic mechanism is involved in ESRP1 overexpression, and that ESRP1 has a role in OC progression.
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Ascosphaera apis is a bee pathogen that causes bee larvae infection disease, to which treatment is not yet well investigated. The aim of this study was to investigate antifungal susceptibility in vitro against A. apis and to identify a new antifungal agent for this pathogen through minimal inhibitory concentration (MIC) assay and western blot analysis. Macelignan had 1.56 and 3.125 µg/mL MIC against A. apis after 24 and 48 h, respectively, exhibiting the strongest growth inhibition against A. apis among the tested compounds (corosolic acid, dehydrocostus lactone, loganic acid, tracheloside, fangchinoline and emodin-8-O-ß-D-glucopyranoside). Furthermore, macelignan showed a narrow-ranged spectrum against various fungal strains without any mammalian cell cytotoxicity. In spite of miconazole having powerful broad-ranged anti-fungal activity including A. apis, it demonstrated strong cytotoxicity. Therefore, even if macelignan alone was effective as an antifungal agent to treat A. apis, combined treatment with miconazole was more useful to overcome toxicity, drug resistance occurrence and cost effectiveness. Finally, HOG1 was revealed as a target molecule of macelignan in the anti-A. apis activity by inhibiting phosphorylation using S. cerevisiae as a model system. Based on our results, macelignan, a food-grade antimicrobial compound, would be an effective antifungal agent against A. apis infection in bees.
Assuntos
Antifúngicos/farmacologia , Ascomicetos/efeitos dos fármacos , Abelhas/microbiologia , Lignanas/farmacologia , Proteínas Quinases Ativadas por Mitógeno/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/efeitos dos fármacos , Animais , Western Blotting , Sinergismo Farmacológico , Formazans , Larva/efeitos dos fármacos , Larva/microbiologia , Larva/patogenicidade , Testes de Sensibilidade Microbiana , Proteínas Quinases Ativadas por Mitógeno/análise , Micoses/tratamento farmacológico , Proteínas de Saccharomyces cerevisiae/análise , Sais de Tetrazólio , Fatores de TempoRESUMO
We have used in situ tapping mode atomic force microscopy (AFM) to study the structural morphology of two fragments of the influenza hemagglutinin protein bound to supported bilayers. The two proteins that we studied are the bromelain-cleaved hemagglutinin (BHA), corresponding to the full ectodomain of the hemagglutinin protein, and FHA2, the 127 amino acid N-terminal fragment of the HA2 subunit of the hemagglutinin protein. While BHA is water soluble at neutral pH and is known to bind to membranes via specific interactions with a viral receptor, FHA2 can only be solubilized in water with an appropriate detergent. Furthermore, FHA2 is known to readily bind to membranes at neutral pH in the absence of a receptor. Our in situ AFM studies demonstrated that, when bound to supported bilayers at neutral pH, both these proteins are self-assembled as single trimeric molecules. In situ acidification resulted in further lateral association of the FHA2 without a large perturbation of the bilayer. In contrast, BHA remained largely unaffected by acidification, except in areas of exposed mica where it is aggregated. Remarkably, these results are consistent with previous observations that FHA2 promotes membrane fusion while BHA only induces liposome leakage at low pH. The results presented here are the first example of in situ imaging of the ectodomain of a viral envelope protein allowing characterization of the real-time self-assembly of a membrane fusion protein.
Assuntos
Hemaglutininas Virais/química , Microscopia de Força Atômica , Orthomyxoviridae/fisiologia , Montagem de Vírus , Bromelaínas , Concentração de Íons de Hidrogênio , Bicamadas Lipídicas/química , Orthomyxoviridae/química , Fragmentos de Peptídeos/química , Conformação ProteicaRESUMO
BACKGROUND: Ischemia followed by reperfusion in the presence of polymorphonuclear leukocytes (PMNs) results in cardiac contractile dysfunction as well as cardiomyocyte injury. These deleterious effects are due in large part to endothelial dysfunction leading to the upregulation of cell adhesion molecules and subsequent neutrophil-endothelium interaction. At clinically relevant doses, simvastatin, an HMG-CoA reductase inhibitor, has been shown to lower serum cholesterol levels and normalize endothelial cell function. We wanted to test the effects of simvastatin on neutrophil-mediated cardiac dysfunction in a controlled model of myocardial ischemia-reperfusion. METHODS AND RESULTS: This study examines the effects of simvastatin in a neutrophil-dependent isolated perfused rat heart model of ischemia (I) (20 minutes) and reperfusion (R) (45 minutes) injury. Administration of simvastatin 25 micrograms/rat improved coronary flow and preserved left ventricular developed pressure (LVDP) and dP/dtmax, indexes of cardiac contractile function. Final LVDP was 95+/-5 mm Hg in I/R hearts perfused with PMNs and simvastatin, compared with 49+/-4 mm Hg in PMN-perfused I/R hearts receiving only vehicle (P<0.001). In addition, simvastatin significantly reduced PMN accumulation in the ischemic myocardium (P<0.01). In PMN-perfused rat hearts after I/R, simvastatin also significantly attenuated P-selectin expression, CD18 upregulation in rat PMNs, and PMN adherence to rat vascular endothelium. Significant, although less potent, effects were obtained with pravastatin. CONCLUSIONS: These results provide evidence that HMG-CoA reductase inhibitors are potent and effective cardioprotective agents that inhibit leukocyte-endothelial cell interactions and preserve cardiac contractile function and coronary perfusion after myocardial ischemia and reperfusion. Moreover, these effects are unrelated to the cholesterol-lowering action of this agent and appear to be mediated by enhanced endothelial release of NO.
Assuntos
Colesterol/sangue , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Isquemia Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Sinvastatina/uso terapêutico , Animais , Circulação Coronária/efeitos dos fármacos , Técnicas In Vitro , Masculino , Contração Miocárdica/efeitos dos fármacos , Isquemia Miocárdica/patologia , Isquemia Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio/patologia , Neutrófilos/metabolismo , Neutrófilos/patologia , Neutrófilos/fisiologia , Selectina-P/metabolismo , Pressão , Ratos , Ratos Sprague-Dawley , Valores de Referência , Função Ventricular Esquerda/efeitos dos fármacosRESUMO
Epstein-Barr virus (EBV) infection in vitro immortalizes primary B cells and generates B lymphoblastoid cell lines (LCLs). These EBV-LCLs have been used for several purposes in immunological and genetic studies, but some trials involving these transformations fail for unknown reasons, and several EBV-LCLs do not grow in normal culture. In this study, we improved the immortalization method by CD19 and B-cell receptor (BCR) co-ligation. This method shortens the time required for the immortalization and generation of EBV-LCLs but does not alter the cell phenotype of the LCLs nor the expression of the EBV genes. In particular, the CD19 and BCR co-ligation method was found to be the most effective method examined. EBV-infected B cells induced by CD19 and/or BCR ligation expressed the intracellular latent membrane protein LMP-1 earlier than EBV-infected B cells, and the expression of intracellular LMP-1 was found to be closely related to the time of immortalization. These results suggest that the modified method, using CD19 and/or BCR ligation, may efficiently generate EBV-LCLs, by expressing intracellular LMP-1 at an early stage.