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1.
J Appl Toxicol ; 31(2): 150-6, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20737424

RESUMEN

Since aflatoxin B(1) (AFB(1))-mediated hepatic damage is related to the production of AFB(1)-8,9-epoxide and reactive oxygen species, bioactive compounds having antioxidant potentials are suggested to be capable of reducing AFB(1)-induced toxicity. We previously purified a mixture of flavonoids that we named RCMF (Rhus verniciflua Stokes chloroform-methanol fraction), from a traditional Korean food additive and herbal medicine. RCMF exhibited various biological effects, including antioxidant and antitumor activities. In this study, we examined whether RCMF protects against AFB(1)-induced liver injury using in vitro and in vivo systems. Pretreatment of HepG2 cells with RCMF significantly reduced AFB(1)-stimulated production of ROS and malondialdehyde (MDA) to the control levels. RCMF also prevented the reduction in HepG2 cell viability caused by AFB(1). Oral administration of RCMF to mice significantly suppressed an AFB(1)-induced increase in serum levels of alanine aminotransferase, alkaline phosphatase and lactate dehydrogenase. It also prevented MDA formation and blocked decreases in glutathione levels and superoxide dismutase activities in the livers of AFB(1)-treated mice. In addition, RCMF supplementation prevented an AFB(1) -induced decrease in serum titers of IgA and IgG1. Collectively, these results suggest that RCMF attenuates AFB(1)-mediated damage to the liver, and that this effect is at least partially related to the restoration of antioxidant defense systems and an increase in AFB(1)-GSH conjugate formation.


Asunto(s)
Aflatoxina B1/toxicidad , Antioxidantes/uso terapéutico , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Flavonoides/uso terapéutico , Extractos Vegetales/uso terapéutico , Rhus/química , Aflatoxina B1/antagonistas & inhibidores , Animales , Supervivencia Celular/efectos de los fármacos , Enfermedad Hepática Inducida por Sustancias y Drogas/inmunología , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Flavonoides/análisis , Glutatión/metabolismo , Células Hep G2 , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Isotipos de Inmunoglobulinas/sangre , Masculino , Malondialdehído/metabolismo , Ratones , Ratones Endogámicos ICR , Extractos Vegetales/química , Distribución Aleatoria , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/metabolismo
2.
Mol Cells ; 29(2): 131-44, 2010 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-20069385

RESUMEN

Comprehensive analysis of the transcriptome of the P. chrysosporium is a useful approach to improve our understanding of its special and unique enzyme system and fungal evolution in molecular and industrial aspects. In order to unveil the functional diversity of this white-rot fungus in gene level and the expression patterns of its genes, in this study we carried out sequencing and annotation of 4,917 P. chrysosporium expressed sequence tags (ESTs). Through our bioinformatic ESTs analysis, we elucidated that 1,751 genes were derived from the present dataset of 4,917 ESTs, based on clustering and comparative genomic analyses of the ESTs. Of the 1,751 unique ESTs, 1,006 (57.5%) had homologues and orthologues in similarity searches. Our P. chrysosporium ESTs showed many genes for encoding 23 secreted proteins, many proteins for the degradation of cellulose and hemicelluloses, and heat shock proteins for stress resistance, which explain the reason why P. chrysosporium is very important and unique white-rot fungus in dealing with contaminated resources and in degrading lignin and in applying this organism to several industrial aspects.In addition, comparative analysis has shed the fresh light on the mystery about how its unique enzyme system and stress resistance have been evolved differently from its closest relatives.


Asunto(s)
Etiquetas de Secuencia Expresada/metabolismo , Phanerochaete/genética , Mapeo Cromosómico , Biología Computacional , Bases de Datos Genéticas , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Lignina/metabolismo , Neurospora crassa/genética , Phanerochaete/enzimología , Estructura Terciaria de Proteína , ARN Mensajero/genética , ARN Mensajero/metabolismo , Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética
3.
Apoptosis ; 14(6): 796-808, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19418225

RESUMEN

It has been proposed that continuously generated hydrogen peroxide (H(2)O(2)) inhibits typical apoptosis and instead initiates an alternate, apoptosis-inducing factor (AIF)-dependent process. Aside from the role of AIF, however, the detailed morphological characterization of H(2)O(2)-induced cell death is not complete. This study examined the cellular mechanism(s) by which the continuous presence of H(2)O(2) induces cell death. We also further analyzed the precise role of AIF by inhibiting its expression with siRNA. Exposure of cells to H(2)O(2) generated by glucose oxidase caused mitochondrion-mediated, caspase-independent cell death. In addition, H(2)O(2) exposure resulted in cell shrinkage and chromatin condensation without nuclear fragmentation, indicating that H(2)O(2) stimulates a pyknotic cell death. Further analysis of AIF-transfected cells clearly demonstrated that nuclear translocation of AIF is the most important event required for nuclear condensation, phosphatidyl serine translocation, and ultimately cell death in H(2)O(2)-exposed cells. Furthermore, ATP was rapidly and severely depleted in cells exposed to H(2)O(2) generated by glucose oxidase but not by H(2)O(2) added as a bolus. Suppression of the H(2)O(2)-mediated ATP depletion by 3-aminobenzamide led to a significant increase of nuclear fragmentation in glucose oxidase-exposed cells. Collectively, these findings suggest that an acute energy reduction by H(2)O(2) causes caspase-independent and AIF-dependent cell death.


Asunto(s)
Factor Inductor de la Apoptosis/metabolismo , Peróxido de Hidrógeno/farmacología , Adenosina Trifosfato/metabolismo , Caspasas/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Supervivencia Celular/efectos de los fármacos , Cromatina/metabolismo , Fragmentación del ADN/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Glucosa Oxidasa/metabolismo , Humanos , Espacio Intracelular/efectos de los fármacos , Espacio Intracelular/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Fosfatidilserinas/metabolismo , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Transporte de Proteínas/efectos de los fármacos , ARN Interferente Pequeño/metabolismo , Transfección
4.
J Pharm Sci ; 98(6): 2104-12, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18823029

RESUMEN

In this study, we prepared adriamycin (ADR)-encapsulated core-shell type nanoparticles of a poly(DL-lactide-co-glycolide) (PLGA) grafted-dextran (DexLG) copolymer and evaluated its antitumor activity in vitro and in vivo. The particle size of ADR-encapsulated DexLG nanoparticles was around 50-200 nm and the morphology was spherical shapes at transmission electron microscopy (TEM) observation. Since reconstitution of lyophilized nanoparticles is essential to practical use in vivo, ADR-encapsulated DexLG nanoparticles were lyophilized and reconstituted them into deionized water. Although reconstitution process caused increase of particle size, drug release behavior of nanoparticles was not significantly changed before and after reconstitution process. The ADR-encapsulated DexLG nanoparticles were less cytotoxic than free ADR plus empty nanoparticles at in vitro, while empty DexLG nanoparticles did not significantly affect cell viability. Even if free ADR plus empty nanoparticles are most effective to inhibit tumor growth at tumor-induced animal model using CT-26 cells, ADR-encapsulated DexLG nanoparticles showed increased survivability of mice. These results indicated that ADR-encapsulated DexLG nanoparticles are promising vehicles for antitumor drug delivery.


Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Neoplasias Colorrectales/tratamiento farmacológico , Dextranos , Doxorrubicina/administración & dosificación , Portadores de Fármacos , Ácido Láctico , Nanopartículas , Ácido Poliglicólico , Animales , Antibióticos Antineoplásicos/uso terapéutico , Antibióticos Antineoplásicos/toxicidad , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Neoplasias Colorrectales/patología , Doxorrubicina/uso terapéutico , Doxorrubicina/toxicidad , Liofilización , Humanos , Ratones , Ratones Endogámicos BALB C , Tamaño de la Partícula , Copolímero de Ácido Poliláctico-Ácido Poliglicólico
5.
Toxicol Res ; 25(2): 107-111, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32038827

RESUMEN

The alcohol extract of the larvae of Bombus ignitus, otherwise known as the Bumblebee, was orally administered to rats at doses of 0, 0.04, 0.2, 1 or 2 g/kg as a single oral dose. There were no observed clinical signs or deaths related to treatment in all the groups tested. Therefore, the approximate lethal dose of the alcohol extract of B. ignitus was considered to be higher than 2 g/kg in rats. Mild decreases in body weight gain in male rats were observed dose-dependently within the B. ignitus treated groups over 2 weeks. Throughout the administration periods, no significant changes in diet consumption, ophthalmologic findings, clinical pathology (hematology, clinical chemistry and coagulation) or gross pathology were detected. Minor changes in male rats were found with in the hematological parameters in groups treated with the 0.04 g/kg, 1 g/kg or 2 g/kg of B. ignitus larvae extract, however, all the changes observed were within the physiological range. From these results, it was concluded that there was no evidence of specific toxicity related to the ingestion of alcohol extract of B. ignitus larvae.

6.
Arch Pharm Res ; 31(11): 1463-9, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19023543

RESUMEN

In this study, we prepared amphotericin B (AmpB)-encapsulated polymeric micelle of poly(DL-lactideco-glycolide) (PLGA) grafted-dextran (DexLG) copolymer for the cytotoxicity test. The average particle size of AmpB-encapsulated DexLG polymeric micelles was around 30 approximately 70 nm and their morphology showed spherical shapes. Since aggregation states of AmpB are related to intrinsic cytotoxicity, prevention of AmpB aggregation in aqueous solution will provide low cytotoxicity and increased antimicrobial activity for the infectious disease. At UV/VIS spectrum measurement, polymeric micelle prepared from methanol/water mixture (method B) showed a monomeric state of AmpB while polymeric micelle prepared from DMSO (method A) showed an aggregated state. During the hemolysis activity test, polymeric micelle from method B showed reduced hemolysis activity compared to AmpB itself and polymeric micelle from method A. These results indicated that AmpB-incorporated polymeric micelle prepared from methanol/water mixture has low cytotoxicity and favorable antimicrobial activity.


Asunto(s)
Anfotericina B/administración & dosificación , Anfotericina B/farmacología , Antifúngicos/administración & dosificación , Antifúngicos/farmacología , Anfotericina B/química , Antifúngicos/química , Candida albicans/efectos de los fármacos , Química Farmacéutica , Dextranos , Composición de Medicamentos , Eritrocitos/efectos de los fármacos , Hemólisis , Humanos , Técnicas In Vitro , Ácido Láctico , Micelas , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Ácido Poliglicólico , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Espectrofotometría Ultravioleta
7.
Cell Biol Int ; 32(8): 871-8, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18468460

RESUMEN

Hypoxia alters the biological functions of skeletal muscle cells to proliferate and differentiate into myotubes. However, the cellular responses of myoblasts to hypoxia differ according to the levels of oxygen and the types of cells studied. This study examined the effect of hypoxia (1% oxygen) on bovine satellite cells. Hypoxia significantly increased the proliferation of satellite cells cultured in a growth medium. In addition, the levels of PCNA, cyclin D1, cyclin-dependent kinase-1 (CDK1) and CDK2 expression were increased. Hypoxia facilitated the formation of myotubes as well as the stimulation of MyoD, myogenin, and myosin heavy chain (MHC) expression in differentiating medium (DM) cultures. In particular, satellite cells cultured under hypoxic/DM conditions showed increased p21 expression but not p27. The transfection of satellite cells with antisense MyoD oligonucleotides resulted in a decrease in the MHC, myogenin, MRF4 RNA and protein levels with the concomitant decrease in fused cells to levels similar to those observed under normoxia/DM conditions. This indicates that MyoD up-regulation is closely associated with hypoxia-stimulated myogenic differentiation. In conclusion, hypoxia stimulates the proliferation of satellite cells and promotes their myogenic differentiation with MyoD playing an important role.


Asunto(s)
Hipoxia de la Célula , Proteína MioD/metabolismo , Miogenina/metabolismo , Células Satélite del Músculo Esquelético/citología , Animales , Proteína Quinasa CDC2/metabolismo , Bovinos , Ciclo Celular , Diferenciación Celular , Proliferación Celular , Ciclina D1/metabolismo , Quinasa 2 Dependiente de la Ciclina/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Mioblastos/metabolismo , Cadenas Pesadas de Miosina/metabolismo , Antígeno Nuclear de Célula en Proliferación/metabolismo , Células Satélite del Músculo Esquelético/metabolismo , Regulación hacia Arriba , Quinasas p21 Activadas/metabolismo
8.
Mol Cells ; 25(4): 479-86, 2008 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-18443411

RESUMEN

Mitogen-activated protein kinases (MAPKs) play an indispensable role in activation of the myogenic program, which is responsive to mechanical stimulation. Although there is accumulating evidence of mechanical force-mediated cellular responses, the role of MAPK in regulating the myogenic process in myoblasts exposed to cyclic stretch is unclear. Cyclic stretch induced the proliferation of C2C12 myoblasts and inhibited their differentiation into myotubes. In particular, it induced persistent phosphorylation of p38 kinase, and decreased the level of phosphorylation of extracellular-signal regulated kinase (ERK). Partial inhibition of p38 phosphorylation increased cellular levels of MyoD and p-ERK in stretched C2C12 cells, along with increased myotube formation. Treatment with 10 microM PD98059 prevented myogenin expression in response to a low dose of SB203580 (3 microM) in the stretched cells, suggesting that adequate ERK activation is also needed to allow the cells to differentiate into myotubes. These results suggest that cyclic stretch inhibits the myogenic differentiation of C2C12 cells by activating p38-mediated signaling and inhibiting ERK phosphorylation. We conclude that p38 kinase, not ERK, is the upstream signal transducer regulating cellular responses to mechanical stretch in skeletal muscle cells.


Asunto(s)
Proteínas de Ciclo Celular/genética , Mecanotransducción Celular , Mioblastos Esqueléticos/citología , Mioblastos Esqueléticos/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Animales , Proteínas de Ciclo Celular/metabolismo , Diferenciación Celular/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Flavonoides/farmacología , Imidazoles/farmacología , MAP Quinasa Quinasa Quinasa 3/antagonistas & inhibidores , Masculino , Mecanotransducción Celular/fisiología , Ratones , Desarrollo de Músculos , Fosforilación/efectos de los fármacos , Piridinas/farmacología , Estrés Mecánico
9.
Mol Cell Biochem ; 310(1-2): 85-92, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18057999

RESUMEN

Calpeptin inhibits myoblast fusion by inhibiting the activity of calpain. However, the mechanism by which calpeptin inhibits myogenesis is not completely understood. This study examined how calpeptin affects the expression of the myogenic regulatory factors (MRFs) and the phosphorylation of p38 mitogen-activated protein kinase (MAPK) in differentiating C2C12 myoblasts. Consistent with previous reports, calpeptin inhibited the induction of mu-calpain and the formation of myotubes in these cells. In particular, calpeptin inhibited the expression of the early and mid differentiation markers including MyoD, Myf5, myogenin, and MRF4 as well as the expression of the late markers such as troponin T and myosin heavy chain (MyHC). Calpeptin also suppressed the phosphorylation of p38 MAPK in C2C12 cells. SB203580, a specific p38 inhibitor, prevented the expression of the muscle-specific markers and their fusion into myotubes in these cells, which was further accelerated in the presence of calpeptin. These findings suggest that calpeptin inhibits the myogenesis of skeletal muscle cells by down-regulating the MRFs and involving p38 MAPK signaling.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Dipéptidos/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Desarrollo de Músculos/efectos de los fármacos , Mioblastos/citología , Mioblastos/enzimología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Calpaína/metabolismo , Fusión Celular , Células Cultivadas , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Ratones , Fibras Musculares Esqueléticas/citología , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/enzimología , Proteína MioD/metabolismo , Mioblastos/efectos de los fármacos , Factores Reguladores Miogénicos/metabolismo , Cadenas Pesadas de Miosina/metabolismo , Troponina T/metabolismo
10.
Mol Cell Biochem ; 309(1-2): 133-41, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18008139

RESUMEN

Mechanical stress leads to satellite cell activation, which is an important event in the development, growth, and remodeling of postnatal skeletal muscle. Although there is a considerable knowledge on the events involved in skeletal muscle regeneration and development, the precise role of mechanical stress on activation of satellite cells remains unclear. Previously, satellite cells were isolated from adult bovine muscle and it was shown that the cells are multipotent, i.e., capable of proliferating and to differentiating into both myoblasts and adipocytes. This study investigated the cellular mechanisms by which cyclic mechanical stretching modulates the proliferation and differentiation of adult bovine satellite cells. The application of cyclic stretch induced the proliferation of satellite cells and inhibited their differentiation into myotubes. This response is believed to be closely related to the stretch-mediated changes in the expression of myogenic and cell cycle regulatory factors. Cyclic stretching increased the level of extracellular signal-regulated kinase (ERK) phosphorylation, whereas a specific ERK inhibitor (PD98058) blocked the stretch-mediated inhibition of myogenesis in a dose-dependent manner. Overall, this study demonstrates for the first time that cyclic mechanical stretch induces the proliferation of bovine satellite cells and suppresses their myogenic differentiation through the activation of ERK.


Asunto(s)
Diferenciación Celular , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Células Satélite del Músculo Esquelético/citología , Células Satélite del Músculo Esquelético/enzimología , Animales , Bovinos , Ciclo Celular , Fusión Celular , Proliferación Celular , Forma de la Célula , Ciclina D1/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Activación Enzimática , Regulación de la Expresión Génica , Sistema de Señalización de MAP Quinasas , Fibras Musculares Esqueléticas/citología , Fibras Musculares Esqueléticas/enzimología , Factores Reguladores Miogénicos/genética , Factores Reguladores Miogénicos/metabolismo , Cadenas Pesadas de Miosina/genética , Cadenas Pesadas de Miosina/metabolismo , Antígeno Nuclear de Célula en Proliferación/metabolismo , Estrés Mecánico
11.
J Microbiol ; 45(5): 373-8, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17978795

RESUMEN

Based on observations that lactic acid bacteria have the ability to activate macrophages, we assessed the potential effects of eight different Lactobacillus strains treated with gastrointestinal enzymes on the production of nitric oxide and various cytokines in macrophages. RAW 264.7 murine macrophage cells were cultured with either precipitates or supernatants of Lactobacillus strains digested with pepsin followed by pancreatin. The increased production of nitric oxide and interleukin (IL)-1beta, IL-6, IL-12 and tumour necrosis factor (TNF)-alpha were observed when cultured with precipitates, and this effect was largely strain-dependent. In contrast, the exposure of RAW 264.7 cells to supernatants produced weaker or nearly undetectable effects in comparison to the effects of exposure to precipitates. The induction of nitric oxide appeared to be unaffected. These results demonstrate that nitric oxide and cytokines were effectively induced when the bacterial precipitate was treated with macrophages. The results of the present study also indicate that Lactobacillus strains treated with digestive enzymes are capable of stimulating the production of nitric oxide and cytokines in macrophages, which may modulate the gastrointestinal immune function of the host when it is given as a feed additive.


Asunto(s)
Citocinas/biosíntesis , Lactobacillus/fisiología , Macrófagos/microbiología , Macrófagos/fisiología , Óxido Nítrico/biosíntesis , Animales , Línea Celular , Hidrólisis , Interleucina-12/biosíntesis , Interleucina-1beta/biosíntesis , Interleucina-6/biosíntesis , Ratones , Factor de Necrosis Tumoral alfa/biosíntesis
12.
J Microbiol ; 45(4): 305-10, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17846583

RESUMEN

The principal objective of this study was to compare the effects of whole and hydrolyzed cells (bifidobacteria) treated with gastrointestinal digestive enzymes on the activation of cloned macrophages. Seven different strains of Bifidobacterium obtained from swine, chickens, and rats, were digested with pepsin followed by pancreatin and the precipitate (insoluble fraction) and supernatant (soluble fraction) obtained via centrifugation. The RAW 264.7 murine macrophages were incubated with either whole cells, the precipitate, or supernatant at various concentrations. Pronounced increases in the levels of nitric oxide (NO), interleukin (IL)-1beta, IL-6, IL-12, and tumor necrosis factor (TNF)-alpha were observed in the whole cells and precipitates, but these effects were less profound in the supernatants. The precipitates also evidenced a slight, but significant, inductive activity for NO and all tested cytokines, with the exception of TNF-alpha in the macrophage model as compared with the whole cells. By way of contrast, TNF-alpha production when cultured with whole cells (100 ng/ml) resulted in marked increases as compared with what was observed with the precipitates. The results of this study indicated, for the first time, that digested Bifidobacterium sp. can induce the production of NO and several cytokines in RAW 264.7 murine macrophage cells. In the current study, it was demonstrated that Bifidobacterium strains treated with digestive enzymes, as compared with whole cells, are capable of stimulating the induction of macrophage mediators, which reflects that they may be able to modulate the gastrointestinal immune functions of the host.


Asunto(s)
Bifidobacterium/metabolismo , Citocinas/metabolismo , Macrófagos/metabolismo , Óxido Nítrico/metabolismo , Animales , Bifidobacterium/crecimiento & desarrollo , Línea Celular , Células Cultivadas , Pollos , Interleucina-1/metabolismo , Interleucina-12/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Activación de Macrófagos , Macrófagos/citología , Macrófagos/microbiología , Ratones , Pancreatina/metabolismo , Pepsina A/metabolismo , Ratas , Porcinos , Factor de Necrosis Tumoral alfa/metabolismo
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