Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Más filtros

Medicinas Complementárias
Métodos Terapéuticos y Terapias MTCI
Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Biochemistry (Mosc) ; 86(9): 1128-1138, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34565316

RESUMEN

Potato virus Y (PVY) is one of the most common and harmful plant viruses. Translation of viral RNA starts with the interaction between the plant cap-binding translation initiation factors eIF4E and viral genome-linked protein (VPg) covalently attached to the viral RNA. Disruption of this interaction is one of the natural mechanisms of plant resistance to PVY. The multigene eIF4E family in the potato (Solanum tuberosum L.) genome contains genes for the translation initiation factors eIF4E1, eIF4E2, and eIF(iso)4E. However, which of these factors can be recruited by the PVY, as well as the mechanism of this interaction, remain obscure. Here, we showed that the most common VPg variant from the PVY strain NTN interacts with eIF4E1 and eIF4E2, but not with eIF(iso)4E. Based on the VPg, eIF4E1, and eIF4E2 models and data on the natural polymorphism of VPg amino acid sequence, we suggested that the key role in the recognition of potato cap-binding factors belongs to the R104 residue of VPg. To verify this hypothesis, we created VPg mutants with substitutions at position 104 and examined their ability to interact with potato eIF4E factors. The obtained data were used to build the theoretical model of the VPg-eIF4E2 complex that differs significantly from the earlier models of VPg complexes with eIF4E proteins, but is in a good agreement with the current biochemical data.


Asunto(s)
Factor 4E Eucariótico de Iniciación/metabolismo , Proteínas de Plantas/metabolismo , Potyvirus/metabolismo , Proteínas Virales/metabolismo , Sitios de Unión , Factor 4E Eucariótico de Iniciación/química , Enlace de Hidrógeno , Simulación de Dinámica Molecular , Mutagénesis Sitio-Dirigida , Proteínas de Plantas/química , Unión Proteica , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Estructura Terciaria de Proteína , Solanum tuberosum/metabolismo , Técnicas del Sistema de Dos Híbridos , Proteínas Virales/química , Proteínas Virales/genética
2.
Int J Mol Sci ; 22(6)2021 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-33805784

RESUMEN

Hepatocellular carcinoma (HCC) frequently shows early invasion into blood vessels as well as intrahepatic metastasis. Innovations of novel small-molecule agents to block HCC invasion and subsequent metastasis are urgently needed. Moscatilin is a bibenzyl derivative extracted from the stems of a traditional Chinese medicine, orchid Dendrobium loddigesii. Although moscatilin has been reported to suppress tumor angiogenesis and growth, the anti-metastatic property of moscatilin has not been elucidated. The present results revealed that moscatilin inhibited metastatic behavior of HCC cells without cytotoxic fashion in highly invasive human HCC cell lines. Furthermore, moscatilin significantly suppressed the activity of urokinase plasminogen activator (uPA), but not matrix metalloproteinase (MMP)-2 and MMP-9. Interestingly, moscatilin-suppressed uPA activity was through down-regulation the protein level of uPA, and did not impair the uPA receptor and uPA inhibitory molecule (PAI-1) expressions. Meanwhile, the mRNA expression of uPA was inhibited via moscatilin in a concentration-dependent manner. In addition, the expression of phosphorylated Akt, rather than ERK1/2, was inhibited by moscatilin treatment. The expression of phosphor-IκBα, and -p65, as well as κB-luciferase activity were also repressed after moscatilin treatment. Transfection of constitutively active Akt (Myr-Akt) obviously restored the moscatilin-inhibited the activation of NF-κB and uPA, and cancer invasion in HCC cells. Taken together, these results suggest that moscatilin impedes HCC invasion and uPA expression through the Akt/NF-κB signaling pathway. Moscatilin might serve as a potential anti-metastatic agent against the disease progression of human HCC.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Compuestos de Bencilo/farmacología , Movimiento Celular/efectos de los fármacos , FN-kappa B/genética , Proteínas Proto-Oncogénicas c-akt/genética , Activador de Plasminógeno de Tipo Uroquinasa/genética , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Embrión de Pollo , Membrana Corioalantoides/irrigación sanguínea , Membrana Corioalantoides/efectos de los fármacos , Factor 4E Eucariótico de Iniciación/genética , Factor 4E Eucariótico de Iniciación/metabolismo , Regulación Neoplásica de la Expresión Génica , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Neovascularización Patológica/prevención & control , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Quinasas S6 Ribosómicas 70-kDa/genética , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Activador de Plasminógeno de Tipo Uroquinasa/antagonistas & inhibidores , Activador de Plasminógeno de Tipo Uroquinasa/metabolismo
3.
Oxid Med Cell Longev ; 2020: 5363546, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32064026

RESUMEN

The present study was performed to evaluate the antioxidant and intestinal protective effects of baicalin-copper on deoxynivalenol-challenged piglets. Forty weaned piglets were randomly divided into four groups and assigned to different diets: (1) basal diet (Con), (2) 4 mg/kg deoxynivalenol of basal diet (DON), (3) 5 g/kg baicalin-copper of basal diet (BCU); and (4) 4 mg/kg deoxynivalenol + 5 g/kg baicalin-copper of basal diet (DBCU). The results showed that the ADFI and ADG of piglets in the DON group were markedly lower than those in the Con group, but the ADFI and ADG of the DBCU group were not significantly different from those of the Con group. In piglets fed a DON-contaminated diet, dietary supplementation with BCU significantly decreased the mRNA levels of P70S6K, 4E-BP1, and HSP70 in the liver, the protein expression of HO-1 in the jejunum, and the expression of p-Nrf2 and p-NF-κB in the ileum but increased Mn-SOD activity in serum. Dietary supplementation with BCU increased jejunal maltase, ZIP4 and MT mRNA levels, and serum concentrations of Arg, Val, Ile, Leu, Lys, and Tyr in DON-contaminated piglets. In summary, BCU can alleviate the growth impairment induced by DON and enhance antioxidant capacity and nutrition absorption in piglets fed DON-contaminated diets.


Asunto(s)
Antioxidantes/metabolismo , Flavonoides/farmacología , Íleon/efectos de los fármacos , Yeyuno/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Tricotecenos/toxicidad , Aminoácidos/sangre , Alimentación Animal , Animales , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Cobre/química , Dieta , Suplementos Dietéticos , Factor 4E Eucariótico de Iniciación/genética , Factor 4E Eucariótico de Iniciación/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Hemo-Oxigenasa 1/genética , Hemo-Oxigenasa 1/metabolismo , Íleon/metabolismo , Yeyuno/citología , Yeyuno/enzimología , Yeyuno/metabolismo , Hígado/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Estrés Oxidativo/genética , Proteínas Quinasas S6 Ribosómicas 70-kDa/genética , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Suero/enzimología , Suero/metabolismo , Superóxido Dismutasa-1/sangre , Porcinos , alfa-Glucosidasas/genética , alfa-Glucosidasas/metabolismo
4.
J Med Food ; 23(1): 29-36, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31532323

RESUMEN

Muscle atrophy, which is characterized by a decrease in muscle mass, function, and protein content, can be caused by aging, disease, and physical inactivity. Red bean or Adzuki bean (Vigna angularis) has been consumed as an edible legume. Red bean possesses various functional properties, such as antidiabetes, antiaging, anti-inflammatory, anticancer, and hepatoprotective activities. However, little is known about its potential inhibitory effect on muscle atrophy. In this study, we investigated the inhibitory effect of red bean extract (RBE) on muscle atrophy in an immobilized hindlimb muscle of C57BL/6J mice. RBE dose-dependently increased grip strength, exercise endurance, muscle weight, and myofiber area. At the molecular level, RBE significantly reduced the mRNA expression of proteolysis-related genes, such as muscle ring finger and muscle atrophy F-box by preventing the translocation of Forkhead box 3. RBE also activated the phosphatidylinositol 3 kinase/Akt pathway, subsequently stimulating the mammalian target of rapamycin/70-kDa ribosomal protein S6 kinase/eukaryotic initiation factor 4E binding protein 1 pathway involved in protein synthesis. Overall, red bean could be used as a functional food ingredient or therapeutic agent to inhibit muscle atrophy.


Asunto(s)
Músculo Esquelético/efectos de los fármacos , Atrofia Muscular/tratamiento farmacológico , Extractos Vegetales/uso terapéutico , Vigna/química , Aminoácidos de Cadena Ramificada , Animales , Biomarcadores/análisis , Factor 4E Eucariótico de Iniciación/metabolismo , Ratones , Ratones Endogámicos C57BL , Distribución Aleatoria , Restricción Física , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Serina-Treonina Quinasas TOR/metabolismo
5.
Med Sci Sports Exerc ; 50(8): 1540-1548, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29554013

RESUMEN

PURPOSE: Neuromuscular electrical stimulation (NMES) is commonly used in rehabilitation settings to increase muscle mass and strength. However, the effects of NMES on muscle growth are not clear and no human studies have compared anabolic signaling between low-frequency (LF) and high-frequency (HF) NMES. The purpose of this study was to determine the skeletal muscle anabolic signaling response to an acute bout of LF- and HF-NMES. METHODS: Eleven young healthy volunteers (6 men, 5 women) received an acute bout of LF-NMES (20 Hz) and HF-NMES (60 Hz). Muscle biopsies were obtained from the vastus lateralis muscle before the first NMES treatment and 30 min after each NMES treatment. Phosphorylation of the following key anabolic signaling proteins was measured by Western blot, and proteins are expressed as a ratio of phosphorylated to total: mammalian target of rapamycin, p70-S6 kinase 1, and eukaryotic initiation factor 4E binding protein 1. RESULTS: Compared with pre-NMES, phosphorylation of mammalian target of rapamycin was upregulated 40.2% for LF-NMES (P = 0.018) and 68.4% for HF-NMES (P < 0.0001), and HF-NMES was 29.3% greater than LF-NMES (P = 0.026). Phosphorylation of p70-S6 kinase 1 after HF-NMES was 96.6% higher than pre-NMES (P = 0.001) and was not different between pre-NMES and LF-NMES (although it was 50.4% higher after LF-NMES) or LF- and HF-NMES (P > 0.05). There were no differences between treatment conditions for eukaryotic initiation factor 4E binding protein 1 phosphorylation (P > 0.05). CONCLUSIONS: An acute bout of LF- and HF-NMES upregulated anabolic signaling with HF-NMES producing a greater anabolic response compared with LF-NMES, suggesting that HF stimulation may provide a stronger stimulus for processes that initiate muscle hypertrophy. In addition, the stimulation frequency parameter should be considered by clinicians in the design of optimal NMES treatment protocols.


Asunto(s)
Estimulación Eléctrica/métodos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Unión Neuromuscular/metabolismo , Músculo Cuádriceps/crecimiento & desarrollo , Músculo Cuádriceps/metabolismo , Transducción de Señal , Adulto , Estudios Cruzados , Terapia por Estimulación Eléctrica/métodos , Factor 4E Eucariótico de Iniciación/metabolismo , Femenino , Humanos , Masculino , Fuerza Muscular/fisiología , Músculo Cuádriceps/inervación , Entrenamiento de Fuerza , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Regulación hacia Arriba , Adulto Joven
6.
Mol Plant Microbe Interact ; 30(9): 754-762, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28609214

RESUMEN

The viral protein genome-linked (VPg) of potyviruses is a protein covalently linked to the 5' end of viral RNA. It interacts with eIF4E, a component of the cellular translation initiation complex. It has been suggested that the 5' RNA-linked VPg could mimic the cellular mRNA cap, promoting synthesis of viral proteins. Here, we report evidence for recruitment of the plant eIF4E by Lettuce mosaic virus (LMV, potyvirus) particles via the 5' RNA-linked VPg. Analysis of the viral population was performed by enzyme-linked immunosorbent assay-based tests, either with crude extracts of LMV-infected tissues or purified viral particles. In both cases, LMV-VPg and LMV-eIF4E subpopulations could be detected. After reaching a maximum within the first 2 weeks postinoculation, these populations decreased and very few labeled particles were found later than 3 weeks postinoculation. The central domain of VPg (CD-VPg) was found to be exposed at the surface of the particles. Using a purified recombinant lettuce eIF4E and CD-VPg-specific antibodies, we demonstrate that the plant factor binds to the VPg via its central domain. Moreover, the plant eIF4E factor could be imaged at one end of the particles purified from LMV plant extracts, by immunoredox atomic force microscopy coupled to scanning electrochemical microscopy. We discuss the biological significance of these results.


Asunto(s)
Factor 4E Eucariótico de Iniciación/metabolismo , Genoma Viral , Lactuca/virología , Potyvirus/metabolismo , ARN Viral/metabolismo , Proteínas Virales/metabolismo , Virión/metabolismo , Anticuerpos , Proteínas de la Cápside/metabolismo , Microscopía de Fuerza Atómica , Oxidación-Reducción , Enfermedades de las Plantas/virología , Unión Proteica , Recombinación Genética/genética
7.
Am J Physiol Cell Physiol ; 310(11): C874-84, 2016 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-27053525

RESUMEN

Protein synthesis is stimulated by resistance exercise and intake of amino acids, in particular leucine. Moreover, activation of mammalian target of rapamycin complex 1 (mTORC1) signaling by leucine is potentiated by the presence of other essential amino acids (EAA). However, the contribution of the branched-chain amino acids (BCAA) to this effect is yet unknown. Here we compare the stimulatory role of leucine, BCAA, and EAA ingestion on anabolic signaling following exercise. Accordingly, eight trained volunteers completed four sessions of resistance exercise during which they ingested either placebo, leucine, BCAA, or EAA (including the BCAA) in random order. Muscle biopsies were taken at rest, immediately after exercise, and following 90 and 180 min of recovery. Following 90 min of recovery the activity of S6 kinase 1 (S6K1) was greater than at rest in all four trials (Placebo

Asunto(s)
Aminoácidos de Cadena Ramificada/administración & dosificación , Aminoácidos Esenciales/administración & dosificación , Leucina/administración & dosificación , Complejos Multiproteicos/agonistas , Músculo Esquelético/efectos de los fármacos , Entrenamiento de Fuerza , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adulto , Biopsia , Glucemia/metabolismo , Proteínas de Ciclo Celular , Metabolismo Energético/efectos de los fármacos , Factor 4E Eucariótico de Iniciación/metabolismo , Voluntarios Sanos , Humanos , Insulina/sangre , Ácido Láctico/sangre , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina , Complejos Multiproteicos/metabolismo , Músculo Esquelético/enzimología , Fosfoproteínas/metabolismo , Fosforilación , Biosíntesis de Proteínas/efectos de los fármacos , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Factores de Tiempo , Resultado del Tratamiento
8.
Molecules ; 21(2)2016 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-26861281

RESUMEN

Preparations of Deguelia duckeana, known in Brazil as timbó, are used by indigenous people to kill fish. Reinvestigation of its extracts resulted in the isolation and identification of 11 known flavonoids identified as 3,5,4'-trimethoxy-4-prenylstilbene (1), 4-methoxyderricidine (2), lonchocarpine (3), 4-hydroxylonchocarpine (4), 4-methoxylonchocarpine (5), 5-hydroxy-4',7-dimethoxy-6-prenylflavanone (6), 4'-hydroxyisolonchocarpine (7), 4'-methoxyisolonchocarpine (8), 3',4',7-trimethoxyflavone (9), 3',4'-methylenedioxy-7-methoxyflavone (10), and 2,2-dimethyl-chromone-5,4'-hydroxy-5'-methoxyflavone (11). Except for 1, 3, and 4 all of these flavonoids have been described for the first time in D. duckeana and the flavanone 6 for the first time in nature. Compounds 2, 3, 4, 7, 9, and 10 were studied for their potential to induce cell death in neuronal SK-N-SH cells. Only the chalcone 4 and the flavanone 7 significantly induced lactate dehydrogenase (LDH) release, which was accompanied by activation of caspase-3 and impairment of energy homeostasis in the MTT assay and may explain the killing effect on fish. Interestingly, the flavone 10 reduced cell metabolism in the MTT assay without inducing cytotoxicity in the LDH assay. Furthermore, the flavonoids 2, 3, 4, 7, and 10 induced phosphorylation of the AMP-activated protein kinase (AMPK) and the eukaryotic elongation factor 2 (eEF2). The initiation factor eIF4E was dephosphorylated in the presence of these compounds. The initiation factor eIF2alpha was not affected. Further studies are needed to elucidate the importance of the observed effects on protein synthesis and potential therapeutic perspectives.


Asunto(s)
Fabaceae/química , Flavonoides/toxicidad , Extractos Vegetales/toxicidad , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Adenilato Quinasa/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Factor 2 Eucariótico de Iniciación/metabolismo , Factor 4E Eucariótico de Iniciación/metabolismo , Flavonoides/aislamiento & purificación , Humanos , Factor 2 de Elongación Peptídica/metabolismo , Fosforilación , Extractos Vegetales/aislamiento & purificación
9.
Sci Rep ; 6: 18800, 2016 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-26728896

RESUMEN

The eukaryotic translation initiation factor 4E (eIF4E) is considered as a key survival protein involved in cell cycle progression, transformation and apoptosis resistance. Herein, we demonstrate that medicinal plant derivative 3-AWA (from Withaferin A) suppressed the proliferation and metastasis of CaP cells through abrogation of eIF4E activation and expression via c-FLIP dependent mechanism. This translational attenuation prevents the de novo synthesis of major players of metastatic cascades viz. c-FLIP, c-Myc and cyclin D1. Moreover, the suppression of c-FLIP due to inhibition of translation initiation complex by 3-AWA enhanced FAS trafficking, BID and caspase 8 cleavage. Further ectopically restored c-Myc and GFP-HRas mediated activation of eIF4E was reduced by 3-AWA in transformed NIH3T3 cells. Detailed underlying mechanisms revealed that 3-AWA inhibited Ras-Mnk and PI3-AKT-mTOR, two major pathways through which eIF4E converges upon eIF4F hub. In addition to in vitro studies, we confirmed that 3-AWA efficiently suppressed tumor growth and metastasis in different mouse models. Given that 3-AWA inhibits c-FLIP through abrogation of translation initiation by co-targeting mTOR and Mnk-eIF4E, it (3-AWA) can be exploited as a lead pharmacophore for promising anti-cancer therapeutic development.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Proteínas de Transporte de Catión/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Proteínas ras/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/genética , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/metabolismo , Carcinoma de Ehrlich/genética , Carcinoma de Ehrlich/metabolismo , Carcinoma de Ehrlich/patología , Proteínas Portadoras/metabolismo , Caspasa 8/metabolismo , Proteínas de Ciclo Celular , Línea Celular Tumoral , Movimiento Celular/genética , ATPasas Transportadoras de Cobre , Modelos Animales de Enfermedad , Factor 4E Eucariótico de Iniciación/metabolismo , Factores Eucarióticos de Iniciación , Humanos , Masculino , Ratones , Metástasis de la Neoplasia , Fosfoproteínas/metabolismo , Fosforilación , Biosíntesis de Proteínas/efectos de los fármacos , Transporte de Proteínas , Witanólidos/farmacología , Receptor fas/metabolismo
10.
Amino Acids ; 48(1): 257-267, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26334346

RESUMEN

Suboptimal nutrient intake represents a limiting factor for growth and long-term survival of low-birth weight infants. The objective of this study was to determine if in neonates who can consume only 70 % of their protein and energy requirements for 8 days, enteral leucine supplementation will upregulate the mammalian target of rapamycin (mTOR) pathway in skeletal muscle, leading to an increase in protein synthesis and muscle anabolism. Nineteen 4-day-old piglets were fed by gastric tube 1 of 3 diets, containing (kg body weight(-1) · day(-1)) 16 g protein and 190 kcal (CON), 10.9 g protein and 132 kcal (R), or 10.8 g protein + 0.2 % leucine and 136 kcal (RL) at 4-h intervals for 8 days. On day 8, plasma AA and insulin levels were measured during 6 post-feeding intervals, and muscle protein synthesis rate and mTOR signaling proteins were determined at 120 min post-feeding. At 120 min, leucine was highest in RL (P < 0.001), whereas insulin, isoleucine and valine were lower in RL and R compared to CON (P < 0.001). Compared to RL and R, the CON diet increased (P < 0.01) body weight, protein synthesis, phosphorylation of S6 kinase (p-S6K1) and 4E-binding protein (p-4EBP1), and activation of eukaryotic initiation factor 4 complex (eIF4E · eIF4G). RL increased (P ≤ 0.01) p-S6K1, p-4EBP1 and eIF4E · eIF4G compared to R. In conclusion, when protein and energy intakes are restricted for 8 days, leucine supplementation increases muscle mTOR activation, but does not improve body weight gain or enhance skeletal muscle protein synthesis in neonatal pigs.


Asunto(s)
Alimentación Animal/análisis , Suplementos Dietéticos/análisis , Leucina/metabolismo , Proteínas Musculares/metabolismo , Biosíntesis de Proteínas , Porcinos/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Animales , Metabolismo Energético , Factor 4E Eucariótico de Iniciación/genética , Factor 4E Eucariótico de Iniciación/metabolismo , Femenino , Insulina/metabolismo , Masculino , Proteínas Musculares/genética , Músculo Esquelético/crecimiento & desarrollo , Músculo Esquelético/metabolismo , Fosforilación , Porcinos/genética , Porcinos/crecimiento & desarrollo
11.
Exp Gerontol ; 72: 269-77, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26481769

RESUMEN

The decreased regenerative capacity of old skeletal muscles involves disrupted turnover of proteins. This study investigated whether leucine supplementation in old rats could improve muscle regenerative capacity. Young and old male Wistar rats were supplemented with leucine; then, the muscles were cryolesioned and examined after 3 and 10 days. Leucine supplementation attenuated the decrease in the expression of eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1) and eukaryotic translation initiation factor 4E (eIF4E) in young and old muscles on day 3 post-injury and promoted an increase in the cross-sectional area of regenerating myofibers from both young and old soleus muscles on day 10 post-injury. This supplementation decreased the levels of ubiquitinated proteins and increased the proteasome activity in young regenerating muscles, but the opposite effect was observed in old regenerating muscles. Moreover, leucine decreased the inflammation area and induced an increase in the number of proliferating satellite cells in both young and old muscles. Our results suggest that leucine supplementation improves the regeneration of skeletal muscles from old rats, through the preservation of certain biological responses upon leucine supplementation. Such responses comprise the decrease in the inflammation area, increase in the number of proliferating satellite cells and size of regenerating myofibers, combined with the modulation of components of the phosphoinositide 3-kinase/Akt-protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway and ubiquitin-proteasome system.


Asunto(s)
Envejecimiento/efectos de los fármacos , Leucina/farmacología , Músculo Esquelético/patología , Regeneración/efectos de los fármacos , Células Satélite del Músculo Esquelético/patología , Transducción de Señal/efectos de los fármacos , Animales , Proteínas Portadoras/metabolismo , Suplementos Dietéticos , Factor 4E Eucariótico de Iniciación/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Masculino , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfoproteínas/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar , Serina-Treonina Quinasas TOR/metabolismo , Proteínas Ubiquitinadas/metabolismo
12.
Anticancer Drugs ; 26(6): 641-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25850883

RESUMEN

Dehydrocostus lactone (DHC) is the main active ingredient extracted from a traditional Chinese medicine called Radix Aucklandiael. A few studies recently showed that DHC has anticancer potential. However, no reports exist as yet on the effects of DHC on colorectal carcinoma (CRC). This study aimed to determine whether and how DHC functions in CRC cells. After treatment with DHC, both Lovo and SW480 cells were significantly inhibited in their proliferation, cell cycle progression, migration, and invasion abilities in a dose-dependent and/or treatment time-dependent manner. Also, DHC significantly increased the apoptosis rate of SW480 cells, but not Lovo cells. The expression of eukaryotic translation initiation factor 4E (eIF4E), which was originally highly expressed in both cells, was significantly decreased by DHC. The inhibition of proliferation, migration, and invasion was significantly attenuated by the ectopic transfection of eIF4E, and was promoted by the knockdown of eIF4E in Lovo cells. To the best of our knowledge, this is the first time it has been shown that DHC suppressed the proliferation, cell cycle progression, antiapoptosis, and migration and invasion capabilities of CRC cells by the downregulation of eIF4E expression. In terms of the overexpression of eIF4E in many cancers, it was speculated that DHC might also play an anticancerous role by suppressing eIF4E expression. This discovery could lay the foundations for advancing our understanding of the anticancerous mechanism of DHC and developing DHC into a novel and effective natural anticancer therapeutic.


Asunto(s)
Neoplasias Colorrectales/patología , Factor 4E Eucariótico de Iniciación/metabolismo , Lactonas/farmacología , Sesquiterpenos/farmacología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Neoplasias Colorrectales/metabolismo , Regulación hacia Abajo , Factor 4E Eucariótico de Iniciación/genética , Humanos , Invasividad Neoplásica
13.
Leuk Lymphoma ; 56(3): 730-8, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24884318

RESUMEN

Imatinib resistance has emerged as a significant clinical problem in chronic myeloid leukemia (CML) treatment. In this study, we investigated the effect and mechanism of combination treatment with imatinib and cryptotanshinone (CPT) in CML cells. Cotreatment with imatinib and CPT showed a significant synergistic killing effect in both imatinib sensitive and resistant CML cell lines, as well as primary CML cells. Furthermore, combination treatment induced apoptosis significantly, as indicated by increases in apoptotic cell fraction and activities of proapoptotic proteins. Subsequent studies revealed that CPT significantly inhibited Bcr/Abl protein expression, as well as phosphorylation expression levels of signal transducer and activator of transcription 3 (STAT3), mammalian target of rapamycin (mTOR) and eukaryotic translation initiation factor 4E (eIF4E), which are critical mediators of Bcr/Abl transformation. Furthermore, CPT in combination with imatinib dramatically decreased the activity of the Bcr/Abl pathway in both K562 and K562-R cells. Our results demonstrated that CPT increased imatinib-induced apoptosis in a Bcr/Abl dependent manner, suggesting a novel strategy for the treatment of CML.


Asunto(s)
Apoptosis/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Mesilato de Imatinib/farmacología , Fenantrenos/farmacología , Western Blotting , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Medicamentos Herbarios Chinos/farmacología , Factor 4E Eucariótico de Iniciación/metabolismo , Proteínas de Fusión bcr-abl/antagonistas & inhibidores , Proteínas de Fusión bcr-abl/genética , Proteínas de Fusión bcr-abl/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción STAT3/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Células Tumorales Cultivadas
14.
J Biol Chem ; 289(32): 21909-25, 2014 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-24891504

RESUMEN

Loss of muscle proteins and the consequent weakness has important clinical consequences in diseases such as cancer, diabetes, chronic heart failure, and in aging. In fact, excessive proteolysis causes cachexia, accelerates disease progression, and worsens life expectancy. Muscle atrophy involves a common pattern of transcriptional changes in a small subset of genes named atrophy-related genes or atrogenes. Whether microRNAs play a role in the atrophy program and muscle loss is debated. To understand the involvement of miRNAs in atrophy we performed miRNA expression profiling of mouse muscles under wasting conditions such as fasting, denervation, diabetes, and cancer cachexia. We found that the miRNA signature is peculiar of each catabolic condition. We then focused on denervation and we revealed that changes in transcripts and microRNAs expression did not occur simultaneously but were shifted. Indeed, whereas transcriptional control of the atrophy-related genes peaks at 3 days, changes of miRNA expression maximized at 7 days after denervation. Among the different miRNAs, microRNA-206 and -21 were the most induced in denervated muscles. We characterized their pattern of expression and defined their role in muscle homeostasis. Indeed, in vivo gain and loss of function experiments revealed that miRNA-206 and miRNA-21 were sufficient and required for atrophy program. In silico and in vivo approaches identified transcription factor YY1 and the translational initiator factor eIF4E3 as downstream targets of these miRNAs. Thus miRNAs are important for fine-tuning the atrophy program and their modulation can be a novel potential therapeutic approach to counteract muscle loss and weakness in catabolic conditions.


Asunto(s)
MicroARNs/genética , Atrofia Muscular/etiología , Atrofia Muscular/genética , Regiones no Traducidas 3' , Animales , Secuencia de Bases , Caquexia/genética , Caquexia/metabolismo , Modelos Animales de Enfermedad , Factor 4E Eucariótico de Iniciación/genética , Factor 4E Eucariótico de Iniciación/metabolismo , Perfilación de la Expresión Génica , Masculino , Ratones , Ratones Endogámicos BALB C , MicroARNs/metabolismo , Datos de Secuencia Molecular , Desnervación Muscular , Músculo Esquelético/inervación , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Inanición/genética , Inanición/metabolismo , Factores de Tiempo , Factor de Transcripción YY1/genética , Factor de Transcripción YY1/metabolismo
15.
Arch Dermatol Res ; 305(8): 747-54, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23912479

RESUMEN

We investigated the proliferative effect of a Acanthopanax senticosus extract (ASE) on human CD49f(+)/CD29(+) keratinocytes and isolated phloridzin from A. senticosus as an active compound. In addition, the possible mechanisms of action were examined. We found that the ASE and phloridzin-promoted proliferation of CD49f(+)/CD29(+) cells using MTT and Click-iT™ EdU flow cytometry assays. In addition, phosphorylation of the p44/42 MAPK (ERK), mTOR, p70 S6 kinase (p70S6K), S6 ribosomal protein (S6RP), eukaryotic initiation factor 4B (eIF4B), and eIF4E was stepwise induced in CD49f(+)/CD29(+) cells. Furthermore, the ASE and phloridzin significantly induced the production of vascular endothelial growth factor and interleukin-6 in CD49f(+)/CD29(+) cells. Similarly, ASE and phloridzin-induced phosphorylation of the mTOR/p70S6K/S6RP/eIF4B/eIF4E pathway was blocked in response to pretreatment with PD98059, a specific ERK inhibitor. Taken together, these results indicate that ASE and phloridzin-induced proliferation of CD49f(+)/CD29(+) cells under serum-free conditions was mediated by the ERK-dependent mTOR pathway.


Asunto(s)
Integrina alfa6/metabolismo , Integrina beta1/metabolismo , Queratinocitos/metabolismo , Florizina/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Proliferación Celular , Células Cultivadas , Eleutherococcus , Factor 4E Eucariótico de Iniciación/metabolismo , Factores Eucarióticos de Iniciación/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Flavonoides/farmacología , Prepucio/citología , Humanos , Masculino , Florizina/aislamiento & purificación , Fosforilación , Extractos Vegetales/metabolismo , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo
16.
Mol Biotechnol ; 54(1): 68-78, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-22555850

RESUMEN

Host protein synthesis is shut down in the lytic baculovirus expression vector system (BEVS). This also affects host proteins involved in routing secretory proteins through the endoplasmic reticulum (ER)-Golgi system. It has been demonstrated that a secretory alkaline phosphatase-EGFP fusion protein (SEFP) can act as a traceable and sensitive secretory reporter protein in BEVS. In this study, a chaperone, calreticulin (CALR), and the translation initiation factor eIF4E were co-expressed with SEFP using a bicistronic baculovirus expression vector. We observed that the intracellular distribution of SEFP in cells co-expressing CALR was different from co-expressing eIF4E. The increased green fluorescence emitted by cells co-expressing CALR had a good correlation with the abundance of intracellular SEFP protein and an unconventional ER expansion. Cells co-expressing eIF4E, on the other hand, showed an increase in extracellular SEAP activity compared to the control. Utilization of these baculovirus expression constructs containing either eIF4E or CALR offers a significant advantage for producing secreted proteins for various biotechnological and therapeutic applications.


Asunto(s)
Baculoviridae/genética , Calreticulina/genética , Factor 4E Eucariótico de Iniciación/genética , Chaperonas Moleculares/genética , Fosfatasa Alcalina/genética , Animales , Calreticulina/metabolismo , Retículo Endoplásmico/genética , Retículo Endoplásmico/metabolismo , Factor 4E Eucariótico de Iniciación/metabolismo , Genes Reporteros , Aparato de Golgi/genética , Aparato de Golgi/metabolismo , Proteínas Fluorescentes Verdes/genética , Insectos/citología , Insectos/genética , Insectos/metabolismo , Proteínas Recombinantes de Fusión/genética
17.
Transgenic Res ; 21(5): 929-38, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22146867

RESUMEN

Potato virus Y (PVY) is the most important viral pathogen of cultivated potato (Solanum tuberosum) from a commercial perspective, causing severe losses in both tuber quality and yield worldwide. Specific accessions of wild potato species exhibit resistance against PVY but efforts to transfer the trait to cultivated material have not yielded widely adopted varieties. Because amino acid substitutions at specific domains of host factor eIF4E-1 often confer resistance to various crops, we sequenced the associated genes expressed in wild potato plants. A novel eIF4E-1 variant, designated here as Eva1, was identified in S. chacoense, S. demissum, and S. etuberosum. The protein contains amino acid substitutions at ten different positions when compared to its cultivated potato (S. tuberosum) homolog. In the yeast two-hybrid system, Eva1 failed to bind VPg, a viral protein required for infectivity. Overexpression of the associated cDNA conferred PVY resistance to transgenic potato plants silenced for the native eIF4E-1 gene. Because the gene sources of Eva1 are sexually compatible with potato, the molecular strategies described can be employed to develop 'intragenic' potato cultivars.


Asunto(s)
Resistencia a la Enfermedad , Factor 4E Eucariótico de Iniciación/metabolismo , Silenciador del Gen , Proteínas de Plantas/metabolismo , Potyvirus/patogenicidad , Solanum/inmunología , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Capsicum/genética , Capsicum/metabolismo , Clonación Molecular , ADN Complementario/genética , ADN Complementario/metabolismo , Factor 4E Eucariótico de Iniciación/genética , Regulación de la Expresión Génica de las Plantas , Genotipo , Datos de Secuencia Molecular , Mutación , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/virología , Proteínas de Plantas/genética , Proteínas de Plantas/inmunología , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/inmunología , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/virología , Potyvirus/inmunología , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Solanum/genética , Solanum/metabolismo , Solanum/virología , Transformación Genética , Técnicas del Sistema de Dos Híbridos , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/metabolismo
18.
J Virol ; 85(13): 6784-94, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21525344

RESUMEN

The multifunctional helper component proteinase (HCpro) of potyviruses (genus Potyvirus; Potyviridae) shows self-interaction and interacts with other potyviral and host plant proteins. Host proteins that are pivotal to potyvirus infection include the eukaryotic translation initiation factor eIF4E and the isoform eIF(iso)4E, which interact with viral genome-linked protein (VPg). Here we show that HCpro of Potato virus A (PVA) interacts with both eIF4E and eIF(iso)4E, with interactions with eIF(iso)4E being stronger, as judged by the data of a yeast two-hybrid system assay. A bimolecular fluorescence complementation assay on leaves of Nicotiana benthamiana showed that HCpro from three potyviruses (PVA, Potato virus Y, and Tobacco etch virus) interacted with the eIF(iso)4E and eIF4E of tobacco (Nicotiana tabacum); interactions with eIF(iso)4E and eIF4E of potato (Solanum tuberosum) were weaker. In PVA-infected cells, interactions between HCpro and tobacco eIF(iso)4E were confined to round structures that colocalized with 6K2-induced vesicles. Point mutations introduced to a 4E binding motif identified in the C-terminal region of HCpro debilitated interactions of HCpro with translation initiation factors and were detrimental to the virulence of PVA in plants. The 4E binding motif conserved in HCpro of potyviruses and HCpro-initiation factor interactions suggest new roles for HCpro and/or translation factors in the potyvirus infection cycle.


Asunto(s)
Cisteína Endopeptidasas/química , Cisteína Endopeptidasas/metabolismo , Factor 4E Eucariótico de Iniciación/metabolismo , Potyvirus/enzimología , Unión Proteica , Isoformas de Proteínas/metabolismo , Proteínas Virales/química , Proteínas Virales/metabolismo , Secuencias de Aminoácidos/genética , Secuencia de Aminoácidos , Sitios de Unión , Cisteína Endopeptidasas/genética , Factor 4E Eucariótico de Iniciación/genética , Factores Eucarióticos de Iniciación , Datos de Secuencia Molecular , Enfermedades de las Plantas/virología , Hojas de la Planta/virología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Potyvirus/genética , Potyvirus/metabolismo , Isoformas de Proteínas/genética , Análisis de Secuencia de ADN , Solanum tuberosum/virología , Nicotiana/virología , Técnicas del Sistema de Dos Híbridos , Proteínas Virales/genética
19.
Amino Acids ; 39(5): 1477-86, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20473536

RESUMEN

Recent work with young pigs shows that reducing dietary protein intake can improve gut function after weaning but results in inadequate provision of essential amino acids for muscle growth. Because acute administration of L-leucine stimulates protein synthesis in piglet muscle, the present study tested the hypothesis that supplementing L-leucine to a low-protein diet may maintain the activation of translation initiation factors and adequate protein synthesis in multiple organs of post-weaning pigs. Eighteen 21-day pigs (Duroc×Landrace×Yorkshire) were fed low-protein diets (16.9% crude protein) supplemented with 0, 0.27 or 0.55% L-leucine (total leucine contents in the diets being 1.34, 1.61 or 1.88%, respectively). At 35 days of age, protein synthesis was determined using the [2H] phenylalanine flooding-dose technique. Additionally, total and phosphorylated levels of mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase 1 (S6K1), and eIF4E-binding protein-1 (4E-BP1) were measured in longissimus muscle and liver. Compared with the control group, dietary supplementation with 0.55% L-leucine for 2 weeks increased (P<0.05): (1) the phosphorylated levels of S6K1 and 4E-BP1; (2) protein synthesis in skeletal muscle, liver, the heart, kidney, pancreas, spleen, and stomach; and (3) daily weight gain by 61%. Dietary supplementation with 0.27% L-leucine enhanced (P<0.05) protein synthesis in proximal small intestine, kidney and pancreas. These novel findings provide a molecular basis for designing effective nutritional means to increase the efficiency of nutrient utilization for protein accretion in neonates.


Asunto(s)
Proteínas en la Dieta/administración & dosificación , Suplementos Dietéticos , Leucina/administración & dosificación , Proteínas Musculares/biosíntesis , Aminoácidos/sangre , Animales , Glucemia/análisis , Factor 4E Eucariótico de Iniciación/metabolismo , Insulina/sangre , Músculo Esquelético/metabolismo , Tamaño de los Órganos , Fosforilación , Proteínas Quinasas S6 Ribosómicas/metabolismo , Sirolimus/metabolismo , Porcinos , Destete
20.
Neoplasia ; 12(4): 346-56, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20360945

RESUMEN

The small molecule 4EGI-1 was identified as an inhibitor of cap-dependent translation initiation owing to its disruption of the eIF4E/eIF4G association through binding to eIF4E. 4EGI-1 exhibits growth-inhibitory and apoptosis-inducing activity in cancer cells; thus, we were interested in its therapeutic efficacy in human lung cancer cells. 4EGI-1, as a single agent, inhibited the growth and induced apoptosis of human lung cancer cells.When combined with the death ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), enhanced apoptosis-induced activity was observed. As expected, 4EGI-1 inhibited eIF4E/eIF4G interaction and reduced the levels of cyclin D1 and hypoxia-inducing factor-1alpha (HIF-1alpha), both of which are regulated by a cap-dependent translation mechanism. Moreover, 4EGI-1 induced CCAAT/enhancer-binding protein homologous protein-dependent DR5 expression and ubiquitin/proteasome- mediated degradation of cellular FLICE-inhibitory protein (c-FLIP). Small interfering RNA-mediated blockade of DR5 induction or enforced expression of c-FLIP abrogated 4EGI-1's ability to enhance TRAIL-induced apoptosis, indicating that both DR5 induction and c-FLIP down-regulation contribute to enhancement of TRAIL-induced apoptosis by 4EGI-1. However, inhibition of eIF4E/eIF4G interaction by knockdown of eIF4E effectively reduced the levels of cyclin D1 and HIF-1alpha but failed to induce DR5 expression, downregulate c-FLIP levels, or augment TRAIL-induced apoptosis. These results collectively suggest that 4EGI-1 augments TRAIL-induced apoptosis through induction of DR5 and down-regulation of c-FLIP, independent of inhibition of cap-dependent protein translation.


Asunto(s)
Apoptosis/efectos de los fármacos , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/genética , Nitrocompuestos/farmacología , Biosíntesis de Proteínas/efectos de los fármacos , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/genética , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Tiazoles/farmacología , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Sinergismo Farmacológico , Factor 4E Eucariótico de Iniciación/antagonistas & inhibidores , Factor 4E Eucariótico de Iniciación/metabolismo , Factor 4G Eucariótico de Iniciación/antagonistas & inhibidores , Factor 4G Eucariótico de Iniciación/metabolismo , Humanos , Hidrazonas , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Nitrocompuestos/administración & dosificación , Unión Proteica/efectos de los fármacos , Biosíntesis de Proteínas/genética , Proteínas de Unión a Caperuzas de ARN/antagonistas & inhibidores , Proteínas de Unión a Caperuzas de ARN/fisiología , Ligando Inductor de Apoptosis Relacionado con TNF/administración & dosificación , Tiazoles/administración & dosificación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA