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1.
Behav Sci (Basel) ; 14(3)2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38540461

RESUMEN

With the explosive pace of mobile over-the-top (OTT) video content streaming services, mobile network traffic has seen unprecedented growth in recent years. However, the limitation of antenna performance, the burden of investment cost, and restricted resources hinder improving the current mobile networks' functionality. Accordingly, wireless device-to-device (D2D) caching networks came to the fore as one of the competitive alternatives for alleviating the overloads of mobile network traffic. Wireless D2D caching networks can be a desirable alternative for OTT service providers and telecommunication operators, but the problem is user resistance. User participation is imperative to deliver wireless D2D caching network functionality successfully. Thus, to gain a deeper understanding of user resistance toward wireless D2D caching networks and their underlying sources, this study introduces two perceived cost factors contributing to this resistance and one perceived benefit that mitigates such resistance. Based on an online survey, this study found new theoretical links among perceived costs and benefits, resistance, and participation intention. The findings reveal that user resistance is predicted by perceived costs, encompassing resource sacrifices and privacy concerns, whereas perceived benefits-specifically, perceived usefulness-did not significantly influence resistance. This implies that telecommunication operators should prioritize market requirements over technological advantages, emphasizing the potential for successful commercialization of wireless D2D caching networks.

2.
Nucleic Acids Res ; 51(22): 12242-12260, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-37930826

RESUMEN

Telomeric repeat-containing RNA (TERRA) and its formation of RNA:DNA hybrids (or TERRA R-loops), influence telomere maintenance, particularly in human cancer cells that use homologous recombination-mediated alternative lengthening of telomeres. Here, we report that the RNA-binding motif protein 14 (RBM14) is associated with telomeres in human cancer cells. RBM14 negatively regulates TERRA expression. It also binds to TERRA and inhibits it from forming TERRA R-loops at telomeres. RBM14 depletion has several effects, including elevated TERRA levels, telomeric R-loops, telomere dysfunction-induced DNA damage foci formation, particularly in the presence of DNA replication stress, pRPA32 accumulation at telomeres and telomere signal-free ends. Thus, RBM14 protects telomere integrity via modulating TERRA levels and its R-loop formation at telomeres.


Asunto(s)
Homeostasis del Telómero , Telómero , Humanos , ADN/genética , Estructuras R-Loop , ARN/genética , ARN/metabolismo , ARN Largo no Codificante/genética , Motivos de Unión al ARN , Telómero/genética , Telómero/metabolismo , Neoplasias/genética
3.
J Rheum Dis ; 30(1): 26-35, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37476522

RESUMEN

Objective: To evaluate treatment patterns and healthcare resource utilization (HCRU) after initiating biologic disease-modifying antirheumatic drugs (bDMARDs) in Korean patients with rheumatoid arthritis (RA). Methods: Patients newly diagnosed with RA in 2014 were identified and followed up on using the Korean National Health Insurance Database until 2018. The initial line of therapy (LOT) or LOT1 included patients treated with conventional DMARDs (cDMARD). Patients who started a bDMARD were assigned to LOT2 bDMARD. Those who moved from a bDMARD to a Janus kinase inhibitor were assigned to LOT3. Analyzed outcomes were treatment patterns and HCRU in LOT2 bDMARD. Results: The most prescribed initial bDMARD was a tumor necrosis factor inhibitor. Seventy-five percent of patients had changes in treatment after starting a bDMARD, such as addition/removal or switch of a DMARD, and transition to LOT3. For the first and second changes in LOT2 bDMARD, adding a cDMARD to a bDMARD was more common than switching to another bDMARD (7.98% vs. 2.93% for the first change, and 17.10% vs. 6.51% for the second change). Tocilizumab was the most common bDMARD that was switched to. Forty-eight percent of patients had at least one hospitalization after initiating bDMARDs. Of these patients, 64.3% were admitted due to RA-related reasons. Conclusion: This real-world study provides information on treatment characteristics of RA patients in Korea after starting a bDMARD. In contrary to guidelines, cDMARD addition was more often than bDMARD switches in daily clinical practice.

4.
Behav Sci (Basel) ; 13(3)2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36975267

RESUMEN

This study investigates the factors influencing users' trust in and loyalty to Karrot, a Korean consumer-to-consumer secondhand marketplace platform. This research develops a model with key variables based on the dual model of post-adoption phenomena and adds variables reflecting the specific context of Karrot. An online survey of 305 Karrot users was conducted in South Korea during 19-23 May 2022; the data obtained were analyzed by SEM. The results reveal that two types of trust-trust in Karrot and mutual trust among Karrot users-are direct antecedents of loyalty. Mutual trust among Karrot users is an essential predictor of trust in Karrot. Economic benefits and perceived platform functionality are positively associated with trust in Karrot. Psychological ownership and information interactions were shown to be the important determinants of mutual trust among Karrot users. This study contributes to extending the horizons of post-adoption research by understanding users' affective and practical motivations for trust and loyalty and by confirming the significant role of two types of trust in forming loyalty. Moreover, this study also provides implications for practitioners of C2C secondhand market platforms to develop their management strategies and expand their customer base.

5.
Food Funct ; 13(23): 12268-12277, 2022 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-36345813

RESUMEN

Soy protein, containing isoflavones and bioactive peptides, is shown to have anti-obesity effects, but the main contributor and underlying mechanisms remain unclear. Recent studies have demonstrated that circulating microRNAs (miRNAs) act as important mediators in obesity and metabolic processes. In this study, we investigated whether soy protein components have distinctive effects on adiposity and circulating miRNA profiles in obese mice. C57BL/6J mice were divided into 4 groups, and each group was fed with a control, high-fat (HF), HF with low-isoflavone soy protein (HF/S), or HF with high-isoflavone soy protein (HF/SI) diet for 16 weeks. In the HF/SI group, changes in the serum adipokine levels, adipocyte diameter, and the number of crown-like structures (CLS) were alleviated compared to those of the HF group. In the HF/S group, the number of CLS was reduced. Decreases in body and adipose tissue weights were not observed in both HF/S and HF/SI groups. Through microarray analysis of serum miRNAs, we identified 23 differentially expressed miRNAs (DEMs) among the groups. The levels of most circulating DEMs were correlated with body weight, serum biochemical parameters, and adipose tissue histology. Functional analysis of predicted target genes of DEMs from both HF vs. CON and HF/S vs. CON comparisons revealed several cancer-related pathways. Only 2 DEMs were identified in the HF/SI vs. CON comparison. In conclusion, the present study confirmed that soy isoflavones are the main contributor to the health-beneficial effects of soy protein in diet-induced obesity. Notably, the extent of serum miRNA dysregulation coincided with obesity and altered the circulating adipokine levels. These findings provide additional insights into the role of soy protein in the regulation of circulating miRNAs in diet-induced obesity. Further work is required to validate the proposed functions of miRNAs in target tissues.


Asunto(s)
Isoflavonas , MicroARNs , Ratones , Animales , Dieta Alta en Grasa/efectos adversos , Adipoquinas , Proteínas de Soja , Ratones Endogámicos C57BL , Obesidad/tratamiento farmacológico , Obesidad/genética , Obesidad/metabolismo , Ratones Obesos , Isoflavonas/farmacología , MicroARNs/genética
6.
Artículo en Inglés | MEDLINE | ID: mdl-35529934

RESUMEN

Aim: Higenamine [1-[(4-hydroxyphenyl) methyl]-1, 2, 3, 4-tetrahydroisoquinoline-6, 7-diol], a potent cardiotonic compound from Aconitum, contributes to vascular relaxation and bronchodilation. However, the effects and mechanisms of action of higenamine on skin aging remain poorly understood. In this study, the effects of higenamine on UVB-induced photoaging were examined in the hairless mouse model. Methods: The dorsal skin of hairless mice (CrlOri : SKH1) was exposed to chronic UVB irradiation (100-300 mJ/cm2 for 6 weeks), with subsequent administration of higenamine (1-20 mg/kg, p.o.) for 2 weeks. TGF-ß, Smad3 DNA-binding phosphorylation, and COL1A1 levels were analyzed by immunohistochemistry, and histological analysis of the skin was performed via H&E and MT staining. Results: Higenamine increased TGF-ß, Smad3 DNA-binding phosphorylation, and COL1A1 expression in primary human fibroblast cells and mouse skin. Higenamine suppressed UVB-induced photoaging via skin recovery, improved epidermal thickness, and prevented Smad3, DNA-binding phosphorylation, and COL1A1 depletion via TGF-ß signaling. Conclusion: Higenamine enhances collagen production in the skin through TGF-ß/Smad3 signaling and potentially suppresses UVB-induced skin aging.

7.
STAR Protoc ; 3(1): 101123, 2022 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-35098167

RESUMEN

The AdenoBuilder platform enables the in vitro assembly of recombinant vectors from plasmid inserts that span the adenovirus genome. Two advantages of AdenoBuilder are the ease of modifying the genome and the ability to produce multicomponent vectors in a single step, facilitating parallel approaches to vector optimization. This protocol describes how to introduce transgenes in place of the endogenous Human Adenovirus serotype 5 (HAd5) E1 and/or E3 genes and can be applied to other parts of the HAd5 genome. For complete details on the use and execution of this protocol, please refer to Miciak et al. (2018).


Asunto(s)
Adenoviridae/genética , Recombinación Genética , Vectores Genéticos , Plásmidos , Transgenes
8.
Osong Public Health Res Perspect ; 12(4): 230-235, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34465072

RESUMEN

OBJECTIVE: This study aimed to review the status of sexually transmitted infections (STIs) in children in South Korea between 2010 and 2019, as well as to establish guidelines for the prevention and management to reduce the incidence of STIs in children. METHODS: Data reports from 590 STI surveillance institutions in local health center, hospital-level medical institutions with urology or obstetrics/gynecology departments and public hospitals between 2010 and 2019 in the integrative disease management system of the Korea Disease Control and Prevention Agency as of December 2020 were analyzed. RESULTS: A total of 172,645 cases of STIs were reported over the 10-year period (2010-2019), of which 2,179 cases (1.26%) represented STIs in children below the age of 18 years. A higher incidence of infections was observed in girls (1,499 cases, 68.79%) than in boys (680 cases, 31.21%). The STIs that had the highest incidence were, in descending order, chlamydial infections (997 cases, 45.75%), gonorrhea (592 cases, 27.17%), condyloma acuminata (338 cases, 15.51%), genital herpes (250 cases, 11.47%), and chancroid (2 cases, 0.09%). In adolescents aged 14 to 17 years, chlamydial infections, genital herpes, and gonorrhea were most frequently reported. Condyloma acuminata, in particular, have been consistently reported in children below the age of 14 years. CONCLUSION: Children must be protected legally and institutionally from sexual abuse. Specific management protocols for STIs in children must be established by local governments and associated organizations. National human papillomavirus vaccination programs should be expanded to include boys, and anti-STI educational efforts using modern media should be more activated.

9.
Proc Natl Acad Sci U S A ; 117(10): 5329-5338, 2020 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-32094185

RESUMEN

Accumulating evidence suggests participation of RNA-binding proteins with intrinsically disordered domains (IDPs) in the DNA damage response (DDR). These IDPs form liquid compartments at DNA damage sites in a poly(ADP ribose) (PAR)-dependent manner. However, it is greatly unknown how the IDPs are involved in DDR. We have shown previously that one of the IDPs RBM14 is required for the canonical nonhomologous end joining (cNHEJ). Here we show that RBM14 is recruited to DNA damage sites in a PARP- and RNA polymerase II (RNAPII)-dependent manner. Both KU and RBM14 are required for RNAPII-dependent generation of RNA:DNA hybrids at DNA damage sites. In fact, RBM14 binds to RNA:DNA hybrids. Furthermore, RNA:DNA hybrids and RNAPII are detected at gene-coding as well as at intergenic areas when double-strand breaks (DSBs) are induced. We propose that the cNHEJ pathway utilizes damage-induced transcription and intrinsically disordered protein RBM14 for efficient repair of DSBs.


Asunto(s)
Roturas del ADN de Doble Cadena , Reparación del ADN por Unión de Extremidades , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Intrínsecamente Desordenadas/metabolismo , Proteínas de Unión al ARN/metabolismo , ARN/metabolismo , Quimera , Células HEK293 , Humanos , Autoantígeno Ku/metabolismo , Hibridación de Ácido Nucleico , Dominios Proteicos , ARN/genética , ARN Polimerasa II/metabolismo , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genética
10.
Mater Sci Eng C Mater Biol Appl ; 107: 110352, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31761165

RESUMEN

In this study, we fabricated polyvinyl alcohol hydrogels containing diphlorethohydroxycarmalol (DPHC) from Ishige okamurae for its anti-bacterial effect in wound-dressing applications. First, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of DPHC against Staphylococcus aureus and Pseudomonas aeruginosa were investigated, and these were found to be about 128 µg/mL and 512 µg/mL, respectively. Polyvinyl alcohol hydrogels loaded with different concentrations of DPHC were then produced for the dressing of wounds to assist in the healing process and to provide an antibacterial effect. To investigate the characteristics of the proposed PVA/DPHC hydrogels, we conducted SEM analysis, rheological analysis, thermogravimetric analysis, water swelling analysis, drug release testing, and gel fraction assessment. The antibacterial activity of the PVA/DPHC hydrogels was also tested against the gram-positive bacterium S. aureus and the gram-negative bacterium P. aeruginosa using ASTM E2149 tests. The biocompatibility of the PVA/DPHC hydrogels was assessed using in vitro indirect and direct contact tests and in vivo tests on ICR mice. The PVA/DPHC hydrogels exhibited the ability to reduce the viability of S. aureus and P. aeruginosa by about 99% in ASTM E2149 testing, while not producing any toxic effect on NHDF-Neo or HaCaT cells as shown in MTT assays and in vitro FDA fluorescence analysis. In addition, the PVA/DPHC hydrogels had a strong wound healing effect when compared to non-treated groups of ICR mice in vivo. Based on the characterization of the PVA/DPHC hydrogels in vitro and in vivo, this study suggests that the proposed hydrogel has significant potential for use in wound dressing.


Asunto(s)
Antibacterianos/farmacología , Vendajes , Compuestos Heterocíclicos con 3 Anillos/aislamiento & purificación , Compuestos Heterocíclicos con 3 Anillos/farmacología , Hidrogeles/farmacología , Cicatrización de Heridas/efectos de los fármacos , Animales , Antibacterianos/química , Células Cultivadas , Liberación de Fármacos , Humanos , Hidrogeles/química , Masculino , Ratones Endogámicos ICR , Pruebas de Sensibilidad Microbiana , Phaeophyceae/química , Alcohol Polivinílico/química , Pseudomonas aeruginosa/efectos de los fármacos , Reología , Staphylococcus aureus/efectos de los fármacos , Termogravimetría
11.
Carbohydr Polym ; 198: 197-205, 2018 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-30092991

RESUMEN

Propionibacterium acnes plays a key role in the onset of inflammation leading to acne and in downregulation of the defense system against oxidative stress. Therefore, antibiotics such as macrolides, tetracyclines, azelaic acid, and erythromycin are used to reduce microbial proliferation and resulting inflammation. Nonetheless, antibiotic treatment has side effects including cytotoxicity, allergy, and diarrhea. Therefore, recent studies were focused on the development of alternative antimicrobial materials. We conjugated chitooligosaccharide (COS) with gallic acid (GA) by the hydrogen peroxide-mediated method and evaluated antioxidant and antimicrobial activities. Then, we fabricated a polyvinyl alcohol (PVA) hydrogel containing COS conjugated with GA (GA-COS) for acne treatment. GA-COS at 5-10 kDa showed an excellent antioxidant activity and a better antimicrobial activity against P. acnes as compared with COS. In addition, the PVA hydrogel with GA-COS inhibited intracellular formation of reactive oxygen species and exerted antimicrobial action better than controls did.

12.
J Nutr Biochem ; 46: 49-56, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28456081

RESUMEN

Vitamin E gamma-tocotrienol (γTE) is known to have anticancer effects, but mechanisms underlying these actions are not clear. Here using liquid chromatography tandem mass spectrometry, we show that γTE induced marked changes of sphingolipids including rapid elevation of dihydrosphingosine and dihydroceramides (dhCers) in various types of cancer cells. The elevation of dihydrosphingolipids coincided with increased cellular stress, as indicated by JNK phosphorylation, and was prior to any sign of induction of apoptosis. Chemically blocking de novo synthesis of sphingolipids partially counteracted γTE-induced apoptosis and autophagy. Experiments using 13C3, 15N-labeled l-serine together with enzyme assays indicate that γTE inhibited cellular dihydroceramide desaturase (DEGS) activity without affecting its protein expression or de novo synthesis of sphingolipids. Unlike the effect on dhCers, γTE decreased ceramides (Cers) after 8-h treatment but increased C18:0-Cer and C16:0-Cer after 16 and 24 h, respectively. The increase of Cers coincides with γTE-induced apoptosis and autophagy. Since γTE inhibits DEGS and decreases de novo Cer synthesis, elevation of Cers during prolonged γTE treatment is likely caused by sphingomeylinase-mediated hydrolysis of sphingomyelin. This idea is supported by the observation that an acid sphingomeylinase inhibitor partially reversed γTE-induced cell death. Our study demonstrates that γTE altered sphingolipid metabolism by inhibiting DEGS activity and possibly by activating SM hydrolysis during prolonged treatment in cancer cells.


Asunto(s)
Antineoplásicos/farmacología , Cromanos/farmacología , Oxidorreductasas/antagonistas & inhibidores , Esfingolípidos/metabolismo , Vitamina E/análogos & derivados , Isótopos de Carbono , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Ceramidas/metabolismo , Cromatografía Liquida/métodos , Ácido Graso Desaturasas/metabolismo , Células HCT116 , Humanos , Células MCF-7 , Isótopos de Nitrógeno , Estrés Oxidativo/efectos de los fármacos , Oxidorreductasas/metabolismo , Serina/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Espectrometría de Masas en Tándem/métodos , Vitamina E/farmacología
13.
Amino Acids ; 48(11): 2559-2569, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27339788

RESUMEN

Previous studies have reported that homocysteine induced endoplasmic reticulum (ER) stress in neuronal cells, proposing the underlying mechanism by which it could induce neurotoxicity. Induction of pro-apoptotic transcription factor C/EBP homologous protein (CHOP) and activation of caspase-4 by calpain have been suggested to be an important route in inducing apoptosis in response to ER stress. In this study, we investigated the molecular pathway of homocysteine-induced apoptosis in caspase-4 deficient SH-SY5Y human neuroblastoma cells. Homocysteine significantly increased mRNA levels of CHOP and p53, resulting in the upregulation of their downstream target gene, p53 up-regulated modulator of apoptosis (PUMA). In cells treated with homocysteine, Bcl-2-associated X protein (BAX) protein levels, cytochrome c release from the mitochondria, and caspase-9 activation were significantly increased. Consistently, a caspase-9 inhibitor significantly alleviated homocysteine-induced cytotoxicity. Significantly lower BAX mRNA levels and caspase-9 activation were observed in cells transfected with siRNA for PUMA. Taken together, our findings suggest that PUMA would be involved in the possible crosstalk between the ER and the mitochondria in the homocysteine-induced apoptosis of caspase-4 deficient SH-SY5Y cells.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Apoptosis/efectos de los fármacos , Homocisteína/farmacología , Mitocondrias/metabolismo , Neuroblastoma/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/genética , Línea Celular Tumoral , Humanos , Mitocondrias/genética , Mitocondrias/patología , Neuroblastoma/genética , Neuroblastoma/patología , Proteínas Proto-Oncogénicas/genética
14.
Free Radic Biol Med ; 95: 190-9, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27016075

RESUMEN

Vitamin E forms are substantially metabolized to various carboxychromanols including 13'-carboxychromanols (13'-COOHs) that are found at high levels in feces. However, there is limited knowledge about functions of these metabolites. Here we studied δT-13'-COOH and δTE-13'-COOH, which are metabolites of δ-tocopherol and δ-tocotrienol, respectively. δTE-13'-COOH is also a natural constituent of a traditional medicine Garcinia Kola. Both 13'-COOHs are much stronger than tocopherols in inhibition of pro-inflammatory and cancer promoting cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), and in induction of apoptosis and autophagy in colon cancer cells. The anticancer effects by 13'-COOHs appeared to be partially independent of inhibition of COX-2/5-LOX. Using liquid chromatography tandem mass spectrometry, we found that 13'-COOHs increased intracellular dihydrosphingosine and dihydroceramides after short-time incubation in HCT-116 cells, and enhanced ceramides while decreased sphingomyelins during prolonged treatment. Modulation of sphingolipids by 13'-COOHs was observed prior to or coinciding with biochemical manifestation of cell death. Pharmaceutically blocking the increase of these sphingolipids partially counteracted 13'-COOH-induced cell death. Further, 13'-COOH inhibited dihydroceramide desaturase without affecting the protein expression. In agreement with these mechanistic findings, δTE-13'-COOH significantly suppressed the growth and multiplicity of colon tumor in mice. Our study demonstrates that 13'-COOHs have anti-inflammatory and anticancer activities, may contribute to in vivo anticancer effect of vitamin E forms and are promising novel cancer prevention agents.


Asunto(s)
Araquidonato 5-Lipooxigenasa/genética , Neoplasias del Colon/tratamiento farmacológico , Ciclooxigenasa 2/genética , Vitamina E/metabolismo , Animales , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Cromanos/administración & dosificación , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Garcinia kola/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HCT116 , Humanos , Ratones , Esfingolípidos/metabolismo , Tocoferoles/metabolismo
15.
J Immunol ; 195(1): 126-33, 2015 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-26002975

RESUMEN

NF-κB plays a central role in pathogenesis of inflammation and cancer. Many phytochemicals, including γ-tocotrienol (γTE), a natural form of vitamin E, have been shown to inhibit NF-κB activation, but the underlying mechanism has not been identified. In this study, we show that γTE inhibited cytokine-triggered activation of NF-κB and its upstream regulator TGF-ß-activated kinase-1 in murine RAW 264.7 macrophages and primary bone marrow-derived macrophages. In these cells, γTE induced upregulation of A20, an inhibitor of NF-κB. Knockout of A20 partially diminished γTE's anti-NF-κB effect, but γTE increased another NF-κB inhibitor, Cezanne, in A20(-/-) cells. In search of the reason for A20 upregulation, we found that γTE treatment increased phosphorylation of translation initiation factor 2, IκBα, and JNK, indicating induction of endoplasmic reticulum stress. Liquid chromatography-tandem mass spectrometry analyses revealed that γTE modulated sphingolipids, including enhancement of intracellular dihydroceramides, sphingoid bases in de novo synthesis of the sphingolipid pathway. Chemical inhibition of de novo sphingolipid synthesis partially reversed γTE's induction of A20 and the anti-NF-κB effect. The importance of dihydroceramide increase is further supported by the observation that C8-dihydroceramide mimicked γTE in upregulating A20, enhancing endoplasmic reticulum stress, and attenuating TNF-triggered NF-κB activation. Our study identifies a novel anti-NF-κB mechanism where A20 is induced by stress-induced adaptive response as a result of modulation of sphingolipids, and it demonstrates an immunomodulatory role of dihydrocermides.


Asunto(s)
Adaptación Fisiológica , Péptidos y Proteínas de Señalización Intracelular/agonistas , FN-kappa B/antagonistas & inhibidores , Esfingolípidos/inmunología , gamma-Tocoferol/farmacología , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/inmunología , Línea Celular , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/inmunología , Endopeptidasas/genética , Endopeptidasas/inmunología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/inmunología , Regulación de la Expresión Génica , Proteínas I-kappa B/genética , Proteínas I-kappa B/inmunología , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/inmunología , MAP Quinasa Quinasa 4/genética , MAP Quinasa Quinasa 4/inmunología , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/inmunología , Macrófagos/citología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Ratones , Ratones Endogámicos C57BL , Inhibidor NF-kappaB alfa , FN-kappa B/genética , FN-kappa B/inmunología , Cultivo Primario de Células , Transducción de Señal , Esfingolípidos/metabolismo , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/inmunología , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa
16.
Free Radic Biol Med ; 65: 1069-1077, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24013093

RESUMEN

Inflammation can promote colon cancer. Mechanistic studies indicate that γ-tocopherol (γT), a major form of vitamin E in diets, has anti-inflammatory and anticancer properties. Here we investigated the effectiveness of γT and a mixture of tocopherols against colitis and colitis-promoted colon tumorigenesis in male BALB/c mice. γT or mixed tocopherols (at 0.1% diet) did not show any effect on colon tumorigenesis induced by azoxymethane (AOM, 10mg/kg) with three cycles of dextran sodium sulfate (DSS at 1.5-2.5%). γT failed to exhibit protection of severe colitis caused by three cycles of DSS at 2.5%. In contrast, when AOM-initiated carcinogenesis was promoted by relatively mild colitis induced by one-cycle DSS (1.5%), γT, but not mixed tocopherols, suppressed total multiplicity of macroscopic adenomas (P=0.06) and large adenomatous polyps (>2mm(2), P<0.05) by 60 and 85%, respectively. γT also significantly decreased tumor multiplicity (>2mm(2)) induced by AOM with two cycles of 1.5% DSS even when dietary supplementation was started after AOM injection. Consistently, γT but not mixed tocopherols attenuated DSS (1.5%)-induced colon inflammation and damage as well as formation of atypical glandular hyperplasia. Mice supplemented with tocopherols had high fecal excretion of 13'-carboxychromanol, a long-chain vitamin E metabolite shown to have potent anti-inflammatory activities. Our study demonstrates that γT is able to alleviate moderate but not severe colitis and its promoted tumorigenesis, and indicates that inflammation severity should be considered in evaluating anticancer effectiveness of chemoprevention agents.


Asunto(s)
Anticarcinógenos/farmacología , Carcinogénesis/efectos de los fármacos , Colitis/tratamiento farmacológico , Neoplasias del Colon/prevención & control , gamma-Tocoferol/farmacología , Animales , Anticarcinógenos/farmacocinética , Antioxidantes/farmacocinética , Antioxidantes/farmacología , Colitis/inducido químicamente , Colitis/patología , Neoplasias del Colon/inducido químicamente , Neoplasias del Colon/inmunología , Sulfato de Dextran , Progresión de la Enfermedad , Masculino , Ratones Endogámicos BALB C , gamma-Tocoferol/farmacocinética
17.
Neurochem Res ; 38(8): 1561-71, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23624826

RESUMEN

Mammalian AMP-activated protein kinase (AMPK) acts as a metabolite-sensing protein kinase in multiple tissues. Recent studies have shown that AMPK activation also regulates intracellular signaling pathways involved in cellular survival and apoptosis. Previously, we have reported that AMPK activation alleviates the endoplasmic reticulum (ER) stress-mediated neurotoxicity and tau hyperphosphorylation caused by palmitate. Therefore, we investigated whether AMPK activation alleviates ER stress-mediated neurotoxicity in SH-SY5Y human neuroblastoma cells incubated with homocysteine. Regulation of AMPK activity by isoflavone was also determined to investigate the underlying mechanism of its neuroprotective effect. Treatment of SH-SY5Y human neuroblastoma cells with N (1)-(ß-D-ribofuranosyl)-5-aminoimidazole-4-carboxamide (AICAR), a pharmacological activator of AMPK, significantly protected cells against cytotoxicity imposed by tunicamycin and homocysteine. Homocysteine significantly suppressed AMPK activation, which was alleviated by AICAR. We observed a significant inhibition of the unfolded protein response by AICAR in cells incubated with homocysteine, suggesting a protective role of AMPK activation against ER stress-mediated neurotoxicity. AICAR also significantly reduced tau hyperphosphorylation by inactivating glycogen synthase kinase-3ß and c-Jun N-terminal kinase in cells incubated with homocysteine. Furthermore, treatment of cells with soy isoflavone, genistein and daidzein significantly activated AMPK, which was repressed by tunicamycin and homocysteine. Therefore, our results suggest that AMPK activation by isoflavone as well as AICAR alleviates homocysteine-mediated neurotoxicity in SH-SY5Y cells.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Homocisteína/toxicidad , Secuencia de Bases , Línea Celular Tumoral , Cartilla de ADN , Activación Enzimática , Humanos , Reacción en Cadena de la Polimerasa
18.
Mol Nutr Food Res ; 56(12): 1803-11, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23065795

RESUMEN

SCOPE: This study further examines mechanisms involved in the pro-apoptotic action of gamma-tocopherol (γT) and gamma-tocotrienol (γT3) in human breast cancer cell lines. METHODS AND RESULTS: γT upregulates phospho-JNK (pJNK), CCAAT/enhancer-binding protein homologous protein (CHOP), and death receptor-5 (DR5) protein expression as detected by Western blot assays. siRNA knockdown of JNK, CHOP, or DR5 shows that γT-induced apoptosis is JNK/CHOP/DR5 signaling dependent, which is similar to γT3-mediated apoptotic signaling. Furthermore, both γT and γT3 induce increased levels of cellular ceramides and dihydroceramides as determined by LC-MS/MS analyses. Inhibition of de novo ceramide synthesis using chemical inhibitors blocked the ability of γT and γT3 to induce apoptosis as detected by Annexin V-FITC/PI assay and to activate JNK/CHOP/DR5 pro-apoptotic signaling thereby demonstrating the involvement of de novo ceramide synthesis in γT- and γT3-induced apoptosis. CONCLUSION: Taken together, data show that both γT and γT3 induce apoptosis via de novo ceramide synthesis dependent activation of JNK/CHOP/DR5 pro-apoptotic signaling.


Asunto(s)
Apoptosis/efectos de los fármacos , Ceramidas/biosíntesis , Cromanos/farmacología , Factor de Transcripción CHOP/metabolismo , Vitamina E/análogos & derivados , gamma-Tocoferol/farmacología , Western Blotting , Neoplasias de la Mama/patología , Línea Celular Tumoral , Cromatografía Liquida , Femenino , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/genética , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Células MCF-7 , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/aislamiento & purificación , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/genética , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Transducción de Señal , Espectrometría de Masas en Tándem , Factor de Transcripción CHOP/genética , Regulación hacia Arriba , Vitamina E/farmacología
19.
Asian-Australas J Anim Sci ; 25(2): 286-90, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25049564

RESUMEN

The majority of laboratory animals were transported from commercial breeders to a research facility by ground transportation. During the transportation, many biological functions and systems can be affected by stress. In this experiment, the change of body weight during the transportation was measured and the recovery periods from the transportation stress established based on the body weight changes. Total 676 laboratory animals which were aged between 3 to 9 wk old were studied. The transportation time taken from container packing to unpacking the container was approximately 24 h. The temperature of animal container was constantly maintained by air-conditioning and heating equipment. Rats were found to be more sensitive than mice. The body weight of rats was significantly decreased 3.71% (p<0.05) compared to the body weight of mice which decreased 0.9% There was no significant difference between the strains in the same species. When the changes of body weights were compared between delivery days, C57BL/6 mice showed the most variable changes compared to other species and strains. Consequently, C57BL/6 was more sensitive to stress than the other strains and the transportation process needs to be standardized to reduce between day variability. To establish the recovery periods from transportation stress, the body weight changes were measured during the acclimation period. Although the body weight of animals decreased during transportation, animals recovered their weight loss after the next day.

20.
Brain Res ; 1418: 42-51, 2011 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-21937027

RESUMEN

Obesity and diabetes have been shown to be associated with cognitive impairment or early neurodegeneration. However, the cellular mechanisms that link between these two pathologies have not been clarified. In this study, we treated SH-SY5Y human neuroblastoma cells with palmitate and observed its effect on cell apoptosis and tau hyperphosphorylation. Dose- and time-dependent effects of palmitate on apoptosis were observed. Palmitate treatment induced endoplasmic reticulum (ER) stress, determined by the expression of spliced X-box binding protein 1 (XBP-1) mRNA and immunoglobin heavy chain-binding protein (BiP). We also observed increases in c-Jun N-terminal kinase (JNK) activation and tau hyperphosphorylation in response to palmitate. Although palmitate did not impair insulin signaling as shown by the immunoblotting analysis of AKT phosphorylation, it did inactivate AMP-activated protein kinase (AMPK). Activation of AMPK by N(1)-(ß-d-Ribofuranosyl)-5-aminoimidazole-4-carboxamide (AICAR), significantly reduced the apoptosis of cells treated with palmitate. AICAR also significantly inhibited ER stress, resulting in reduced tau hyperphosphorylation in cells treated with palmitate. Similarly, A769662, a direct activator of AMPK, also abolished the ER stress-mediated apoptosis and tau hyperphosphorylation. Therefore, these data suggest that palmitate triggers ER stress-mediated lipotoxicity and that AMPK activation inhibits apoptosis and tau hyperphosphorylation mediated by palmitate in SH-SY5Y cells.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Apoptosis/efectos de los fármacos , Palmitatos/farmacología , Proteínas tau/metabolismo , Adenosina Trifosfato/metabolismo , Análisis de Varianza , Caspasa 3/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Relación Dosis-Respuesta a Droga , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Indoles , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuroblastoma/patología , Oligopéptidos/genética , Oligopéptidos/metabolismo , Fosforilación/efectos de los fármacos , Factores de Transcripción del Factor Regulador X , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteína 1 de Unión a la X-Box
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