RESUMEN
Some species of lactic acid bacteria have been shown to be beneficial in inflammatory bowel disease (IBD). In the present study, a strain of lactic acid bacterium (Lactobacillus paracasei LS2) was isolated from the Korean food, kimchi, and was shown to inhibit the development of experimental colitis induced by dextran sulfate sodium (DSS). To investigate the role of LS2 in IBD, mice were fed DSS in drinking water for seven days along with LS2 bacteria which were administered intragastrically to some of the mice, while phosphate-buffered saline (PBS) was administered to others (the controls). The administration of LS2 reduced body weight loss and increased survival, and disease activity indexes (DAI) and histological scores indicated that the severity of colitis was significantly reduced. The production of inflammatory cytokines and myeloperoxidase (MPO) activity also decreased. Flow cytometry analysis showed that the number of Th1 (IFN-γ) population cells was significantly reduced in the LS2-administered mice compared with the controls. The administration of LS2 induced the increase of CD4+FOXP3+ Treg cells, which are responsible for IL-10. Numbers of macrophages (CD11b+ F4/80+), and neutrophils (CD11b+ Gr-1+) among lamina propria lymphocytes (LPL) were also reduced. These results indicate that LS2 has an anti-inflammatory effect and ameliorates DSS-induced colitis.
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Colitis/prevención & control , Lacticaseibacillus paracasei/metabolismo , Probióticos/administración & dosificación , Animales , Peso Corporal , Colitis/inducido químicamente , Colitis/patología , Citocinas/análisis , Sulfato de Dextran/administración & dosificación , Sulfato de Dextran/toxicidad , Modelos Animales de Enfermedad , Citometría de Flujo , Microbiología de Alimentos , Histocitoquímica , Inmunofenotipificación , Lacticaseibacillus paracasei/aislamiento & purificación , Macrófagos/inmunología , Ratones , Neutrófilos/inmunología , Peroxidasa/análisis , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Linfocitos T Reguladores/inmunología , Células TH1/inmunología , Resultado del TratamientoRESUMEN
Low molecular weight P2VP-b-PS-b-P2VP triblock copolymer (poly(2-vinlypyridine)-block-polystyrene-block-poly(2-vinylpyridine)] is doped with copper chloride and microphase separated into lamellar line patterns with ultrahigh area density. Salt-doped P2VP-b-PS-b-P2VP triblock copolymer is self-assembled on the top of the nanoimprinted photoresist template, and metallic nanowires with long-range ordering are prepared with platinum-salt infiltration and plasma etching.
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The composition of lichen ecosystems except mycobiont and photobiont has not been evaluated intensively. In addition, recent studies to identify algal genotypes have raised questions about the specific relationship between mycobiont and photobiont. In the current study, we analyzed algal and fungal community structures in lichen species from King George Island, Antarctica, by pyrosequencing of eukaryotic large subunit (LSU) and algal internal transcribed spacer (ITS) domains of the nuclear rRNA gene. The sequencing results of LSU and ITS regions indicated that each lichen thallus contained diverse algal species. The major algal operational taxonomic unit (OTU) defined at a 99% similarity cutoff of LSU sequences accounted for 78.7-100% of the total algal community in each sample. In several cases, the major OTUs defined by LSU sequences were represented by two closely related OTUs defined by 98% sequence similarity of ITS domain. The results of LSU sequences indicated that lichen-associated fungi belonged to the Arthoniomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, and Sordariomycetes of the Ascomycota, and Tremellomycetes and Cystobasidiomycetes of the Basidiomycota. The composition of major photobiont species and lichen-associated fungal community were mostly related to the mycobiont species. The contribution of growth forms or substrates on composition of photobiont and lichen-associated fungi was not evident.
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Hongos/clasificación , Líquenes/clasificación , Regiones Antárticas , Biodiversidad , Chlorophyta/clasificación , Ecosistema , Genes de ARNr , Genotipo , Líquenes/genética , Filogenia , Análisis de Secuencia de ADNRESUMEN
We describe a simple route to fabricate two dimensionally well-ordered, periodic nanopatterns using the self-assembly of brush block copolymers (brush BCPs). Well-developed lamellar microdomains oriented perpendicular to the substrate are achieved, without modification of the underlying substrates, and structures with feature sizes greater than 200 nm are generated due to the reduced degree of chain entanglements of brush BCPs. A near-perfect linear scaling law was found for the period, L, as a function of backbone degree of polymerization (DP) for two series of brush BCPs. The exponent increases slightly from 0.99 to 1.03 as the side chain molecular weight increases from â¼2.4 to â¼4.5 kg/mol(-1) and saturated with further increase in the side chain molecular weight due to the entropic penalty associated with the packing of the side chains. Porous templates and scaffolds from brush BCP thin films are also obtained by selective etching of one component.
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BACKGROUND: Leukemic cells originate from hypoxic bone marrow, which protects them from anti-cancer drugs. Although many factors that cause drug resistance in leukemic cells have been studied, the effect of hypoxia on drug-induced apoptosis is still poorly understood. METHODS: In this study, we examined the effect of hypoxia on anti-leukemic drug resistance in leukemic cell lines treated with cobalt chloride (CoCl(2)), a hypoxia-mimetic agent. Cellular proliferation was evaluated using the methyl thiazolyl tetrazolium (MTT) assay. Flow cytometry analysis and western blots were performed to investigate apoptosis-related proteins. RESULTS: Unlike its previously known apoptotic effect, the expression of HIF-1α increased the survival rate of human promyelocytic leukemia HL-60 cells when these cells were exposed to anti-leukemic drugs; these effects were mediated by heat-shock protein HSP70 and the pro-apoptotic protein Bax. CONCLUSION: These findings may provide new insights for understanding the mechanisms underlying hypoxia and for designing new therapeutic strategies for acute myeloid leukemia.
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Pulmonary fibrosis is a type of interstitial lung disease that causes progressive scarring in lung tissues. Although there have been many studies on fibrosis, there is no standard treatment for fibrotic disease. Thus, there is an urgent need for the development of effective anti-fibrotic drugs. Transforming growth factor beta (TGF-beta) is a major fibrotic mediator known to stimulate fibrosis. To identify small molecules that inhibit TGF-beta responses, we performed cell-based chemical screening using genetically engineered HEK293 reporter cells. Among 8000 chemical compounds containing biologically active natural products and synthetic or clinically used compounds, we found that 3-(2-chlorobenzyl)-1,7-dimethyl-1H-imidazo[2,1-f]purine-2,4(3H,8H)-dione (IM-412) significantly decreased TGF-beta stimulated reporter activity in a dose-dependent manner. In addition, IM-412 inhibited TGF-beta-induced expression of the fibrotic markers alpha-smooth muscle actin (alpha-SMA) and fibronectin, and collagen accumulation in CCD-18Lu human normal lung fibroblasts without cell cytotoxicity. IM-412 decreased Smad2 and -3 phosphorylation as well as JNK and ERK activity. Moreover, expression levels of TGF-beta receptor I (TbetaRI) and receptor II (TbetaRII) were down-regulated by IM-412 in a dose-dependent manner. Thus, our findings indicate that the small molecule IM-412 attenuated TGF-beta-mediated fibroblast differentiation through inhibition of the overall TGF-beta response and may be a promising novel agent for the treatment of pathological fibrotic conditions.
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Diferenciación Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Imidazoles/farmacología , Pulmón/efectos de los fármacos , Fibrosis Pulmonar/patología , Purinas/farmacología , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Línea Celular , Fibroblastos/citología , Humanos , Pulmón/citología , Fibrosis Pulmonar/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Factor de Crecimiento Transformador beta/fisiologíaRESUMEN
Leuconostoc kimchii IMSNU 11154, isolated from kimchi, a traditional Korean fermented food, is known to be an important antimicrobial lactic acid bacterium with probiotic potential. Here we announce the complete genome sequence of L. kimchii IMSNU 11154 consisting of a 2,101,787-bp chromosome and five plasmids. The strain has genes for dextran formation from sucrose and for mannitol formation from fructose. Antimicrobial and antioxidative functions of L. kimchii IMSNU 11154 could be attributed to a leucosin B-like peptide and multiple enzymes to reduce hydrogen peroxide and oxidized thiols, respectively.
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Genoma Bacteriano , Leuconostoc/genética , Fermentación , Microbiología de Alimentos , Datos de Secuencia MolecularRESUMEN
Acetyltransferase, p300 is a transcriptional cofactor of signal-responsive transcriptional regulation. The surveillance kinase ataxia-telangiectasia mutated (ATM) plays a central role in regulation of a wide range of cellular DNA damage responses. Here, we investigated whether and how ATM mediates phosphorylation of p300 in response to DNA damage and how p300 phosphorylation is functionally linked to DNA damage. ATM-phosphorylated p300 in vitro and in vivo, in response to DNA damage. Phosphorylation of p300 proteins was observed upon gamma-irradiation in ATM(+) cells but not ATM(-) cells. Importantly, expression of nonphosphorylatable serine to alanine form of p300 (S106A) destabilized both p300 and NBS1 proteins, after DNA damage. These data demonstrate that ATM transduces a DNA damage signal to p300, and that ATM-dependent phosphorylation of p300 is required for stabilization of NBS1 proteins in response to DNA damage.
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Proteínas de Ciclo Celular/metabolismo , Daño del ADN , Proteínas de Unión al ADN/metabolismo , Proteína p300 Asociada a E1A/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada , Proteína p300 Asociada a E1A/genética , Células HeLa , Humanos , Fosforilación , Estabilidad Proteica , Serina/genética , Serina/metabolismoRESUMEN
Radiation-induced fibrosis (RIF) is a long-term adverse effect of curative radiotherapy; however, the distinct molecular mechanisms of RIF in neighboring normal tissue are not fully understood. We investigated the mechanisms underlying radiation-induced fibroblast differentiation into myofibroblasts. Lung fibroblasts produced reactive oxygen species (ROS) immediately after irradiation, the level of which remained increased for 24 h. The NADPH oxidase inhibitor, diphenyleneiodonium (DPI), suppressed ROS production and significantly decreased the radiation-induced expression of alpha-smooth muscle actin (alpha-SMA) and fibronectin (FN). The mRNA and protein expression of Nox4 was increased by radiation, and siRNA knockdown of Nox4 reduced alpha-SMA and FN levels. Increased phosphorylation of p38MAPK, Erk, and PI3k/Akt was observed after irradiation. Inhibitors of p38 MAPK and Akt, but not of Erk, reduced radiation-induced fibroblast differentiation and Nox4 expression. Notably, DPI partially decreased phosphorylation of p38MAPK and Akt, suggesting that p38MAPK, Akt, and Nox4 may cooperate in a positive feedback loop. Nox4 expression was also increased during bleomycin-induced fibroblast differentiation, and downregulation of Nox4 reduced alpha-SMA levels and extracellular matrix (ECM) accumulation. These results demonstrate that interfering Nox4 activation can be a potential strategy to disrupt fibrotic process.
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Diferenciación Celular/efectos de la radiación , Fibroblastos/efectos de la radiación , Pulmón/citología , NADPH Oxidasas/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Antibióticos Antineoplásicos/farmacología , Bleomicina/farmacología , Línea Celular , Fibroblastos/citología , Regulación de la Expresión Génica/efectos de la radiación , Humanos , Mioblastos/citología , NADPH Oxidasa 4 , NADPH Oxidasas/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Chromatin structure has a crucial role in a diversity of physiological processes, including development, differentiation and stress responses, via regulation of transcription, DNA replication and DNA damage repair. Histone deacetylase (HDAC) inhibitors regulate chromatin structure and activate the DNA damage checkpoint pathway involving Ataxia-telangiectasia mutated (ATM). Herein, we investigated the impact of histone acetylation/deacetylation modification on the ATM-mediated transcriptional modulation to provide a better understanding of the transcriptional function of ATM. The prototype HDAC inhibitor trichostain A (TSA) reprograms expression of the myeloid cell leukemia-1 (MCL1) and Gadd45 genes via the ATM-mediated signal pathway. Transcription of MCL1 and Gadd45alpha is enhanced following TSA treatment in ATM(+) cells, but not in isogenic ATM(-) or kinase-dead ATM expressing cells, in the ATM-activated E2F1 or BRCA1- dependent manner, respectively. These findings suggest that ATM and its kinase activity are essential for the TSA-induced regulation of gene expression. In summary, ATM controls the transcriptional upregulation of MCL1 and Gadd45 through the activation of the ATM-mediated signal pathway in response to HDAC inhibition. These findings are important in helping to design combinatory treatment schedules for anticancer radio- or chemo-therapy with HDAC inhibitors.
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Proteínas de Ciclo Celular/metabolismo , Daño del ADN/genética , Proteínas de Unión al ADN/metabolismo , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transcripción Genética , Proteínas Supresoras de Tumor/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada , Proteínas de Ciclo Celular/genética , Factor de Transcripción E2F1/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Ácidos Hidroxámicos/farmacología , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Regiones Promotoras Genéticas/genética , Unión Proteica/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transcripción Genética/efectos de los fármacosRESUMEN
The objective of this study was to evaluate the immunomodulatory effects of specific bacterial metabolites of Lactobacillus plantarum 10hk2 to induce anti-inflammatory mediators in cell cultures of the murine macrophage cell line, RAW 264.7. The effects of the extracellular metabolites of this bacterial strain were examined by dividing them into protein and polysaccharide fractions. A specific protein fraction (8.7 kDa) was found to be a strong IL-10 inducer in LPS-stimulated RAW 264.7 cells and suppressed LPS-induced NF-κB induction and inhibited LPS-induced phosphorylation of I-κB and p38 MAPK. To the best of our knowledge, this was the first study that investigated the anti-inflammatory effects of an extracellular peptide derived from lactic acid bacteria. In addition, we characterized the inhibitory mode of this molecule in the induction of proinflammatory cytokines. Based on the findings presented in this study, this molecule holds promise for use as an agent to modulate inflammation related diseases.
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Citocinas/biosíntesis , Inmunomodulación , Lactobacillus plantarum/metabolismo , Macrófagos/inmunología , FN-kappa B/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Western Blotting , Línea Celular , Citocinas/inmunología , Electroforesis Capilar , Electroforesis en Gel de Poliacrilamida , Regulación de la Expresión Génica/efectos de los fármacos , Proteínas I-kappa B/metabolismo , Mediadores de Inflamación/metabolismo , Interleucina-10/biosíntesis , Interleucina-10/genética , Lipopolisacáridos/inmunología , Macrófagos/metabolismo , Ratones , Óxido Nítrico/análisis , Péptidos/metabolismo , Fosforilación , Polisacáridos Bacterianos/aislamiento & purificación , Polisacáridos Bacterianos/metabolismo , Transducción de SeñalRESUMEN
AIM OF THE STUDY: A herbal preparation using Scutellaria baicalensis (S. baicalensis) Georgi (Huang Qin, SB) was formulated to effectively protect cancer patients from inflammatory reactions. Although SB, is one of the most widely used herbs in oriental medicine for anti-inflammation, anti-cancer, anti-viral, anti-bacterial and tonifying the immune response, the underlying mechanism(s) by which these effects are induced remains unclear. RESULTS: Here, we report that SB displays anti-inflammatory effects in a zymosan-induced mouse air-pouch model by reducing the expression of nitric oxide (NO), inducible NOS (iNOS), Cyclooxygenase2 (COX-2), Prostaglandin E2 (PGE2), Nuclear Factor-kappaB (NF-kappaB) and IkappaBalpha as well as inflammatory cytokines, such as IL-1beta, IL-2, IL-6, IL-12 and TNF-alpha. In a similar manner, SB also reduced the production of nitric oxide, PGE2, IL-1beta, IL-2, IL-6, IL-12 and TNF-alpha, by decreasing the expression of iNOS, COX-2, IkappaB kinase alphabeta (IKKalphabeta) phosphorylation, IkappaBalpha and IkappaBalpha phosphorylation in LPS-treated Raw 264.7 cells. Additionally, SB interfered with the nuclear translocation of NF-kappaB p65 and p50, resulting in NF-kappaB-dependent transcriptional repression. We further demonstrate that SB attenuated the activity of c-Raf-1/MEK1/2, Erk1/2, p38 and JNK phosphorylation in LPS-treated Raw 264.7 cells. CONCLUSIONS: Taken together, these results confirm the strong anti-inflammatory properties of SB by inhibition of iNOS, COX-2, PGE2, IL-1beta, IL-2, IL-6, IL-12 and TNF-alpha expression. This was achieved through the down-regulation of IKKalphabeta, IkappaBalpha, NF-kappaB activation via suppression of c-Raf-1/MEK1/2 (Mitogen-activated protein kinase/ERK kinase) and MAP kinase phosphorylation in the zymosan-induced mice air-pouch and Raw 264.7 cells. These results support the use of SB herbs for its potent anti-inflammatory activity.
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Antiinflamatorios/farmacología , Factores Inmunológicos/antagonistas & inhibidores , Mediadores de Inflamación/sangre , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Extractos Vegetales/farmacología , Scutellaria baicalensis/química , Transducción de Señal/efectos de los fármacos , Animales , Antiinflamatorios/uso terapéutico , Regulación hacia Abajo , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Inflamación/sangre , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , Macrófagos/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Modelos Animales , Fitoterapia , Extractos Vegetales/uso terapéutico , ARN Mensajero/metabolismo , Distribución Aleatoria , Transducción de Señal/genética , ZimosanRESUMEN
Histone deacetylases (HDACs), a promising target for cancer therapy, play a role in regulating cell-cycle progression. The mechanisms for HDAC inhibition-induced regulation of G(2)/M transition and mitotic progression remain to be elucidated. Herein, we report that trichostatin A (TSA), an HDAC inhibitor, induces a delay at the G(2)/M transition, chromosome missegregation and multi-nucleation, and thereby leads to cell death by promoting exit from aberrant mitosis without spindle checkpoint. These results are associated with a transcriptional modulation of key regulator genes of the cell cycle, including CyclinB1, Plk1, Survivin, and p21(WAF1/Cip1). Actinomycin D, a transcriptional inhibitor, abrogated the TSA-induced delay of G(2)/M transition and transcriptional modulation of cell-cycle regulator genes, indicating that the impact of TSA in this manner is transcription dependent. Overall, our findings indicate that TSA provides a barrier to cell-cycle progression for antiproliferation and promotes escape from mitotic catastrophe and cell death, by inhibiting an HDAC-mediated transcriptional action.
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Apoptosis , Proliferación Celular/efectos de los fármacos , Segregación Cromosómica/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Inhibidores de Histona Desacetilasas , Ácidos Hidroxámicos/farmacología , Huso Acromático/efectos de los fármacos , Apoptosis/genética , Proteínas de Ciclo Celular/genética , División Celular/efectos de los fármacos , Ciclina B/metabolismo , Ciclina B1 , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Fase G2/efectos de los fármacos , Regulación de la Expresión Génica , Células HeLa , Humanos , Proteínas Inhibidoras de la Apoptosis , Proteínas Asociadas a Microtúbulos/genética , Mitosis/efectos de los fármacos , Proteínas de Neoplasias/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Survivin , Transcripción Genética/efectos de los fármacos , Quinasa Tipo Polo 1RESUMEN
In low-pathogenic avian influenza (LPAI) virus, the effects of prophylactic oral administration of Lactobacillus plantarum KFCC11389P on immunity, viral loads and levels of nitric oxide and interferon-gamma in splenocytes from specific pathogen free (SPF) chickens were investigated. For in vitro screening of the antiviral effect, haemagglutination activities of four different lactic acid bacterial strains by direct contact with virus were measured. L. plantarum KFCC11389P only neutralized the virus on the SPF eggs. For in vivo studies, four groups of chickens were fed with various L. plantarum KFCC11389P bacterial components and were then challenged with LPAI virus at 28 days. Additionally, two control groups were used as negative (virus-unchallenged) control and positive (virus-challenged) control. We show that some parameters such as nitric oxide production in serum and splenic adherent cells and interferon-gamma levels in splenic cells from SPF chickens could be used for the evaluation of LPAI virus infection. This is the first report demonstrating the interferon-gamma production in cultured splenic mononuclear cells and nitric oxide production in serum as well as virus shedding in trachea and cloacae in LPAI virus-infected SPF chickens fed specific lactic acid bacterial components.
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Pollos/virología , Subtipo H9N2 del Virus de la Influenza A/patogenicidad , Gripe Aviar/virología , Lactobacillus plantarum/fisiología , Animales , Pruebas de Hemaglutinación , Subtipo H9N2 del Virus de la Influenza A/efectos de los fármacos , Interferón gamma/metabolismo , Óxido Nítrico/metabolismo , Oseltamivir/farmacología , Óvulo/virología , Organismos Libres de Patógenos Específicos , Bazo/metabolismo , Carga ViralRESUMEN
Although Astragali Radix (Astragalus, AR), the root of Astragalus membranaceus (Fisch) Bunge, is widely used in oriental medicine for tonifying the immune response and improving circulation, the underlying mechanism(s) by which these effects are induced remains unclear. Here, we report that AR displays anti-inflammatory effects in zymosan air-pouch mice by reducing the expression of iNOS, COX-2, IL-6, IL-1beta and TNF-alpha and by decreasing the production of nitric oxide (NO). In a similar manner, AR reduces the expression of IL-6, iNOS, and COX-2 in lipopolysaccharide (LPS)-treated Raw 264.7 cells. We further demonstrate that AR attenuates the activity of p38 and Erk1/2 and stimulates mitogen-activated protein kinase phosphatase-1 (MKP-1) in LPS-treated Raw 264.7 cells. Additionally, AR interferes with the translocation of NFkappaB to the nucleus, subsequently resulting in NFkappaB-dependent transcriptional repression. Taken together, these data reveal that AR has an anti-inflammatory effect that is mediated by the MKP-1-dependent inactivation of p38 and Erk1/2 and inhibition of NFkappaB-mediated transcription. These results imply that the AR herb has a potential anti-inflammatory activity.
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Antiinflamatorios/farmacología , Astragalus propinquus/química , Inflamación/tratamiento farmacológico , Extractos Vegetales/farmacología , Animales , Fosfatasa 1 de Especificidad Dual/efectos de los fármacos , Fosfatasa 1 de Especificidad Dual/metabolismo , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Medicina Tradicional de Asia Oriental , Ratones , Ratones Endogámicos BALB C , Proteína Quinasa 1 Activada por Mitógenos/efectos de los fármacos , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/efectos de los fármacos , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , FN-kappa B/antagonistas & inhibidores , Raíces de Plantas , Transcripción Genética/efectos de los fármacos , Proteínas Quinasas p38 Activadas por Mitógenos/efectos de los fármacos , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
BRCA1, a tumor suppressor gene, is implicated in the repression and activation of transcription via interactions with a diverse range of proteins. The mechanisms regulating the action of BRCA1 are not fully understood. Here, we use the promoters of Gadd45alpha, p27(KIP1) and p21(WAF1/CIP1) to demonstrate that SUMO1 represses transactivation potential of BRCA1 by causing BRCA1 to be released from the promoters and augmenting histone deacetylation via recruitment of histone deacetylase (HDAC) activity. Consistently, silencing of SUMO1 led to recruitment of BRCA1 and release of HDAC1 at the BRCA1 target promoters, and subsequent transcriptional activation of the BRCA1 target genes. Furthermore, a sumoylation-incompetent mutant missing the sumoylation donor site suppressed BRCA1-induced activation of transcription, whereas E2 UBC9 or the dominant-negative mutant UBC9 had no effect, implying that repression of BRCA1-mediated activation of transcription by SUMO1 is independent of sumoylation. Repression of BRCA1-mediated activation of transcription by SUMO1 was reversed by DNA damage by inducing the release of SUMO1 from the Gadd45alpha promoter and the recruitment of BRCA1, along with increased histone acetylation, to enhance activation of transcription. Together, our data provide evidence that SUMO1 plays a role in the activation-repression switch of BRCA1-mediated transcription via modulation of promoter occupancy.
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Proteína BRCA1/antagonistas & inhibidores , Histona Desacetilasas/metabolismo , Regiones Promotoras Genéticas , Proteína SUMO-1/metabolismo , Activación Transcripcional , Proteína BRCA1/metabolismo , Sitios de Unión , Proteínas de Ciclo Celular/genética , Línea Celular , Daño del ADN , Regulación hacia Abajo , Histonas/metabolismo , Humanos , Proteínas Nucleares/genética , Interferencia de ARN , Proteína SUMO-1/antagonistas & inhibidores , Proteína SUMO-1/genética , Técnicas del Sistema de Dos HíbridosRESUMEN
Hypoxia is known to regulate the expression of genes involved in the migration of various cell types. Although many studies have shown that hypoxia increases cell migration, it still remains unclear whether hypoxia could modulate the stromal cell derived factor-1 (SDF-1)-dependent migration of leukemic cell. Herein, we demonstrated that the SDF-1-dependent migration of HL-60, was reduced under hypoxia with no comparable decrease of CXC-type chemokine receptor CXCR4, a cognate receptor for SDF-1. Furthermore, we showed that migration toward SDF-1 was reduced by inactivation of either serine/threonine kinase Akt or extracellular signal regulated kinase Erk, which was confirmed by selective pathway inhibitor LY294002 and PD98059. In our results, phosphorylation of Erk was increased under hypoxia, but phosphorylation of Akt was attenuated on the contrary. These results led us to conclusion that hypoxia could inhibit the SDF-1-dependent migration of HL-60 via blocking of Akt activation.
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Quimiocina CXCL12/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Hipoxia de la Célula , Quimiotaxis , Cromonas/farmacología , Inhibidores Enzimáticos/farmacología , Flavonoides/farmacología , Células HL-60 , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/biosíntesis , Morfolinas/farmacología , Fosforilación , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Receptores CXCR4/biosíntesisRESUMEN
Ginsan, an acidic polysaccharide prepared from Panax ginseng, demonstrated multiple immunomodulatory effects in previous studies. This study was conducted to elucidate the antiseptic mechanism induced by ginsan in mice infected with Staphylococcus aureus. When mice were treated with ginsan before the bacterial challenge with S. aureus, they were highly protected from sepsis-induced death. The numbers of S. aureus recovered from ginsan-treated mice were considerably lower than those recovered from nontreated mice. The in vivo depletion of monocytes/macrophages caused more S. aureus to be recovered from the bacteria-infected mice. Nevertheless, mice treated with both etoposide and ginsan were able to maintain an antibacterial activity. In addition, the phagocytic activity of ginsan-treated macrophage against S. aureus was considerably enhanced. The synthesis of inflammatory cytokines, such as tumor necrosis factor-alpha interleukin (IL)-1beta, IL-6, IFN-gamma, IL-12, IL-18 and interferon gamma, was significantly downregulated at the early phase of sepsis in mice that were treated with ginsan before the bacterial challenge. Expression of Toll-like receptors (TLRs), including TLR2, TLR4, and TLR9, as well as the adaptor molecule MyD88, was considerably reduced in peritoneal macrophages that were treated with ginsan before a subsequent contact with S. aureus. These data indicated that ginsan protected mice from S. aureus-induced sepsis through the suppression of acute inflammatory responses at an early phase and the enhancement of antimicrobial activities at subsequent phases of infection.
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Adyuvantes Inmunológicos/farmacología , Antibacterianos/farmacología , Fitoterapia , Polisacáridos , Sepsis/tratamiento farmacológico , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Animales , Línea Celular , Citocinas/metabolismo , Regulación hacia Abajo , Humanos , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Panax/química , Fagocitosis , Extractos Vegetales/inmunología , Extractos Vegetales/farmacología , Polisacáridos/inmunología , Polisacáridos/farmacología , Sepsis/inmunología , Sepsis/microbiología , Sepsis/mortalidad , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/mortalidadRESUMEN
Ginsan, a polysaccharide extracted from Panax ginseng, has multiple immunomodulatory effects. In this study, we show that pretreatment of ginsan (25 mug/kg) protected mice from lethality induced by Staphylococcus aureus challenge. This survival benefit was associated with enhanced bacterial clearance from circulation, spleen and kidney. The phagocytic activity of macrophages treated with ginsan was significantly enhanced against S. aureus. However, the production of proinflammatory cytokines, such as TNF-alpha, IL-1beta, IL-6, IFN-gamma, IL-12, and IL-18, was markedly down-regulated in ginsan-treated mice compared with those of control-infected mice. The expression of Toll-like receptor (TLR) 2 and the adaptor molecule MyD88, which was greatly increased in septic macrophages, was significantly reduced by ginsan treatment in vitro. Similarly, the expression of phospho-JNK1/2, phospho-p38 MAPK, and NF-kappaB was decreased in the same culture system. These results illustrate that the antiseptic activity of ginsan can be attributed to enhanced bacterial clearance, and reduced proinflammatory cytokines via the TLR signaling pathway.
Asunto(s)
Antiinflamatorios/uso terapéutico , Polisacáridos/uso terapéutico , Sepsis/prevención & control , Receptores Toll-Like/efectos de los fármacos , Proteínas Adaptadoras Transductoras de Señales , Animales , Citocinas/efectos de los fármacos , Citocinas/inmunología , Modelos Animales de Enfermedad , Ensayo de Cambio de Movilidad Electroforética , Ensayo de Inmunoadsorción Enzimática , Immunoblotting , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Quinasas de Proteína Quinasa Activadas por Mitógenos/efectos de los fármacos , Quinasas de Proteína Quinasa Activadas por Mitógenos/inmunología , Factor 88 de Diferenciación Mieloide , FN-kappa B , Panax/química , Fagocitosis/efectos de los fármacos , Fagocitosis/inmunología , Extractos Vegetales/uso terapéutico , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sepsis/etiología , Infecciones Estafilocócicas/complicaciones , Staphylococcus aureus , Receptores Toll-Like/inmunologíaRESUMEN
Histone deacetylase inhibitors (HDI) have been reported to inhibit the growth and survival of cancer cells while leaving normal cells untouched. However, the mechanisms underlying this selective cell death are poorly understood. Gene expression analysis revealed that HDI treatment induced up-regulation of p21(WAF1/Cip1) and down-regulation of ErbB2 in cancer cells but not normal cells. Overexpression of p21(WAF1/Cip1) and/or silencing of ErbB2 enhanced cancer cell growth inhibition, suggesting that HDI-induced up-regulation/down-regulation of these genes play critical roles in HDI-induced growth inhibition of cancer cells. Most importantly, we found that the gene silencing factor methyl CpG-binding domain protein 3 (MBD3) was not only released from cancer-selective promoter of the HDI up-regulated p21(WAF1/Cip1) gene but also recruited to that of the HDI-down-regulated ErbB2 gene. Furthermore, silencing of MBD3 by small interfering RNA abrogated the HDI-induced gene regulation and growth inhibition in lung cancer but not in normal cells. Together, our results support the critical potential of MBD3 in HDI-induced cancer-selective cell death via cancer differential gene expression.