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1.
Int J Psychophysiol ; 193: 112242, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37716441

RESUMO

Despite the growing necessity of understanding the dynamics of emotion by naturalistic stimuli, averaging time-locked responses seems insufficient to capture emotional experiences that change over time. Intersubject correlation (ISC) has been implemented to examine dynamic emotional experiences by quantifying the consistency of responses across individuals. While previous research has shown that enhanced psychophysiological ISC can capture dynamic emotional experiences in response to long-lasting videos that evoke dimensional emotions, it is not yet fully understood how psychophysiological consistency varies during videos that elicit distinct emotions, such as fear. In this study, we re-analyzed publicly available data consisting of continuous affect annotations and psychophysiological signals, namely heart rate (HR), electrodermal activity (EDA), electromyographic signals from zygomaticus major (EMG-z), and corrugator supercilii (EMG-c), in response to categorical emotional videos, namely amusing, boring, relaxing, and fearful. Results showed an overall increase in ISC in multiple measures during fearful videos, indicating that emotional experiences during fearful videos were reliably consistent across participants. The effect of amusing and boring videos on ISC revealed varying results depending on the measurements. In particular, larger ISC in valence rating, EDA, and EMG-z was found for amusing than boring videos, whereas larger ISC in HR and EMG-c was observed for boring than amusing movies. Lastly, decreased ISC for relaxing videos was observed across multiple measurements, showing inconsistent emotional experiences during relaxing videos. This study builds on previous research on physiological consistency during emotional experiences by examining how the consistency of continuous affect annotations and psychophysiological measures differs in response to videos that elicit distinct emotions.

2.
Small ; 19(17): e2206668, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36703517

RESUMO

Low-dimensional Cu(I)-based metal halide materials are gaining attention due to their low toxicity, high stability and unique luminescence mechanism, which is mediated by self-trapped excitons (STEs). Among them, Cs5 Cu3 Cl6 I2 , which emits blue light, is a promising candidate for applications as a next-generation blue-emitting material. In this article, an optimized colloidal process to synthesize uniform Cs5 Cu3 Cl6 I2 nanocrystals (NCs) with a superior quantum yield (QY) is proposed. In addition, precise control of the synthesis parameters, enabling anisotropic growth and emission wavelength shifting is demonstrated. The synthesized Cs5 Cu3 Cl6 I2 NCs have an excellent photoluminescence (PL) retention rate, even at high temperature, and exhibit high stability over multiple heating-cooling cycles under ambient conditions. Moreover, under 850-nm femtosecond laser irradiation, the NCs exhibit three-photon absorption (3PA)-induced PL, highlighting the possibility of utilizing their nonlinear optical properties. Such thermally stable and highly luminescent Cs5 Cu3 Cl6 I2 NCs with nonlinear optical properties overcome the limitations of conventional blue-emitting nanomaterials. These findings provide insights into the mechanism of the colloidal synthesis of Cs5 Cu3 Cl6 I2 NCs and a foundation for further research.

3.
Adv Sci (Weinh) ; 9(5): e2104660, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34957694

RESUMO

Although metal halide perovskites are candidate high-performance light-emitting diode (LED) materials, blue perovskite LEDs are problematic: mixed-halide materials are susceptible to phase segregation and bromide-based perovskite quantum dots (QDs) have low stability. Herein, a novel strategy for highly efficient, stable cesium lead bromide (CsPbBr3 ) QDs via in situ surface reconstruction of CsPbBr3 -Cs4 PbBr6 nanocrystals (NCs) is reported. By controlling precursor reactivity, the ratio of CsPbBr3 to Cs4 PbBr6 NCs is successfully modulated. A high photoluminescence quantum yield (PLQY) of >90% at 470 nm is obtained because octahedron CsPbBr3 QD surface defects are removed by the Cs4 PbBr6 NCs. The defect-engineered QDs exhibit high colloidal stability, retaining >90% of their initial PLQY after >120 days of ambient storage. Furthermore, thermal stability is demonstrated by a lack of heat-induced aggregation at 120 °C. Blue LEDs fabricated from CsPbBr3 QDs with reconstructed surfaces exhibit a maximum external quantum efficiency of 4.65% at 480 nm and excellent spectral stability.

4.
ACS Omega ; 6(41): 26952-26958, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34853820

RESUMO

Recently, the double perovskite Cs2AgInCl6, which has high stability and low toxicity, has been proposed as a potential alternative to Pb-based perovskites. However, the calculated parity-allowed transition bandgap of Cs2AgInCl6 is 4.25 eV; this wide bandgap makes it difficult to use as an efficient solar absorber. In this study, we explored the effect of Cu doping on the optical properties of Cs2AgInCl6 double perovskite nano- and microcrystals (MCs), particularly in its changes of absorption profile from the ultraviolet (UV) to near-infrared (NIR) region. Undoped Cs2AgInCl6 showed the expected wide bandgap absorbance, but the Cu-doped sample showed a new sharp absorption peak at 419 nm and broad absorption bands near 930 nm, indicating bandgap reduction. Electron paramagnetic resonance (EPR) spectroscopy demonstrated that this bandgap reduction effect was due to the Cu doping in the double perovskite and confirmed that the Cu2+ paramagnetic centers were located on the surface of the nanocrystals (NCs) and at the center of the perovskite octahedrons (g∥ > g⊥ > ge). Finally, we synthesized Cu-doped Cs2AgInCl6 MCs and observed results similar to those of the NCs, showing that the application range could be expanded to multidimensions.

5.
Nanomaterials (Basel) ; 10(12)2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33271971

RESUMO

Silica aerogels have attracted much attention owing to their excellent thermal insulation properties. However, the conventional synthesis of silica aerogels involves the use of expensive and toxic alkoxide precursors and surface modifiers such as trimethylchlorosilane. In this study, cost-effective water-glass silica aerogels were synthesized using an eco-friendly catechol derivative surface modifier instead of trimethylchlorosilane. Polydopamine was introduced to increase adhesion to the SiO2 surface. The addition of 4-tert-butyl catechol and hexylamine imparted hydrophobicity to the surface and suppressed the polymerization of the polydopamine. After an ambient pressure drying process, catechol-modified aerogel exhibited a specific surface area of 377 m2/g and an average pore diameter of approximately 21 nm. To investigate their thermal conductivities, glass wool sheets were impregnated with catechol-modified aerogel. The thermal conductivity was 40.4 mWm-1K-1, which is lower than that of xerogel at 48.7 mWm-1K-1. Thus, by precisely controlling the catechol coating in the mesoporous framework, an eco-friendly synthetic method for aerogel preparation is proposed.

6.
Antioxidants (Basel) ; 9(10)2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33066301

RESUMO

The chili pepper (Capsicum annuum L.) is a food source that is rich in flavonoids such as luteolin and apigenin. Flavonoids are known to have anti-inflammatory and antioxidant activities; however, studies on the flavonoids composition identified and the anti-inflammatory and antioxidant effects in pepper leaves (PL) and fruits (PF) are insufficient. In the present study, we investigated the antioxidant and anti-inflammatory effects in vitro, and the flavonoids contents of the PL and PF. Pepper extracts showed radical scavenging activities and ameliorated the lipopolysaccharide (LPS)-stimulated inflammatory response by decreasing nitric oxide production and interluekin-6 and tumor necrosis factor alpha levels in RAW 264.7 cells, with more effective activities noted for PL than for PF. Furthermore, PL extracts markedly inhibited the LPS-induced production of reactive oxygen species accumulation. The flavonoid profile and content of pepper were dependent on the part, with PL showing higher total flavonoids than PF. In particular, the content of luteolin glycosides in PL was twice that in PF. Thus, PL may be useful to prevent oxidative stress and inflammation-related diseases.

7.
Small ; 11(37): 4976-84, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26153227

RESUMO

Nano-floating gate memory (NFGM) devices are transistor-type memory devices that use nanostructured materials as charge trap sites. They have recently attracted a great deal of attention due to their excellent performance, capability for multilevel programming, and suitability as platforms for integrated circuits. Herein, novel NFGM devices have been fabricated using semiconducting cobalt ferrite (CoFe2O4) nanoparticles (NPs) as charge trap sites and pentacene as a p-type semiconductor. Monodisperse CoFe2O4 NPs with different diameters have been synthesized by thermal decomposition and embedded in NFGM devices. The particle size effects on the memory performance have been investigated in terms of energy levels and particle-particle interactions. CoFe2O4 NP-based memory devices exhibit a large memory window (≈73.84 V), a high read current on/off ratio (read I(on)/I(off)) of ≈2.98 × 10(3), and excellent data retention. Fast switching behaviors are observed due to the exceptional charge trapping/release capability of CoFe2O4 NPs surrounded by the oleate layer, which acts as an alternative tunneling dielectric layer and simplifies the device fabrication process. Furthermore, the NFGM devices show excellent thermal stability, and flexible memory devices fabricated on plastic substrates exhibit remarkable mechanical and electrical stability. This study demonstrates a viable means of fabricating highly flexible, high-performance organic memory devices.

8.
J Cell Sci ; 125(Pt 24): 5960-73, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23077174

RESUMO

Transmembrane 4 L six family member 5 (TM4SF5) plays an important role in cell migration, and focal adhesion kinase (FAK) activity is essential for homeostatic and pathological migration of adherent cells. However, it is unclear how TM4SF5 signaling mediates the activation of cellular migration machinery, and how FAK is activated during cell adhesion. Here, we showed that direct and adhesion-dependent binding of TM4SF5 to FAK causes a structural alteration that may release the inhibitory intramolecular interaction in FAK. In turn, this may activate FAK at the cell's leading edge, to promote migration/invasion and in vivo metastasis. TM4SF5-mediated FAK activation occurred during integrin-mediated cell adhesion. TM4SF5 was localized at the leading edge of the cells, together with FAK and actin-organizing molecules, indicating a signaling link between TM4SF5/FAK and actin reorganization machinery. Impaired interactions between TM4SF5 and FAK resulted in an attenuated FAK phosphorylation (the signaling link to actin organization machinery) and the metastatic potential. Our findings demonstrate that TM4SF5 directly binds to and activates FAK in an adhesion-dependent manner, to regulate cell migration and invasion, suggesting that TM4SF5 is a promising target in the treatment of metastatic cancer.


Assuntos
Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Quinase 1 de Adesão Focal/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Tetraspaninas/genética , Sequência de Aminoácidos , Animais , Carcinoma Hepatocelular/enzimologia , Adesão Celular/fisiologia , Movimento Celular/fisiologia , Ativação Enzimática , Feminino , Xenoenxertos , Humanos , Neoplasias Hepáticas/enzimologia , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Metástase Neoplásica , Fosforilação , Transdução de Sinais , Tetraspaninas/metabolismo
9.
Biochem J ; 443(3): 691-700, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22292774

RESUMO

The EMT (epithelial-mesenchymal transition) is involved in fibrosis and cancer, and is regulated by different signalling pathways mediated through soluble factors, actin reorganization and transcription factor actions. Because the tetraspan (also called tetraspanin) TM4SF5 (transmembrane 4 L6 family member 5) is highly expressed in hepatocellular carcinoma and induces EMT, understanding how TM4SF5 expression in hepatocytes is regulated is important. We explored the mechanisms that induce TM4SF5 expression and whether impaired signalling pathways for TM4SF5 expression inhibit the acquisition of mesenchymal cell features, using human and mouse normal hepatocytes. We found that TGFß1 (transforming growth factor ß1)-mediated Smad activation caused TM4SF5 expression and EMT, and activation of the EGFR [EGF (epidermal growth factor) receptor] pathway. Inhibition of EGFR activity following TGFß1 treatment abolished acquisition of EMT, suggesting a link from Smads to EGFR for TM4SF5 expression. Further, TGFß1-mediated EGFR activation and TM4SF5 expression were abolished by EGFR suppression or extracellular EGF depletion. Smad overexpression mediated EGFR activation and TM4SF5 expression in the absence of serum, and EGFR kinase inactivation or EGF depletion abolished Smad-overexpression-induced TM4SF5 and mesenchymal cell marker expression. Inhibition of Smad, EGFR or TM4SF5 using Smad7 or small compounds also blocked TM4SF5 expression and/or EMT. These results indicate that TGFß1- and growth factor-mediated signalling activities mediate TM4SF5 expression leading to acquisition of mesenchymal cell features, suggesting that TM4SF5 induction may be involved in the development of liver pathologies.


Assuntos
Transição Epitelial-Mesenquimal , Receptores ErbB/metabolismo , Proteínas de Membrana/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta1/metabolismo , Linhagem Celular Tumoral , Humanos
10.
Can J Microbiol ; 58(2): 206-11, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22279963

RESUMO

The thioredoxin system, consisting of thioredoxin, thioredoxin reductase, and NADPH, is involved in the response against a variety of stresses. The TRX3(+) and TrxR(+) genes encode thioredoxin 3 and thioredoxin reductase, respectively, in the fission yeast Schizosaccharomyces pombe . Their transcriptional regulations were studied using the lacZ fusion genes. Synthesis of ß-galactosidase from the TRX3(+)-lacZ fusion gene was markedly enhanced by nitric-oxide-generating sodium nitroprusside in the Pap1p-positive cells but not in the Pap1p-negative cells. Similarly, synthesis of ß-galactosidase from the TrxR(+)-lacZ fusion gene was upregulated by sodium nitroprusside in a Pap1p-dependent manner. Synthesis of ß-galactosidase from the TRX3(+)-lacZ and TrxR(+)-lacZ fusion genes was also enhanced by S-nitrosoglutathione in the Pap1p-positive cells but not in the Pap1p-negative cells. In brief, the S. pombe genes encoding thioredoxin 3 and thioredoxin reductase are upregulated under nitrosative stress in a Pap1p-dependent manner.


Assuntos
Schizosaccharomyces/fisiologia , Tiorredoxina Dissulfeto Redutase/genética , Tiorredoxinas/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica , Nitroprussiato/metabolismo , S-Nitrosoglutationa , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Estresse Fisiológico , Tiorredoxina Dissulfeto Redutase/metabolismo , Tiorredoxinas/metabolismo , Regulação para Cima/efeitos dos fármacos , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
11.
Cancer Lett ; 314(2): 198-205, 2012 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-22014979

RESUMO

Transmembrane 4L six family member 5 (TM4SF5) can regulate cell-cell adhesion and cellular morphology via cytoplasmic p27(Kip1)-mediated changes in RhoA activity. However, how TM4SF5 causes cytosolic p27(Kip1) stabilization remains unknown. In this study we found that TM4SF5-mediated Ser10 phosphorylation of p27(Kip1) required for cytosolic localization was not always correlated with Akt activity. Inhibition or suppression of c-Jun N-terminal kinase (JNK) in TM4SF5-expressing cells decreased Ser10 phosphorylation of p27(Kip1) and rescued expression levels and localization of adherence junction molecules to cell-cell contacts. These observations suggest involvement of JNKs in TM4SF5-mediated p27(Kip1) Ser10 phosphorylation and localization during epithelial-mesenchymal transition.


Assuntos
Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Sistema de Sinalização das MAP Quinases , Proteínas de Membrana/fisiologia , Adesão Celular , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal , Humanos , Fosforilação
12.
Cancer Biol Ther ; 11(3): 330-6, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21099346

RESUMO

Two separate clinical studies of advanced hepatocarcinoma patients recently reported that the multikinase inhibitor sorafenib (nexavar) could extend survival of the patients only by 2-3 months. We also previously demonstrated that 4'-(p-toluenesulfonylamido)-4-hydroxychalcone (TSAHC) blocks the multilayer growth and migration mediated by TM4SF5, which is highly expressed in approximately 80% of Korean hepatocarcinoma patients. Therefore, we wondered how TSAHC might be different from sorafenib to deal with hepatocarcinoma in terms of the therapeutic characteristics including specificity for TM4SF5. TM4SF5 is previously shown to mediate tumorigenesis through cytosolic p27Kip1-mediated inactivation of RhoA, epithelial-mesenchymal transition, multilayer growth, migration, invasion, and tumor angiogenesis. In this study, TSAHC and two derivatives showed similar antagonistic activities against TM4SF5-mediated signaling and multilayer growth in vitro and anti-tumorigenic activity even in early stages of TM4SF5-mediated tumor formation in nude mice. Meanwhile, sorafenib was only effective much later in tumorigenesis in vivo and affected in vitro proliferation in a TM4SF5-independent manner. Altogether, these observations suggest that TSAHC may be a promising anti-tumorigenic reagent, especially against TM4SF5-mediated hepatocarcinoma.


Assuntos
Antineoplásicos/farmacologia , Benzenossulfonatos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Chalcona/análogos & derivados , Neoplasias Hepáticas/tratamento farmacológico , Proteínas de Membrana/metabolismo , Piridinas/farmacologia , Sulfonamidas/farmacologia , Animais , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Chalcona/metabolismo , Chalcona/farmacologia , Descoberta de Drogas , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Proteínas de Membrana/genética , Camundongos , Camundongos Nus , Niacinamida/análogos & derivados , Compostos de Fenilureia , Transdução de Sinais , Sorafenibe , Sulfonamidas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
13.
J Biol Chem ; 285(46): 36021-31, 2010 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-20829364

RESUMO

Protein-protein interactions and/or signaling activities at focal adhesions, where integrin-mediated adhesion to extracellular matrix occurs, are critical for the regulation of adhesion-dependent cellular functions. Although the phosphorylation and activities of focal adhesion molecules have been intensively studied, the effects of the O-GlcNAc modification of their Ser/Thr residues on cellular functions have been largely unexplored. We investigated the effects of O-GlcNAc modification on actin reorganization and morphology of rat insulinoma INS-1 cells after glucosamine (GlcN) treatment. We found that paxillin, a key adaptor molecule in focal adhesions, could be modified by O-GlcNAc in INS-1 cells treated with GlcN and in pancreatic islets from mice treated with streptozotocin. Ser-84/85 in human paxillin appeared to be modified by O-GlcNAc, which was inversely correlated to Ser-85 phosphorylation (Ser-83 in rat paxillin). Integrin-mediated adhesion signaling inhibited the GlcN treatment-enhanced O-GlcNAc modification of paxillin. Adherent INS-1 cells treated with GlcN showed restricted protrusions, whereas untreated cells showed active protrusions for multiple-elongated morphologies. Upon GlcN treatment, expression of a triple mutation (S83A/S84A/S85A) resulted in no further restriction of protrusions. Together these observations suggest that murine pancreatic ß cells may have restricted actin organization upon GlcN treatment by virtue of the O-GlcNAc modification of paxillin, which can be antagonized by a persistent cell adhesion process.


Assuntos
Acetilglucosamina/metabolismo , Actinas/metabolismo , Glucosamina/farmacologia , Paxilina/metabolismo , Animais , Western Blotting , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Humanos , Imuno-Histoquímica , Insulinoma/metabolismo , Insulinoma/patologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Laminina/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Microscopia de Fluorescência , Mutação , Paxilina/genética , Fosforilação/efeitos dos fármacos , Ratos , Serina/genética , Serina/metabolismo , Estreptozocina
14.
J Cell Biochem ; 111(1): 59-66, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20506553

RESUMO

Overexpression of transmembrane 4 L six family member 5 (TM4SF5), a four-transmembrane L6 family member, causes aberrant cell proliferation and angiogenesis, but the roles of TM4SF5 in migration, invasion, and tumor metastasis remain unknown. Using in vitro hepatocarcinoma cells that ectopically or endogenously express TM4SF5 and in vivo mouse systems, roles of TM4SF5 in metastatic potentials were examined. We found that TM4SF5 expression facilitated migration, invadopodia formation, MMP activation, invasion, and eventually lung metastasis in nude mice, but suppression of TM4SF5 with its shRNA blocked the effects. Altogether, TM4SF5-mediated migration and invasion suggest that TM4SF5 may be therapeutically targeted to deal with TM4SF5-mediated hepatocellular cancers.


Assuntos
Carcinoma Hepatocelular , Movimento Celular/fisiologia , Hepatócitos , Neoplasias Hepáticas , Proteínas de Membrana/metabolismo , Animais , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Feminino , Hepatócitos/citologia , Hepatócitos/patologia , Hepatócitos/fisiologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Metástase Neoplásica
15.
Biochim Biophys Acta ; 1803(8): 975-82, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20399237

RESUMO

Transmembrane 4 L six family member 5 (TM4SF5) causes epithelial-mesenchymal transition (EMT) for aberrant cell proliferation. However, the effects of TM4SF5 expression on cell cycle are unknown so far. In this study, using hepatocytes that either ectopically or endogenously express TM4SF5 and human hepatocarcinoma tissues, the role of TM4SF5 in G1/S phase progression was examined. We found that TM4SF5 expression accelerated G1/S phase progression with facilitated cyclin D1 and E expression and Rb phosphorylation. Furthermore, TM4SF5 enhanced trafficking of CDK4 and cyclin D1 into the nucleus and induced complex formation between them. However, TM4SF5-facilitated G1/S phase progression was blocked by silencing of p27Kip1 using siRNA or by infection of active RhoA. Pharmacological inhibition of ROCK accelerated the G1/S phase progression of control TM4SF5-unexpressing cells. Altogether, these observations suggest that TM4SF5 accelerates G1/S phase progression with facilitated CDK4/cyclin D1 entry into the nucleus, which might be supported by TM4SF5-mediated actin reorganization through cytosolic p27Kip1 expression and Rho GTPase activity.


Assuntos
Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Fase G1/fisiologia , Proteínas de Membrana/metabolismo , Fase S/fisiologia , Proteína rhoA de Ligação ao GTP/metabolismo , Linhagem Celular Tumoral , Ciclina D1/genética , Ciclina D1/metabolismo , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/genética , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Proteínas de Membrana/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/fisiologia , Quinases Associadas a rho/genética , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/genética
16.
FEMS Microbiol Lett ; 280(2): 176-81, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18248428

RESUMO

In the current work, regulation of the pap1(+) gene was investigated by the use of the pap1(+)-lacZ fusion gene and semi-quantitative reverse transcriptase-PCR. The synthesis of beta-galactosidase from the pap1(+)-lacZ fusion gene was significantly enhanced by nitric oxide (NO)-generating sodium nitroprusside (SNP) and nitrogen starvation. However, the induction by SNP and nitrogen starvation was observed to be much less in the Pap1p-negative cells harboring the fusion gene. Exogenous NO was more effectively scavenged in the Pap1p-positive cells than in the Pap1p-negative cells. Oxidative stress such as superoxide anion, hydrogen peroxide and cadmium could not give rise to an effect on the synthesis of beta-galactosidase from the fusion gene. The pap1(+) mRNA level was elevated in the wild-type cells by SNP and nitrogen starvation. Catalase activity, a major enzyme positively regulated by Pap1p, was significantly increased only in the Pap1p-positive cells by SNP. In brief, it is demonstrated that transcription of the Schizosaccharomyces pombe pap1(+) gene is positively regulated by nitrosative and nutritional stress in a Pap1p-dependent manner.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Regulação Fúngica da Expressão Gênica , Nitratos/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Nitrogênio/metabolismo , Nitrosação , Avaliação Nutricional , Proteínas Associadas a Pancreatite , Schizosaccharomyces/fisiologia , Proteínas de Schizosaccharomyces pombe/genética
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