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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 219: 232-239, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31048252

RESUMO

Hypochlorous acid (HClO) is one of the most important ROS (reactive oxygen species) and common pollutant in tap-water. However, the determination of HClO with fast response and high sensitivity/selectivity is still an urgent demanding. Here we fabricated a ratiometric fluorescent probe RC based on TBET (through-bond energy transfer) on the platform of coumarin and rhodamine with the thiosemicarbazide group as the linker. This probe could display the characteristic fluorescence emission of coumarin. Upon addition of HClO, the linker was reacted into an oxadiazole, resulting in the opening of spiro-ring of rhodamine. The resultant then gives ratiometric fluorogenic changes. The probe exhibits fast response and high selectivity and sensitivity towards HClO with a low limit of detection (~140 nM). Eventually, RC is successfully applicated for determining spiked HClO in water samples and imaging endogenous HClO in living cells.


Assuntos
Cumarínicos/química , Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Rodaminas/química , Animais , Células HeLa , Humanos , Camundongos , Imagem Óptica/métodos , Células RAW 264.7 , Espectrometria de Fluorescência/métodos , Água/análise
2.
Acta Pharmacol Sin ; 37(7): 950-62, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27292614

RESUMO

AIM: Tubeimoside-1 (TBMS1), a triterpenoid saponin extracted from the Chinese herbal medicine Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae), has shown anticancer activities in various cancer cell lines. The aim of this study was to investigate the anticancer activity and molecular targets of TBMS1 in human prostate cancer cells in vitro. METHODS: DU145 and P3 human prostate cancer cells were treated with TBMS1. Cell viability and apoptosis were detected. ROS generation, mitochondrial membrane potential and cell cycle profile were examined. Western blotting was used to measure the expression of relevant proteins in the cells. RESULTS: TBMS1 (5-100 µmol/L) significantly suppressed the viability of DU145 and P3 cells with IC50 values of approximately 10 and 20 µmol/L, respectively. Furthermore, TBMS1 dose-dependently induced apoptosis and cell cycle arrest at G0/G1 phase in DU145 and P3 cells. In DU145 cells, TBMS1 induced mitochondrial apoptosis, evidenced by ROS generation, mitochondrial dysfunction, endoplasmic reticulum stress, modulated Bcl-2 family protein and cleaved caspase-3, and activated ASK-1 and its downstream targets p38 and JNK. The G0/G1 phase arrest was linked to increased expression of p53 and p21 and decreased expression of cyclin E and cdk2. Co-treatment with Z-VAD-FMK (pan-caspase inhibitor) could attenuate TBMS1-induced apoptosis but did not prevent G0/G1 arrest. Moreover, co-treatment with NAC (ROS scavenger), SB203580 (p38 inhibitor), SP600125 (JNK inhibitor) or salubrinal (ER stress inhibitor) significantly attenuated TBMS1-induced apoptosis. CONCLUSION: TBMS1 induces oxidative stress-mediated apoptosis in DU145 human prostate cancer cells in vitro via the mitochondrial pathway.


Assuntos
Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Fase G1/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Neoplasias da Próstata/patologia , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Saponinas/farmacologia , Triterpenos/farmacologia , Acetilcisteína/farmacologia , Clorometilcetonas de Aminoácidos/farmacologia , Antracenos/farmacologia , Caspase 3 , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cinamatos/farmacologia , Ciclina E/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Relação Dose-Resposta a Droga , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Imidazóis/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , MAP Quinase Quinase Quinase 5/metabolismo , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Piridinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Saponinas/antagonistas & inibidores , Tioureia/análogos & derivados , Tioureia/farmacologia , Triterpenos/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
3.
Anal Chim Acta ; 919: 85-93, 2016 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-27086103

RESUMO

A new colorimetric and fluorogenic probe (RN3) based on rhodamine-B has been successfully designed and synthesized. It displays a selective response to Hg(2+) in the aqueous buffer solution over the other competing metals. Upon addition of Hg(2+), the solution of RN3 exhibits a 'naked eye' observable color change from colorless to red and an intensive fluorescence with about 105-fold enhancement. The changes in the color and fluorescence are ascribed to the ring-opening of spirolactam in rhodamine fluorophore, which is induced by a binding of the constructed receptor to Hg(2+) with the association and dissociation constants of 0.22 × 10(5) M(-1) and 25.2 µM, respectively. The Job's plot experiment determines a 1:1 binding stoichiometry between RN3 and Hg(2+). The resultant "turn-on" fluorescence in buffer solution, allows the application of a method to determine Hg(2+) levels in the range of 4.0-15.0 µM, with the limit of detection (LOD) calculated at 60.7 nM (3σ/slope). In addition, the fluorescence 'turn-off' and color 'fading-out' happen to the mixture of RN3-Hg(2+) by further addition of I(-) or S(2-). The reversible switching cycles of fluorescence intensity upon alternate additions of Hg(2+) and S(2-) demonstrate that RN3 can perform as an INHIBIT logic gate. Furthermore, the potential of RN3 as a fluorescent probe has been demonstrated for cellular imaging.


Assuntos
Corantes Fluorescentes/química , Lógica , Mercúrio/análise , Imagem Molecular/métodos , Rodaminas/química , Sobrevivência Celular/efeitos dos fármacos , Colorimetria , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/farmacologia , Células HeLa , Humanos , Estrutura Molecular , Rodaminas/síntese química , Rodaminas/farmacologia , Espectrometria de Fluorescência
4.
Sci Rep ; 4: 4841, 2014 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-24788080

RESUMO

Environmental pollution by emerging contaminants, e.g. pharmaceuticals, has become a matter of widespread concern in recent years. We investigated the membrane transport of diclofenac and its toxic effects on gene expression and the development of zebrafish embryos. The association of diclofenac with the embryos conformed to the general partition model at low concentration, the partition coefficient being 0.0033 ml per embryo. At high concentration, the interaction fitted the Freundlich model. Most of the diclofenac remained in the extracellular aqueous solution with less than 5% interacting with the embryo, about half of which was adsorbed on the membranes while the rest entered the cytoplasm. Concentrations of diclofenac over 10.13 µM were lethal to all the embryos, while 3.78 µM diclofenac was teratogenic. The development abnormalities at 4 day post treatment (dpt) include shorter body length, smaller eye, pericardial and body edema, lack of liver, intestine and circulation, muscle degeneration, and abnormal pigmentation. The portion of the diclofenac transferred into the embryo altered the expression of certain genes, e.g. down-regulation of Wnt3a and Gata4 and up-regulation of Wnt8a. The alteration of expression of such genes or the regulation of downstream genes could cause defects in the cardiovascular and nervous systems.


Assuntos
Diclofenaco/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Peixe-Zebra/genética , Animais , Anti-Inflamatórios não Esteroides/toxicidade , Ecotoxicologia , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/genética , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/toxicidade , Fatores de Tempo
5.
Hum Pathol ; 44(10): 2199-203, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23954140

RESUMO

α-Thalassemia/mental retardation syndrome X-linked protein (ATRX) and death domain-associated protein (DAXX) genes are tumor suppressors whose mutations have been identified in sporadic pancreatic neuroendocrine tumors as well as in patients with MEN1. However, it is unknown whether ATRX and DAXX alterations are specific for pancreatic neuroendocrine tumor. In addition, the association of ATRX/DAXX protein loss with tumor cell proliferation has not been examined. We, therefore, immunostained ATRX and DAXX in 10 gastric, 15 duodenal, 20 rectal, 70 pancreatic, and 22 pulmonary neuroendocrine tumors with 15 nonneoplastic pancreases and 27 pancreatic adenocarcinomas to elucidate the site-specific roles of ATRX/DAXX abnormalities. At least 1 loss of ATRX and DAXX immunoreactivity was detected in all neuroendocrine tumor cases but not in any of nonneoplastic pancreatic tissues or pancreatic adenocarcinomas. The loss of DAXX protein was correlated with the Ki-67 index (ATRX, P = .904; DAXX, P = .044). The status of DAXX immunoreactivity correlated positively with World Health Organization histologic grade (P = .026). These results suggest that the status of ATRX or DAXX protein loss in neuroendocrine tumor differed among the organs in which these tumors arose, and these proteins may play site-specific roles in the development of these tumors.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Gastrointestinais/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Pulmonares/patologia , Retardo Mental Ligado ao Cromossomo X/patologia , Tumores Neuroendócrinos/patologia , Talassemia alfa/patologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Neoplasias Gastrointestinais/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Masculino , Retardo Mental Ligado ao Cromossomo X/metabolismo , Pessoa de Meia-Idade , Tumores Neuroendócrinos/metabolismo , Pâncreas/metabolismo , Pâncreas/patologia , Adulto Jovem , Talassemia alfa/metabolismo
6.
Environ Monit Assess ; 185(1): 39-44, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22286838

RESUMO

An on-site solid-phase extraction, consisting of the sorption, the separation and the elution function units, was designed for in situ preconcentration of heavy metals ions. The D401 resin powder was employed as sorbent to capture Pb(2+), Cu(2+), Zn(2+), Cd(2+), Co(2+), and Ni(2+), and then they desorbed with 2 mol/L nitric acid as eluent. Under the optimized conditions, these heavy metals ions in West Lake, Taihu Lake, and Yangtze River of China were captured and then determined by ICP-OES with the recovery of 92.5% to 111.5%. The on-site solid-phase extraction achieved a quick preconcentration of heavy metals to avoid the transport and storage of a large volume water sample. It is suitable for in situ monitoring of water quality in mountains, tablelands or other remote areas.


Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/análise , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , China , Lagos/química , Metais Pesados/química , Poluentes Químicos da Água/química
8.
Molecules ; 17(5): 6046-55, 2012 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-22614859

RESUMO

Sulfide is an important water pollutant widely found in industrial waste water that has attracted much attention. S²â», as a weak acidic anion, is easy hydrolyzed to HS⁻ and H2S in aqueous solution. In this study, biological tests were performed to establish the toxicity of sulfide solutions on luminescent bacteria. Considering the sulfide solution was contained three substances--S²â», HS⁻ and H2S--the toxicity test was performed at different pH values to investigate which form of sulfide increased light emission and which reduced light emission. It was shown that the EC50 values were close at pH 7.4, 8.0 and 9.0 which were higher than pH 5 and 10. The light emission and sulfide concentrations displayed an inverse exponential dose-response relationship within a certain concentration range at pH 5, 6.5 and 10. The same phenomenon occurred for the high concentration of sulfide at pH 7.4, 8 and 9, in which the concentration of sulfide was HS⁻ >> H2S > S²â». An opposite hormesis-effect appeared at the low concentrations of sulfide.


Assuntos
Bactérias/efeitos dos fármacos , Luminescência , Sulfetos/farmacologia , Bactérias/metabolismo , Concentração de Íons de Hidrogênio , Solubilidade , Soluções , Sulfetos/química , Poluentes da Água/química
9.
PLoS One ; 7(4): e32818, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22509249

RESUMO

The increased application of nanomaterials has raised the level of public concern regarding possible toxicities caused by exposure to nanostructures. The interactions of nanosized hydroxyapatite (HA) with cytochrome c and hemoglobin were investigated by zeta-potential, UV-vis, fluorescence and circular dichroism. The experimental results indicated that the interactions were formed via charge attraction and hydrogen bond and obeyed Langmuir adsorption isotherm. The two functional proteins bridged between HA particles to aggregate into the coralloid form, where change of the secondary structure of proteins occurred. From effects of nanosized HA, SiO(2) and TiO(2) particles on the zebrafish embryos development, they were adsorbed on the membrane surface confirmed by the electronic scanning microscopy. Nano-HA aggregated into the biggest particles around the membrane protein and then caused a little toxicity to development of zebrafish embryos. The SiO(2) particles were distributed throughout the outer surface and caused jam of membrane passage, delay of the hatching time and axial malformation. Maybe owing to the oxygen free radical activity, TiO(2) caused some serious deformity characters in the cardiovascular system.


Assuntos
Durapatita/metabolismo , Durapatita/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/fisiologia , Desenvolvimento Embrionário/efeitos dos fármacos , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Adsorção , Animais , Citocromos c/metabolismo , Durapatita/química , Concentração de Íons de Hidrogênio , Larva/efeitos dos fármacos , Nanoestruturas/toxicidade , Concentração Osmolar , Ligação Proteica , Dióxido de Silício/química , Dióxido de Silício/toxicidade , Temperatura Ambiente , Titânio/química , Titânio/toxicidade , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/química
10.
Yi Chuan ; 34(1): 95-101, 2012 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-22306878

RESUMO

SOD is an important enzyme which exists in eukaryote extensively and plays an essential role in stress-tolerance of higher plants. A cDNA of Cu/ZnSOD gene was cloned from Galega orientalis L. using rapid amplification of cDNA ends (RACE) method. The full-length of cDNA sequence is 935 bp, included a 600 bp open reading frame which encoded a 199-amino-acid polypeptide. The molecular weight of this protein was 20.35 kDa. The results of Real-Time PCR indicated that the expression level of Cu/ZnSOD gene was the highest in leaves, moderate in stems, and the least in roots. The expression of Cu/ZnSOD gene under stress of NaCl and PEG was up-regulated firstly and then declined. The expression level was significantly lower than the control after 24 h treated with NaCl. Abscisic acid downregulated the expression of Cu/ZnSOD gene. The result of subcellular localization indicated that Cu/ZnSOD was located in chloroplast. Gene Cu/ZnSOD mainly expressed in the green organs of G. orientalis and played a certain role in resisting osmotic stress.


Assuntos
Clonagem Molecular , Galega/enzimologia , Regulação Enzimológica da Expressão Gênica , Proteínas de Plantas/genética , Superóxido Dismutase/genética , Sequência de Aminoácidos , Galega/classificação , Galega/genética , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/metabolismo , Superóxido Dismutase/metabolismo
11.
Environ Sci Pollut Res Int ; 19(4): 1237-44, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22057851

RESUMO

INTRODUCTION: Ethylenediamine-grafted multiwalled carbon nanotubes (MWCNTs-EDA-I and MWCNTs-EDA-II) are optimized and employed to investigate the preconcentration of lead ions (Pb(II)) in trace level. RESULTS: The results show that Pb(II) can be adsorbed quantitatively on the optimized MWCNTs in the range of pH 4-7 and MWCNTs-EDA-I has a higher maximum Pb(II) adsorption capacity (157.19 mg/g) than MWCNTs-EDA-II (89.16 mg/g). The adsorbed Pb(II) can be eluted completely using 5 mL of 1 mol/L HNO(3). DISCUSSION: A new approach using a microcolumn packed with the obtained MWCNTs-EDA-I has been developed for the preconcentration of trace amount of Pb(II). Parameters influencing the preconcentration of Pb(II), such as pH of the sample, sample volume, elution solution, and interfering ions, have been examined and optimized in detail. Under optimum experimental conditions, the limit of detection is 0.30 ng/mL with the enrichment factor of 60. The relative standard deviation (R.S.D) was 2.6% at the 20 ng/mL Pb(II) level. CONCLUSION: The method has been applied for the preconcentration of trace amount of Pb(II) in environmental water samples with satisfying results.


Assuntos
Etilenodiaminas/química , Chumbo/química , Nanotubos de Carbono/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Oxirredução , Extração em Fase Sólida
12.
Carbohydr Polym ; 89(1): 185-92, 2012 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-24750622

RESUMO

The sorption of copper ions onto natural bamboo sawdust with cellulose-lignin polymeric structure strongly depends on pH. The adsorption capacity for copper ions increases as increasing pH and copper loadings. The fitting of copper pH boundary curve by NEM surface complexation models shows that: three-sites model including the ion exchange reaction of permanent charge fits better than two-sites model. The incorporation of the hydrated ion reaction gives better fitting results. XAFS study shows that: copper ions mainly form inner complexation with sawdust, but there is no obvious evidence on the complexation of carboxylic acid groups with copper ions. EXAFS fitting result shows that: as pH rises, the spatial configuration of copper ions shifts from tetrahedron to octahedron. Meanwhile the increase in the coordination number indicates that hydrated copper ions participate in the adsorption. Both XANES and EXFAS spectrum offer a similar explanation for copper adsorption in the range of experimental and fitting errors.


Assuntos
Bambusa , Cobre/química , Modelos Teóricos , Adsorção , Celulose/química , Concentração de Íons de Hidrogênio , Troca Iônica , Lignina/química , Madeira , Espectroscopia por Absorção de Raios X
13.
Chem Commun (Camb) ; 47(48): 12810-2, 2011 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-22051684

RESUMO

The CR@BaSO(4) hybrid was synthesized, characterized and used as an acid rain-indicating (ARI) material. A painted ARI umbrella was discolored after exposure to simulated acid rain of pH 5 or less and returned to the initial color after the rain stopped. Such a functionalized material may make acid rain visual to remind people in real-time.


Assuntos
Chuva Ácida/análise , Sulfato de Bário/química , Vermelho Congo/química , Concentração de Íons de Hidrogênio , Nanoestruturas/química
14.
Molecules ; 16(6): 5035-53, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-21694669

RESUMO

Common synthetic dyes, e.g., Weak Acid Pink Red B (APRB, C.I. 18073), Mordant Blue 9 (MB, C.I.14855) and Acid Brilliant Blue 6B (ABB6B, C.I. 42660), can be removed from water by in situ hybridization with CaCO(3), BaSO(4) and Ca(3)(PO(4))(2) and the resulting hybrids thus prepared used as plastic colorants. All the hybrids can be processed into polypropylene (PP) at 200 °C with good color intensity, color brightness and homogeneous dispersion. The BaSO(4)-MB hybrid exhibits better migration resistance to acid and alkali, and stronger covering power than the BaSO(4)-MB mixture. The thermal stability and UV resistance of the Ca(3)(PO(4))(2)-ABB6B hybrid are better than those of the Ca(3)(PO(4))(2)-ABB6B mixture. The crystallinity of PP is enhanced by incorporation of these hybrids and the use of these hybrids as colorants in PP instead of the dyes alone is determined to be feasible.


Assuntos
Corantes/química , Corantes/síntese química , Plásticos/química , Sais/química , Temperatura Alta , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Toxicol Sci ; 122(2): 395-405, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21602189

RESUMO

Microcystins (MCs) produced by cyanobacteria and their continuing "blooms" are a worldwide problem owing to the toxicity of microcystin-LR (MC-LR) to plants and animals. In the present study, we investigated membrane transport of MC-LR and its toxic effects on zebrafish embryos using fragmentation of embryos, scanning electron microscope (SEM), fluorescence microscopy, and toxic exposure tests. At a concentration < 0.04 mmol/l, MC-LR was predominantly adsorbed on outer membrane surface of embryos according to Langmuir isotherm. The absorption characteristics of MC-LR within the range from 0.05 to 0.4 mmol/l conformed to Freundlich isotherm model. At concentrations > 0.50 mmol/l MC-LR directly entered the cytoplasm via partition. Thinning and disruption of membranes was confirmed using SEM and fluorescence morphological observations. Exposure to different concentrations of MC-LR resulted in differences in membrane transport and toxicity characteristics. At low concentrations, more than 75% of the adsorbed MC-LR accumulated on the outer membrane surface and resulted in axial malformation, tail curving, and tail twisting. Increasing the concentration of MC-LR to between 0.05 and 0.4 mmol/l improved membrane transport and it was evident in cytoplasm of embryos, resulting in serious pericardial edema, hatching gland edema, hemagglutination, hemorrhage, and vacuolization. At > 0.50 mmol/l, more than 70% of the adsorbed MC-LR entered the cytoplasm and this was lethal to the embryos. The current research outlines a new method and mechanism for the transmembrane transport of large molecular weight organic compounds and could be important for studies concerning molecular toxicology.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Microcistinas/toxicidade , Peixe-Zebra/embriologia , Animais , Relação Dose-Resposta a Droga , Edema , Eletrólitos/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Hemaglutinação , Concentração de Íons de Hidrogênio , Lipossomos/metabolismo , Masculino , Microcistinas/farmacocinética , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Transporte Proteico , Temperatura Ambiente , Peixe-Zebra/crescimento & desenvolvimento , Zigoto/efeitos dos fármacos , Zigoto/metabolismo
16.
Acta Pharmacol Sin ; 32(6): 711-5, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21602841

RESUMO

The expression and role of the aquaporin (AQP) family water channels in the peripheral nervous system was less investigated. Since 2004, however, significant progress has been made in the immunolocalization, regulation and function of AQPs in the peripheral nervous system. These studies showed selective localization of three AQPs (AQP1, AQP2, and AQP4) in dorsal root ganglion neurons, enteric neurons and glial cells, periodontal Ruffini endings, trigeminal ganglion neurons and vomeronasal sensory neurons. Functional characterization in transgenic knockout mouse model revealed important role of AQP1 in pain perception. This review will summarize the progress in this field and discuss possible involvement of AQPs in peripheral neuropathies and their potential as novel drug targets.


Assuntos
Aquaporinas/genética , Aquaporinas/fisiologia , Sistema Nervoso Periférico/metabolismo , Animais , Expressão Gênica , Humanos , Neurônios/metabolismo
17.
Mol Cell Biochem ; 355(1-2): 27-33, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21519921

RESUMO

MED19 is a subunit of Mediator that is an essential component of RNA polymerase II-mediated transcription machinery. High expression levels of MED19 were examined in human lung adenocarcinoma tissues by immunohistochemical assay. MED19-specific short hairpin RNA (shRNA) expressing lentivirus was constructed and infected lung cancer cell line A549. MED19 mRNA and protein expression levels were downregulated in A549 cells as evidenced by real-time PCR and western blot assays. Importantly, MED19 inhibition resulted in impaired proliferation and colony formation, and induced accumulation of G1-phase cells and mitigated invasiveness of cells. More importantly, downregulation of MED19 expression reduced the tumorigenicity of A549 cells in vivo. It was suggested that MED19 is a novel proliferation regulator that promotes growth of lung cancer cells, thereby indicating that MED19 may serve as a new molecular target for lung cancer therapy.


Assuntos
Adenocarcinoma/metabolismo , Proliferação de Células , Transformação Celular Neoplásica , Neoplasias Pulmonares/metabolismo , Complexo Mediador/metabolismo , Adenocarcinoma/patologia , Animais , Estudos de Casos e Controles , Ciclo Celular , Linhagem Celular Tumoral , Feminino , Vetores Genéticos , Humanos , Lentivirus , Neoplasias Pulmonares/patologia , Complexo Mediador/genética , Camundongos , Camundongos Nus , Invasividade Neoplásica/genética , Transplante de Neoplasias , Interferência de RNA , Carga Tumoral/genética
18.
J Hazard Mater ; 184(1-3): 81-8, 2010 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-20810209

RESUMO

Acrylamide (AA) and bisphenol A (BPA) are two kinds of pollutants with different structures and polarities. AA found in fried and toasted starchy foods can cause developmental and reproductive toxicity and BPA has neuro-, immuno- and developmental toxicities. Their transports in zebrafish (Danio rerio) embryos were determined and their toxicity characteristics observed. Approximately 70% of AA was concentrated on the outer membrane surface probably via hydrogen bonds and van der Waals forces, but only 0.3% of AA entered the cytoplasm. In contrast, over 10% of the BPA adsorbed to the cells entered the cytoplasm via the membrane by lipid-water partition. The hydrophilic AA and hydrophobic BPA used different cell transport pathways; AA accumulated on the outer membrane surface whereas BPA readily reached the cytoplasm. AA caused acute and indirect toxicity in developing cells, including serious malnutrition and axial malformation. BPA caused chemical damage to developing cells by causing pericardial edema. The antagonistic effect of the AA/BPA mixture's combinational toxicity to embryos was found and explained by the accumulation of AA on the out surface of membrane inhibiting the transfer of BPA to the cytoplasm.


Assuntos
Acrilamida/metabolismo , Fenóis/metabolismo , Peixe-Zebra/embriologia , Animais , Compostos Benzidrílicos , Transporte Biológico , Membrana Celular/metabolismo , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Concentração Osmolar , Espectrometria de Fluorescência , Temperatura Ambiente
19.
J Hazard Mater ; 182(1-3): 877-85, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20673609

RESUMO

The interactions between bisphenol A (BPA)/acrylamide (AA) and bovine serum albumin (BSA)/deoxyribonucleic acid (DNA) was investigated by the equilibrium dialysis, fluorophotometry, isothermal titration calorimetry (ITC) and circular dichroism (CD). The bindings of BPA and AA to BSA and DNA responded to the partition law and Langmuir isothermal model, respectively. The saturation mole number of AA was calculated to be 24 per mol BSA and 0.26 per mol DNA-P. All the reactions were spontaneous driven by entropy change. BPA stacked into the aromatic hydrocarbon groups of BSA and between adjacent basepairs of DNA via the hydrophobic effect. The interactions of AA with BSA and DNA induced the formation of hydrogen bond and caused changes of their secondary structures. At normal physiological condition, 0.100 mmol/l BPA reduced the binding of vitamin B(2) to BSA by more than 70%, and 2.8 mmol/l AA by almost one half. This work provides an insight into non-covalent intermolecular interaction between organic contaminant and biomolecule, helping to elucidate the toxic mechanism of harmful chemicals.


Assuntos
Acrilamida/metabolismo , DNA/metabolismo , Fenóis/metabolismo , Soroalbumina Bovina/metabolismo , Compostos Benzidrílicos , Concentração de Íons de Hidrogênio , Ligação Proteica , Temperatura Ambiente
20.
Bioresour Technol ; 101(22): 8632-8, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20643544

RESUMO

Transmembrane transports of four kinds of lipophilic organic chemicals (LOCs) on suspending multilamellar liposomes (SML) and Escherichia coli (E. coli) were investigated, where both anthracene and phenanthrene were accorded to the lipid-water partition law and Sudan I and III to the Langmuir isothermal adsorption. Less than half of phenanthrene is transported into E. coli, where more than 60% are located in the cytoplasm. About 60% of anthracene entered the E. coli where only 10% was released into the cytoplasm. The partition coefficients of phenanthrene and anthracene partitioning from the extracellular liquid into membrane are 502 and 1190L/kg but their inverse partition coefficients are only 0.180 and 0.018kg/L. Over 60% of Sudan I and less than 40% of Sudan III accumulated on E. coli where most of them remained on the membrane. The transmembrane impedance effect (TMIE) is proposed for evaluating the cell-transport of polar LOCs.


Assuntos
Membrana Celular/metabolismo , Escherichia coli/metabolismo , Lecitinas/farmacocinética , Lipossomos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Transporte Biológico Ativo/fisiologia
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