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1.
Environ Pollut ; 255(Pt 1): 113128, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31521990

RESUMO

Atmospheric deposition, either dry or wet, has been identified as an important pathway of mercury (Hg) input to terrestrial and aquatic systems. Although East Asia is the major atmospheric Hg emission source region, very few studies have been conducted to quantify atmospheric Hg deposition in its downwind region. In this study, 8-year (2009-2016) atmospheric Hg dry deposition was reported at the Lulin Atmospheric Background Station (LABS), a high mountain forest site in central Taiwan. Dry deposition of speciated Hg was estimated using a bi-directional air-surface flux exchange model for gaseous elemental mercury (GEM) and dry deposition models for gaseous oxidized mercury (GOM) and particulate-bound mercury (PBM), making use of the monitored speciated atmospheric Hg concentrations. Annual total Hg dry deposition ranged from 51.9 to 84.9 µg m-2 yr-1, with a multi-year average of 66.1 µg m-2 yr-1. Among the three forms of atmospheric Hg, GEM was the main contributor to the total dry deposition, contributing about 77.8% to the total, due to the high density of forest canopy as well as the much higher concentration of GEM than GOM and PBM at LABS. Mercury dry deposition is higher in winter and spring than in summer and fall, partly due to the elevated Hg concentrations associated with air masses from East and Southeast Asia where with high atmospheric Hg emissions. The mean annual dry/wet deposition ratio of 2.8 at LABS indicated that Hg deposition to forest landscape was governed by dry rather than wet deposition.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Compostos de Mercúrio/análise , Mercúrio/análise , Óxidos/análise , Grupo com Ancestrais do Continente Asiático , Extremo Oriente , Florestas , Gases/análise , Humanos , Estações do Ano , Taiwan
2.
Sci Total Environ ; 686: 1049-1056, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31200303

RESUMO

Atmospheric mercury (Hg) has been monitored at the Lulin Atmospheric Background Station (LABS) in Taiwan since April 2006 and is still continuing. Here we reported the trend in gaseous elemental Hg (GEM) concentrations at LABS between April 2006 and December 2016, before the Minamata Convention on Mercury entered into force in 2017. Previous research indicated nighttime (0-8 am) data collected at LABS are better representative of regional influence. Therefore, only nighttime GEM data were used for trend analysis. A significant decreasing trend in GEM at a rate of -1.5% yr-1 (-0.022 ng m-3 yr-1, p < 0.01) was found, comparable to the decreasing trends observed in Europe, North America, South Africa, and over the North Atlantic Ocean. Five major GEM source regions to the LABS were identified, including northern Indochina Peninsula, China, Northeast Asia, the Pacific Ocean, and South China Sea. Significant decreasing trends in GEM were found for air masses coming from northern Indochina Peninsula (-0.042 ng m-3 yr-1, -2.6% yr-1, p < 0.01), China (-0.041 ng m-3 yr-1, -2.4% yr-1, p < 0.01), Northeast Asia (-0.031 ng m-3 yr-1, -2.0% yr-1, p < 0.05), and the Pacific Ocean (-0.022 ng m-3 yr-1, -1.7% yr-1, p < 0.05). Decreasing GEM trend (-0.020 ng m-3 yr-1, -1.5% yr-1), but insignificant (p > 0.05), was also found for air masses coming from South China Sea. The decreasing trends observed with air from the Pacific Ocean and South China Sea indicated declining background GEM concentrations in Northern Hemisphere. Decrease in GEM concentrations at the LABS was in agreement with the reduction in atmospheric Hg export from the East Asia continent caused by changes in Hg emission quantity and speciation, and temporal and spatial distribution in emission sources that have been suggested by recent research. Additionally, changes in the frequency distribution of air mass origins and transport paths may also contribute to the changes in GEM concentrations at LABS.

3.
J Biol Chem ; 294(28): 10877-10885, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31138654

RESUMO

Work in yeast models has benefitted tremendously from the insertion of epitope or fluorescence tags at the native gene locus to study protein function and behavior under physiological conditions. In contrast, work in mammalian cells largely relies on overexpression of tagged proteins because high-quality antibodies are only available for a fraction of the mammalian proteome. CRISPR/Cas9-mediated genome editing has recently emerged as a powerful genome-modifying tool that can also be exploited to insert various tags and fluorophores at gene loci to study the physiological behavior of proteins in most organisms, including mammals. Here we describe a versatile toolset for rapid tagging of endogenous proteins. The strategy utilizes CRISPR/Cas9 and microhomology-mediated end joining repair for efficient tagging. We provide tools to insert 3×HA, His6FLAG, His6-Biotin-TEV-RGSHis6, mCherry, GFP, and the auxin-inducible degron tag for compound-induced protein depletion. This approach and the developed tools should greatly facilitate functional analysis of proteins in their native environment.


Assuntos
Imunofluorescência/métodos , Engenharia de Proteínas/métodos , Animais , Sistemas CRISPR-Cas/genética , Sistemas CRISPR-Cas/fisiologia , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Reparo do DNA por Junção de Extremidades/genética , Reparo do DNA por Junção de Extremidades/fisiologia , Corantes Fluorescentes/química , Edição de Genes/métodos , Células HEK293 , Humanos
4.
Methods Mol Biol ; 1866: 37-48, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30725406

RESUMO

Unlike normal cells, transformed cells are unable to grow when methionine in the growth media is restricted. Reversion to methionine independence is a rare event in transformed and malignant cells. Methionine-independent revertants provide an excellent system to identify metabolic signatures and molecular characteristics associated with methionine dependency of transformed cells. Revertants maintain the genetic background and general growth behavior of the parental cell line, except that they proliferate under methionine restriction such as in methionine-free media supplemented with homocysteine. Here we describe a general approach to generate methionine-independent revertants using the example of the triple-negative breast cancer cell line MDA-MB-468. To validate and characterize reversion we describe assays to evaluate cell proliferation and anchorage-independent growth in soft agar.


Assuntos
Separação Celular/métodos , Células Clonais/patologia , Metionina/farmacologia , Neoplasias/patologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular Transformada , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Medições Luminescentes
5.
Opt Express ; 24(11): 11387-95, 2016 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-27410067

RESUMO

In this study, high-performance InGaN-based green light-emitting diodes (LEDs) with a quaternary InAlGaN/GaN superlattice electron blocking layer (QSL-EBL) have been demonstrated. The band structural simulation was employed to investigate the electrostatic field and carriers distribution, show that the efficiency and droop behavior can be intensively improved by using a QSL-EBL in LEDs. The QSL-EBL structure can reduce the polarization-related electrostatic fields in the multiple quantum wells (MQWs), leading to a smoother band diagram and a more uniform carriers distribution among the quantum wells under forward bias. In comparison with green LEDs with conventional bulk-EBL structure, the light output power of LEDs with QSL-EBL was greatly enhanced by 53%. The efficiency droop shows only 30% at 100 A/cm2 comparing to its peak value, suggesting that the QSL-EBL LED is promising for future white lighting with high performance.

6.
Nanoscale ; 8(2): 1192-9, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26666367

RESUMO

Green LEDs do not show the same level of performance as their blue and red cousins, greatly hindering the solid-state lighting development, which is the so-called "green gap". In this work, nano-void photonic crystals (NVPCs) were fabricated to embed within the GaN/InGaN green LEDs by using epitaxial lateral overgrowth (ELO) and nano-sphere lithography techniques. The NVPCs act as an efficient scattering back-reflector to outcouple the guided and downward photons, which not only boost the light extraction efficiency of LEDs with an enhancement of 78% but also collimate the view angle of LEDs from 131.5° to 114.0°. This could be because of the highly scattering nature of NVPCs which reduce the interference giving rise to Fabry-Perot resonance. Moreover, due to the threading dislocation suppression and strain relief by the NVPCs, the internal quantum efficiency was increased by 25% and droop behavior was reduced from 37.4% to 25.9%. The enhancement of light output power can be achieved as high as 151% at a driving current of 350 mA. Giant light output enhancement and directional control via NVPCs point the way towards a promising avenue of solid-state lighting.

7.
Fa Yi Xue Za Zhi ; 31(1): 41-3, 2015 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-26058133

RESUMO

OBJECTIVE: To establish the solid phase extraction (SPE) with GC/MS technology for fish poisoning cases to determine five pesticides in fishpond. METHODS: By three solid phase extraction column including Oasis HLB cartridge, Bond Elut C18 and SampliQ C18, the recovery rate was compared to extract and purify five pesticides in fishpond. The effects of different kinds and dosages of eluents on extract rate were also reviewed. RESULTS: Using Bond Elut C18 as solid phase extraction column and 3 mL benzene as eluent, the linear range of mass concentration of five pesticides in fishpond was 1-50 µg/mL, and the correlation coefficient was 0.996 2-0.999 6. The limit of detection was 3.4-26 µg/L and the recovery was 61.49%-102.48%. The relative standard deviations was less than or equal to 3.01%. CONCLU-SION: With high sensitivity, good accuracy and precision, SPE-GC/MS has simple and quick operation and less solvent. It can be applied to determination of five pesticides in fishpond.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Praguicidas/análise , Poluentes Químicos da Água/análise , Praguicidas/isolamento & purificação , Extração em Fase Sólida , Solventes , Poluentes Químicos da Água/isolamento & purificação
8.
Opt Express ; 22(4): 4516-22, 2014 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-24663772

RESUMO

Micro-patterned PDMS film was fabricated and combined with LED chip on board (COB) package to improve the emission uniformity of LED chip. The micro scale patterned sapphire substrate (PSS) was used as a mold to fabricate micro-cone patterned PDMS (MC-PDMS) film. A strong scattering effect from this MC-PDMS film can be verified by the high haze ratio and the Bi-directional Transmission effect. The angle dependent color temperature measurement system was used to measure the ΔCCT of COB with and without MC-PDMS. The measurement results indicate that the ΔCCT was reduced from 1025K to 428K. This improvement can effectively eliminate the yellow ring effect of LED chip. This technology can be thus considered as a cost-effective way for the next generation of light source packages.

9.
Fa Yi Xue Za Zhi ; 30(6): 463-5, 2014 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-25816581

RESUMO

OBJECTIVE: To develop the accelerated solvent extraction (ASE) for determining pesticides present in blood samples. METHODS: Pesticides were extracted by ASE with optimized parameters to study recovery rate affected by extraction temperature, time and agent. GC/MS was used to perform quantitative analysis. RESULTS: The recovery rates of eight pesticides were 70.6%-92.4%. The coefficient of variation was less than 5.0%. A good linear relationship was obtained at the concentration range of 0.5-5.0 microg/mL. CONCLUSION: The method was fast and simple with high recovery rate and good repeatability. It can be applied to analyze pesticides present in the blood specimen.


Assuntos
Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Praguicidas/sangue , Solventes , Temperatura , Fatores de Tempo
10.
J Cell Sci ; 127(Pt 1): 50-9, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-24155332

RESUMO

The primary methyl group donor S-adenosylmethionine (SAM) is important for a plethora of cellular pathways including methylation of nucleic acids, proteins, and the 5' cap structure of mRNAs, as well as biosynthesis of phospholipids and polyamines. In addition, because it is the cofactor for chromatin methylation, SAM is an important metabolite for the establishment and maintenance of epigenetic marks. Here, we demonstrate that cells halt proliferation when SAM levels become low. Cell cycle arrest occurs primarily in the G1 phase of the cell cycle and is accompanied by activation of the mitogen-activated protein kinase p38 (MAPK14) and subsequent phosphorylation of MAPK-activated protein kinase-2 (MK2). Surprisingly, Cdk4 activity remains high during cell cycle arrest, whereas Cdk2 activity decreases concomitantly with cyclin E levels. Cell cycle arrest was induced by both pharmacological and genetic manipulation of SAM synthesis through inhibition or downregulation of methionine adenosyltransferase, respectively. Depletion of methionine, the precursor of SAM, from the growth medium induced a similar cell cycle arrest. Unexpectedly, neither methionine depletion nor inhibition of methionine adenosyltransferase significantly affected mTORC1 activity, suggesting that the cellular response to SAM limitation is independent from this major nutrient-sensing pathway. These results demonstrate a G1 cell cycle checkpoint that responds to limiting levels of the principal cellular methyl group donor S-adenosylmethionine. This metabolic checkpoint might play important roles in maintenance of epigenetic stability and general cellular integrity.


Assuntos
Linfócitos B/metabolismo , Pontos de Checagem do Ciclo Celular/genética , Fase G1/genética , Proteína Quinase 14 Ativada por Mitógeno/genética , S-Adenosilmetionina/deficiência , Linfócitos B/citologia , Linhagem Celular Tumoral , Ciclina E/genética , Ciclina E/metabolismo , Quinase 2 Dependente de Ciclina/genética , Quinase 2 Dependente de Ciclina/metabolismo , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Metilação de DNA , Epigênese Genética , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Metionina/deficiência , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/metabolismo , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
11.
Nat Commun ; 4: 1407, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23360998

RESUMO

The tumour suppressor p53 is the most frequently mutated gene in human cancer. Reactivation of mutant p53 by small molecules is an exciting potential cancer therapy. Although several compounds restore wild-type function to mutant p53, their binding sites and mechanisms of action are elusive. Here computational methods identify a transiently open binding pocket between loop L1 and sheet S3 of the p53 core domain. Mutation of residue Cys124, located at the centre of the pocket, abolishes p53 reactivation of mutant R175H by PRIMA-1, a known reactivation compound. Ensemble-based virtual screening against this newly revealed pocket selects stictic acid as a potential p53 reactivation compound. In human osteosarcoma cells, stictic acid exhibits dose-dependent reactivation of p21 expression for mutant R175H more strongly than does PRIMA-1. These results indicate the L1/S3 pocket as a target for pharmaceutical reactivation of p53 mutants.


Assuntos
Biologia Computacional/métodos , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Compostos Aza/farmacologia , Sítios de Ligação , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Cisteína/genética , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Simulação de Dinâmica Molecular , Oxepinas/química , Oxepinas/farmacologia , Estabilidade Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas/metabolismo , Reprodutibilidade dos Testes , Relação Estrutura-Atividade , Transcrição Genética/efeitos dos fármacos , Proteína Supressora de Tumor p53/genética
12.
Cell Cycle ; 11(23): 4414-23, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23159852

RESUMO

Methionine and homocysteine are metabolites in the transmethylation pathway leading to synthesis of the methyl-donor S-adenosylmethionine (SAM). Most cancer cells stop proliferating during methionine stress conditions, when methionine is replaced in the growth media by its immediate metabolic precursor homocysteine (Met-Hcy+). Non-transformed cells proliferate in Met-Hcy+ media, making the methionine metabolic requirement of cancer cells an attractive target for therapy, yet there is relatively little known about the molecular mechanisms governing the methionine stress response in cancer cells. To study this phenomenon in breast cancer cells, we selected methionine-independent-resistant cell lines derived from MDAMB468 breast cancer cells. Resistant cells grew normally in Met-Hcy+ media, whereas their parental MDAMB468 cells rapidly arrest in the G 1 phase. Remarkably, supplementing Met-Hcy+ growth media with S-adenosylmethionine suppressed the cell proliferation defects, indicating that methionine stress is a consequence of SAM limitation rather than low amino acid concentrations. Accordingly, mTORC1 activity, the primary effector responding to amino acid limitation, remained high. However, we found that levels of the replication factor Cdc6 decreased and pre-replication complexes were destabilized in methionine-stressed MDAMB468 but not resistant cells. Our study characterizes metabolite requirements and cell cycle responses that occur during methionine stress in breast cancer cells and helps explain the metabolic uniqueness of cancer cells.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Regulação para Baixo/efeitos dos fármacos , Metionina/farmacologia , Proteínas Nucleares/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromatina/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Homocisteína/farmacologia , Humanos , Células MCF-7 , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos , Fosforilação , Proteínas/antagonistas & inibidores , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , S-Adenosilmetionina/farmacologia , Serina-Treonina Quinases TOR
13.
Artigo em Chinês | MEDLINE | ID: mdl-21126480

RESUMO

OBJECTIVE: To observe the therapeutic effect and mechanism of penehyclidine hydrochloride on paraquat-induced acute lung injury. METHODS: 80 healthy adult male Wistar rats were randomly assigned into control groups (10 rats), 100 mg/kg PQ group (10 rats), 100 mg/kg PQ plus 33 µg/kg penehyclidine hydrochloride treatment group (30 rats), 100 mg/kg PQ plus 66 µg/kg penehyclidine hydrochloride treatment group (30 rats). The two treatment groups were executed respectively at 36 h, 72 h and 7 d. Lung tissues were used to assess histopathological change by HE staining. The level of MMP-2, caveolin-1 and HYP were detected in the lung homogenate. The serum and BALF contents of ET were measured. RESULTS: Pathology inspection confirmed that the model of acute rat pulmonary injury were duplicated successfully. The level of MMP-2, HYP in lung tissues and the serum and BALF ET contents in PQ group were (1.77 ± 0.40) µg/g, (2.91 ± 0.79) µg/g, (505.23 ± 124.69) µg/ml, (640.38 ± 136.60) µg/ml. The level of those was higher than that in control group [(0.95 ± 0.66) µg/g, (1.48 ± 0.69) µg/g, (95.48 ± 46.01) µg/ml, (200.40 ± 88.39) µg/ml, P < 0.05]; The above-mentioned index in two treatment groups was lower than that in PQ group (P < 0.05). The caveolin-1 content [(1.77 ± 0.82) µg/g] in PQ group was lower than that in control group [(5.39 ± 1.68) µg/g, P < 0.05]. The level of caveolin-1 in two treatment groups was higher than that in PQ group (P < 0.05). CONCLUSION: Penehyclidine hydrochloride can decrease the level of MMP-2, HYP in lung tissues and the ET in serum and BALF, increase that of caveolin-1 and lessen the damage induced by paraquat.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Paraquat/toxicidade , Quinuclidinas/uso terapêutico , Lesão Pulmonar Aguda/induzido quimicamente , Animais , Caveolina 1/metabolismo , Endotelinas/metabolismo , Hidroxiprolina/metabolismo , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Ratos , Ratos Wistar
14.
Genes Cells ; 13(7): 679-89, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18498354

RESUMO

Mitochondrial DNA synthesis requires the supply of thymidine triphosphate (dTTP) independent of nuclear DNA replication. In resting and differentiating cells that withdraw from the cell cycle, mitochondrial thymidine kinase 2 (TK2) mediates thymidine monophosphate (dTMP) formation for the dTTP biosynthesis in mitochondria. However, a thymidine monophosphate kinase (TMPK) that phosphorylates dTMP to form thymidine diphosphate (dTDP) in mitochondria remains undefined. Here, we identified an expressed sequence tag cDNA, which encodes a TMPK with a mitochondrial import sequence at its N-terminus designated as TMPK2. HeLa cells expressing TMPK2 fused to green fluorescent protein (GFP) displayed green fluorescence in mitochondria. Over-expression of TMPK2 increased the steady-state level of cellular dTTP and promoted the conversion of radioactive labeled-thymidine and -dTMP to dTDP and dTTP in mitochondria. TMPK2 RNA was detected in several tissues and erythroblastoma cell lines. We also generated TMPK2 antibody and used it for immunofluorescence staining to demonstrate endogenous expression of TMPK2 in mitochondria of erythroblastoma cells. Finally, we showed that TMPK2 protein expression was upregulated in monocyte/macrophage differentiating cells, suggesting the coordinated regulation of TMPK2 expression with the terminal differentiation program.


Assuntos
Diferenciação Celular/fisiologia , Macrófagos/citologia , Mitocôndrias/enzimologia , Monócitos/citologia , Núcleosídeo-Fosfato Quinase/fisiologia , Sequência de Aminoácidos , Linhagem Celular , Clonagem Molecular , Células HeLa , Humanos , Macrófagos/enzimologia , Dados de Sequência Molecular , Monócitos/enzimologia , Núcleosídeo-Fosfato Quinase/genética , Nucleotídeos de Timina/biossíntese
15.
J Biol Chem ; 283(22): 15003-14, 2008 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-18387947

RESUMO

CRP2 (cysteine-rich protein) is a vascular smooth muscle cell (VSMC)-expressed LIM-only protein. CRP2 associates with the actin cytoskeleton and interacts with transcription factors in the nucleus to mediate smooth muscle cell gene expression. Using Csrp2 (gene symbol of the mouse CRP2 gene)-deficient mice, we previously demonstrated that an absence of CRP2 enhances VSMC migration and increases neointima formation following arterial injury. Despite its importance in vascular injury, the molecular mechanisms controlling CRP2 expression in VSMC are largely unknown. Transforming growth factor beta (TGFbeta), a key factor present in the vessel wall in the early phases of arterial response to injury, plays an important role in modulating lesion formation. Because both CRP2 and TGFbeta are mediators of VSMC responses, we examined the possibility that TGFbeta might regulate CRP2 expression. TGFbeta significantly induced CRP2 mRNA and protein expression in VSMCs. Promoter analysis identified a conserved cAMP-responsive element (CRE)-like site (TAACGTCA) in the Csrp2 promoter that was critical for basal promoter activity and response to TGFbeta. Gel mobility shift assays revealed that mainly ATF2 bound to this CRE-like element, and mutation of the CRE sequences abolished binding. TGFbeta enhanced the activation of ATF2, leading to increased phospho-ATF2 levels within the DNA-protein complexes. Furthermore, ATF2-transactivated Csrp2 promoter activity and TGFbeta enhanced this activation. In addition, a phosphorylation-negative ATF2 mutant construct decreased basal and TGFbeta-mediated Csrp2 promoter activity. Our results show for the first time in VSMC that TGFbeta activates ATF2 phosphorylation and Csrp2 gene expression via a CRE promoter element.


Assuntos
Fator 2 Ativador da Transcrição/metabolismo , Proteínas Musculares/biossíntese , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteínas Nucleares/biossíntese , Ativação Transcricional , Fator de Crescimento Transformador beta/metabolismo , Actinas/genética , Actinas/metabolismo , Fator 2 Ativador da Transcrição/genética , Animais , Artérias/lesões , Artérias/metabolismo , Movimento Celular/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Células Cultivadas , Citoesqueleto/genética , Citoesqueleto/metabolismo , Proteínas com Domínio LIM , Camundongos , Proteínas Musculares/genética , Mutação , Proteínas Nucleares/genética , Fosforilação , Ratos , Elementos de Resposta/genética , Ativação Transcricional/genética
17.
Artigo em Chinês | MEDLINE | ID: mdl-19309586

RESUMO

OBJECTIVE: To investigate the clinical therapeutic effect of methylprednisolone combined with cyclophosphamide and Etanercept method on acute paraquat poisoning. METHODS: 136 patients with acute paraquat poisoning were divided into the normal therapy group and the intensive therapy group randomly. Methylprednisolone, cyclophosphamide and Etanercept were used in the intensive therapy group. Methylprednisolone 500 mg was given intravenously per day for continuous three days followed by 200 mg intravenous per day. Then methylprednisolone was decreased gradually 14 d or 21 d later according to the patient's condition. Cyclophosphamide 600 mg was given intravenously twice weekly for 2 weeks and Etanercept 25 mg was given hypodermic injection twice weekly for 3 weeks. Curative effect evaluation was done at 7, 14, 21 d and 12 weeks after therapy. RESULTS: The survival rate of the intensive therapy group was obviously higher than that of the normal therapy group (P<0.01) on 7, 4, 21 d and 12 weeks. The cure rate of the intensive group were 94.6% (intake dose<50 ml 20% paraquat solution), 75.0% (intake dose 50 approximately 100 ml 20% paraquat solution), 12.5% (intake dose>100 ml 20% paraquat solution) respectively, while the cure rate of the normal group were 16.7% (intake dose<50 ml 20% paraquat solution), 8.3% (intake dose 50 approximately 100 ml 20% paraquat solution), 0% (intake dose>100 ml 20% paraquat solution) respectively. The total cure rate of the intensive therapy group (78.3%) 12 weeks later was higher than that of the normal group (11.9%). CONCLUSION: Methylprednisolone combined with cyclophosphamide and Etanercept intensive therapy has the curative effect on acute paraquat poisoning.


Assuntos
Paraquat/envenenamento , Envenenamento/tratamento farmacológico , Doença Aguda , Adolescente , Adulto , Ciclofosfamida/administração & dosagem , Ciclofosfamida/uso terapêutico , Quimioterapia Combinada , Etanercepte , Feminino , Humanos , Imunoglobulina G/administração & dosagem , Imunoglobulina G/uso terapêutico , Masculino , Metilprednisolona/administração & dosagem , Metilprednisolona/uso terapêutico , Pessoa de Meia-Idade , Receptores do Fator de Necrose Tumoral/administração & dosagem , Receptores do Fator de Necrose Tumoral/uso terapêutico , Resultado do Tratamento , Adulto Jovem
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