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1.
Arch Virol ; 168(6): 169, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37233865

RESUMO

Japanese encephalitis virus (JEV) infection can cause brain tissue lesions characterized by neuronal death, and apoptosis is involved in JEV-induced neuronopathy. In the present study, mouse microglia were infected with JEV, and pyknosis with dark-staining nuclei of infected cells was detected using Hoechst 33342 staining. TUNEL staining showed that JEV infection promoted the apoptosis of BV2 cells, and the apoptosis rate was significantly increased at 24-60 hours postinfection (hpi) (P < 0.01) and was the highest at 36 h (P < 0.0001). Western blot results showed that the expression of the Bcl-2 protein in JEV-infected cells was downregulated significantly at 60 hpi (P < 0.001), whereas that of the Bax protein was observably upregulated at 60 hpi (P < 0.001). At the same time, the level of cytochrome c (Cyt c) was significantly increased (P < 0.001), and the expression levels of two apoptosis-related proteins, namely, cleaved caspase-3 (P < 0.01) and caspase-9 (P < 0.001), were elevated significantly. Immunofluorescence staining showed that the amount of Cyt c increased with time after infection. After BV2 cells were infected with JEV, the expression of RIG-1 increased significantly from 24 hpi to 60 h (P < 0.001). The expression of MAVS increased significantly at 24 h (P < 0.001) and decreased gradually from 24 h to 60 hpi. The expression of TBK1 and NF-κB (p65) was not significantly changed. The expression of p-TBK1 and p-NF-κB (p-p65) increased significantly within 24 h (P < 0.001) and decreased from 24 to 60 hpi. The expression levels of IRF3 and p-IRF3 peaked at 24 hpi (P < 0.001) and decreased gradually from 24 to 60 hpi. However, the expression levels of JEV proteins showed no significant change at 24 and 36 hpi but were markedly elevated at 48 and 60 hpi. Interference with the expression of the RIG-1 protein in BV2 cells resulted in a dramatic increase in the expression of the anti-apoptotic protein Bcl-2 (P < 0.05), whereas the pro-apoptotic protein Bax, cleaved caspase-9, and especially cleaved caspase-3 were downregulated (P < 0.05), and viral protein expression was notably reduced (P < 0.05). These results indicate that JEV induces apoptosis through mitochondrial-dependent apoptosis pathways, interfering with the expression of RIG-1 in BV2 cells can inhibit viral replication and inhibit apoptosis.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Animais , Camundongos , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Caspase 3/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , NF-kappa B/metabolismo , Linhagem Celular , Apoptose , Transdução de Sinais , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
2.
Arch Virol ; 167(3): 849-859, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35119507

RESUMO

Japanese encephalitis (JE) is a zoonotic epidemic disease caused by Japanese encephalitis virus (JEV), and currently, no medicines are available to treat this disease. Autophagy modulators play an important role in the treatment of tumors, heart disease, and some viral diseases. The aim of this study was to investigate the effects of autophagy modulators on JEV infection and the host response in mice. The experimental mice were grouped as follows: DMEM (control), JEV, JEV+rapamycin (JEV+Rapa), JEV+wortmannin (JEV+Wort), JEV+chloroquine (JEV+CQ), Rapa, Wort, and CQ. The control group was treated with DMEM. The mice in other groups were infected with 105 PFU of JEV, and Rapa, Wort, and CQ were administered 2 h prior to JEV challenge and then administered daily for 10 consecutive days. All mice were monitored for neurological signs and survival. The damage of subcellular structures in the mouse brain was evaluated by transmission electron microscopy. The distribution of virus in the mouse brain was determined by RNAScope staining and immunohistochemical staining. The neuroinflammatory responses in the brain were examined via quantitative real-time PCR, and the signal pathways involved in neuroinflammation were identified by Western blot. The mice in the JEV+Wort and JEV+CQ groups showed milder neurological symptoms, less damage to the mitochondria in the brain tissue, and a higher survival rate than those in the JEV+Rapa and JEV groups. Compared with the JEV+Rapa and JEV groups, the distribution of JEV in the brain of mice in the JEV+Wort and JEV+CQ groups was lower, and the inflammatory response was weaker. No significant difference was observed in the expression of the PI3K/AKT/NF-κB pathway in mouse brain among the different groups. Our study suggests that the autophagy inhibitors Wort and CQ reduce JEV infection and weaken the inflammatory response, which does not depend on the PI3K/AKT/NF-κB pathway in mouse brain.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Animais , Autofagia , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Encefalite Japonesa/tratamento farmacológico , Inflamação/tratamento farmacológico , Camundongos , Fosfatidilinositol 3-Quinases
3.
Appl Microbiol Biotechnol ; 103(6): 2821-2831, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30680435

RESUMO

The soybean oil refinery (SOR) wastewater contains a high concentration of chemical oxygen demand (COD) and lipid, so the direct emissions of SOR wastewater will result in environmental pollution and waste of resources. Oleaginous yeast Trichosporon fermentans can consume organic materials in SOR wastewater to synthesize microbial oil, which achieves the purpose of SOR wastewater resource utilization. The effective harvesting technology of oleaginous yeasts can improve the utilization efficiency. In this study, Paecilomyces sp. M2-1 with high flocculating activity was isolated. The flocculants produced by M2-1 (MBF2-1) include 75% (w/w) polysaccharides, rely on cations, and display the flocculation percentage of above 77% in the range of pH 2-11. Especially under alkaline conditions, the flocculation percentage can be kept above 97%. The results of scanning electron microscope observation and zeta potential measurements suggested that the bridging, net trapping, and sweeping were the main flocculation mechanism of MBF2-1. MBF2-1 could flocculate T. fermentans that was used to reduce the organic matter in SOR wastewater and to produce microbial oil. Under the optimum conditions, the flocculation percentage of MBF2-1 against T. fermentans from SOR wastewater can reach 95%. Fatty acid content percent in microbial oil from T. fermentans was not almost affected by flocculation of MBF2-1. Moreover, MBF2-1 can further remove 55% and 53% of COD and oil content in the fermented SOR wastewater, respectively. The properties and high flocculating percentage displayed by MBF2-1 indicated its potential application prospect in oleaginous yeast harvest and food industry wastewater treatment.


Assuntos
Biomassa , Paecilomyces/metabolismo , Óleo de Soja/metabolismo , Trichosporon/metabolismo , Águas Residuárias/microbiologia , Purificação da Água/métodos , Ácidos Graxos/análise , Fermentação , Floculação
4.
Plant Cell ; 27(3): 711-23, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25724641

RESUMO

Phosphate transporters (PTs) mediate phosphorus uptake and are regulated at the transcriptional and posttranslational levels. In one key mechanism of posttranslational regulation, phosphorylation of PTs affects their trafficking from the endoplasmic reticulum (ER) to the plasma membrane. However, the kinase(s) mediating PT phosphorylation and the mechanism leading to ER retention of phosphorylated PTs remain unclear. In this study, we identified a rice (Oryza sativa) kinase subunit, CK2ß3, which interacts with PT2 and PT8 in a yeast two-hybrid screen. Also, the CK2α3/ß3 holoenzyme phosphorylates PT8 under phosphate-sufficient conditions. This phosphorylation inhibited the interaction of PT8 with PHOSPHATE TRANSPORTER TRAFFIC FACILITATOR1, a key cofactor regulating the exit of PTs from the ER to the plasma membrane. Additionally, phosphorus starvation promoted CK2ß3 degradation, relieving the negative regulation of PT phosphorus-insufficient conditions. In accordance, transgenic expression of a nonphosphorylatable version of OsPT8 resulted in elevated levels of that protein at the plasma membrane and enhanced phosphorus accumulation and plant growth under various phosphorus regimes. Taken together, these results indicate that CK2α3/ß3 negatively regulates PTs and phosphorus status regulates CK2α3/ß3.


Assuntos
Caseína Quinase II/metabolismo , Oryza/enzimologia , Proteínas de Transporte de Fosfato/metabolismo , Fosfatos/farmacologia , Proteínas de Plantas/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Modelos Biológicos , Mutação/genética , Oryza/efeitos dos fármacos , Fenótipo , Fosforilação/efeitos dos fármacos , Plantas Geneticamente Modificadas , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Serina/metabolismo
5.
Microb Cell Fact ; 16(1): 191, 2017 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-29121938

RESUMO

BACKGROUND: The present study compared the effects of soybean meal fermented by three different probiotics organisms with non-fermented soybean meal on growth performance, serum parameters, immune chemistry and intestinal morphology in weaned piglets. METHODS: One hundred and forty-four 35-day old crossbred (Duroc × Landrace × Yorkshire) piglets were randomly allocated into four different dietary treatments (n = 36 per group) containing 0, 5, 10 and 15% fermented soybean meal. RESULTS: The piglets fed fermented soybean meal showed an increase (p < 0.05) in average daily weight gain and a reduction in feed consumption (p < 0.05).The piglets fed 10 and 15% fermented soybean meal showed the greatest growth improvement with higher levels of serum alkaline phosphatase and total serum proteins. Serum urea nitrogen in the experimental group was significantly lower than control whereas serum IgG, IgM and IgA levels were all significantly higher. Moreover, villus height in the duodenum, jejunum, and ileum was significantly higher (p < 0.05) and the crypt depth was significantly lower (p < 0.05). The levels of the autophagy factor LC3B in piglets showed a downward trend in the jejunum and ileum compared to control. CONCLUSIONS: Fermented soybean meal could significantly improve the growth, immune function and intestinal health in weaned piglets, and the best effective benefits showed in 10% FSBM group.


Assuntos
Bacillus subtilis/metabolismo , Glycine max/metabolismo , Imunidade , Lactobacillus plantarum/metabolismo , Saccharomyces cerevisiae/metabolismo , Sus scrofa/crescimento & desenvolvimento , Ração Animal/análise , Animais , Fermentação , Alimentos Fermentados , Mucosa Intestinal/metabolismo , Sus scrofa/anatomia & histologia , Sus scrofa/imunologia , Desmame
6.
New Phytol ; 211(2): 658-70, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26918637

RESUMO

Arsenic (As) contamination in a paddy environment can cause phytotoxicity and elevated As accumulation in rice (Oryza sativa). The mechanism of As detoxification in rice is still poorly understood. We isolated an arsenate (As(V))-sensitive mutant of rice. Genomic resequencing and complementation identified OsCLT1, encoding a CRT-like transporter, as the causal gene for the mutant phenotype. OsCLT1 is localized to the envelope membrane of plastids. The glutathione and γ-glutamylcysteine contents in roots of Osclt1 and RNA interference lines were decreased markedly compared with the wild-type (WT). The concentrations of phytochelatin PC2 in Osclt1 roots were only 32% and 12% of that in WT after As(V) and As(III) treatments, respectively. OsCLT1 mutation resulted in lower As accumulation in roots but higher As accumulation in shoots when exposed to As(V). Under As(III) treatment, Osclt1 accumulated a lower As concentration in roots but similar As concentration in shoots to WT. Further analysis showed that the reduction of As(V) to As(III) was decreased in Osclt1. Osclt1 was also hypersensitive to cadmium (Cd). These results indicate that OsCLT1 plays an important role in glutathione homeostasis, probably by mediating the export of γ-glutamylcysteine and glutathione from plastids to the cytoplasm, which in turn affects As and Cd detoxification in rice.


Assuntos
Adaptação Fisiológica , Arsênio/toxicidade , Glutationa/metabolismo , Homeostase , Proteínas de Membrana Transportadoras/metabolismo , Oryza/metabolismo , Oryza/fisiologia , Proteínas de Plantas/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Sequência de Bases , Cádmio/toxicidade , Clonagem Molecular , Dipeptídeos/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Teste de Complementação Genética , Proteínas de Membrana Transportadoras/genética , Mutação/genética , Especificidade de Órgãos/genética , Oryza/efeitos dos fármacos , Oryza/genética , Fenótipo , Filogenia , Fitoquelatinas/metabolismo , Proteínas de Plantas/genética , Transporte Proteico , Interferência de RNA , Frações Subcelulares/metabolismo
7.
PLoS One ; 19(3): e0299116, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38489307

RESUMO

The current highway waveform guardrail recognition technology has encountered problems with low segmentation accuracy and strong noise interference. Therefore, an improved U-net semantic segmentation model is proposed to improve the efficiency of road maintenance detection. The model training is guided by mixed expansion convolution and mixed loss function, while the presence of guardrail shedding is investigated by using partial mean values of gray values in ROI region based on segmentation results, while the first-order detail coefficients of wavelet transform are applied to detect guardrail defects and deformation. It has been determined that the Miou and Dice of the improved model are improved by 8.63% and 17.67%, respectively, over the traditional model, and that the method of detecting defects in the data is more accurate than 85%. As a result of efficient detection of highway waveform guardrail, the detection process is shortened and the effectiveness of the detection is improved later on during road maintenance.


Assuntos
Aprendizado de Máquina , Reconhecimento Psicológico , Semântica , Tecnologia , Análise de Ondaletas , Processamento de Imagem Assistida por Computador
8.
Int J Dev Neurosci ; 83(1): 3-15, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36401305

RESUMO

Gamma-aminobutyric acid-expressing (GABAergic) neurons are implicated in a variety of neuropsychiatric disorders, such as epilepsy, anxiety, autism, and other pathological processes, including cerebral ischemia injury and drug addiction. Therefore, GABAergic neuronal processes warrant further research. The development of GABAergic neurons is a tightly controlled process involving the activity of multiple transcription and growth factors. Here, we focus on the gene expression pathways and the molecular modulatory networks that are engaged during the development of GABAergic neurons with the goal of exploring regulatory mechanisms that influence GABAergic neuron fate (i.e., maturation). Overall, we hope to provide a basis for clarifying the pathogenesis of neurodegenerative disorders.


Assuntos
Epilepsia , Ácido gama-Aminobutírico , Humanos , Ácido gama-Aminobutírico/metabolismo , Neurônios GABAérgicos/fisiologia
9.
ACS Omega ; 7(41): 36157-36164, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36278094

RESUMO

In order to study the influence of asphalt from different origins on the compatibility of rubber powder and asphalt, the four most representative 90# asphalts from different origins were selected for the four-component test, namely, Karamay, Shell, Esso, and HuanxiLing, which have differences in their microstructure and molecular structure. First, Materials Studio software was used to build the asphalt molecular model based on the four-component test data, and styrene butadiene rubber and natural rubber were used as representative molecules of rubber powder to build the molecular model. The solubility parameters, molecular potential energy, and radial distribution function were obtained by molecular dynamics simulation of rubber powder and four asphalt molecules. The gray correlation degree analysis of the four components of asphalt is carried out with the gray correlation method. The results show that the solubility parameter difference between Esso asphalt and the rubber molecule is the smallest, and the potential energy between them is the largest; that is, the compatibility between Esso asphalt and rubber powder is the best, followed by Shell, Huanxiling, and Karamay. The analysis of the radial distribution function between two molecules also further confirmed the compatibility of the four modified asphalt. The gray correlation degree between the four components of asphalt and the solubility and molecular potential energy index is as follows: saturates > aromatics > resin > asphaltene. It is concluded that the influence of light components on the compatibility of asphalt is greater than that of heavy components. Therefore, in future industrial production, the rubber powder-modified asphalt made of more light components has better performance and storage stability.

10.
PLoS Negl Trop Dis ; 15(6): e0008442, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34153060

RESUMO

Japanese encephalitis virus (JEV) is a pathogen that causes severe vector-borne zoonotic diseases, thereby posing a serious threat to human health. Although JEV is potentially neurotropic, its pathogenesis and distribution in the host have not been fully elucidated. In this study, an infected mouse model was established using a highly virulent P3 strain of JEV. Immunohistochemistry and in situ hybridization, combined with anatomical imaging of the mouse brain, were used to dynamically localize the virus and construct three-dimensional (3D) images. Consequently, onset of mild clinical signs occurred in some mice at 3.5 d post JEV infection, while most mice displayed typical neurological signs at 6 d post-infection (dpi). Moreover, brain pathology revealed typical changes associated with non-suppurative encephalitis, which lasted up to 8 d. The earliest detection of viral antigen was achieved at 3 dpi in the thalamus and medulla oblongata. At 6 dpi, the positive viral antigen signals were mainly distributed in the cerebral cortex, olfactory area, basal ganglia, thalamus, and brainstem regions in mice. At 8 dpi, the antigen signals gradually decreased, and the localization of JEV tended to concentrate in the cerebrum and thalamus, while no viral antigen was detected in the brain at 21 dpi. In this model, the viral antigen was first expressed in the reticular thalamic nucleus (Rt), and the virus content is relatively stable. The expression of the viral antigen in the hippocampal CA2 region, the anterior olfactory nucleus, and the deep mesencephalic nucleus was high and persistent. The 3D images showed that viral signals were mostly concentrated in the parietal cortex, occipital lobe, and hippocampus, near the mid-sagittal plane. In the early stages of infection in mice, a large number of viral antigens were detected in denatured and necrotic neurons, suggesting that JEV directly causes neuronal damage. From the time of its entry, JEV is widely distributed in the central nervous system thereby causing extensive damage.


Assuntos
Encéfalo/virologia , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Encefalite Japonesa/virologia , Animais , Encéfalo/patologia , Imageamento Tridimensional , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Fatores de Tempo
11.
J Med Microbiol ; 67(8): 1181-1190, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29923819

RESUMO

PURPOSE: The microbiota composition of faeces and colonic contents were analysed to investigate the mechaninsm by which fermented soybean meal improves intestinal microbial communities, growth and immunity in weaning piglets. METHODOLOGY: Microbiota were investigated using16S rRNA gene sequencing and systematical bio-information Operational Taxonomic Units; α-diversity analyses indicated that fermented soybean meal increased bacterial species diversity. RESULTS: The levels of Actinobacteria and Proteobacteia in faeces, and Firmicutes and Tenericutes in the colon, increased significantly in piglets fed fermented soybean meal (P<0.05). The relative abundance of Clostridium sensu stricto1, Lachnospira and Bacteoides had positive correlations with diarrhoea in the piglets. Lactobacillus, Blautia and Clostridium sensu stricto1 levels were correlated with increases in the average daily feed intake of piglets. Lactobacillus and Lachnospira also had positive relationships with IgM levels, and lymphocytes levels were increased relative to Clostridium sensu stricto1. Lymphocyte numbers also increased with higher levels of Blautia and decreased with Clostridium sensu stricto1. Increased levels of Blautia were also correlated with significant increases in white blood cells. CONCLUSION: The significant differences in faecal and colonic bacteria were correlated with enhanced immunity and overall improved health in the weaning piglets.


Assuntos
Bactérias/classificação , Bactérias/genética , Biodiversidade , Biota , Dieta/métodos , Fezes/microbiologia , Glycine max , Ração Animal , Animais , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Suínos
12.
FEBS Lett ; 581(27): 5315-20, 2007 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-17977533

RESUMO

We hypothesized that the ambient air pollution particles (particulate matter; PM) induce cell cycle arrest in alveolar epithelial cells (AEC). Exposure of PM (25microg/cm(2)) to AEC induced cells cycle arrest in G1 phase, inhibited DNA synthesis, blocked cell proliferation and caused decrease in cyclin E, A, D1 and Cyclin E- cyclin-dependent kinase (CDK)-2 kinase activity after 4h. PM induced upregulation of CDK inhibitor, p21 protein and p21 activity in AEC. SiRNAp21 blocked PM-induced downregulation of cyclins and AEC G1 arrest. Accordingly, we provide the evidence that PM induces AEC G1 arrest by altered regulation of G1 cyclins and CDKs.


Assuntos
Ciclo Celular/efeitos dos fármacos , Ciclinas/metabolismo , Material Particulado/toxicidade , Alvéolos Pulmonares/citologia , Alvéolos Pulmonares/efeitos dos fármacos , Poluentes Atmosféricos/toxicidade , Linhagem Celular , Ciclina G , Ciclina G1 , Inibidor de Quinase Dependente de Ciclina p21/antagonistas & inibidores , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Fase G1/efeitos dos fármacos , Humanos , Alvéolos Pulmonares/metabolismo , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacos
13.
Sci Rep ; 7(1): 8281, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28811519

RESUMO

The recent dramatic increase in millimeter- to centimeter- resolution topographic datasets obtained via multi-view photogrammetry raises the possibility of mapping detailed offset geomorphology and constraining the spatial characteristics of active faults. Here, for the first time, we applied this new method to acquire high-resolution imagery and generate topographic data along the Altyn Tagh fault, which is located in a remote high elevation area and shows preserved ancient earthquake surface ruptures. A digital elevation model (DEM) with a resolution of 0.065 m and an orthophoto with a resolution of 0.016 m were generated from these images. We identified piercing markers and reconstructed offsets based on both the orthoimage and the topography. The high-resolution UAV data were used to accurately measure the recent seismic offset. We obtained the recent offset of 7 ± 1 m. Combined with the high resolution satellite image, we measured cumulative offsets of 15 ± 2 m, 20 ± 2 m, 30 ± 2 m, which may be due to multiple paleo-earthquakes. Therefore, UAV mapping can provide fine-scale data for the assessment of the seismic hazards.

14.
Sci Rep ; 6: 29797, 2016 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-27404212

RESUMO

In this study, we proposed three optimized models for calculating the total volume of landslides triggered by the 2008 Wenchuan, China Mw 7.9 earthquake. First, we calculated the volume of each deposit of 1,415 landslides triggered by the quake based on pre- and post-quake DEMs in 20 m resolution. The samples were used to fit the conventional landslide "volume-area" power law relationship and the 3 optimized models we proposed, respectively. Two data fitting methods, i.e. log-transformed-based linear and original data-based nonlinear least square, were employed to the 4 models. Results show that original data-based nonlinear least square combining with an optimized model considering length, width, height, lithology, slope, peak ground acceleration, and slope aspect shows the best performance. This model was subsequently applied to the database of landslides triggered by the quake except for two largest ones with known volumes. It indicates that the total volume of the 196,007 landslides is about 1.2 × 10(10) m(3) in deposit materials and 1 × 10(10) m(3) in source areas, respectively. The result from the relationship of quake magnitude and entire landslide volume related to individual earthquake is much less than that from this study, which reminds us the necessity to update the power-law relationship.

15.
Mol Cancer Ther ; 2(9): 855-62, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14555704

RESUMO

Treatment of solid tumors with combinations of chemotherapeutic agents has not led to significant increases in long-term survival. Recent studies support a role for inhibitors of checkpoint arrest as a means to enhance the cytotoxicity of chemotherapy. We have shown previously that triptolide (PG490), an oxygenated diterpene derived from a Chinese medicinal plant, induces apoptosis in cultured tumor cells and sensitizes tumor cells to topoisomerase inhibitors by blocking p53-mediated induction of p21. Here we extend our studies to a tumor xenograft model and evaluate the efficacy and safety of PG490-88 (14-succinyl triptolide sodium salt), a water-soluble prodrug of PG490. We also look at the combination of PG490 or PG490-88 with CPT-11, a topoisomerase I inhibitor, in cultured cells and in the tumor xenograft model. We show that PG490-88 is a safe and potent antitumor agent when used alone, causing tumor regression of lung and colon tumor xenografts. We also show that PG490-88 acts in synergy with CPT-11 to cause tumor regression. A phase I trial of PG490-88 for solid tumors began recently and safety and optimal dosing data should accrue within the next 12 months. Our findings that PG490-88 causes tumor regression and that it acts in synergy with DNA-damaging chemotherapeutic agents suggest a role as an antineoplastic agent and chemosensitizer for the treatment of patients with solid tumors.


Assuntos
Antineoplásicos/uso terapêutico , Camptotecina/análogos & derivados , Neoplasias do Colo/tratamento farmacológico , Diterpenos/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Animais , Camptotecina/uso terapêutico , Ciclo Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/metabolismo , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Compostos de Epóxi , Humanos , Irinotecano , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Fenantrenos/uso terapêutico , Transplante Heterólogo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismo
16.
Eur J Pharmacol ; 721(1-3): 208-14, 2013 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-24076185

RESUMO

Multidrug resistance (MDR) is a key element in the failure of chemotherapies, and development of agents to overcome MDR is crucial to improving cancer treatments. The overexpression of glutathione-S-transferases (GSTs) is one of the major mechanisms of MDR. Because some agents used in traditional Chinese medicine have strong antitumor effects coupled with low toxicity; we investigated the ability of N,N-bis(2-chloroethyl)docos-13-enamide (compound J), the synthesized analog of a highly unsaturated fatty acid from Isatis tinctoria L., to reverse the MDR induced by adriamycin (ADM) in TCA8113/ADM cells. We found that compound J significantly increased the cytotoxicity of ADM in TCA8113/ADM cells, with a reversal fold of 2.461. Analysis of the mechanisms through which compound J reversed MDR indicated that compound J significantly decreased the activity of GSTs and enhanced the depletion of GSH in TCA8113/ADM cells, but did not affect the P-glycoprotein (P-gp) efflux. Taken together, our data suggested that compound J was an excellent candidate for reversing MDR in cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Ácidos Erúcicos/química , Ácidos Erúcicos/farmacologia , Ácidos Graxos/farmacologia , Neoplasias da Língua/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Doxorrubicina/farmacologia , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Humanos
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