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1.
Colloids Surf B Biointerfaces ; 228: 113364, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37290201

RESUMO

The nano/micron sized-fluticasone propionate inhalable suspension (FPs) is used for asthma treatment, and this study aimed to elucidate the effects of particle size on the absorption of FPs by various pulmonary cells and the subsequent therapeutic efficacy for asthma. FPs of 727, 1136 and 1612 nm were prepared, and an increase in diameter diminished the endocytosis and macropinocytosis of FPs by alveolar epithelial cells (A549 and Calu-3 cells) but facilitated their uptake by M2-like macrophages; results about the transport across Calu-3 monolayer showed the mucus layer was the main rate-limiting step for the uptake of FPs by epithelial cells; the animal tests showed that although a decrease in diameter improved the pulmonary absorption of FPs, the particle size did not affect the lung distribution of FPs; a further detection revealed that larger FPs were taken more effectively by alveolar macrophages and lymphocytes and exerted a better therapeutic effect on asthma than the smaller ones. This study showed that the particle size of FPs had a significant impact on their absorption, elimination and cellular distribution in the lung after inhalation and further on their effectiveness in asthma treatment, and the particle size of the nano/micron sized-FPs should be designed and optimized for asthma treatment on the premise of meeting the requirements of inhalation preparations.


Assuntos
Androstadienos , Asma , Animais , Fluticasona/farmacologia , Fluticasona/uso terapêutico , Tamanho da Partícula , Androstadienos/uso terapêutico , Asma/tratamento farmacológico , Pulmão , Administração por Inalação
2.
Bioresour Technol ; 305: 123044, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32114305

RESUMO

In this work, the kinetic mechanisms of pyrolysis of cellulose with different physical structures were illustrated. The crystalline cellulose showed better thermal stability and required higher energy for decomposition with more concentrated reactions due to the highly ordered structure. The crystallinity of the ball milling and ionic liquid pretreated cellulose decreased and the structure was relatively loose and disordered, thereby reducing the thermal stability, so the global activation energy of both samples decreased and the intensive reaction caused by the collapse of structure was alleviated. In fast pyrolysis, crystalline cellulose favored fast pyrolytic saccharification, and the highest levoglucosan yield reached 64.3 wt% at 400 °C. This research was helpful to deduce the influence of physical structure on the pyrolytic product distribution of cellulose, thereby providing useful information to promote the development of pyrolytic saccharification.

3.
Rice (N Y) ; 12(1): 99, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31883029

RESUMO

BACKGROUND: Salt stress is an important factor that limits rice yield. We identified a novel, strongly salt tolerant rice landrace called Changmaogu (CMG) collected from a coastal beach of Zhanjiang, Guangdong Province, China. The salt tolerance of CMG was much better than that of the international recognized salt tolerant rice cultivar Pokkali in the germination and seedling stages. RESULTS: To understand the molecular basis of salt tolerance in CMG, we performed BSA-seq for two extreme bulks derived from the cross between CMG and a cultivar sensitive to salt, Zhefu802. Transcriptomic sequencing was conducted for CMG at the germination and young seedling stages. Six candidate regions for salt tolerance were mapped on Chromosome 1 by BSA-seq using the extreme populations. Based on the polymorphisms identified between both parents, we detected 32 genes containing nonsynonymous coding single nucleotide polymorphisms (SNPs) and frameshift mutations in the open reading frame (ORF) regions. With transcriptomic sequencing, we detected a large number of differentially expressed genes (DEGs) at the germination and seedling stages under salt stress. KEGG analysis indicated two of 69 DEGs shared at the germination and seedling stages were significantly enriched in the pathway of carotenoid biosynthesis. Of the 169 overlapping DEGs among three sample points at the seedling stage, 13 and six DEGs were clustered into the pathways of ABA signal transduction and carotenoid biosynthesis, respectively. Of the 32 genes carrying sequence variation, only OsPP2C8 (Os01g0656200) was differentially expressed in the young seedling stage under salt stress and also showed sequence polymorphism in the ORFs between CMG and Zhefu802. CONCLUSION: OsPP2C8 was identified as the target candidate gene for salinity tolerance in the seedling stage. This provides an important genetic resource for the breeding of novel salt tolerant rice cultivars.

4.
Int J Nanomedicine ; 14: 6035-6060, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31534335

RESUMO

Background: The clearance of nanomaterials (NMs) from the liver is essential for clinical safety, and their hepatic clearance is primarily determined by the co-disposition process of various types of hepatic cells. Studies of this process and the subsequent clearance routes are urgently needed for organic NMs, which are used as drug carriers more commonly than the inorganic ones. Materials and methods: In this study, the co-disposition of chitosan-based nanoparticles (CsNps) by macrophages and hepatocytes at both the cellular and animal levels as well as their subsequent biological elimination were investigated. RAW264.7 and Hepa1-6 cells were used as models of Kupffer cells and hepatocytes, respectively. Results: The cellular studies showed that CsNps released from RAW264.7 cells could enter Hepa1-6 cells through both clathrin- and caveolin-mediated endocytosis. The transport from Kupffer cells to hepatocytes was also studied in mice, and it was observed that most CsNps localized to the hepatocytes after intravenous injection. Following the distribution in hepatocytes, the hepatobiliary-fecal excretion route was shown to be the primary elimination route for CsNps, besides the kidney-urinary excretion route. The elimination of CsNps in mice was a lengthy process, with a half time of about 2 months. Conclusion: The demonstration in this study of the transport of CsNps from macrophages to hepatocytes and the subsequent hepatobiliary-fecal excretion provides basic information for the future development and clinical application of NMs.


Assuntos
Quitosana/farmacologia , Hepatócitos/citologia , Hepatócitos/metabolismo , Nanopartículas/química , Animais , Transporte Biológico , Linhagem Celular Tumoral , Portadores de Fármacos/metabolismo , Exocitose , Hepatócitos/efeitos dos fármacos , Cinética , Fígado/metabolismo , Macrófagos/metabolismo , Camundongos , Nanopartículas/ultraestrutura , Fótons
5.
Bioresour Technol ; 274: 281-286, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30529333

RESUMO

In this study, ball milling and ionic liquid pretreatments were utilized to alter cellulose structure prior to fast pyrolysis and enzymatic hydrolysis. The variations in the products distribution of cellulose fast pyrolysis, and their dependence on the structure of cellulose, and the temperature of fast pyrolysis were illustrated. Fast pyrolysis of pretreated cellulose yielded more levoglucosan than crystalline cellulose (14.7%) at 300 °C. Nevertheless, the levoglucosan achieved higher yield (64.3%) from crystalline cellulose at 400 °C. At last, a comparison between fast pyrolysis and enzymatic hydrolysis for cellulose saccharifaction was made. Fast pyrolysis was a promising alternative to liberate levoglucosan from cellulose. Further investigation and development were required to maximize the levoglucosan production.


Assuntos
Celulose/metabolismo , Glucose/análogos & derivados , Biomassa , Fermentação , Glucose/biossíntese , Hidrólise , Pirólise , Temperatura , Fatores de Tempo
6.
Cell Rep ; 25(11): 3086-3098.e3, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30540941

RESUMO

Mediator of IRF3 activation (MITA), also known as stimulator of interferon genes (STING), plays a vital role in the innate immune responses to cytosolic dsDNA. The trafficking of MITA from the ER to perinuclear vesicles is necessary for its activation of the downstream molecules, which lead to the production of interferons and pro-inflammatory cytokines. However, the exact mechanism of MITA activation remains elusive. Here, we report that transmembrane emp24 protein transport domain containing 2 (TMED2) potentiates DNA virus-induced MITA signaling. The suppression or deletion of TMED2 markedly impairs the production of type I IFNs upon HSV-1 infection. TMED2-deficient cells harbor greater HSV-1 load than the control cells. Mechanistically, TMED2 associates with MITA only upon viral stimulation, and this process potentiates MITA activation by reinforcing its dimerization and facilitating its trafficking. These findings suggest an essential role of TMED2 in cellular IFN responses to DNA viruses.


Assuntos
Vírus de DNA/fisiologia , Interferons/metabolismo , Proteínas de Membrana/metabolismo , Multimerização Proteica , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Citosol/metabolismo , DNA/metabolismo , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Células HEK293 , Herpesvirus Humano 1/fisiologia , Humanos , Imunidade Inata , Transporte Proteico , Transdução de Sinais , Células THP-1 , Proteínas de Transporte Vesicular
7.
Rev Sci Instrum ; 89(12): 123104, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30599549

RESUMO

High-frequency gating InGaAs/InP single-photon detectors (SPDs) are widely used for applications requiring single-photon detection in the near-infrared region such as quantum key distribution. Reducing SPD size is highly desired for practical use, which is favorable to the implementation of further system integration. Here we present, to the best of our knowledge, the most compact high-frequency sine wave gating (SWG) InGaAs/InP SPD. We design and fabricate an InGaAs/InP single-photon avalanche diode (SPAD) with optimized semiconductor structure and then encapsulate the SPAD chip and a mini-thermoelectric cooler inside a butterfly package with a size of 12.5 mm × 22 mm × 10 mm. Moreover, we implement a monolithic readout circuit for the SWG SPD in order to replace the quenching electronics that is previously designed with board-level integration. Finally, the components of SPAD, the monolithic readout circuit, and the affiliated circuits are integrated into a single module with a size of 13 cm × 8 cm × 4 cm. Compared with the 1.25 GHz SWG InGaAs/InP SPD module (25 cm × 10 cm × 33 cm) designed in 2012, the volume of our miniaturized SPD is reduced by 95%. After the characterization, the SPD exhibits excellent performance with a photon detection efficiency of 30%, a dark count rate of 2.0 kcps, and an afterpulse probability of 8.8% under the conditions of 1.25 GHz gating rate, 100 ns hold-off time, and 243 K. Also, we perform the stability test over one week, and the results show the high reliability of the miniaturized SPD module.

8.
Cell Mol Immunol ; 15(9): 858-867, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-28435159

RESUMO

Interferon-induced transmembrane protein 3 (IFITM3) is a restriction factor that can be induced by viral infection and interferons (IFNs). It inhibits the entry and replication of many viruses, which are independent of receptor usage but dependent on processes that occur in endosomes. In this study, we demonstrate that IFITM3 plays important roles in regulating the RNA-virus-triggered production of IFN-ß in a negative-feedback manner. Overexpression of IFITM3 inhibited Sendai virus-triggered induction of IFN-ß, whereas knockdown of IFITM3 had the opposite effect. We also showed that IFITM3 was constitutively associated with IRF3 and regulated the homeostasis of IRF3 by mediating the autophagic degradation of IRF3. These findings suggest a novel inhibitory function of IFITM3 on the RNA-virus-triggered production of type I IFNs and cellular antiviral responses.


Assuntos
Autofagossomos/metabolismo , Fator Regulador 3 de Interferon/imunologia , Interferon Tipo I/imunologia , Proteínas de Membrana/imunologia , Proteólise , Infecções por Vírus de RNA/imunologia , Vírus de RNA/imunologia , Proteínas de Ligação a RNA/imunologia , Células HEK293 , Células HeLa , Humanos , Fator Regulador 3 de Interferon/genética , Interferon Tipo I/genética , Proteínas de Membrana/genética , Infecções por Vírus de RNA/genética , Infecções por Vírus de RNA/patologia , Vírus de RNA/genética , Proteínas de Ligação a RNA/genética
9.
Int J Nanomedicine ; 12: 6383-6398, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28919742

RESUMO

Biodegradable nanomaterials have been widely used in numerous medical fields. To further improve such efforts, this study focused on the intracellular disposition of chitosan nanoparticles (CsNPs) in macrophages, a primary cell of the mononuclear phagocyte system (MPS). Such interactions with the MPS determine the nanoparticle retention time in the body and consequently play a significant role in their own clinical safety. In this study, various dye-labeled CsNPs (about 250 nm) were prepared, and a murine macrophage cell line (RAW 264.7) was selected as a model macrophage. The results showed two mechanisms of macrophage incorporation of CsNPs, ie, a clathrin-mediated endocytosis pathway (the primary) and phagocytosis. Following internalization, the particles partly dissociated in the cells, indicating cellular digestion of the nanoparticles. It was proved that, after intracellular uptake, a large proportion of CsNPs were exocytosed within 24 h; this excretion induced a decrease in fluorescence intensity in cells by 69%, with the remaining particles possessing difficulty being cleared. Exocytosis could be inhibited by both wortmannin and vacuolin-1, indicating that CsNP uptake was mediated by lysosomal and multivesicular body pathways, and after exocytosis, the reuptake of CsNPs by neighboring cells was verified by further experiments. This study, thus, elucidated the fate of CsNPs in macrophages as well as identified cellular disposition mechanisms, providing the basis for how CsNPs are recognized by the MPS; such information is crucial to numerous medical applications of CsNPs.


Assuntos
Quitosana/farmacocinética , Exocitose/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Nanopartículas/química , Androstadienos/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Linhagem Celular , Quitosana/química , Quitosana/farmacologia , Endocitose/efeitos dos fármacos , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacocinética , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Macrófagos/metabolismo , Camundongos , Sistema Fagocitário Mononuclear/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Wortmanina
10.
EMBO Rep ; 16(4): 447-55, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25736436

RESUMO

Toll-like receptors (TLRs) are pattern recognition receptors that sense a variety of pathogens, initiate innate immune responses, and direct adaptive immunity. All TLRs except TLR3 recruit the adaptor MyD88 to ultimately elicit inflammatory gene expression, whereas TLR3 and internalized TLR4 use TIR-domain-containing adaptor TRIF for the induction of type I interferon and inflammatory cytokines. Here, we identify the WD repeat and FYVE-domain-containing protein WDFY1 as a crucial adaptor protein in the TLR3/4 signaling pathway. Overexpression of WDFY1 potentiates TLR3- and TLR4-mediated activation of NF-κB, interferon regulatory factor 3 (IRF3), and production of type I interferons and inflammatory cytokines. WDFY1 depletion has the opposite effect. WDFY1 interacts with TLR3 and TLR4 and mediates the recruitment of TRIF to these receptors. Our findings suggest a crucial role for WDFY1 in bridging the TLR-TRIF interaction, which is necessary for TLR signaling.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/genética , Proteínas Nucleares/genética , Receptor 3 Toll-Like/genética , Receptor 4 Toll-Like/genética , Fatores de Transcrição/genética , Proteínas Adaptadoras de Transdução de Sinal , Proteínas Adaptadoras de Transporte Vesicular/imunologia , Motivos de Aminoácidos , Citocinas/genética , Citocinas/imunologia , Regulação da Expressão Gênica , Células HEK293 , Humanos , Indutores de Interferon/farmacologia , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/imunologia , Interferon Tipo I/genética , Interferon Tipo I/imunologia , Dados de Sequência Molecular , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/imunologia , Plasmídeos/química , Plasmídeos/imunologia , Poli I-C/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Receptor 3 Toll-Like/imunologia , Receptor 4 Toll-Like/imunologia , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/imunologia , Transfecção
11.
J Innate Immun ; 7(2): 153-64, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25228397

RESUMO

Upon binding to RNA structures from invading viruses, RIG-I and MDA5 are recruited to mitochondria to interact with VISA and initiate antiviral type I interferon (IFN) responses. How this process is mediated is less understood. In this report, we demonstrate that ECSIT is an essential scaffolding protein that mediates the association of VISA and RIG-I or MDA5. Overexpression of ECSIT potentiated virus-triggered activation of IFN-regulatory factor 3 (IRF3) and expression of IFNB1, whereas knockdown of ECSIT impaired viral infection-induced activation of IRF3 and expression of IFNB1 as well as cellular antiviral responses. Mechanistically, ECSIT was associated with VISA on mitochondria and important for bridging RIG-I and MDA5 to VISA. Our findings suggest that ECSIT mediates virus-triggered type I IFN induction by bridging RIG-I and MDA5 to the VISA complex, and provide new insights into the molecular events of innate antiviral immune responses.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , RNA Helicases DEAD-box/metabolismo , Mitocôndrias/metabolismo , Viroses/imunologia , Vírus/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Antígenos Virais/imunologia , Proteína DEAD-box 58 , Regulação Viral da Expressão Gênica , Células HEK293 , Humanos , Imunidade Inata , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Helicase IFIH1 Induzida por Interferon , Interferon beta/genética , Interferon beta/metabolismo , Ligação Proteica/genética , RNA Interferente Pequeno/genética , Receptores Imunológicos , Transdução de Sinais/genética , Transgenes/genética
12.
Bioresour Technol ; 153: 69-78, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24342947

RESUMO

Recent years, great interest has been devoted to the conversion of biomass-derived carbohydrate into sugars, such as glucose, mannose and fructose. These are important versatile intermediate products that are easily processed into high value-added biofuels. In this work, microwave-assisted dilute sulfuric acid hydrolysis of deproteinated palm kernel cake (DPKC) was systematically studied using Response Surface Methodology. The highest mannose yield (92.11%) was achieved at the optimized condition of 148°C, 0.75N H2SO4, 10min 31s and substrate to solvent (SS) ratio (w/v) of 1:49.69. Besides that, total fermentable sugars yield (77.11%), was obtained at 170°C, 0.181N H2SO4, 6min 6s and SS ratio (w/v) of 1:40. Ridge analysis was employed to further verify the optimum conditions. Thus, this work provides fundamental data of the practical use of DPKC as low cost, high yield and environmental-friendly material for the production of mannose and other sugars.


Assuntos
Araceae/química , Biotecnologia/métodos , Carboidratos/biossíntese , Micro-Ondas , Proteínas de Plantas/isolamento & purificação , Ácidos Sulfúricos/farmacologia , Análise de Variância , Araceae/efeitos dos fármacos , Reatores Biológicos , Hidrólise/efeitos dos fármacos , Monossacarídeos/análise , Análise de Regressão , Solventes , Temperatura , Fatores de Tempo
13.
Zhongguo Zhong Yao Za Zhi ; 38(11): 1800-5, 2013 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-24010299

RESUMO

OBJECTIVE: To study the toxic effects of aqueous extract of Crotalariae Assamicae Semen (CAS), one of the pyrrolizidine alkaloid-containing Chinese herbal medicines, in rats and the possible mechanism in association with liver damage. METHOD: The aqueous extract of CAS (CASE) was prepared by the conventional water extracting-alcohol precipitating method. The LD50 value of CASE in rats was determined by Kärber method. Rats were randomly divided into four groups in which three groups were orally administered with different doses of the CASE and one group with distilled water as control. Toxic effects were assessed by morphological, biochemical and histopathological changes. Moreover, in vitro metabolism using rat liver microsomes was also conducted and applied for the exploration of the underlying mechanism of liver damage. RESULT: The LD50 value of CASE in Wistar rats was (2.36 +/- 0.26) g x kg(-1). The toxic effects were found in all groups of rats dosed with CASE, in which serum levels of ALT and AST were significantly elevated, and the obvious and dose-dependent damages in liver and lung were observed by histopathological examination. Moreover, the liver tissue-bound pyrroles were detected and generated in a dose-dependent manner, and the pyrrole metabolites observed in the in vitro microsomal metabolism. All the evidences suggested a strong correlation between metabolism and toxicity of CASE in rats. CONCLUSION: CASE could induce the acute toxicity in rats, of which liver and lung were the major targets. Toxic effects were strongly correlated with pyrrolizidine alkaloids in CAS. The possible mechanism for its liver toxicity may be related to the formation of pyrrole metabolites as well as the corresponding tissue-binding products.


Assuntos
Crotalaria/química , Medicamentos de Ervas Chinesas/toxicidade , Fígado/efeitos dos fármacos , Alanina Transaminase/metabolismo , Animais , Medicamentos de Ervas Chinesas/administração & dosagem , Dose Letal Mediana , Fígado/enzimologia , Fígado/lesões , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Alcaloides de Pirrolizidina/administração & dosagem , Alcaloides de Pirrolizidina/toxicidade , Ratos , Ratos Wistar
14.
AMB Express ; 3: 48, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23958155

RESUMO

Abundant Jatropha waste is a promising renewable feedstock for the production of sugars and 2,3-butanediol fermentation. To obtain high yield of water-soluble products and high concentration of reducing-sugars, ionic liquid (IL) pretreatment and dilute acid hydrolysis at 150°C were combined in this work. The destruction of crystalline structure and increase surface area of biomasses after IL-pretreatment, made their hydrolysis more efficient. Compared with original cellulose, after IL-pretreatment, both the yield and concentration of reducing-sugars increased by 139%, and the water-soluble products yield increased by 128% after hydrolysis. Compared with water-washed Jatropha hulls, after IL-pretreatment, the yield and concentration of reducing-sugars increased by 80% and 76%, respectively, and the water-soluble products yield increased by 70% after hydrolysis. IL-pretreatment benefited the fermentation of Jatropha hull hydrolysate with 66.58% diol yield and its productivity increased from 0.35 to 0.40 g/(L · h).

15.
Bioresour Technol ; 140: 447-50, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23908993

RESUMO

Catalytic conversion of un-pretreated Jatropha oil with high-acid value (13.8 mg KOH/g) to biodiesel was studied in ionic liquids (ILs) with metal chlorides. Several commercial ILs were used to catalyze the esterification of oleic acid. It was found that 1-butyl-3-methylimidazolium tosylate {[BMIm][TS]} had high catalytic activity with 93% esterification rate for oleic acid at 140 °C but only 63.7% Jatropha biodiesel yield at 200 °C. When ZnCl2 was added to [BMIm][TS], a maximum Jatropha biodiesel yield of 92.5% was achieved at 180 °C. Addition of metal ions supplied Lewis acidic sites in ILs promoted both esterification and transestrification reactions. It was also found that the transition metal ions performed higher catalytic activity in transestrification than the ions of Group A. Mixture of [BMIm][TS] and ZnCl2 was easily separated from products for reuse to avoid producing pollutants.


Assuntos
Biocombustíveis , Biotecnologia/métodos , Líquidos Iônicos/farmacologia , Jatropha/química , Ácido Oleico/química , Óleos de Plantas/química , Cloretos/farmacologia , Esterificação/efeitos dos fármacos , Imidazóis/farmacologia , Jatropha/efeitos dos fármacos
16.
J Biol Chem ; 288(18): 12596-604, 2013 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-23532851

RESUMO

Viral infection causes activation of the transcription factor IRF3, which is critical for production of type I interferons (IFNs) and innate antiviral immune response. How virus-induced type I IFN signaling is controlled is not fully understood. Here we identified the transcription factor FoxO1 as a negative regulator for virus-triggered IFN-ß induction. Overexpression of FoxO1 inhibited virus-triggered ISRE activation, IFN-ß induction as well as cellular antiviral response, whereas knockdown of FoxO1 had opposite effects. FoxO1 interacted with IRF3 in a viral infection-dependent manner and promoted K48-linked polyubiquitination and degradation of IRF3 in the cytosol. Furthermore, FoxO1-mediated degradation of IRF3 was independent of the known E3 ubiquitin ligases for IRF3, including RBCK1 and RAUL. Our findings thus suggest that FoxO1 negatively regulates cellular antiviral response by promoting IRF3 ubiquitination and degradation, providing a previously unknown mechanism for control of type I IFN induction and cellular antiviral response.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/metabolismo , Proteólise , Ubiquitinação , Vesiculovirus/metabolismo , Animais , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/genética , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Fator Regulador 3 de Interferon/genética , Interferon beta/genética , Camundongos , Infecções por Rhabdoviridae/genética , Infecções por Rhabdoviridae/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Vesiculovirus/genética
17.
Bioresour Technol ; 107: 405-10, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22230777

RESUMO

Jatropha hulls were successfully for the first time used as raw materials for the production of 2,3-butanediol via dilute sulfuric acid hydrolysis and fermentation with Klebsiella oxytoca. Two-step hydrolysis was used to effectively hydrolyze the hulls at 150°C after pretreatment. In the first-step, hemicellulose was hydrolyzed under mild conditions (0.5h, 1.5% acid) to avoid secondary decomposition. The remained cellulose was further hydrolyzed in the second-step under severer conditions (1h, 4% acid). After hydrolysis, total hydrolysis yield was 64%, which was much higher than that (37%) from the first-step. Maximum yields of 2,3-butanediol and acetoin in flask experiments were 35.6% and 41.4% from the hydrolysates of the first- and second-step hydrolysis, equivalent to 71.2% and 82.8% of the theoretical values, respectively. Similar yields were obtained in a controlled bioreactor but with higher productivities. Jatropha hulls are attractive raw materials for the production of 2,3-butanediol with high yield.


Assuntos
Butileno Glicóis/metabolismo , Jatropha/metabolismo , Klebsiella oxytoca/metabolismo , Celulose/metabolismo , Fermentação , Cromatografia Gasosa-Espectrometria de Massas , Hidrólise , Espectrofotometria Ultravioleta
18.
Zhong Yao Cai ; 35(9): 1500-7, 2012 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-23451507

RESUMO

OBJECTIVE: The aim of this study was to load Verapamil Hydrochloride to carboxylated multi-walled carbon nanotubes( c-CNTs) and discuss the mechanism of drug release which could act as an effective basis for c-MWNTs used as drug carriers of controlled and sustained release delivery system. METHODS: Raw CNTs were treated with mixed strong acid to obtain c-CNTs. Raman, IR, SEM and HR-TEM were used to characterize the CNTs and investigate the loading sites for drugs. The release behavior of the drug delivery system in vitro and the release model were studied. RESULTS: The raw CNTs were successfully grafted with carboxyl group by acid treatment. The water-soluble ability of c-CNTs was greatly improved. The length of c-CNTs was 200-300nm. Meanwhile, the ends of c-CNTs were opened. The results of the drug loading experiment showed that the more adding drugs, the larger loading content of drugs. Most of the drugs were loaded into the inner pores of c-CNTs when adding drugs was no more than 0.1 as quantity as c-CNTs. As the quantity of adding drugs increased, the drugs were loaded both in the inner pores and on the out-wall of c-CNTs. The release results in vitro showed release mechanism had something with the quantity of adding drugs. CONCLUSION: C-CNTs can be used as carriers of sustained and controlled release delivery system. Ideal release behavior of drugs can be achieved by choosing appropriate formula.


Assuntos
Portadores de Fármacos/química , Nanotubos de Carbono/química , Verapamil/administração & dosagem , Verapamil/química , Preparações de Ação Retardada , Estudos de Viabilidade , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Nanotecnologia/métodos , Nanotubos de Carbono/ultraestrutura , Solubilidade , Temperatura , Verapamil/metabolismo
19.
Bioresour Technol ; 102(13): 6884-6, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21530245

RESUMO

Biodiesel and lactic acid from rapeseed oil was produced using sodium silicate as catalyst. The transesterification in the presence of the catalyst proceeded with a maximum yield of 99.6% under optimized conditions [3% (w/w) sodium silicate, methanol/oil molar ratio 9/1, reaction time 60 min, reaction temperature 60°C, and stirring rate 250 rpm]. After six consecutive transesterification reactions, the catalyst was collected and used for catalysis of the conversion of glycerol to lactic acid. A maximum yield of 80.5% was achieved when the reaction was carried out at a temperature of 300°C for 90 min. Thus, sodium silicate is an effective catalyst for transesterification and lactic acid production from the biodiesel by-product, glycerol.


Assuntos
Biocombustíveis/análise , Biotecnologia/métodos , Ácido Láctico/síntese química , Óleos de Plantas/química , Silicatos/química , Catálise , Ácidos Graxos Monoinsaturados , Glicerol/química , Óleo de Brassica napus , Temperatura , Fatores de Tempo , Água/química
20.
Bioresour Technol ; 102(11): 6469-72, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21420854

RESUMO

Catalytic conversion of un-pretreated Jatropha oil with high-acid value (13.8 mg KOH/g) to biodiesel was studied in ionic liquids (ILs) with metal chlorides. Several commercial ILs were used to catalyze the esterification of oleic acid. It was found that 1-butyl-3-methylimidazolium tosylate ([BMIm][CH(3)SO(3)]; a Brønsted acidic IL) had the highest catalytic activity with 93% esterification rate for oleic acid at 140°C but only 12% biodiesel yield at 120°C. When FeCl(3) was added to [BMIm][CH(3)SO(3)], a maximum biodiesel yield of 99.7% was achieved at 120°C. Because metal ions in ILs supplied Lewis acidic sites, and more of the sites could be provided by trivalent metallic ions than those of bivalent ones. It was also found that the catalytic activity with bivalent metallic ions increased with atomic radius. Mixture of [BMIm][CH(3)SO(3)] and FeCl(3) was easily separated from products for reuse to avoid producing pollutants.


Assuntos
Biocombustíveis/análise , Biotecnologia/métodos , Líquidos Iônicos/química , Jatropha/química , Ácido Oleico/química , Óleos de Plantas/química , Cloretos/química , Esterificação , Imidazóis/química , Metais/química
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