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1.
Artigo em Inglês | MEDLINE | ID: mdl-32157863

RESUMO

Currently, four-dimensional (4D) printing programming methods are mainly structure-based, which usually requires more than one material to endow products with site-specific attributes. Here, we propose a new 4D printing programming approach that enables site-specific shape-morphing behaviors in a single material by regulating the printing parameters. Specifically, a direct ink writing three-dimensional (3D) printer with the ability to change printing parameters (e.g., deposition speed) on the fly is reported. By site-specifically adjusting print speed and print path to control the local nematic arrangements of printed liquid crystal elastomers (LCEs), the shape-morphing behaviors of the LCEs can be successfully programmed. In this way, locally programmed popping-up, self-assembling, and oscillating behaviors can be designed by varying the print speed in specific regions. Snake-like curling is realized by uniformly boosting the print speed in a single line. Furthermore, two theories and an ultrasound image diagnostic apparatus are employed to reveal the mechanism behind this behavior. This work provides a feasible way to realize the gradient transition of material properties through a single material. It broadens the design space and pushes the envelope of 4D printing, which is expected to be helpful in the fabrication of soft robotics and flexible electronics.

2.
ACS Appl Mater Interfaces ; 12(5): 6351-6361, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31920076

RESUMO

Programmable nonuniform deformation is of great significance for self-shape-morphing systems that are commonly seen in biological systems and also has practical applications in drug delivery, biomedical devices and robotics, etc. Here, we present a novel gradient four-dimensional (4D) printing method toward biomimetic nonuniform, dual-stimuli self-morphing. By modeling and printing graded active materials with water swelling properties, we can configure continuously smooth gradients of volume fraction of the active material in bilayer structures. The variation of swelling ratio mismatch between the two layers can be delicately regulated, which results in the programmable nonuniform shape transformation. The shape-shifting results can be predicted by the established mathematical model and computational simulations. Furthermore, we demonstrate dual-stimuli self-morphing structures by printing the graded water-responsive elastomer materials onto a heat-shrinkable shape memory polymer, which could produce different shape changes in response to humidity and different temperatures. This method pioneers a versatile approach to broaden the design space for 4D printing and will be compatible with a wide range of active materials meeting various requirements in diverse potential applications.

3.
Ecotoxicol Environ Saf ; 184: 109616, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31493588

RESUMO

The application of biogas slurry as an organic fertilizer is a promising method for utilizing breeding manure wastewater. At present, the impact of biogas slurry on the properties of organic matter in soil is not clear. In this study, a pot experiment in which chemical fertilizers were replaced with biogas slurry from a swine farm was performed. The fluorescence spectra combined with parallel factor (PARAFAC) analysis and principal component analysis (PCA) were used to explore the influence of biogas slurry on the protein and humic substance contents in the dissolved organic matter (DOM) in soil. The results showed that there were two proteins (component 3 (C3) and component 4 (C4)) and two humic substances ( component 1 (C1) and component 2 (C2)) in the DOM of the experimental soil. The application of swine biogas slurry can significantly increase the content of DOM in soil, but the increase was weakened with extended time. Compared with the CKA, the biogas slurry significantly increased the C1, C2, C3 and C4 contents in the initial stage by 116.17%, 76.41%, 578.71% and 278.13%, respectively. Within 28 days of planting corn, proteins with simple molecular structure in the DOM in the soil began to be transformed into humic substances with high molecular weight and more complex molecular structures. On the 60th day, the contents of C1 and C2 in the DOM of the treated treatments soil increased by 13.72%-34.40% and 5.05%-17.78% respectively, and tyrosine content decreased by 90.11%-94.41%. This study provides a new perspective on the effects of biogas slurry application on soil properties and sustainable utilization of soil.


Assuntos
Biocombustíveis/análise , Fertilizantes/análise , Solo/química , Animais , Conservação dos Recursos Naturais , Substâncias Húmicas/análise , Espectrometria de Fluorescência , Suínos , Fatores de Tempo , Eliminação de Resíduos Líquidos
4.
Sci Rep ; 9(1): 11263, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31375773

RESUMO

Evolution of cellular innate immune genes in response to viral threats represents a rich area of study for understanding complex events that shape mammalian genomes. One of these genes, TRIM5, is a retroviral restriction factor that mediates a post-entry block to infection. Previous studies on the genomic cluster that contains TRIM5 identified different patterns of gene amplification and the independent birth of CypA gene fusions in various primate species. However, the evolution of Trim5 in the largest order of mammals, Rodentia, remains poorly characterized. Here, we present an expansive phylogenetic and genomic analysis of the Trim5 cluster in rodents. Our findings reveal substantial evolutionary changes including gene amplifications, rearrangements, loss and fusion. We describe the first independent evolution of TrimCyp fusion genes in rodents. We show that the TrimCyp gene found in some Peromyscus species was acquired about 2 million years ago. When ectopically expressed, the P. maniculatus TRIMCyp shows anti-retroviral activity that is reversed by cyclosporine, but it does not activate Nf-κB or AP-1 promoters, unlike the primate TRIMCyps. These results describe a complex pattern of differential gene amplification in the Trim5 cluster of rodents and identify the first functional TrimCyp fusion gene outside of primates and tree shrews.

5.
PLoS One ; 14(7): e0219576, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31291374

RESUMO

Inbred laboratory mouse strains carry endogenous retroviruses (ERVs) classed as ecotropic, xenotropic or polytropic mouse leukemia viruses (E-, X- or P-MLVs). Some of these MLV ERVs produce infectious virus and/or contribute to the generation of intersubgroup recombinants. Analyses of selected mouse strains have linked the appearance of MLVs and virus-induced disease to the strain complement of MLV E-ERVs and to host genes that restrict MLVs, particularly Fv1. Here we screened inbred strain DNAs and genome assemblies to describe the distribution patterns of 45 MLV ERVs and Fv1 alleles in 58 classical inbred strains grouped in two ways: by common ancestry to describe ERV inheritance patterns, and by incidence of MLV-associated lymphomagenesis. Each strain carries a unique set of ERVs, and individual ERVs are present in 5-96% of the strains, often showing lineage-specific distributions. Two ERVs are alternatively present as full-length proviruses or solo long terminal repeats. High disease incidence strains carry the permissive Fv1n allele, tested strains have highly expressed E-ERVs and most have the Bxv1 X-ERV; these three features are not present together in any low-moderate disease strain. The P-ERVs previously implicated in P-MLV generation are not preferentially found in high leukemia strains, but the three Fv1 alleles that restrict inbred strain E-MLVs are found only in low-moderate leukemia strains. This dataset helps define the genetic basis of strain differences in spontaneous lymphomagenesis, describes the distribution of MLV ERVs in strains with shared ancestry, and should help annotate sequenced strain genomes for these insertionally polymorphic and functionally important proviruses.


Assuntos
Retrovirus Endógenos/isolamento & purificação , Vírus da Leucemia Murina/isolamento & purificação , Linfoma/virologia , Camundongos Endogâmicos/virologia , Proteínas/genética , Alelos , Animais , Carcinogênese/genética , Conjuntos de Dados como Assunto , Retrovirus Endógenos/genética , Vírus da Leucemia Murina/genética , Linfoma/genética , Linfoma/veterinária , Camundongos , Camundongos Endogâmicos/genética
6.
J Mech Behav Biomed Mater ; 89: 132-142, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30268869

RESUMO

Biological materials have fascinating mechanical properties built up from simple basic material blocks. It is worthwhile to learn how biological materials are constructed, and to apply the knowledge in advanced manufacturing, and to realize new materials by design. In this study, we chose the tubular cell in the soft wood as a biological prototype, and tried to mimic its intelligent construction principle to regulate the compression mechanical behavior through the helical structure. First, by using the multi-material three-dimensional printing technology, we fabricated a series of tubular composites with the helix fibers of a rigid plastic embedded into an elastomeric matrix. Then, through the uniaxial compression tests, we characterized the mechanical behavior of the specimens, having different fiber angle from 0 to 50 deg at constant volume fraction. The results showed that both stiffness and fracture toughness of the printed composite could be regulated effectively by adjusting the fiber angle of the helical structure. Moreover, the helical structure with high fiber angle is able to improve the compression stability of the tubular composite with big lumen. In addition, for the biomimetic composites, the volume fraction of the reinforcements should exceed 40%. Finally, we proposed a new structural design method by combining the reinforcements of different architectures into a double-layered configuration. The intelligent strategy is proven to balance the conflict between the stiffness and toughness of the composites to some extent, and without changing in the building constituents.


Assuntos
Biomimética , Fenômenos Mecânicos , Madeira/citologia , Análise de Elementos Finitos , Impressão Tridimensional , Estresse Mecânico
7.
Ir J Med Sci ; 188(3): 801-806, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30460452

RESUMO

OBJECTIVE: To investigate cardiac manifestations and the risk factors in Han Chinese patients with systemic lupus erythematosus (SLE). METHODS: Seven hundred fifty SLE patients who were hospitalized at our department were recruited in the present study. The patients were divided into two groups-those with or without cardiac manifestations. Cardiac manifestations in those SLE patients, such as pericarditis, myocarditis, heart valve disease, arrhythmia, were analyzed. The risk and protective factors of cardiac diseases in patients with SLE, as well as the predictors of mortality, were assessed, respectively. RESULTS: In all 750 SLE patients, there were 339 (45.20%) patients suffered from one or more cardiac manifestations, involving pericarditis in 9.5%, myocarditis in 5.7%, heart valve disease in 15.6%, arrhythmia in 16.67%, and cardiovascular diseases (CVD) in 14%. 15.7% of SLE patients were accompanied with pulmonary arterial hypertension (PAH), of which 13.7% were mild, 1.2% were moderate, and 0.8% were severe. No significant differences were found between the two groups in age, disease duration, gender, antibody, and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). The incidence of pericarditis, heart valve disease, arrhythmia, and PAH was positively correlated with age. The incidence of arrhythmia, CVD, and PAH was correlated with SLEDAI. PAH and myocarditis were the risk factors of mortality in SLE patients with disease duration ≤ 10 years (P = 0.034 and 0.001, respectively). CONCLUSION: Cardiac involvement is common in Han Chinese SLE patients and associated with age and disease activity. PAH and myocarditis are the risk factors of mortality in SLE.


Assuntos
Cardiopatias/etiologia , Hipertensão Pulmonar/etiologia , Lúpus Eritematoso Sistêmico/complicações , Adulto , Grupo com Ancestrais do Continente Asiático , Feminino , Cardiopatias/patologia , Humanos , Hipertensão Pulmonar/patologia , Incidência , Lúpus Eritematoso Sistêmico/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
8.
Bioresour Technol ; 275: 153-162, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30583116

RESUMO

In this study, the performance of simultaneous nitrification and denitrification via nitrite was investigated by alternating the dissolved oxygen (DO) concentration in a sequencing batch reactor with the DO-control area and the non-control area. In addition, bacterial communities and their metabolic functions were analyzed by high-throughput sequencing technology and phylogenetic investigation of the communities by reconstruction of unobserved states (PICRUSt). The removal efficiencies of NH4+-N and total nitrogen via the nitrite pathway were 97.91 ±â€¯2.04% and 72.28 ±â€¯2.23%, respectively, by maintaining low DO levels (0.7 ±â€¯0.1 mg/L) in the DO-control area. PICRUSt analysis showed that the metabolic potential of the bacterial community for amino acids, nucleotides, coenzymes and inorganic ions decreased, while the relative abundance of key enzymes involved in nitrification and denitrification, and the relative population of denitrifying bacteria increased when the DO decreased from 1.2 ±â€¯0.2 mg/L to 0.7 ±â€¯0.1 mg/L.


Assuntos
Nitritos/metabolismo , Oxigênio/metabolismo , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Desnitrificação , Nitrificação , Nitrogênio/metabolismo , Filogenia
9.
Int Immunopharmacol ; 67: 186-193, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30553912

RESUMO

The aggressive phenotype displayed by fibroblast-like synoviocytes (FLSs) contributes to cartilage and bone destruction in rheumatoid arthritis (RA). Betulinic acid has been demonstrated to have a positive therapeutic effect on tumor, inflammation and immune disorder, however, the effects of betulinic acid on RA FLSs have not been verified. Therefore, in the present study, we observed the effect of betulinic acid on the migration and invasion of RA FLSs and explored its underlying signal mechanisms. Our results showed that betulinic acid treatment suppressed the migration, invasion and reorganization of the actin cytoskeleton of RA FLSs. In addition, we found that the mRNA expression of IL-1ß, IL-6, IL-8 and IL-17A were markedly down-regulated by treatment with betulinic acid in TNF-α-induced RA FLSs. To gain insight into the molecular mechanisms, we evaluated the effect of betulinic acid on NF-κB activation in RA FLSs. The results indicated that betulinic acid treatment reduced the TNF-α-induced activation of NF-κB signal pathway and the NF-κB nuclear accumulation. We also observed that treatment with betulinic acid attenuated synovial inflammation and joint destruction in mice with CIA. Taken together, these results suggest that betulinic acid inhibits the migration and invasion of RA FLSs by blocking NF-κB signal pathway activation.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Fibroblastos/efeitos dos fármacos , Inflamação/tratamento farmacológico , Sinoviócitos/efeitos dos fármacos , Triterpenos/uso terapêutico , Adulto , Idoso , Animais , Movimento Celular , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Fibroblastos/fisiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos DBA , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Transdução de Sinais , Sinoviócitos/fisiologia
10.
IEEE J Biomed Health Inform ; 23(3): 1129-1140, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-29993565

RESUMO

Spatial resolution is a critical imaging parameter in magnetic resonance imaging. The image super-resolution (SR) is an effective and cost efficient alternative technique to improve the spatial resolution of MR images. Over the past several years, the convolutional neural networks (CNN)-based SR methods have achieved state-of-the-art performance. However, CNNs with very deep network structures usually suffer from the problems of degradation and diminishing feature reuse, which add difficulty to network training and degenerate the transmission capability of details for SR. To address these problems, in this work, a progressive wide residual network with a fixed skip connection (named FSCWRN) based SR algorithm is proposed to reconstruct MR images, which combines the global residual learning and the shallow network based local residual learning. The strategy of progressive wide networks is adopted to replace deeper networks, which can partially relax the above-mentioned problems, while a fixed skip connection helps provide rich local details at high frequencies from a fixed shallow layer network to subsequent networks. The experimental results on one simulated MR image database and three real MR image databases show the effectiveness of the proposed FSCWRN SR algorithm, which achieves improved reconstruction performance compared with other algorithms.


Assuntos
Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética/métodos , Algoritmos , Neoplasias Encefálicas/diagnóstico por imagem , Humanos , Lactente
11.
J Pak Med Assoc ; 68(11): 1644-11649, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30410143

RESUMO

OBJECTIVE: To investigate if lectin-like oxidised low density lipoprotein receptor is implicated in oxidised low density lipoprotein induced up regulation of tissue factor and whether recombinant domain V of beta (2)-Glycoprotein I expressed in Pichia pastoris inhibits the binding of oxidised and lectin-like low density lipoprotein. METHODS: The expression of tissue factor and lectin-like oxidised low density lipoprotein receptor was detected using Western blot methods. Small interference ribonucleic acid of lectin-like oxidised low density lipoprotein receptor was used to block lectin-like oxidised low density lipoprotein receptor expression. Flow cytometry was used to test the effect of beta (2)-Glycoprotein I expressed in Pichia pastoris on the binding of oxidised low density lipoprotein with lectin-like oxidised low density lipoprotein receptor by using the lectin-like oxidised low density lipoprotein receptor-expressing 293T cells. RESULTS: Oxidised low density lipoprotein at 5-10 g/mL increased tissue factor and lectin-like oxidised low density lipoprotein receptor expression, whereas 20-50 g/mL oxidised low density lipoprotein attenuated tissue factor expression. Inhibiting lectin-like oxidised low density lipoprotein receptor expression by small interference ribonucleic acid of lectin-like oxidised low density lipoprotein receptor impaired oxidised low density lipoprotein-induced tissue factor over expression in macrophages. Pretreatment with beta (2)-Glycoprotein I expressed in Pichia pastoris led to a strong inhibition of tissue factor and lectin-like oxidised low density lipoprotein receptor expression in a dose-dependent manner in macrophages. Flow cytometry analysis showed that beta (2)-Glycoprotein I expressed in Pichia pastoris attenuated the interaction of oxidised low density lipoprotein with lectin-like oxidised low density lipoprotein receptor in lectin-like oxidised low density lipoprotein receptor-expressing 293T cells. CONCLUSIONS: Lectin-like oxidised low density lipoprotein receptor was implicated in the expression of tissue factor induced by oxidised low density lipoprotein, and beta (2)-Glycoprotein I expressed in Pichia pastoris inhibited oxidised low density lipoprotein-induced tissue factor and lectin-like oxidised low density lipoprotein receptor expression, at least in part, via inhibition of the interaction between oxidised low density lipoprotein and lectin-like oxidised low density lipoprotein receptor.


Assuntos
Regulação da Expressão Gênica , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Tromboplastina/biossíntese , beta 2-Glicoproteína I/metabolismo , Animais , Western Blotting , Camundongos , Oxirredução , Coelhos
12.
Neural Netw ; 108: 527-532, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30336327

RESUMO

This paper is concerned with the reachable set estimation for Markovian jump neural networks with time-varying delay and bounded peak inputs. The objective is to find a description of a reachable set that is containing all reachable states starting from the origin. In the framework of Lyapunov-Krasovskii functional method, an appropriate Lyapunov-Krasovskii functional is constructed firstly. Then by using the Wirtinger-based integral inequality and the extended reciprocally convex matrix inequality, an ellipsoidal description of the reachable set for the considered neural networks is derived. Finally, a numerical example with simulation results is provided to verify the effectiveness of our results.


Assuntos
Cadeias de Markov , Algoritmos , Simulação por Computador , Fatores de Tempo
13.
Materials (Basel) ; 11(5)2018 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-29701707

RESUMO

Based on microstructure characteristics of Meretrix lusoria shell and Rapana venosa shell, bionic coupling layered B4C/5083Al composites with different layered structures and hard/soft combination models were fabricated via hot pressed sintering. The simplified bionic coupling models with hard and soft layers were similar to layered structure and hardness tendency of shells, guiding the bionic design and fabrication. B4C/5083Al composites with various B4C contents and pure 5083Al were treated as hard and soft layers, respectively. Hot pressed sintering maintained the designed bionic structure and enhanced high bonding strength between ceramics and matrix. Compared with B4C/5083Al composites, bionic layered composites exhibited high mechanical properties including flexural strength, fracture toughness, compressive strength and impact toughness. The hard layers absorbed applied loads in the form of intergranular fracture. Besides connection role, soft layers restrained slabbing phenomenon and reset extension direction of cracks among layers. The coupling functions of bionic composites proved the feasibility and practicability of bionic fabrication, providing a new method for improvement of ceramic/Al composite with properties of being lightweight and high mechanical strength.

14.
Phys Med Biol ; 63(8): 085011, 2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29583134

RESUMO

Spatial resolution is one of the key parameters of magnetic resonance imaging (MRI). The image super-resolution (SR) technique offers an alternative approach to improve the spatial resolution of MRI due to its simplicity. Convolutional neural networks (CNN)-based SR algorithms have achieved state-of-the-art performance, in which the global residual learning (GRL) strategy is now commonly used due to its effectiveness for learning image details for SR. However, the partial loss of image details usually happens in a very deep network due to the degradation problem. In this work, we propose a novel residual learning-based SR algorithm for MRI, which combines both multi-scale GRL and shallow network block-based local residual learning (LRL). The proposed LRL module works effectively in capturing high-frequency details by learning local residuals. One simulated MRI dataset and two real MRI datasets have been used to evaluate our algorithm. The experimental results show that the proposed SR algorithm achieves superior performance to all of the other compared CNN-based SR algorithms in this work.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Simulação por Computador , Humanos , Aprendizado de Máquina
15.
Toxicol Lett ; 288: 35-43, 2018 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-29444456

RESUMO

Cadmium (Cd), a toxic heavy metal, is known to induce renal toxicity by primarily targeting at renal proximal tubule. Endoplasmic reticulum (ER) stress and gap junctional intercellular communication (GJIC) regulate many pathophysiological processes. Yet, how ER stress and GJIC regulate Cd-induced nephrotoxicity remain elusive. In this study, we treated human proximal tubule (HK-2) cells with 1 µM CdCl2 every other day for 12 days and found that Cd significantly increased cell apoptosis at 10 and 12 days. This cytotoxicity correlated with activation of ER stress and apoptotic signaling evidenced by upregulation of inositol-requiring enzyme 1 (IRE1α), splice X-box binding protein-1 (XBP-1s), and apoptosis signal-regulating kinase 1 (ASK1) proteins. Interestingly, the AKT signaling was activated at 2- and 4-day and then inhibited at 10- and 12-day of Cd treatment; by contrast, Cd decreased GJIC levels at 2- and 4-day followed by a significant increase at 10- and 12-day treatment. Activation of AKT by SC79 or inhibition of GJIC by 18α-glycyrrhetinic acid (18α-GA) completely abolished Cd-induced AKT inhibition and IRE1α-ASK1 activation. Importantly, pretreatment with ER stress inhibitor or 18α-GA significantly mitigated Cd-induced apoptosis. These results suggest that GJIC collaborates with AKT signaling and ER stress in regulating prolonged Cd-treatment-induced apoptosis in HK-2 cells.


Assuntos
Apoptose/efeitos dos fármacos , Cloreto de Cádmio/toxicidade , Comunicação Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Junções Comunicantes/efeitos dos fármacos , Cloreto de Cádmio/antagonistas & inibidores , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Espaço Extracelular , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/efeitos dos fármacos , Proteína Oncogênica v-akt , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
16.
Sheng Wu Gong Cheng Xue Bao ; 34(1): 110-121, 2018 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-29380576

RESUMO

CD36, the major scavenger receptor, is intimately involved in the uptake of oxLDL in macrophages. To further study the function of CD36 in macrophages, we constructed CD36 gene silence cell lines (J774A.1) by lentivirus-mediated RNA interference technique, and analyzed the effect of CD36 in caveolin-1 protein expression. At first, 5 shRNA fragments were designed and synthesized according to the coding sequence (CDS) region of CD36 gene. Next, the CD36-shRNA was inserted into lentiviral vector to yield pLKO.1-CD36-shRNA plasmid. After DNA sequencing, the pLKO.1-CD36-shRNA plasmid and psiCHECK-II-CD36 were co-transfected into the 293T cells to screen the efficient CD36-shRNA. The efficient CD36-shRNA plasmid and the helper plasmid were co-transfected into the 293T cells to package the lentivirus, and then infected the J774A.1 cells. After screening by puromycin, CD36 gene silence cell lines (J774A.1) was established. Western blotting and confocal fluorescence microscopy results showed that the CD36 silencing efficiency in the gene silence cell line was 90%. Accompanied by a decrease in CD36 protein on cell surface, oxLDL binding to CD36 was significantly inhibited, indicating that the CD36 gene silence cell line is successfully established. Finally, the oxLDL stimulation and inhibitor experiments results showed that the CD36 knockdown significantly suppresses the phosphorylation of JNK and ERK, thereby inhibiting the oxLDL-induced caveolin-1 protein expression, demonstrating that CD36 modulates the caveolin-1 protein expression through the JNK/ERK-mediated signaling transduction.


Assuntos
Antígenos CD36/genética , Caveolina 1/metabolismo , Lentivirus , Interferência de RNA , Animais , Linhagem Celular , Vetores Genéticos , Camundongos , RNA Interferente Pequeno , Transdução de Sinais
17.
Int Immunopharmacol ; 55: 174-182, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29268189

RESUMO

In rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLSs) play an essential role in cartilage destruction. Aggressive migration and invasion by FLSs significantly affect RA pathology. Kaempferol has been shown to inhibit cancer cell migration and invasion. However, the effects of kaempferol on RA FLSs have not been investigated. Our study aimed to determine the effects of kaempferol on RA both in vitro and in vivo. In vitro, cell migration and invasion were measured using scratch assays and the Boyden chamber method, respectively. The cytoskeletal reorganization of RA FLSs was evaluated by immunofluorescence staining. Matrix metalloproteinase (MMP) levels were measured by real-time PCR, and protein expression levels were measured by western blotting. In vivo, the effects of kaempferol were evaluated in mice with CIA. The results showed that kaempferol reduced migration, invasion and MMP expression in RA FLSs. In addition, we demonstrated that kaempferol inhibited reorganization of the actin cytoskeleton during cell migration. Moreover, kaempferol dramatically suppressed tumor necrosis factor (TNF)-α-induced MAPK activation without affecting the expression of TNF-α receptors. We also demonstrated that kaempferol attenuated the severity of arthritis in mice with CIA. Taken together, these results suggested that kaempferol inhibits the migration and invasion of FLSs in RA by blocking MAPK pathway activation without affecting the expression of TNF-α receptors.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Fibroblastos/fisiologia , Quempferóis/uso terapêutico , Sinoviócitos/fisiologia , Actinas/metabolismo , Adulto , Idoso , Animais , Artrite Experimental , Movimento Celular , Células Cultivadas , Citoesqueleto/metabolismo , Feminino , Humanos , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos DBA , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/metabolismo
18.
Sheng Wu Gong Cheng Xue Bao ; 33(1): 122-131, 2017 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-28959869

RESUMO

We analyzed the binding of P.rß2-GPI-DV with ox-LDL by fluorescence, molecular simulation and circular dichroism. We used SDS-PAGE and Western blotting to identify the purity of P.rß2-GPI-DV, fluorescence, circular dichroism spectroscopy and molecular docking simulation to analyze the binding between P.rß2-GPI-DV and oxLDL. P.rß2-GPI-DV was specifically recognized by anti-His antibody at 12 kDa position. The chromophoric groups, the changes of secondary structure and the molecular docking simulations revealed that the active pocket formed by Cys281-Lys-Asn-Lys-Glu-Lys-Lys287 and Leu313-Ala-Phe-Trp316 of P.rß2-GPI-DV and the -COOH carboxyl of oxLig-1 were the key for binding. P.rß2-GPI combined with ox-LDL via the fifth functional domain and the -COOH group. Our findings provide theoretical basis to further study the binding between ß2-GPI and ox-LDL in serum.


Assuntos
Lipoproteínas LDL/metabolismo , Simulação de Acoplamento Molecular , beta 2-Glicoproteína I/metabolismo , Anticorpos , Western Blotting , Ésteres do Colesterol , Dipeptídeos , Eletroforese em Gel de Poliacrilamida , Glicoproteínas , Humanos
19.
J Virol ; 91(21)2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28794032

RESUMO

Ecotropic, xenotropic, and polytropic mouse leukemia viruses (E-, X-, and P-MLVs) exist in mice as infectious viruses and endogenous retroviruses (ERVs) inserted into mouse chromosomes. All three MLV subgroups are linked to leukemogenesis, which involves generation of recombinants with polytropic host range. Although P-MLVs are deemed to be the proximal agents of disease induction, few biologically characterized infectious P-MLVs have been sequenced for comparative analysis. We analyzed the complete genomes of 16 naturally occurring infectious P-MLVs, 12 of which were typed for pathogenic potential. We sought to identify ERV progenitors, recombinational hot spots, and segments that are always replaced, never replaced, or linked to pathogenesis or host range. Each P-MLV has an E-MLV backbone with P- or X-ERV replacements that together cover 100% of the recombinant genomes, with different substitution patterns for X- and P-ERVs. Two segments are always replaced, both coding for envelope (Env) protein segments: the N terminus of the surface subunit and the cytoplasmic tail R peptide. Viral gag gene replacements are influenced by host restriction genes Fv1 and Apobec3 Pathogenic potential maps to the env transmembrane subunit segment encoding the N-heptad repeat (HR1). Molecular dynamics simulations identified three novel interdomain salt bridges in the lymphomagenic virus HR1 that could affect structural stability, entry or sensitivity to host immune responses. The long terminal repeats of lymphomagenic P-MLVs are differentially altered by recombinations, duplications, or mutations. This analysis of the naturally occurring, sometimes pathogenic P-MLV recombinants defines the limits and extent of intersubgroup recombination and identifies specific sequence changes linked to pathogenesis and host interactions.IMPORTANCE During virus-induced leukemogenesis, ecotropic mouse leukemia viruses (MLVs) recombine with nonecotropic endogenous retroviruses (ERVs) to produce polytropic MLVs (P-MLVs). Analysis of 16 P-MLV genomes identified two segments consistently replaced: one at the envelope N terminus that alters receptor choice and one in the R peptide at the envelope C terminus, which is removed during virus assembly. Genome-wide analysis shows that nonecotropic replacements in the progenitor ecotropic MLV genome are more extensive than previously appreciated, covering 100% of the genome; contributions from xenotropic and polytropic ERVs differentially alter the regions responsible for receptor determination or subject to APOBEC3 and Fv1 restriction. All pathogenic viruses had modifications in the regulatory elements in their long terminal repeats and differed in a helical segment of envelope involved in entry and targeted by the host immune system. Virus-induced leukemogenesis thus involves generation of complex recombinants, and specific replacements are linked to pathogenesis and host restrictions.


Assuntos
Especificidade de Hospedeiro/genética , Vírus da Leucemia Murina/classificação , Vírus da Leucemia Murina/patogenicidade , Leucemia Experimental/virologia , Infecções por Retroviridae/virologia , Infecções Tumorais por Vírus/virologia , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Evolução Molecular , Genoma Viral , Vírus da Leucemia Murina/genética , Camundongos , Simulação de Dinâmica Molecular , Conformação Proteica , Receptores Virais/genética , Receptores Virais/metabolismo , Homologia de Sequência , Sequências Repetidas Terminais , Proteínas Virais/química , Proteínas Virais/metabolismo
20.
Int J Biochem Cell Biol ; 90: 121-135, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28789920

RESUMO

CD36 signal transduction modulates the uptake of oxidized low-density lipoprotein (oxLDL) and foam cell formation. We previously observed that 7-ketocholesteryl-9-carboxynonanoate (oxLig-1), the lipid moiety of oxLDL, activates the CD36-Src-JNK/ERK1/2 signalling pathway. In this study, we assessed the role of the ω-carboxyl group in the binding of oxLig-1 to CD36 and investigated whether the binding of the ω-carboxyl group to CD36 triggers CD36-mediated signalling, thereby resulting in the upregulation of caveolin-1 expression. Our results showed that oxLig-1 bound to CD36 and that the ω-carboxyl group was critical for this binding. Furthermore, immunoprecipitation and Western blot analyses showed that interaction between the ω-carboxyl group of oxLig-1 and CD36 triggered intracellular Src-JNK/ERK1/2 signal transduction. Moreover, the binding of the ω-carboxyl group to CD36 induced caveolin-1 expression and translocation to the membrane in macrophages. Additionally, inhibitors of Src, JNK and ERK and siRNA targeting CD36 and NF-κB significantly suppressed the enhanced caveolin-1 expression induced by oxLig-1. In conclusion, these observations suggest that oxLig-1 is a critical epitope of oxLDL that mediates the binding of oxLDL to CD36 and activates downstream Src-JNK/ERK1/2-NF-κB signal transduction, resulting in upregulation of caveolin-1 expression in macrophages.


Assuntos
Antígenos CD36/metabolismo , Caveolina 1/metabolismo , Ésteres do Colesterol/química , Ésteres do Colesterol/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Lipoproteínas LDL/metabolismo , Macrófagos/efeitos dos fármacos , Antígenos CD36/química , Linhagem Celular , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Lipoproteínas LDL/química , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/metabolismo , Simulação de Acoplamento Molecular , NF-kappa B/metabolismo , Ligação Proteica/efeitos dos fármacos , Conformação Proteica , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Relação Estrutura-Atividade
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