Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 87
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 158(3): 481-91, 2014 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-25065977

RESUMO

Development of strategies for induction of HIV-1 broadly neutralizing antibodies (bnAbs) by vaccines is a priority. Determining the steps of bnAb induction in HIV-1-infected individuals who make bnAbs is a key strategy for immunogen design. Here, we study the B cell response in a bnAb-producing individual and report cooperation between two B cell lineages to drive bnAb development. We isolated a virus-neutralizing antibody lineage that targeted an envelope region (loop D) and selected virus escape mutants that resulted in both enhanced bnAb lineage envelope binding and escape mutant neutralization-traits associated with increased B cell antigen drive. Thus, in this individual, two B cell lineages cooperated to induce the development of bnAbs. Design of vaccine immunogens that simultaneously drive both helper and broadly neutralizing B cell lineages may be important for vaccine-induced recapitulation of events that transpire during the maturation of neutralizing antibodies in HIV-1-infected individuals.


Assuntos
Vacinas contra a AIDS/química , Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/fisiologia , Sequência de Aminoácidos , Linfócitos B/imunologia , Evasão da Resposta Imune , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Alinhamento de Sequência , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
2.
Immunity ; 49(6): 1162-1174.e8, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30552024

RESUMO

Elicitation of VRC01-class broadly neutralizing antibodies (bnAbs) is an appealing approach for a preventative HIV-1 vaccine. Despite extensive investigations, strategies to induce VRC01-class bnAbs and overcome the barrier posed by the envelope N276 glycan have not been successful. Here, we inferred a high-probability unmutated common ancestor (UCA) of the VRC01 lineage and reconstructed the stages of lineage maturation. Env immunogens designed on reverted VRC01-class bnAbs bound to VRC01 UCA with affinity sufficient to activate naive B cells. Early mutations defined maturation pathways toward limited or broad neutralization, suggesting that focusing the immune response is likely required to steer B cell maturation toward the development of neutralization breadth. Finally, VRC01 lineage bnAbs with long CDR H3s overcame the HIV-1 N276 glycan barrier without shortening their CDR L1, revealing a solution for broad neutralization in which the heavy chain, not CDR L1, is the determinant to accommodate the N276 glycan.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Polissacarídeos/imunologia , Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/genética , Sequência de Aminoácidos , Anticorpos Monoclonais/classificação , Anticorpos Monoclonais/genética , Anticorpos Neutralizantes/classificação , Anticorpos Neutralizantes/genética , Linfócitos B/imunologia , Linfócitos B/metabolismo , Sítios de Ligação/genética , Anticorpos Amplamente Neutralizantes , Antígenos CD4/genética , Antígenos CD4/imunologia , Antígenos CD4/metabolismo , Anticorpos Anti-HIV , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp120 do Envelope de HIV/metabolismo , Infecções por HIV/terapia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Humanos , Filogenia , Polissacarídeos/metabolismo , Homologia de Sequência de Aminoácidos
3.
J Org Chem ; 89(2): 1083-1090, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38173188

RESUMO

A metal-free and thiol-free organophosphorus-catalyzed method for forming thioethers was disclosed, driven by PIII/PV═O redox cycling. In this work, one-step dehydroxylative thioetherification of alcohols was fulfilled with various hypervalent organosulfur compounds. This established strategy features an excellent functional group tolerance and broad substrate scope, especially inactivated alcohols. The scale-up reaction and further transformation of the product were also successful. Additionally, this method offers a protecting-group-free and step-efficient approach for synthesizing peroxisome proliferator-activated receptor agonists which exhibited promising potential for treating osteoporosis in mammals.

4.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(2): 124-128, 2023 Feb 08.
Artigo em Zh | MEDLINE | ID: mdl-37096462

RESUMO

This study proposed a vessel segmentation method based on Gabor features. According to the eigenvector of Hessian matrix of each pixel in the image, the vessel direction of each point was obtained to set the direction angle of Gabor filter, and the Gabor features of different vessel width at each point were extracted to establish the 6D vectors of each point. By reducing the dimension of the 6D vector, the 2D vector of each point was obtained and fused with the original image G channel. U-Net neural network was used to classify the fused image to segment vessels. The experimental results of this method in DRIVE dataset showed that this method had a good effect on the detection of small vessels and vessels at the intersection.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Vasos Retinianos
5.
Clin Sci (Lond) ; 135(11): 1427-1444, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34061176

RESUMO

We aimed to investigate the role of cMet agonistic antibody (cMet Ab) in preventing kidney fibrosis during acute kidney injury (AKI) to chronic kidney disease (CKD) transition. Additionally, we explored the effect of cMet Ab on TGF-ß1/Smad pathway during the pathogenesis of kidney fibrosis. A unilateral ischemia-reperfusion injury (UIRI) mouse model was established to induce AKI-to-CKD transition. Furthermore, we incubated human proximal tubular epithelial cells (hPTECs) under hypoxic conditions as in vitro model of kidney fibrosis. We analyzed the soluble plasma cMet level in patients with AKI requiring dialysis. Patients who did not recover kidney function and progressed to CKD presented a higher increase in the cMet level. The kidneys of mice treated with cMet Ab showed fewer contractions and weighed more than the controls. The mice in the cMet Ab-treated group showed reduced fibrosis and significantly decreased expression of fibronectin and α-smooth muscle actin. cMet Ab treatment decreased inflammatory markers (MCP-1, TNF-α, and IL-1ß) expression, reduced Smurf1 and Smad2/3 level, and increased Smad7 expressions. cMet Ab treatment increased cMet expression and reduced the hypoxia-induced increase in collagen-1 and ICAM-1 expression, thereby reducing apoptosis in the in vitro cell model. After cMet Ab treatment, hypoxia-induced expression of Smurf1, Smad2/3, and TGF-ß1 was reduced, and suppressed Smad7 was activated. Down-regulation of Smurf1 resulted in suppression of hypoxia-induced fibronectin expression, whereas treatment with cMet Ab showed synergistic effects. cMet Ab can successfully prevent fibrosis response in UIRI models of kidney fibrosis by decreasing inflammatory response and inhibiting the TGF-ß1/Smad pathway.


Assuntos
Injúria Renal Aguda/patologia , Insuficiência Renal Crônica/metabolismo , Proteína Smad7/metabolismo , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/metabolismo , Animais , Fibrose/patologia , Humanos , Rim/metabolismo , Camundongos Endogâmicos C57BL , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/patologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Fator de Crescimento Transformador beta/metabolismo
6.
J Immunol ; 203(4): 864-872, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31243090

RESUMO

Cyclooxygenase (COX)-1, one of the critical enzymes required for the conversion of arachidonic acid to PGs, has been demonstrated to play an important role not only in the cardiovascular system but also in the immune system. COX-1 has been found to regulate early B cell differentiation, germinal center formation, and Ab production of B cells. However, the underlying mechanisms of COX-1-mediated B cell activation remains not fully understood. In this study, we reported that COX-1 is a potential regulator for the development of follicular Th (TFH) cells. COX-1-deficient (COX-1-/- ) mice displayed a significant reduction of TFH cells upon influenza infection or immunization with keyhole limpet hemocyanin, which led to a severe impairment of germinal center responses. We further demonstrated that COX-1-derived PGE2, via binding with its receptors EP2/EP4, represents the underlying mechanism. The administration of EP2/EP4 agonists or PGE2 almost completely rescued the defective TFH cell generation in COX-1-/- mice. Taken together, our observations indicate that COX-1 plays an important role in the development of TFH cells.


Assuntos
Ciclo-Oxigenase 1/imunologia , Dinoprostona/imunologia , Ativação Linfocitária/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Diferenciação Celular/imunologia , Centro Germinativo/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T Auxiliares-Indutores/citologia
7.
J Recept Signal Transduct Res ; 40(6): 541-549, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32515250

RESUMO

Context: Curcumin has shown efficacy in promoting radiosensitivity combined with radiotherapy. However, the role and mechanism of curcumin on radiosensitivity in laryngeal squamous cell cancer (LSCC) is largely unknown.Objective: The aim of our study is to explore the role of IKKγ-NF-κB signaling in curcumin enhancing LSCC cell radiosensitivity in vitro.Materials and methods: Curcumin and X-ray were used to induce cell DNA damage and apoptosis, or inhibit cell clone formation. IKKγ siRNA and plasmid were used to change IKKγ expression. The CCK8 assay was used to detect cell viability. Clone formation ability was analyzed using a clonogenic assay, cell apoptosis was examined using flow cytometry, an immunofluorescence assay was used to detect DNA damage, while mRNA and protein levels were assayed using real time PCR and western blotting, respectively.Results: Curcumin significantly enhanced irradiation-induced DNA damage and apoptosis, while weakening clone-forming abilities of LSCC cell line Hep2 and Hep2-max. Compared to Hep2 cells, Hep2-max cells are more sensitive to curcumin post-irradiation. Curcumin suppressed irradiation-induced NF-κB activation by suppressing IKKγ expression, but not IKKα and IKKß. Overexpression of IKKγ decreased irradiation-induced DNA damage and apoptosis, while promoting clone-forming abilities of Hep2 and Hep2-max cells. IKKγ overexpression further increased expression of NF-κB downstream genes, Bcl-XL, Bcl-2, and cyclin D1. Conversely, IKKγ silencing enhanced irradiation-induced DNA damage and apoptosis, but promoted clone formation in Hep2 and Hep2-max cells. Additionally, IKKγ silencing inhibited expression of Bcl-XL, Bcl-2, and cyclin D1.Conclusions: Curcumin enhances LSCC radiosensitivity via NF-ΚB inhibition by suppressing IKKγ expression.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Curcumina/farmacologia , Quinase I-kappa B/antagonistas & inibidores , Neoplasias Laríngeas/radioterapia , NF-kappa B/antagonistas & inibidores , Tolerância a Radiação/efeitos dos fármacos , Radiossensibilizantes/farmacologia , Antineoplásicos/farmacologia , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Laríngeas/tratamento farmacológico , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/patologia , Fosforilação , Transdução de Sinais , Células Tumorais Cultivadas
8.
Rapid Commun Mass Spectrom ; 34(20): e8888, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32656937

RESUMO

RATIONALE: Succinylcholine has been increasingly used in the theft of animals. Because of the presence of residual levels of succinylcholine in poisoned animals, it is harmful for people to eat foods derived from these animals. Therefore, a method should be immediately established to determine succinylcholine and its metabolite in animal-derived foods. METHODS: A fast, highly sensitive method, combining solid-phase extraction (SPE) with ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC/ESI-MS/MS), was developed for the determination of succinylcholine and its metabolite in animal-derived foods. The sample was initially extracted with heptafluorobutyric acid and then further cleaned up using an SPE cartridge. Succinylcholine and its metabolite were separated using acetonitrile: 0.1% formic acid in 5 mmol L-1 ammonium acetate as the mobile phase. Quantitative results were based on positive ion ESI multiple reaction monitoring mode. RESULTS: The results show good linearity over a wide range with correlation coefficients of determination of more than 0.998. Both the limits of detection of succinylcholine and succinylmonocholine are 0.2 µg kg-1 . The intra- and inter-day accuracies of the method are in the range 91.4%-104.6%, and the intra- and inter-day precisions are in the range 2.5%-6.6%. CONCLUSIONS: This method can be used for the determination of succinylcholine as an illicit drug in animal-derived foods. It was successfully applied to the identification and quantification of succinylcholine and succinylmonocholine in animal-derived foods collected from a local farmers market in Jilin Province of China.


Assuntos
Cromatografia Líquida/métodos , Contaminação de Alimentos/análise , Extração em Fase Sólida/métodos , Succinilcolina/análise , Espectrometria de Massas em Tandem/métodos , Animais , Calibragem , Galinhas , China , Cães , Análise de Alimentos/métodos , Limite de Detecção , Produtos da Carne/análise , Reprodutibilidade dos Testes , Succinilcolina/análogos & derivados , Succinilcolina/metabolismo
9.
Biotechnol Lett ; 42(4): 583-595, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31980972

RESUMO

OBJECTIVE: The unique GH5 cellulase, AgCMCase, from Aspergillus glaucus CCHA was identified and characterized as having high cellulose and straw hydrolysis activities that were thermostable, pH stable and salt-tolerant. Therefore, it is a potential straw-degradation enzyme that can release reducing sugars in industrial applications. To increase the efficiency of the AgCMCase' hydrolysis of straw to release simple sugars, response surface methodology (RSM) was introduced to optimize hydrolysis parameters such as pH, temperature, reaction time and enzyme dose. RESULTS: The enzyme showed only one major protein band from the fermentation broth by the Pichia pastoris GS115 expression. The crude enzyme (without purification) showed a satisfactory capability to hydrolyze CMC-Na after 4 days of production. Here, the crude AgCMCase also showed cellulose and straw hydrolysis capabilities as assessed by scanning electron microscopic and Fourier-transform infrared spectroscopic analyses. A high-performance liquid chromatographic analysis demonstrated that the degradation of corn and rice straw by crude AgCMCase mainly produced glucose and cellobiose. Temperature, reaction time and enzyme dose were the significant variables affecting corn and rice straw degradation. After the optimization of RSM, a model was proposed to predict 1.48% reducing sugar yield with the optimum temperature (51.45 °C) and reaction time (3.84 h) from the straw degradation. The reaction of crude AgCMCase and rice straw in the optimized condition resulted in reducing sugar production of 1.61% that agrees the prediction. CONCLUSION: Our findings suggest that the crude AgCMCase is suitable to be used in straw conversion.


Assuntos
Aspergillus/crescimento & desenvolvimento , Celulase/metabolismo , Oryza/química , Açúcares/metabolismo , Zea mays/química , Aspergillus/metabolismo , Celulase/química , Celulose/química , Estabilidade Enzimática , Fermentação , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Hidrólise , Termodinâmica
10.
J Mol Cell Cardiol ; 129: 144-153, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30797815

RESUMO

Ischemia postconditioning (PTC) can reduce myocardial ischemia/reperfusion injury. However, the effectiveness of PTC cardioprotection is reduced or lost in diabetes and the mechanisms are largely unclear. Hyperglycemia can induce overexpression of inducible nitric oxide synthesis (iNOS) in the myocardium of diabetic subjects. However, it is unknown whether or not iNOS especially its overexpression plays an important role in the loss of cardioprotection of PTC in diabetes. C57BL6 and iNOS-/- mice were treated with streptozotocin to induce diabetes. Part of diabetic C57BL6 mice were also treated with an iNOS specific inhibitor, 1400 W. Mice were subjected to myocardial ischemia/ reperfusion with/without PTC. The hemodynamic parameters, plasma levels of cardiac troponin T (cTnT), TNF-α, IL-6 and nitric oxide (NO) were monitored. The myocardial infarct size, superoxide anion (O2-) generation, nitrotyrosine production and apoptosis were measured. The expression of phosphorylated Akt, endothelial NOS (eNOS), iNOS and Erk1/2 in ischemic heart were detected by immunoblot analysis. In diabetic C57BL6 and iNOS-/- mice, the post-ischemic hemodynamics were impaired, the cTnT, TNF-α, IL-6 level, myocardial infarct size, apoptotic index, O2- and nitrotyrosine generation were increased and the Akt/eNOS signal pathways were inhibited. PTC improved hemodynamic parameters, reduced cTnT level, myocardial infarct size, apoptotic index, O2- and nitrotyrosine generation and activated Akt/eNOS and Erk1/2 signal pathways in both non-diabetic C57BL6 and iNOS-/- mice as well as diabetic iNOS-/- mice, but not in diabetic C57BL6 mice. PTC also increased NO production in both non-diabetic and diabetic C57BL6 and iNOS-/- mice, and enhanced iNOS expression in non-diabetic C57BL6 mice. 1400 W restored the cardioprotection of PTC in diabetic C57BL6 mice. Our data demonstrated that PTC reduced myocardial ischemia/reperfusion injury in non-diabetic mice but not C57BL6 diabetic mice. Deletion of iNOS restored the cardioprotection of PTC in diabetic mice. Our findings suggest that iNOS plays a key role in the reduction of cardioprotection of PTC in diabetes and may provide a therapeutic target for diabetic patients.


Assuntos
Diabetes Mellitus Experimental/enzimologia , Pós-Condicionamento Isquêmico , Miocárdio/enzimologia , Óxido Nítrico Sintase Tipo II/metabolismo , Animais , Apoptose , Glicemia/metabolismo , Peso Corporal , Citocinas/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Mediadores da Inflamação/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Óxido Nítrico/metabolismo , Superóxidos/metabolismo , Troponina T/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismo , Função Ventricular
11.
J Immunol ; 198(3): 1047-1055, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28011932

RESUMO

In the RV144 gp120 HIV vaccine trial, decreased transmission risk was correlated with Abs that reacted with a linear epitope at a lysine residue at position 169 (K169) in the HIV-1 envelope (Env) V2 region. The K169 V2 response was restricted to Abs bearing Vλ rearrangements that expressed aspartic acid/glutamic acid in CDR L2. The AE.A244 gp120 in AIDSVAX B/E also bound to the unmutated ancestor of a V2-glycan broadly neutralizing Ab, but this Ab type was not induced in the RV144 trial. In this study, we sought to determine whether immunodominance of the V2 linear epitope could be overcome in the absence of human Vλ rearrangements. We immunized IgH- and Igκ-humanized mice with the AE.A244 gp120 Env. In these mice, the V2 Ab response was focused on a linear epitope that did not include K169. V2 Abs were isolated that used the same human VH gene segment as an RV144 V2 Ab but paired with a mouse λ L chain. Structural characterization of one of these V2 Abs revealed how the linear V2 epitope could be engaged, despite the lack of aspartic acid/glutamic acid encoded in the mouse repertoire. Thus, despite the absence of the human Vλ locus in these humanized mice, the dominance of Vλ pairing with human VH for HIV-1 Env V2 recognition resulted in human VH pairing with mouse λ L chains instead of allowing otherwise subdominant V2-glycan broadly neutralizing Abs to develop.


Assuntos
Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Vacinas contra a AIDS/imunologia , Motivos de Aminoácidos , Animais , Anticorpos Neutralizantes/imunologia , Epitopos , Humanos , Cadeias Pesadas de Imunoglobulinas/imunologia , Cadeias lambda de Imunoglobulina/imunologia , Camundongos
12.
Nature ; 496(7446): 469-76, 2013 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-23552890

RESUMO

Current human immunodeficiency virus-1 (HIV-1) vaccines elicit strain-specific neutralizing antibodies. However, cross-reactive neutralizing antibodies arise in approximately 20% of HIV-1-infected individuals, and details of their generation could provide a blueprint for effective vaccination. Here we report the isolation, evolution and structure of a broadly neutralizing antibody from an African donor followed from the time of infection. The mature antibody, CH103, neutralized approximately 55% of HIV-1 isolates, and its co-crystal structure with the HIV-1 envelope protein gp120 revealed a new loop-based mechanism of CD4-binding-site recognition. Virus and antibody gene sequencing revealed concomitant virus evolution and antibody maturation. Notably, the unmutated common ancestor of the CH103 lineage avidly bound the transmitted/founder HIV-1 envelope glycoprotein, and evolution of antibody neutralization breadth was preceded by extensive viral diversification in and near the CH103 epitope. These data determine the viral and antibody evolution leading to induction of a lineage of HIV-1 broadly neutralizing antibodies, and provide insights into strategies to elicit similar antibodies by vaccination.


Assuntos
Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Evolução Molecular , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/imunologia , HIV-1/química , HIV-1/imunologia , Vacinas contra a AIDS/imunologia , África , Sequência de Aminoácidos , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/genética , Antígenos CD4/química , Antígenos CD4/imunologia , Linhagem da Célula , Células Cultivadas , Células Clonais/citologia , Reações Cruzadas/imunologia , Cristalografia por Raios X , Epitopos/química , Epitopos/imunologia , Anticorpos Anti-HIV/genética , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/classificação , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Testes de Neutralização , Filogenia , Estrutura Terciária de Proteína
13.
J Cardiovasc Pharmacol ; 72(4): 176-185, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29985281

RESUMO

Simvastatin treatment is cardioprotective in patients undergoing noncoronary artery cardiac surgery. However, the mechanisms by which simvastatin treatment protects the myocardium under these conditions are not fully understood. Seventy patients undergoing noncoronary cardiac surgery, 35 from a simvastatin treatment group and 35 from a control treatment group, were enrolled in our clinical study. Simvastatin (20 mg/d) was administered preoperatively for 5-7 days. Myocardial tissue biopsies were taken before and after surgery. Apoptosis was detected by TUNEL staining. The expressions of Bcl-2 and Bak in myocardial tissue were detected by immunoblotting. The expressions of miRNA and Bcl-2 mRNA were detected by quantitative real-time polymerase chain reaction assays. Cardiomyocytes were isolated from rat and cultured cells. MiR-15a-5p mimic was transfected into cardiomyocytes, and the Bcl-2 was detected by immunoblotting. TUNEL staining showed significantly less myocardial apoptosis in the simvastatin treatment group when compared with the control treatment group. Protein expression of Bcl-2 was increased in the simvastatin treatment group before surgery, and Bak expression was increased in the control treatment group after surgery. Further comparisons showed that Bcl-2/Bak ratios were reduced in the control treatment group but were not significantly changed in the simvastatin treatment group after surgery. Furthermore, microarray assays revealed that miR-15a-5p was significantly decreased by simvastatin treatment. This was validated by quantitative real-time polymerase chain reaction analysis. MiR-15a-5p was predicted to target Bcl-2 mRNA at nucleotide positions 2529-2536. This was validated by luciferase binding assays. Coincident with the change in miR-15a-5p, the mRNA expression of Bcl-2 was increased in the simvastatin treatment group. MiR-15a-5p mimic significantly inhibited Bcl-2 expression in cardiomyocytes. Our findings strongly suggest that simvastatin treatment preoperatively protected the myocardium in patients undergoing noncoronary artery cardiac surgery, at least in part, by inhibiting apoptosis via suppressing miR-15a-5p expression, leading to increasing expression of Bcl-2 and decreasing expression of Bak.


Assuntos
Apoptose/efeitos dos fármacos , Procedimentos Cirúrgicos Eletivos/efeitos adversos , Cardiopatias/prevenção & controle , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , MicroRNAs/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Sinvastatina/administração & dosagem , Adulto , Animais , Células Cultivadas , China , Esquema de Medicação , Feminino , Cardiopatias/genética , Cardiopatias/metabolismo , Cardiopatias/patologia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Sinvastatina/efeitos adversos , Resultado do Tratamento , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo
14.
J Mol Cell Cardiol ; 112: 40-48, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28870504

RESUMO

Endothelial dysfunction is an early stage of atherosclerosis. We recently have shown that 25-hydroxycholesterol found in atherosclerotic lesions could impair endothelial function and vasodilation by uncoupling and inhibiting endothelial nitric oxide synthase (eNOS). 1-Palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC), the oxidation product of oxidized low-density lipoprotein, is another proinflammatory lipid and has also been found in atherosclerotic lesions. However, whether POVPC promotes atherosclerosis like 25-hydroxycholesterol remains unclear. The purpose of this study was to explore the effects of POVPC on endothelial function and vasodilation. Human umbilical vein endothelial cells (HUVECs) were incubated with POVPC. Endothelial cell proliferation, migration and tube formation were measured. Nitric oxide (NO) production and superoxide anion generation (O2-) were determined. The expression and phosphorylation of endothelial nitric oxide synthase (eNOS), AKT, PKC-ßII and P70S6K as well as the association of eNOS and heat shock protein 90 (HSP90) were detected by immunoblotting and immunoprecipitation. Endothelial cell apoptosis was monitored by TUNEL staining. The expression of Bcl-2, Bax, and Cleaved Caspase 3 were detected by immunoblotting. Finally, aortic ring from C57BL6 mice were isolated and treated with POVPC and the endothelium-dependent vasodilation was evaluated. POVPC significantly inhibited HUVECs proliferation, migration, tube formation, decreased NO production but increased O2- generation. POVPC inhibited the phosphorylation of Akt and eNOS at Ser1177, increased activation of PKC-ßII, P70S6K and the phosphorylation of eNOS at Thr495, reduced the association of HSP90 with eNOS. Meanwhile, POVPC induced endothelial cell apoptosis by inhibiting Bcl-2 expression, increasing Bax and cleaved caspase-3 expressions as well as caspase-3 activity and impaired endothelium-dependent vasodilation. These data demonstrated that POVPC impaired endothelial function by uncoupling and inhibiting eNOS as well as by inducing endothelial cell apoptosis. Therefore, POVPC may play an important role in the development of atherosclerosis and may be considered as a potential therapeutic target for atherosclerosis.


Assuntos
Células Endoteliais da Veia Umbilical Humana/patologia , Óxido Nítrico Sintase Tipo III/metabolismo , Éteres Fosfolipídicos/farmacologia , Vasodilatação/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Neovascularização Fisiológica/efeitos dos fármacos , Óxido Nítrico/metabolismo , Oxirredução , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Quinase C beta/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Superóxidos/metabolismo
15.
J Biol Chem ; 291(41): 21771-21785, 2016 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-27573240

RESUMO

Glucocorticoids (GCs) used as inflammation suppressors have harmful side effects, including induction of hepatic steatosis. The underlying mechanisms of GC-promoted dysregulation of lipid metabolism, however, are not fully understood. GCs could facilitate the accumulation of myeloid-derived suppressor cells (MDSC) in the liver of animals, and the potential role of MDSCs in GC-induced hepatic steatosis was therefore investigated in this study. We demonstrated that granulocytic (G)-MDSC accumulation mediated the effects of GCs on the fatty liver, in which activating transcription factor 3 (ATF3)/S100A9 signaling plays an important role. ATF3-deficient mice developed hepatic steatosis and displayed expansion of G-MDSCs in the liver and multiple immune organs, which shared high similarity with the phenotype observed in GC-treated wild-type littermates. Adoptive transfer of GC-induced or ATF3-deficient G-MDSCs promoted lipid accumulation in the liver, whereas depletion of G-MDSCs alleviated these effects. Mechanistic studies showed that in MDSCs, ATF3 was transrepressed by the GC receptor GR through direct binding to the negative GR-response element. S100A9 is the major transcriptional target of ATF3 in G-MDSCs. Silencing S100A9 clearly alleviated G-MDSCs expansion and hepatic steatosis caused by ATF3 deficiency or GC treatment. Our study uncovers an important role of G-MDSCs in GC-induced hepatic steatosis, in which ATF3 may have potential therapeutic implications.


Assuntos
Fator 3 Ativador da Transcrição/metabolismo , Calgranulina B/metabolismo , Fígado Gorduroso/metabolismo , Glucocorticoides/metabolismo , Granulócitos/metabolismo , Transdução de Sinais , Fator 3 Ativador da Transcrição/genética , Animais , Calgranulina B/genética , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Inativação Gênica , Granulócitos/patologia , Camundongos , Camundongos Knockout
16.
Biochem Biophys Res Commun ; 487(3): 552-559, 2017 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-28427943

RESUMO

Increased evidence has showed that normal high density lipoprotein (HDL) could convert to dysfunctional HDL in diseases states including coronary artery disease (CAD), which regulated vascular endothelial cell function differently. Long non-coding RNAs (lncRNAs) play an extensive role in various important biological processes including endothelial cell function. However, whether lncRNAs are involved in the regulation of HDL metabolism and HDL-induced changes of vascular endothelial function remains unclear. Cultured human umbilical vein endothelial cells (HUVECs) were treated with HDL from healthy subjects and patients with CAD and hypercholesterolemia for 24 h, then the cells were collected for lncRNA-Seq and the expressions of lncRNAs, genes and mRNAs were identified. The bioinformatic analysis was used to evaluate the relationship among lncRNAs, encoding genes and miRNAs. HDL from healthy subjects and patients with CAD and hypercholesterolemia leaded to different expressions of lncRNAs, genes and mRNAs, and further analysis suggested that the differentially expressed lncRNAs played an important role in the regulation of vascular endothelial function. Thus, HDL from patients with CAD and hypercholesterolemia could cause abnormal expression of lncRNAs in vascular endothelial cells to affect vascular function.


Assuntos
Doença da Artéria Coronariana/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Lipoproteínas HDL/metabolismo , RNA Longo não Codificante/genética , Células Cultivadas , Feminino , Humanos , Lipoproteínas HDL/administração & dosagem , Masculino , Pessoa de Meia-Idade , RNA Longo não Codificante/metabolismo
17.
Small ; 13(35)2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28639331

RESUMO

The lack of stable and efficient techniques to synthesize high-quality large-area thin films is one of the major bottlenecks for the real-world application of the 2D transition metal dichalcogenides. In this work, the growth of molybdenum disulfide (MoS2 ) on sapphire substrates by sulfurizing the MoO3 film deposited by atomic layer deposition (ALD) is reported. The advantages of the ALD method can be well inherited, and the synthesized MoS2 films exhibit excellent layer controllability, wafer-scale uniformity, and homogeneity. MoS2 films with desired thickness can be obtained by varying MoO3 ALD cycles. The atomic force microscope and Raman measurements demonstrate that the ALD-based MoS2 has good uniformity. Clear Raman shift as a function of the film thickness is observed. Field-effect transistor devices are fabricated through a transfer-free and top-down process. High On/Off current ratio (≈104 ) and medium-level electron mobilities (≈0.76 cm2 V-1 s-1 for monolayer, and 5.9 cm2 V-1 s-1 for four-layer) are obtained. The work opens up an attractive approach to realize the application of wafer-scale 2D materials in integrated circuits and systems.

18.
PLoS Pathog ; 11(8): e1005042, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26237403

RESUMO

HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4+ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant region of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Thus, some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Imunofluorescência , HIV-1/imunologia , Humanos , Mucosa Intestinal/virologia , Macaca mulatta , Conformação Proteica , Reto , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ressonância de Plasmônio de Superfície , Proteínas do Envelope Viral/química
19.
Sheng Li Xue Bao ; 68(4): 547-56, 2016 Aug 25.
Artigo em Zh | MEDLINE | ID: mdl-27546514

RESUMO

Estrogen is one of the steroid hormones. Besides the genomic action mediated by its intracellular receptor on target cells, there is now increasing body of evidence indicating that estrogen also has non-genomic action. For the non-genomic action, estrogen binds to its receptor on cell membrane, subsequently rapidly activates various intracellular signaling pathways, such as PLC/Ca(2+), ERK/MAPK, cAMP-PKA, PI3K-AKT-NOS, and finally induces biological effects. The non-genomic effects of estrogen on physiologic and pathologic processes have been found in many tissues within the reproductive, nervous and cardiovascular systems and bone etc. In reproductive system, it has been demonstrated that estrogen plays important roles in follicle development, fertilization and embryo implantation, and it is involved in the genesis and development of genital tract tumors and breast cancer. In this review, we focus on the general characteristics of non-genomic action of estrogen, its main nonnuclear signaling pathways and physiological and pathological significance, especially its influences in female reproductive functions.


Assuntos
Reprodução , Neoplasias da Mama , Estrogênios , Feminino , Humanos , Fosfatidilinositol 3-Quinases , Transdução de Sinais
20.
J Virol ; 88(6): 3329-39, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24390332

RESUMO

UNLABELLED: The development of a vaccine that can induce high titers of functional antibodies against HIV-1 remains a high priority. We have developed an adjuvant based on an oil-in-water emulsion that incorporates Toll-like receptor (TLR) ligands to test whether triggering multiple pathogen-associated molecular pattern receptors could enhance immunogenicity. Compared to single TLR agonists or other pairwise combinations, TLR7/8 and TLR9 agonists combined were able to elicit the highest titers of binding, neutralizing, and antibody-dependent cellular cytotoxicity-mediating antibodies against the protein immunogen, transmitted/founder HIV-1 envelope gp140 (B.63521). We further found that the combination of TLR7/8 and TLR9 agonists was associated with the release of CXCL10 (IP-10), suggesting that this adjuvant formulation may have optimally stimulated innate and adaptive immunity to elicit high titers of antibodies. IMPORTANCE: Combining TLR agonists in an adjuvant formulation resulted in higher antibody levels compared to an adjuvant without TLR agonists. Adjuvants that combine TLR agonists may be useful for enhancing antibody responses to HIV-1 vaccines.


Assuntos
Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistas , Receptor Toll-Like 9/agonistas , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Feminino , Infecções por HIV/virologia , HIV-1/genética , Humanos , Imunização , Ligantes , Macaca mulatta , Masculino , Receptor 7 Toll-Like/imunologia , Receptor 8 Toll-Like/imunologia , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/administração & dosagem , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA