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1.
BMC Psychiatry ; 24(1): 439, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38867159

RESUMO

BACKGROUND: To analyze the economic benefits of paliperidone palmitate in the treatment of schizophrenia. METHODS: We collected 546 patients who met the diagnostic criteria for schizophrenia according to the 《International Statistical Classification of Diseases and Related Health Problems,10th》(ICD-10). We gathered general population data such as gender, age, marital status, and education level, then initiated treatment with paliperidone palmitate. Then Follow-up evaluations were conducted at 1, 3, 6, 9, and 12 months after the start of treatment to assess clinical efficacy, adverse reactions, and injection doses. We also collected information on the economic burden before and after 12 months of treatment, as well as the number of outpatient visits and hospitalizations in the past year to analyze economic benefits. RESULTS: The baseline patients totaled 546, with 239 still receiving treatment with paliperidone palmitate 12 months later. After 12 months of treatment, the number of outpatient visits per year increased compared to before (4 (2,10) vs. 12 (4,12), Z=-5.949, P < 0.001), while the number of hospitalizations decreased (1 (1,3) vs. 1 (1,2), Z = 5.625, P < 0.001). The inpatient costs in the direct medical expenses of patients after 12 months of treatment decreased compared to before (5000(2000,12000) vs. 3000 (1000,8050), P < 0.05), while there was no significant change in outpatient expenses and direct non-medical expenses (transportation, accommodation, meal, and family accompanying expenses, etc.) (P > 0.05); the indirect costs of patients after 12 months of treatment (lost productivity costs for patients and families, economic costs due to destructive behavior, costs of seeking non-medical assistance) decreased compared to before (300(150,600) vs. 150(100,200), P < 0.05). CONCLUSION: Palmatine palmitate reduces the number of hospitalizations for patients, as well as their direct and indirect economic burdens, and has good economic benefits.


Assuntos
Antipsicóticos , Palmitato de Paliperidona , Esquizofrenia , Humanos , Palmitato de Paliperidona/uso terapêutico , Palmitato de Paliperidona/economia , Palmitato de Paliperidona/administração & dosagem , Esquizofrenia/tratamento farmacológico , Esquizofrenia/economia , Masculino , Feminino , Antipsicóticos/economia , Antipsicóticos/uso terapêutico , Adulto , Pessoa de Meia-Idade , Hospitalização/economia , Hospitalização/estatística & dados numéricos , Estudos de Coortes , Efeitos Psicossociais da Doença , Resultado do Tratamento
2.
Nucleic Acids Res ; 51(10): 4774-4790, 2023 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-36929421

RESUMO

Normal erythropoiesis requires the precise regulation of gene expression patterns, and transcription cofactors play a vital role in this process. Deregulation of cofactors has emerged as a key mechanism contributing to erythroid disorders. Through gene expression profiling, we found HES6 as an abundant cofactor expressed at gene level during human erythropoiesis. HES6 physically interacted with GATA1 and influenced the interaction of GATA1 with FOG1. Knockdown of HES6 impaired human erythropoiesis by decreasing GATA1 expression. Chromatin immunoprecipitation and RNA sequencing revealed a rich set of HES6- and GATA1-co-regulated genes involved in erythroid-related pathways. We also discovered a positive feedback loop composed of HES6, GATA1 and STAT1 in the regulation of erythropoiesis. Notably, erythropoietin (EPO) stimulation led to up-regulation of these loop components. Increased expression levels of loop components were observed in CD34+ cells of polycythemia vera patients. Interference by either HES6 knockdown or inhibition of STAT1 activity suppressed proliferation of erythroid cells with the JAK2V617F mutation. We further explored the impact of HES6 on polycythemia vera phenotypes in mice. The identification of the HES6-GATA1 regulatory loop and its regulation by EPO provides novel insights into human erythropoiesis regulated by EPO/EPOR and a potential therapeutic target for the management of polycythemia vera.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Eritropoese , Fator de Transcrição GATA1 , Proteínas Repressoras , Animais , Humanos , Camundongos , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Células Eritroides/metabolismo , Fator de Transcrição GATA1/metabolismo , Perfilação da Expressão Gênica , Policitemia Vera/genética , Policitemia Vera/metabolismo , Proteínas Repressoras/metabolismo
3.
Br J Haematol ; 199(3): 427-442, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35974424

RESUMO

Normal early erythropoiesis depends on the precise regulation of protein expression and phosphorylation modification. Dysregulation of protein levels or modification contributes to erythroid disorders. To date, the dynamics of protein phosphorylation profiling across human erythroid development is not fully understood. Here, we characterized quantitative proteomic and phosphoproteomic profiling by tandem mass-tagging technology. We systemically built phospho-expression profiling and expression clusters of 11 414 phosphopeptides for human early erythropoiesis. The standardization methods for multitier integrative analyses revealed multiple functional modules of phosphoproteins (e.g., regulation of the G2/M transition) and active phosphorylated signalling (e.g., cell cycle-related pathways). Our further analysis revealed that CDK family members were the main kinases that phosphorylate substrates in erythroid progenitors and identified that CDK9 played an important role in the proliferation of erythroid progenitors. Collectively, our phosphoproteomic profiling, integrative network analysis and functional studies define landscapes of the phosphoproteome and reveal signalling pathways that are involved in human early erythropoiesis. This study will serve as a valuable resource for further investigations of phosphatase and kinase functions in human erythropoiesis and erythroid-related diseases.


Assuntos
Eritropoese , Proteômica , Humanos , Eritropoese/genética , Fosfopeptídeos , Fosfoproteínas/genética , Monoéster Fosfórico Hidrolases
4.
J Phys Chem B ; 125(24): 6451-6478, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34115515

RESUMO

An accurate account of disordered protein conformations is of central importance to deciphering the physicochemical basis of biological functions of intrinsically disordered proteins and the folding-unfolding energetics of globular proteins. Physically, disordered ensembles of nonhomopolymeric polypeptides are expected to be heterogeneous, i.e., they should differ from those homogeneous ensembles of homopolymers that harbor an essentially unique relationship between average values of end-to-end distance REE and radius of gyration Rg. It was posited recently, however, that small-angle X-ray scattering (SAXS) data on conformational dimensions of disordered proteins can be rationalized almost exclusively by homopolymer ensembles. Assessing this perspective, chain-model simulations are used to evaluate the discriminatory power of SAXS-determined molecular form factors (MFFs) with regard to homogeneous versus heterogeneous ensembles. The general approach adopted here is not bound by any assumption about ensemble encodability, in that the postulated heterogeneous ensembles we evaluated are not restricted to those entailed by simple interaction schemes. Our analysis of MFFs for certain heterogeneous ensembles with more narrowly distributed REE and Rg indicates that while they deviate from MFFs of homogeneous ensembles, the differences can be rather small. Remarkably, some heterogeneous ensembles with asphericity and REE drastically different from those of homogeneous ensembles can nonetheless exhibit practically identical MFFs, demonstrating that SAXS MFFs do not afford unique characterizations of basic properties of conformational ensembles in general. In other words, the ensemble to MFF mapping is practically many-to-one and likely nonsmooth. Heteropolymeric variations of the REE-Rg relationship were further showcased using an analytical perturbation theory developed here for flexible heteropolymers. Ramifications of our findings for interpretation of experimental data are discussed.


Assuntos
Proteínas Intrinsicamente Desordenadas , Conformação Proteica , Espalhamento a Baixo Ângulo , Difração de Raios X , Raios X
5.
J Cell Mol Med ; 25(3): 1507-1517, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33369124

RESUMO

Ubiquitin-specific protease 11 (USP11) has been implicated in the regulation of DNA repair, apoptosis, signal transduction and cell cycle. It belongs to a USP subfamily of deubiquitinases. Although previous research has shown that USP11 overexpression is frequently found in melanoma and is correlated with a poor prognosis, the potential molecular mechanism of USP11 in melanoma remains indefinitive. Here, we report that USP11 and NONO colocalize and interact with each other in the nucleus of melanoma cells. As a result, the knockdown of USP11 decreases NONO levels. Whereas, overexpression of USP11 increases NONO levels in a dose-dependent manner. Furthermore, we reveal that USP11 protects NONO protein from proteasome-mediated degradation by removing poly-ubiquitin chains conjugated onto NONO. Functionally, USP11 mediated melanoma cell proliferation via the regulation of NONO levels because ablation of USP11 inhibits the proliferation which could be rescued by ectopic expression of NONO protein. Moreover, a significant positive correlation between USP11 and NONO concentrations was found in clinical melanoma samples. Collectively, these results demonstrate that USP11 is a new deubiquitinase of NONO and that the signalling axis of USP11-NONO is significantly involved in melanoma proliferation.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Melanoma/metabolismo , Proteínas de Ligação a RNA/metabolismo , Tioléster Hidrolases/metabolismo , Animais , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Melanoma/genética , Melanoma/patologia , Camundongos , Complexo de Endopeptidases do Proteassoma/metabolismo , Interferência de RNA , Tioléster Hidrolases/genética , Ubiquitinação
6.
Front Pharmacol ; 11: 339, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32265711

RESUMO

Ulcerative colitis (UC) is an idiopathic inflammatory bowel disease (IBD) that causes long-lasting inflammation and ulcers in the innermost lining of the colon and rectum. Previous studies demonstrated that resveratrol suppresses colitis and colon cancer associated with colitis by improving glucose metabolism, but resveratrol use is limited by its low oral bioavailability. Combretastatin-A4 phosphate (CA4P) is a vascular-disrupting agent with antitumor activity. CA4P is structurally similar to resveratrol, but whether CA4P has the same effect as resveratrol on UC is not clear. In this study, we examined the pharmacological effects of CA4P administration on dextran sulfate sodium (DSS)-induced inflammation in a mouse model of UC. C57BL/6 mice were administered 2.5% DSS in the drinking water to induce acute UC. CA4P (11 mg/kg/d) was injected intraperitoneally daily. The Disease Activity Index (DAI) score and histological score were evaluated to determine the severity of UC. Colon tissues and blood samples were collected for histological analyses. The results show that CA4P plus DSS significantly decreased colon length (P < 0.05 versus DSS+PBS group) and body weight (P < 0.001 versus PBS group), while increased spleen weight (P < 0.01 versus DSS+PBS group), DAI score (P < 0.01 versus DSS+PBS group), and histological score (P < 0.01 versus DSS+PBS group). Moreover, CA4P exacerbated the pathological features of colitis and significantly increased proinflammatory cytokines (IL-1ß, IL-6, TNF-α) and inflammatory cells (neutrophil, lymphocyte, monocyte). These findings reveal that CA4P aggravates the symptoms of DSS-induced UC and provide a key reference for the potential of CA4P as an anticancer drug.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32028710

RESUMO

Periphyton is an effective matrix for the removal of pollutants in wastewater and has been considered a promising method of bioremediation. However, it still needs to be verified whether periphyton can maintain microbial activity and pollutant removal efficiency when dealing with the influence with complex components, and the underlying mechanisms of periphyton need to be revealed further. Herein, this study investigated the microbial growth, activity and functional responses of periphyton after removal of Cu from wastewater. Results showed that the cultivated periphyton was dominated by filamentous algae, and high Cu removal efficiencies by periphyton were obtained after 108 h treatments. Although 2 mg/L Cu2+ changed the microalgal growth (decreasing the contents of total chlorophyll-a (Chla), the carbon source utilization and microbial metabolic activity in periphyton were not significantly affected and even increased by 2 mg/L Cu2+. Moreover, chemical oxygen demand (COD) removal rates were sustained after 0.5 and 2 mg/L Cu2+ treatments. Our work showed that periphyton had strong tolerance and resistance on Cu stress and is environmentally friendly in dealing with wastewater containing heavy metals, as the microbial functions in pollutant removal could be maintained.


Assuntos
Biodegradação Ambiental , Cobre , Poluentes Ambientais , Metais Pesados , Perifíton , Poluentes Químicos da Água , Biodegradação Ambiental/efeitos dos fármacos , Cobre/toxicidade , Poluentes Ambientais/metabolismo , Metais Pesados/toxicidade , Perifíton/efeitos dos fármacos , Águas Residuárias/química , Águas Residuárias/microbiologia , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
8.
J Cell Mol Med ; 22(12): 5978-5990, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30353654

RESUMO

Hepatocyte growth factor (HGF)/c-met pathway activation has been implicated in the pathogenesis of multiple myeloma (MM), and blocking this pathway has been considered a rational therapeutic strategy for treating MM. Aptamers are single-stranded nucleic acid molecules that fold into complex 3D structures and bind to a variety of targets. Recently, it was reported that DNA aptamer SL1 exhibited high specificity and affinity for c-met and inhibited HGF/c-met signaling in SNU-5 cells. However, as the first c-met-targeted DNA aptamer to be identified, application of SL1 to myeloma treatment requires further investigation. Here, we explore the potential application of SL1 in MM. Our results indicated that c-met expression is gradually increased in MM patients and contributes to poor outcomes. SL1 selectively bound to c-met-positive MM cells but not to normal B cells and suppressed the growth, migration and adhesion of MM cells in vitro in a co-culture model performed with HS5 cells, wherein SL1 inhibited HGF-induced activation of c-met signaling. In vivo and ex vivo fluorescence imaging showed that SL1 accumulated in the c-met positive tumour areas. In addition, SL1 was active against CD138+ primary MM cells and displayed a synergistic inhibition effect with bortezomib. Collectively, our data suggested that SL1 could be beneficial as a c-met targeted antagonist in MM.


Assuntos
Aptâmeros de Nucleotídeos/uso terapêutico , Terapia de Alvo Molecular , Mieloma Múltiplo/tratamento farmacológico , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Aptâmeros de Nucleotídeos/farmacologia , Bortezomib/farmacologia , Bortezomib/uso terapêutico , Adesão Celular/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Fluorescência , Fator de Crescimento de Hepatócito/farmacologia , Humanos , Mieloma Múltiplo/patologia , Proteínas Proto-Oncogênicas c-met/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sindecana-1/metabolismo , Distribuição Tecidual/efeitos dos fármacos , Resultado do Tratamento
9.
ACS Appl Mater Interfaces ; 10(1): 53-58, 2018 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-29260842

RESUMO

We explored the interfacial synthesis of 2D N-graphdiyne films at the gas/liquid and liquid/liquid interfaces. Triazine- or pyrazine-based monomers containing ethynyl group were polymerized through the Glaser coupling reactions at interfaces. Several layered, highly ordered and conjugated 2D N-graphdiyne were obtained. Their structures were characterized by TEM, SEM, AFM, XPS, and Raman spectra. Thin films with minimum thickness of 4 nm could be prepared.

10.
Biophys J ; 113(5): 1012-1024, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28877485

RESUMO

A mathematico-physically valid formulation is required to infer properties of disordered protein conformations from single-molecule Förster resonance energy transfer (smFRET). Conformational dimensions inferred by conventional approaches that presume a homogeneous conformational ensemble can be unphysical. When all possible-heterogeneous as well as homogeneous-conformational distributions are taken into account without prejudgment, a single value of average transfer efficiency 〈E〉 between dyes at two chain ends is generally consistent with highly diverse, multiple values of the average radius of gyration 〈Rg〉. Here we utilize unbiased conformational statistics from a coarse-grained explicit-chain model to establish a general logical framework to quantify this fundamental ambiguity in smFRET inference. As an application, we address the long-standing controversy regarding the denaturant dependence of 〈Rg〉 of unfolded proteins, focusing on Protein L as an example. Conventional smFRET inference concluded that 〈Rg〉 of unfolded Protein L is highly sensitive to [GuHCl], but data from SAXS suggested a near-constant 〈Rg〉 irrespective of [GuHCl]. Strikingly, our analysis indicates that although the reported 〈E〉 values for Protein L at [GuHCl] = 1 and 7 M are very different at 0.75 and 0.45, respectively, the Bayesian Rg2 distributions consistent with these two 〈E〉 values overlap by as much as 75%. Our findings suggest, in general, that the smFRET-SAXS discrepancy regarding unfolded protein dimensions likely arise from highly heterogeneous conformational ensembles at low or zero denaturant, and that additional experimental probes are needed to ascertain the nature of this heterogeneity.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Modelos Teóricos , Conformação Proteica , Desdobramento de Proteína , Algoritmos , Método de Monte Carlo , Espalhamento a Baixo Ângulo , Difração de Raios X
11.
Nat Commun ; 8: 13943, 2017 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-28045046

RESUMO

The ubiquitin ligase SCFCdc4 mediates phosphorylation-dependent elimination of numerous substrates by binding one or more Cdc4 phosphodegrons (CPDs). Methyl-based NMR analysis of the Cdc4 WD40 domain demonstrates that Cyclin E, Sic1 and Ash1 degrons have variable effects on the primary Cdc4WD40 binding pocket. Unexpectedly, a Sic1-derived multi-CPD substrate (pSic1) perturbs methyls around a previously documented allosteric binding site for the chemical inhibitor SCF-I2. NMR cross-saturation experiments confirm direct contact between pSic1 and the allosteric pocket. Phosphopeptide affinity measurements reveal negative allosteric communication between the primary CPD and allosteric pockets. Mathematical modelling indicates that the allosteric pocket may enhance ultrasensitivity by tethering pSic1 to Cdc4. These results suggest negative allosteric interaction between two distinct binding pockets on the Cdc4WD40 domain may facilitate dynamic exchange of multiple CPD sites to confer ultrasensitive dependence on substrate phosphorylation.


Assuntos
Ciclina E/química , Proteínas Inibidoras de Quinase Dependente de Ciclina/química , Regulação Fúngica da Expressão Gênica , Proteínas Repressoras/química , Proteínas Ligases SKP Culina F-Box/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Regulação Alostérica , Sítio Alostérico , Sítios de Ligação , Clonagem Molecular , Ciclina E/genética , Ciclina E/metabolismo , Proteínas Inibidoras de Quinase Dependente de Ciclina/genética , Proteínas Inibidoras de Quinase Dependente de Ciclina/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Cinética , Modelos Moleculares , Fosfopeptídeos , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteínas Ligases SKP Culina F-Box/genética , Proteínas Ligases SKP Culina F-Box/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Especificidade por Substrato , Termodinâmica
12.
Blood ; 129(2): 226-237, 2017 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-27879259

RESUMO

Terminal erythroid differentiation is tightly coordinated with cell-cycle exit, which is regulated by cyclins, cyclin-dependent kinases, and cyclin-dependent kinase inhibitors (CDKI), yet their roles in erythropoiesis remain to be fully defined. We show here that p19INK4d, a member of CDKI family, is abundantly expressed in erythroblasts and that p19INK4d knockdown delayed erythroid differentiation, inhibited cell growth, and led to increased apoptosis and generation of abnormally nucleated late-stage erythroblasts. Unexpectedly, p19INK4d knockdown did not affect cell cycle. Rather, it led to decreased expression of GATA1 protein. Importantly, the differentiation and nuclear defects were rescued by ectopic expression of GATA1. Because the GATA1 protein is protected by nuclear heat shock protein family (HSP) member HSP70, we examined the effects of p19INK4d knockdown on HSP70 and found that p19INK4d knockdown led to decreased expression of HSP70 and its nuclear localization. The reduced levels of HSP70 are the result of reduced extracellular signal-regulated kinase (ERK) activation. Further biochemical analysis revealed that p19INK4d directly binds to Raf kinase inhibitor PEBP1 and that p19INK4d knockdown increased the expression of PEBP1, which in turn led to reduced ERK activation. Thus we have identified an unexpected role for p19INK4d via a novel PEBP1-p-ERK-HSP70-GATA1 pathway. These findings are likely to have implications for improved understanding of disordered erythropoiesis.


Assuntos
Inibidor de Quinase Dependente de Ciclina p19/metabolismo , Eritropoese/fisiologia , Fator de Transcrição GATA1/metabolismo , Regulação da Expressão Gênica/fisiologia , Western Blotting , Células Cultivadas , Sangue Fetal , Citometria de Fluxo , Imunofluorescência , Técnicas de Silenciamento de Genes , Humanos , Imunoprecipitação , Reação em Cadeia da Polimerase , Transdução de Sinais/fisiologia
13.
ACS Appl Mater Interfaces ; 8(30): 19739-46, 2016 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-27410199

RESUMO

Most hydrogels involve synthetic polymers and organic cross-linkers that cannot simultaneously fulfill the mechanical and cell-compatibility requirements of biomedical applications. We prepared a new type of chitosan physical hydrogel with various degrees of deacetylation (DDs) via the heterogeneous deacetylation of nanoporous chitin hydrogels under mild conditions. The DD of the chitosan physical hydrogels ranged from 56 to 99%, and the hydrogels were transparent and mechanically strong because of the extra intra- and intermolecular hydrogen bonding interactions between the amino and hydroxyl groups on the nearby chitosan nanofibrils. The tensile strength and Young's modulus of the chitosan physical hydrogels were 3.6 and 7.9 MPa, respectively, for a DD of 56% and increased to 12.1 and 92.0 MPa for a DD of 99% in a swelling equilibrium state. In vitro studies demonstrated that mouse bone mesenchymal stem cells (mBMSCs) cultured on chitosan physical hydrogels had better adhesion and proliferation than those cultured on chitin hydrogels. In particular, the chitosan physical hydrogels promoted the differentiation of the mBMSCs into epidermal cells in vitro. These materials are promising candidates for applications such as stem cell research, cell therapy, and tissue engineering.


Assuntos
Materiais Biocompatíveis/química , Técnicas de Cultura de Células/métodos , Quitosana/química , Hidrogéis/química , Células-Tronco Mesenquimais/citologia , Animais , Células Cultivadas , Hidrogéis/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos
14.
Carbohydr Polym ; 148: 61-8, 2016 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-27185116

RESUMO

Yeast ß-glucan has many formulations with different chemical structures, water solubility and purity. In particular, the purity of ß-glucan in these formulations is variable and relatively low, contributing to different data on its biological activity. In this study, the major polysaccharide component in the crude Baker's yeast polysaccharides coded as BBG with high purity of 99% was obtained, and its chemical structure was determined to be a linear ß-(1,3)-glucan. It was found that BBG interacted with complement receptor 3 (CR3) and toll-like receptor 2 (TLR2) on the surface of macrophage-like RAW264.7 cells, and initiated activation of RAW264.7 cells characterized by significant production of tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1). Additionally, activation of the nuclear factor kappaB p65 (NF-κB p65), c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) induced by BBG, were also observed, further confirming the stimulation of RAW264.7 cells by BBG. All these findings provided important scientific evidences for better understanding the molecular mechanism of action for the linear ß-(1,3)-glucan in cells.


Assuntos
Macrófagos/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , beta-Glucanas/química , beta-Glucanas/farmacologia , Animais , Antígenos de Superfície/metabolismo , Macrófagos/enzimologia , Camundongos , Células RAW 264.7 , Saccharomyces cerevisiae/química , Fator de Necrose Tumoral alfa/metabolismo , beta-Glucanas/metabolismo
15.
Biophys J ; 110(7): 1510-1522, 2016 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-27074677

RESUMO

Conformational states of the metastable drkN SH3 domain were characterized using single-molecule fluorescence techniques. Under nondenaturing conditions, two Förster resonance energy transfer (FRET) populations were observed that corresponded to a folded and an unfolded state. FRET-estimated radii of gyration and hydrodynamic radii estimated by fluorescence correlation spectroscopy of the two coexisting conformations are in agreement with previous ensemble x-ray scattering and NMR measurements. Surprisingly, when exposed to high concentrations of urea and GdmCl denaturants, the protein still exhibits two distinct FRET populations. The dominant conformation is expanded, showing a low FRET efficiency, consistent with the expected behavior of a random chain with excluded volume. However, approximately one-third of the drkN SH3 conformations showed high, nearly 100%, FRET efficiency, which is shown to correspond to denaturation-induced looped conformations that remain stable on a timescale of at least 100 µs. These loops may contain interconverting conformations that are more globally collapsed, hairpin-like, or circular, giving rise to the observed heterogeneous broadening of this population. Although the underlying mechanism of chain looping remains elusive, FRET experiments in formamide and dimethyl sulfoxide suggest that interactions between hydrophobic groups in the distal regions may play a significant role in the formation of the looped state.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Modelos Moleculares , Polímeros/química , Domínios de Homologia de src , Animais , Drosophila melanogaster/enzimologia , Estabilidade Enzimática , Desnaturação Proteica/efeitos dos fármacos
16.
Mol Plant ; 9(5): 650-661, 2016 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-26961720

RESUMO

Abscisic acid (ABA) plays crucial roles in plant growth and development, as well as in response to various environmental stresses. To date, many regulatory genes involved in the ABA response network have been identified; however, their roles have remained to be fully elucidated. In this study, we identified AtYY1, an Arabidopsis homolog of the mammalian C2H2 zinc-finger transcription factor Yin Yang 1 (YY1), as a novel negative regulator of the ABA response. AtYY1 is a dual-function transcription factor with both repression and activation domains. The expression of AtYY1 was induced by ABA and stress conditions including high salt and dehydration. The yy1 mutant was more sensitive to ABA and NaCl than the wild-type, while overexpressing AtYY1 plants were less sensitive. AtYY1 loss also enhanced ABA-induced stomatal closing and drought resistance. Moreover, AtYY1 can bind the ABA REPRESSOR1 (ABR1) promoter and directly upregulate ABR1 expression, as well as negatively regulate ABA- and salt-responsive gene expression. Additional analysis indicated that ABA INSENSITIVE4 (ABI4) might positively regulate AtYY1 expression and that ABR1 can antagonize this regulation. Our findings provide direct evidence that AtYY1 is a novel negative regulator of the ABA response network and that the ABI4-AtYY1-ABR1 regulatory pathway may fine-tune ABA-responsive gene expression in Arabidopsis.


Assuntos
Ácido Abscísico/farmacologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Fatores de Transcrição/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Secas , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Cloreto de Sódio/farmacologia , Estresse Fisiológico , Fatores de Transcrição/genética , Fator de Transcrição YY1/genética , Fator de Transcrição YY1/metabolismo
17.
J Phys Chem B ; 119(49): 15191-202, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26566073

RESUMO

Single-molecule Förster resonance energy transfer (smFRET) is an important tool for studying disordered proteins. It is commonly utilized to infer structural properties of conformational ensembles by matching experimental average energy transfer ⟨E⟩exp with simulated ⟨E⟩sim computed from the distribution of end-to-end distances in polymer models. Toward delineating the physical basis of such interpretative approaches, we conduct extensive sampling of coarse-grained protein chains with excluded volume to determine the distribution of end-to-end distances conditioned upon given values of radius of gyration Rg and asphericity A. Accordingly, we infer the most probable Rg and A of a protein disordered state by seeking the best fit between ⟨E⟩exp and ⟨E⟩sim among various (Rg,A) subensembles. Application of our method to residues 1-90 of the intrinsically disordered cyclin-dependent kinase (Cdk) inhibitor Sic1 results in inferred ensembles with more compact conformations than those inferred by conventional procedures that presume either a Gaussian chain model or the mean-field Sanchez polymer theory. The Sic1 compactness we infer is in good agreement with small-angle X-ray scattering data for Rg and NMR measurement of hydrodynamic radius Rh. In contrast, owing to neglect or underappreciation of excluded volume, conventional procedures can significantly overestimate the probabilities of short end-to-end distances, leading to unphysically large smFRET-inferred Rg at high [GdmCl]. It follows that smFRET Sic1 data are incompatible with the presumed homogeneously expanded or contracted conformational ensembles in conventional procedures but are consistent with heterogeneous ensembles allowed by our subensemble method of inference. General ramifications of these findings for smFRET data interpretation are discussed.


Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Proteínas Intrinsicamente Desordenadas/química
18.
Oncotarget ; 6(40): 43033-47, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26543232

RESUMO

MicroRNAs (miRNAs), a class of small non-coding linear RNAs, have been shown to play a crucial role in erythropoiesis. To evaluate the indispensable role of constant suppression of miR-150 during terminal erythropoiesis, we performed miR-150 gain- and loss-of-function experiments on hemin-induced K562 cells and EPO-induced human CD34+ cells. We found that forced expression of miR-150 suppresses commitment of hemoglobinization and CD235a labeling in both cell types. Erythroid proliferation is also inhibited via inducing apoptosis and blocking the cell cycle when miR-150 is overexpressed. In contrast, miR-150 inhibition promotes terminal erythropoiesis. 4.1 R gene is a new target of miR-150 during terminal erythropoiesis, and its abundance ensures the mechanical stability and deformability of the membrane. However, knockdown of 4.1 R did not affect terminal erythropoiesis. Transcriptional profiling identified more molecules involved in terminal erythroid dysregulation derived from miR-150 overexpression. These results shed light on the role of miR-150 during human terminal erythropoiesis. This is the first report highlighting the relationship between miRNA and membrane protein and enhancing our understanding of how miRNA works in the hematopoietic system.


Assuntos
Diferenciação Celular/genética , Células Eritroides/citologia , Eritropoese/genética , MicroRNAs/genética , Western Blotting , Linhagem Celular , Citometria de Fluxo , Humanos , Células K562 , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , Transdução Genética
19.
Curr Opin Struct Biol ; 30: 32-42, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25544254

RESUMO

The diverse biological functions of intrinsically disordered proteins (IDPs) have markedly raised our appreciation of protein conformational versatility, whereas the existence of energetically favorable yet functional detrimental nonnative interactions underscores the physical limitations of evolutionary optimization. Here we survey recent advances in using biophysical modeling to gain insight into experimentally observed nonnative behaviors and IDP properties. Simulations of IDP interactions to date focus mostly on coupled folding-binding, which follows essentially the same organizing principle as the local-nonlocal coupling mechanism in cooperative folding of monomeric globular proteins. By contrast, more innovative theories of electrostatic and aromatic interactions are needed for the conceptually novel but less-explored 'fuzzy' complexes in which the functionally bound IDPs remain largely disordered.


Assuntos
Biofísica/métodos , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Substâncias Macromoleculares/metabolismo , Modelos Moleculares , Ligação Proteica , Dobramento de Proteína , Simulação de Dinâmica Molecular
20.
ACS Appl Mater Interfaces ; 6(10): 7204-13, 2014 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-24779576

RESUMO

Three-dimensionally nanoporous cellulose gels (NCG) were prepared by dissolution and coagulation of cellulose from aqueous alkali hydroxide-urea solution, and used to fabricate NCG/poly(ε-caprolactone) (PCL) nanocomposites by in situ ring-opening polymerization of ε-CL monomer in the NCG. The NCG content of the NCG/PCL nanocomposite could be controlled between 7 and 38% v/v by changing water content of starting hydrogel by compression dewatering. FT-IR and solid-state (13)C NMR showed that the grafting of PCL onto cellulose are most likely occurred at the C6-OH groups and the grafting percentage of PCL is 25 wt % for the nanocomposite with 7% v/v NCG. (1)H NMR, XRD, and DSC results indicate that the number-average molecular weight and crystal formation of PCL in the nanocomposites are remarkably restricted by the presence of NCG. AFM images confirm that the interconnected nanofibrillar cellulose network structure of NCG are finely distributed and preserved well in the PCL matrix after polymerization. DMA results show remarkable increase in tensile storage modulus of the nanocomposites above glass transition and melting temperatures of the PCL matrix. The percolation model was used to evaluate the mechanical properties of the nanocomposites, in which stress transfer among the interconnected nanofibrillar network is facilitated through strong intermolecular hydrogen bonding and entanglement of cellulose nanofibers.


Assuntos
Celulose/química , Géis/química , Nanocompostos/química , Poliésteres/química , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética , Microscopia de Força Atômica , Nanoporos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
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