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1.
Cell Death Dis ; 12(2): 202, 2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608512

RESUMO

Ring1b is a core subunit of polycomb repressive complex 1 (PRC1) and is essential in several high-risk cancers. However, the epigenetic mechanism of Ring1b underlying breast cancer malignancy is poorly understood. In this study, we showed increased expression of Ring1b promoted metastasis by weakening cell-cell adhesions of breast cancer cells. We confirmed that Ring1b could downregulate E-cadherin and contributed to an epigenetic rewiring via PRC1-dependent function by forming distinct complexes with DEAD-box RNA helicases (DDXs) or epithelial-mesenchymal transition transcription factors (EMT TFs) on site-specific loci of E-cadherin promoter. DDXs-Ring1b complexes moderately inhibited E-cadherin, which resulted in an early hybrid EMT state of epithelial cells, and EMT TFs-Ring1b complexes cooperated with DDXs-Ring1b complexes to further repress E-cadherin in mesenchymal-like cancer cells. Clinically, high expression of Ring1b with DDXs or EMT TFs predicted low levels of E-cadherin, metastatic behavior, and poor prognosis. These findings provide an epigenetic regulation mechanism of Ring1b complexes in E-cadherin expression. Ring1b complexes may be potential therapeutic targets and biomarkers for diagnosis and prognosis in invasion breast cancer.

2.
Anal Methods ; 13(6): 789-795, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33496288

RESUMO

Fluorescent carbon dots derived from natural biomass have received widespread attention in recent years due to their superior optical and chemical properties. In this work, we proposed a method to synthesize fluorescent nitrogen, sulfur, and phosphorus co-doped carbon dots (NSP-CDs) using biomass waste as a precursor. The blue emitting carbon dots were prepared from the seeds of green pepper, and Fe3+ ions could quench the fluorescence of NSP-CDs. Therefore, a fluorescent "turn-off" sensor based on NSP-CDs was constructed for the detection of Fe3+ ions. Further, NSP-CDs were evaluated as a fluorescent biosensor for the detection of Fe3+ in tap water and lake water samples, showing their potential value in practical applications. The cytotoxicity test further confirmed that NSP-CDs have good biocompatibility and can be extended to cell imaging and intracellular Fe3+ detection. The proposed method is simple, economical and green, which can meet the requirements of environmental monitoring and biological imaging.

3.
Mol Cells ; 43(9): 793-803, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32863280

RESUMO

Myeloid-derived suppressor cells (MDSCs) promote tumour progression by contributing to angiogenesis, immunosuppression, and immunotherapy resistance. Although recent studies have shown that microRNAs (miRNAs) can promote the expansion of MDSCs in the tumour environment, the mechanisms involved in this process are largely unknown. Here, we report that microRNA 449c (miR-449c) expression was upregulated in myeloid progenitor cells upon activation of C-X-C motif chemokine receptor 2 (CXCR2) under tumour conditions. MiR-449c upregulation increased the generation of monocytic MDSCs (mo-MDSCs). The increased expression of miR-449c could target STAT6 mRNA in myeloid progenitor cells to shift the differentiation balance of myeloid progenitor cells and lead to an enhancement of the mo-MDSCs population in the tumour environment. Thus, our results demonstrate that the miR-449c/STAT6 axis is involved in the expansion of mo-MDSCs from myeloid progenitor cells upon activation of CXCR2, and thus, inhibition of miR-449c/STAT6 signalling may help to attenuate tumour progression.

4.
Nucleic Acids Res ; 48(3): 1353-1371, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31943071

RESUMO

The human apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3 (APOBEC3, A3) family member proteins can deaminate cytosines in single-strand (ss) DNA, which restricts human immunodeficiency virus type 1 (HIV-1), retrotransposons, and other viruses such as hepatitis B virus, but can cause a mutator phenotype in many cancers. While structural information exists for several A3 proteins, the precise details regarding deamination target selection are not fully understood. Here, we report the first parallel, comparative analysis of site selection of A3 deamination using six of the seven purified A3 member enzymes, oligonucleotides having 5'TC3' or 5'CT3' dinucleotide target sites, and different flanking bases within diverse DNA secondary structures. A3A, A3F and A3H were observed to have strong preferences toward the TC target flanked by A or T, while all examined A3 proteins did not show a preference for a TC target flanked by a G. We observed that the TC target was strongly preferred in ssDNA regions rather than dsDNA, loop or bulge regions, with flanking bases influencing the degree of preference. CT was also shown to be a potential deamination target. Taken together, our observations provide new insights into A3 enzyme target site selection and how A3 mutagenesis impacts mutation rates.


Assuntos
Citidina Desaminase/genética , DNA de Cadeia Simples/genética , Proteínas de Ligação a DNA/genética , Desaminação/genética , Sítios de Ligação/genética , Linhagem Celular , Citidina Desaminase/química , Citosina Desaminase/química , Citosina Desaminase/genética , DNA de Cadeia Simples/química , Proteínas de Ligação a DNA/química , HIV-1/genética , HIV-1/patogenicidade , Vírus da Hepatite B/genética , Humanos , Mutagênese/genética , Conformação de Ácido Nucleico , Estrutura Secundária de Proteína , Retroelementos/genética
5.
Cell Death Dis ; 10(9): 641, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488810

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

6.
Cell Death Dis ; 10(8): 598, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31395859

RESUMO

Myeloid-derived suppressor cells (MDSCs) comprise a critical component of the tumor environment and CXCR2 reportedly plays a key role in the pathophysiology of various inflammatory diseases. Here, CXCR2 expression on granulocyte and macrophage progenitor cells (GMPs) was found to participate in myeloid cell differentiation within the tumor environment. In CXCR2-deficient tumor-bearing mice, GMPs exhibited fewer macrophage and dendritic cell progenitor cells than wild-type tumor-bearing mice, thereby decreasing monocytic MDSCs (mo-MDSCs) expansion. CXCR2 deficiency increased SAP18 expression in tumor-bearing mice, which reduced STAT3 phosphorylation through restraining ERK1/2 activation. Our findings reveal a critical role for CXCR2 in regulating hematopoietic progenitor cell differentiation under tumor conditions, and SAP18 is a key negative regulator in this process. Thus, inhibiting CXCR2 expression may alter the tumor microenvironment and attenuate tumor progression.


Assuntos
Proteínas Correpressoras/genética , Células Progenitoras de Granulócitos e Macrófagos/metabolismo , Melanoma Experimental/genética , Proteínas de Ligação a RNA/genética , Receptores de Interleucina-8B/genética , Fator de Transcrição STAT3/genética , Animais , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Células Progenitoras de Granulócitos e Macrófagos/patologia , Humanos , Sistema de Sinalização das MAP Quinases/genética , Melanoma Experimental/patologia , Camundongos , Monócitos/metabolismo , Monócitos/patologia , Células Supressoras Mieloides/metabolismo , Células Supressoras Mieloides/patologia , RNA Interferente Pequeno/farmacologia , Receptores de Interleucina-8B/antagonistas & inibidores , Microambiente Tumoral/genética
7.
Nano Lett ; 18(2): 957-963, 2018 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-29376383

RESUMO

Active tunability of photonic resonances is of great interest for various applications such as optical switching and modulation based on optoelectronic materials. Manipulation of charged excitons in atomically thin transition metal dichalcogenides (TMDCs) like monolayer MoS2 offers an unexplored route for diverse functionalities in optoelectronic nanodevices. Here, we experimentally demonstrate the dynamic photochemical and optoelectronic control of the photonic crystal Fano resonances by optical and electrical tuning of monolayer MoS2 refractive index via trions without any chemical treatment. The strong spatial and spectral overlap between the photonic Fano mode and the active MoS2 monolayer enables efficient modulation of the Fano resonance. Our approach offers new directions for potential applications in the development of optical modulators based on emerging 2D direct band gap semiconductors.

8.
Nano Lett ; 17(11): 6715-6720, 2017 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-28991494

RESUMO

Atomically thin transition metal dichalcogenides like MoS2 monolayers exhibit unique luminescent properties. However, weak quantum yield and low light absorption hinder their practical applications in two-dimensional light emitting devices. Here, we report 1300 times enhancement in photoluminescence emission from a MoS2 monolayer via simultaneous Fano resonances in a dielectric photonic crystal. The spatially extended double Fano resonance scheme allows resonant enhancement of both the MoS2 absorption and emission. We also achieve unidirectional emission within a narrow divergence angle of 5° by engineering the Fano resonance angular dispersion. Our approach provides a new platform for efficient light sources with high directionality based on emerging two-dimensional materials.

9.
Nanoscale Res Lett ; 10(1): 409, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26474890

RESUMO

Titanium oxyhydroxy-fluoride, TiO0.9(OH)0.9F1.2 · 0.59H2O rods with a hexagonal tungsten bronze (HTB) structure, was synthesized via a facile one-step solvothermal method. The structure, morphology, and component of the products were characterized by X-ray powder diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), ion chromatograph, energy-dispersive X-ray (EDX) analyses, and so on. Different rod morphologies which ranged from nanoscale to submicron scale were simply obtained by adjusting reaction conditions. With one-dimension channels for Li/Na intercalation/de-intercalation, the electrochemical performance of titanium oxyhydroxy-fluoride for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) was also studied. Electrochemical tests revealed that, for LIBs, titanium oxyhydroxy-fluoride exhibited a stabilized reversible capacity of 200 mAh g(-1) at 25 mA g(-1) up to 120 cycles in the electrode potential range of 3.0-1.2 V and 140 mAh g(-1) at 250 mA g(-1) up to 500 cycles, especially; for SIBs, a high capacity of 100 mAh g(-1) was maintained at 25 mA g(-1) after 115 cycles in the potential range of 2.9-0.5 V.

10.
ISME J ; 8(8): 1691-703, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24671088

RESUMO

A variety of microbially mediated metabolic pathways impact biogeochemical cycling in terrestrial subsurface environments. However, the role that viruses have in influencing microbial mortality and microbial community structure is poorly understood. Here we investigated the production of viruses and change in microbial community structure within shallow alluvial aquifer sediment slurries amended with (13)C-labeled acetate and nitrate. Biostimulation resulted in production of viruses concurrent with acetate oxidation, (13)CO2 production and nitrate reduction. Interestingly, change in viral abundance was positively correlated to acetate consumption (r(2)=0.6252, P<0.05) and (13)CO2 production (r(2)=0.6572, P<0.05); whereas change in cell abundance was not correlated to acetate consumption or (13)CO2 production. Viral-mediated cell lysis has implications for microbial community structure. Betaproteobacteria predominated microbial community composition (62% of paired-end reads) upon inoculation but decreased in relative abundance and was negatively correlated to changes in viral abundance (r(2)=0.5036, P<0.05). As members of the Betaproteobacteria decreased, Gammaproteobacteria, specifically Pseudomonas spp., increased in relative abundance (82% of paired-end reads) and was positively correlated with the change in viral abundance (r(2)=0.5368, P<0.05). A nitrate-reducing bacterium, Pseudomonas sp. strain Alda10, was isolated from these sediments and produced viral-like particles with a filamentous morphology that did not result in cell lysis. Together, these results indicate that viruses are linked to carbon biogeochemistry and community structure in terrestrial subsurface sediments. The subsequent cell lysis has the potential to alter available carbon pools in subsurface environments, additionally controlling microbial community structure from the bottom-up.


Assuntos
Bactérias/classificação , Carbono/metabolismo , Sedimentos Geológicos/microbiologia , Nitratos/metabolismo , Fenômenos Fisiológicos Virais , Acetatos/metabolismo , Bactérias/isolamento & purificação , Bactérias/metabolismo , Betaproteobacteria/isolamento & purificação , Dióxido de Carbono/metabolismo , Gammaproteobacteria/isolamento & purificação , Sedimentos Geológicos/virologia , Água Subterrânea , Oxirredução
11.
Nanoscale ; 5(4): 1570-5, 2013 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-23329060

RESUMO

In this work, AgInS(2) hierarchical flowerlike nanoarchitectures, which are composed of ultrathin nanowires, were synthesized by thermolysis of a mixed solution of AgNO(3), InCl(3)·4H(2)O and n-dodecanethiol at elevated temperature. The average diameter and length of the nanowires composing the nanoarchitectures can reach 5 nm and ∼300 nm, respectively. We investigated the growth process of the nanoarchitectures and the effects of reaction parameters by XRD, SEM and TEM. In particular, the use of InCl(3)·4H(2)O played a decisive role in the synthesis of the nanoarchitectures. Moreover, it was found that polyhedra formed in the initial reaction time, and then the nanowires grew on the facets of these polyhedra, which resulted in the nanoarchitectures. The reaction temperature and the concentration of metal salts could influence the size of the nanowires.


Assuntos
Cristalização/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Compostos de Prata/síntese química , Índio , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície
12.
Appl Opt ; 51(31): 7576-80, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23128705

RESUMO

A method for obtaining the intensity fluctuation spectra of dynamic laser speckle patterns is introduced, which is based on the temporal modulation of the illumination and the subsequent integration of the intensity signals. This approach does not rely on the fast sampling rate to meet the Nyquist criterion, making it applicable for full-field imaging applications. The intensity fluctuation spectra created by the in-plane motion of a random phase object was investigated by using both a single-channel detector and a multichannel sensor. The power spectra obtained by using the full-field temporal modulation method were found to agree with the homodyne Doppler spectra obtained by using the method of autocorrelation and Fourier transform.

13.
Nanoscale ; 4(21): 6850-5, 2012 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-23034730

RESUMO

Various CuO nanostructures have been well studied as anode materials for lithium ion batteries (LIBs); however, there are few reports on the synthesis of porous CuO nanostructures used for anode materials, especially one-dimensional (1D) porous CuO. In this work, novel 1D highly porous CuO nanorods with tunable porous size were synthesized in large-quantities by a new, friendly, but very simple approach. We found that the pore size could be controlled by adjusting the sintering temperature in the calcination process. With the rising of calcination temperature, the pore size of CuO has been tuned in the range of ∼0.4 nm to 22 nm. The porous CuO materials have been applied as anode materials in LIBs and the effects of porous size on the electrochemical properties were observed. The highly porous CuO nanorods with porous size in the range of ∼6 nm to 22 nm yielded excellent high specific capacity, good cycling stability, and high rate performance, superior to that of most reported CuO nanocomposites. The CuO material delivers a high reversible capacity of 654 mA h g(-1) and 93% capacity retention over 200 cycles at a rate of 0.5 C. It also exhibits excellent high rate capacity of 410 mA h g(-1) even at 6 C. These results suggest that the facile synthetic method of producing a tunable highly porous CuO nanostructure can realize a long cycle life with high reversible capacity, which is suitable for next-generation high-performance LIBs.


Assuntos
Fontes de Energia Elétrica , Lítio/química , Nanotubos/química , Cobre/química , Técnicas Eletroquímicas , Eletrodos , Porosidade , Temperatura
14.
J Colloid Interface Sci ; 298(2): 713-9, 2006 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16458916

RESUMO

An array of the colloidal photonic crystals was directly fabricated using an ink-jet printing. The colloidal ink droplets containing the monodispersed polystyrene latex particles were selectively deposited on a hydrophobic surface. Solvent evaporation from each ink droplet leads to a formation of microdome-shaped colloidal assembles of close-packed structures. Microspectroscopic analysis has confirmed that the individual assembly serves as a photonic crystal and its optical properties can be correlated with the microstructural features. Unlike other techniques of patterned growth of colloidal photonic crystal, the substrate does not need to be patterned first and no template is needed in the direct writing by the ink-jet printing. Using our strategy, we have rapidly produced the colloidal photonic crystal microarrays composed of different-sized spheres addressably patterned on the same substrate.

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