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1.
J Recept Signal Transduct Res ; 39(5-6): 407-414, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31847659

RESUMO

Activating transcription factor 4 (ATF4) promotes bone formation in human bone marrow mesenchymal stem cells. However, the underlying mechanisms of ATF4 in high glucose-induced injury of osteoblast still remain unclear. Small interfering RNA and plasmid targeting ATF4 were used to transfect MC3T3-E1 cells to knock down and overexpress ATF4 using Lipofectamin 3000. Cell viability, alkaline phosphatase (ALP) activity and levels were determined by MTT, ALP kit assay, quantitative real-time (qRT)-PCR and Western blot. Osteocalcin (OCN) expression was determined by ELISA, PCR and Western blot. The mRNA and protein levels of ATF4, glucose regulated protein 78 kDa (GRP78) and C/EBP homologous protein (CHOP) were detected by PCR and Western blot. In the current study, viabilities of MC3T3-E1 cells were inhibited by high glucose. Meanwhile, the mRNA and protein levels of ATF4 were effectively up-regulated in high glucose-incubated MC3T3-E1 cells. By conducting functional experiments, silencing ATF4 induced by small interfering RNA partially reversed the inhibitory effects of high glucose on viabilities of MC3T3-E1 cells. We also found that the expressions of ER stress-related proteins (ATF4, GRP78 and CHOP) were higher in high glucose-treated MC3T3-E1 cells but were inhibited by siATF4. However, overexpression of AFT4 had opposite results, and high glucose attenuated the protein levels of osteogenic marker genes ALP and OCN, which were further inhibited by ATF4 knockout gene. Thus, ATF4 was a necessary gene for high glucose to inhibit the proliferation and differentiation of MC3T3-E1 cells.

2.
Anal Chim Acta ; 1091: 112-118, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31679564

RESUMO

The fabrication of nanomaterials-based sensing platform has attracted a great deal of interest due to their unique properties. Here, we report a novel hybrid platform of g-C3N4 nanosheets/DNA-stabilized Ag nanoclusters (CNNS/AgNCs) for sensing application. In this platform, the fluorescent AgNCs was synthesized using a pair of double-functional ssDNA sequence as a template, including the aptamer segment against thrombin and C-rich segment for AgNCs. Next, the interaction between the fluorescent Apt-AgNCs and CNNS was investigated. It is verified that DNA-stabilized AgNCs could absorb on the CNNS surface via the stronger π-π interaction to form the hybrid platform, whose fluorescence is quenched by CNNS through the photoelectron transfer effect (PET). When targets are introduced into the system, target/Apt-AgNCs complex will fall off from the CNNS surface, resulting in the fluorescence recovery. This hybrid platform can achieve the detection of biomolecule with high sensitivity and selectivity. Considering the fluorescence variability of DNA scaffold AgNCs, this hybrid platform is promising to extend to other target and even multi-target detection.

3.
Chem Commun (Camb) ; 55(100): 15065-15068, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31777871

RESUMO

Graphitic carbon nitride (g-CN) nanosheets (CNNs) with an ultra-high quantum yield (80.1%) ultraviolet fluorescence (FL) were prepared. The effects of the lateral size and the polymerization temperature on the optical properties of CNNs have been studied. The ultraviolet FL was proved to have originated from the isolated melem units according to the density functional theory calculation and mass spectra. The obtained CNNs are further used as a pH probe due to the dependence of the FL signal on the pH of the solution.

4.
Cell Metab ; 30(5): 937-951.e5, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31668872

RESUMO

Obesity-induced adipose dysfunction is a major contributor to atherosclerosis. Cold exposure has been reported to affect atherosclerosis through regulation of adipose function, but the mechanism has not been well clarified. Here, adipocyte hypoxia-inducible factor 2α (HIF-2α) was upregulated after mild cold exposure at 16°C and mediated cold-induced thermogenesis. Adipocyte HIF-2α deficiency exacerbated Western-diet-induced atherosclerosis by increasing adipose ceramide levels, which blunted hepatocyte cholesterol elimination and thermogenesis. Mechanistically, Acer2, the gene encoding alkaline ceramidase 2, was identified as a novel target gene of HIF-2α, triggering ceramide catabolism. Adipose overexpression of ACER2 rescued adipocyte HIF-2α-deficiency-induced exacerbation of atherosclerosis. Furthermore, activation of adipose HIF-2α by the HIF prolyl hydroxylase inhibitor FG-4592 had protective effects on atherosclerosis, accompanied by a reduction in adipose and plasma ceramide and plasma cholesterol levels. This study highlights adipocyte HIF-2α as a putative drug target against atherosclerosis.

5.
Front Genet ; 10: 966, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31649733

RESUMO

Cancer subtypes can improve our understanding of cancer, and suggest more precise treatment for patients. Multi-omics molecular data can characterize cancers at different levels. Up to now, many computational methods that integrate multi-omics data for cancer subtyping have been proposed. However, there are no consistent criteria to evaluate the integration methods due to the lack of gold standards (e.g., the number of subtypes in a specific cancer). Since comprehensive evaluation and comparison between different methods serves as a useful tool or guideline for users to select an optimal method for their own purpose, we develop a scalable platform, CEPICS, for comprehensively evaluating and comparing multi-omics data integration methods in cancer subtyping. Given a user-specified maximum number of subtypes, k-max, CEPICS provides (1) cancer subtyping results using up to five built-in state-of-the-art integration methods under the number of subtypes from two to k-max, (2) a report including the evaluation of each user-selected method and comparisons across them using clustering performance metrics and clinical survival analysis, and (3) an overall analysis of subtyping results by different methods representing a robust cancer subtype prediction for samples. Furthermore, users can upload subtyping results of their own methods to compare with the built-in methods. CEPICS is implemented as an R package and is freely available at https://github.com/GaoLabXDU/CEPICS.

6.
Nat Commun ; 9(1): 3044, 2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-30072690

RESUMO

The development of intelligent materials, in particular those showing the highly sensitive mechanoresponsive luminescence (MRL), is desirable but challenging. Here we report a design strategy for constructing high performance On-Off MRL materials by introducing nitrophenyl groups to molecules with aggregation-induced emission (AIE) characteristic. The on-off methodology employed is based on the control of the intersystem crossing (ISC) process. Experimental and theoretical investigations reveal that the nitrophenyl group effectively opens the nonradiative ISC channel to impart the high sensitivity and contrast On-Off behavior. On the other hand, the twisted AIE luminogen core endows enhanced reversibility and reduces the pressure required for the luminescence switching. Thin films can be readily fabricated from the designed materials to allow versatile applications in optical information recording and haptic sensing. The proposed design strategy thus provides a big step to expand the scope of the unique On-Off MRL family.

7.
Anal Chem ; 90(18): 10872-10880, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30139256

RESUMO

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF MSI) is rapidly maturing as an innovative technique for spatial molecule ( m/ z > 1000 Da) profiling. However, direct identification of low-molecular-weight compounds ( m/ z < 600 Da) by MALDI-TOF MSI using conventional organic matrixes remains a challenge because of ionization suppression and serious matrix-related background interference. Furthermore, the heterogeneous cocrystallization that is inherent to organic matrixes can degrade spatial resolution in MSI. Herein, we developed a negative ion surface-assisted laser desorption/ionization time-of-flight mass spectrometry imaging (SALDI-TOF MSI) protocol to detect bisphenol S (BPS) and map its spatial distribution in mouse tissues by applying nitrogen- and sulfur-co-doped carbon dots (N,S-co-doped CDs) as a new matrix through spraying. The SALDI-TOF MS and imaging parameters, such as matrix concentration, ionization mode, and matrix deposition, were optimized to improve imaging performance. In comparison to organic matrixes, the use of N,S-co-doped CDs in negative ion mode exhibited free matrix background interference, enhanced MS signal intensity, and provided high spatial resolution (acquired at ∼50 µm) in the analysis of BPS, which allowed sensitive detection of the target compound on the surfaces of tissue sections. Quantitative assessment was also made by spotting BPS standards directly onto the tissue surface, and a good correlation between the color change and BPS concentrations was found. The corresponding detection limit as low as the ∼pmol level for BPS was observed with the direct visualization from MS images. Furthermore, the feasibility of the proposed SALDI-TOF MSI method was extended for in situ identification of exogenous BPS in the different tissues of mouse involving liver, kidney, spleen, and heart for exposure and profiling its spatial localization at different administration times. In addition, the general applicability of the proposed method was also evaluated by SALDI-TOF MSI analysis of BPAF in tissues. These successful applications of SALDI-TOF MSI not only demonstrated its promising potential as an alternative to MALDI-TOF MSI in profiling small molecules in tissue sections but also provided tremendous insight into the assessment of BPS exposure.


Assuntos
Carbono/química , Nitrogênio/química , Fenóis/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Sulfonas/metabolismo , Enxofre/química , Animais , Camundongos , Camundongos Endogâmicos BALB C , Distribuição Tecidual
8.
EBioMedicine ; 31: 202-216, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29735414

RESUMO

The adipose Nod-like receptor protein 3 (NLRP3) inflammasome senses danger-associated molecular patterns (DAMPs) and initiates insulin resistance, but the mechanisms of adipose inflammasome activation remains elusive. In this study, Homocysteine (Hcy) is revealed to be a DAMP that activates adipocyte NLRP3 inflammasomes, participating in insulin resistance. Hcy-induced activation of NLRP3 inflammasomes were observed in both adipocytes and adipose tissue macrophages (ATMs) and mediated insulin resistance. Lysophosphatidylcholine (lyso-PC) acted as a second signal activator, mediating Hcy-induced adipocyte NLRP3 inflammasome activation. Hcy elevated adipocyte lyso-PC generation in a hypoxia-inducible factor 1 (HIF1)-phospholipase A2 group 16 (PLA2G16) axis-dependent manner. Lyso-PC derived from the Hcy-induced adipocyte also activated ATM NLRP3 inflammasomes in a paracrine manner. This study demonstrated that Hcy activates adipose NLRP3 inflammasomes in an adipocyte lyso-PC-dependent manner and highlights the importance of the adipocyte NLRP3 inflammasome in insulin resistance.


Assuntos
Adipócitos/metabolismo , Homocisteína/farmacologia , Inflamassomos/metabolismo , Resistência à Insulina , Lisofosfatidilcolinas/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Adipócitos/química , Adipócitos/citologia , Animais , Feminino , Humanos , Inflamassomos/genética , Lisofosfatidilcolinas/química , Macrófagos/citologia , Masculino , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética
9.
Mikrochim Acta ; 185(6): 291, 2018 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-29748769

RESUMO

A kind of single-layer carbon based dots (CDs) with abundant carboxyl functional groups was hybridized with manganese dioxide (MnO2). The resulting nanohybrid is stable and can be well dispersed in water. MnO2 is capable of oxidizing the substrate 3,3'5,5'-tetramethylbenzidine (TMB) to form a blue product whose absorption (peaking at 655 nm) fades in the presence of glutathione (GSH). A sensitive and selective colorimetric GSH assay was worked out that has a linear response in the 10 to 0.1 µM GSH concentration range, with a 0.095 µM detection limit. The method was applied to the determination of GSH in spiked fetal calf serum where it gave excellent recoveries. Graphical abstract Schematic of the preparation of a nanohybrid composed of manganese dioxide and carbon based dots (MnO2/CDs). They can be used for the colorimetric detection of glutathione (GSH) based on the color change of 3,3'5,5'-tetramethylbenzidine (TMB).

10.
Chemistry ; 24(17): 4250-4254, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-29392832

RESUMO

Single-layer carbon-based dots (SCDs) were chosen as a model to investigate the effect of the C-related dangling bonds with spin S=1/2 and functional groups on the electrochemiluminescent (ECL) and fluorescent (FL) properties of CDs. The C-related dangling bonds and functional groups of SCDs were tuned by chemical reduction with NaBH4 . There have several main findings via investigating the ECL and FL properties of SCDs before and after the chemical reduction. First, the FL and ECL of CDs are highly dependent on their concentration, and luminescent resonance energy transfer is observed in ECL studies when the concentration of CDs is high. Second, the ECL activity of CDs is greatly enhanced as the C-related dangling bonds increase, proving that the ECL of CDs originates from the C-related dangling bonds. Third, the FL of CDs is the synthesis of the inner FL originated from the contained isolated sp2 units and the defect FL from the C-related dangling bonds. The inner FL of CDs is enhanced greatly by removing the carboxyl groups, while the defect FL is increased slightly due to the increased C-related dangling bonds. We believe this study would promote our understanding in the ECL and FL mechanisms of CDs, advancing the applications of CDs based on their ECL and FL properties.

11.
Acta Pharmacol Sin ; 38(12): 1601-1610, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28933423

RESUMO

Hyperhomocysteinemia (HHcy) is a key risk factor in hepatic steatosis. In this study, we applied a metabolomic approach to investigate the changes in the metabolite profile due to HHcy-induced hepatic steatosis and the effects of omega-3 PUFA (polyunsaturated fatty acid) supplementation in mice. HHcy was induced in mice by giving DL-Hcy (1.8 g/L) in drinking water for 6 weeks, then the mice were sacrificed, and the metabolic profiles of the liver and plasma were analyzed through UPLC-ESI-QTOFMS-based lipidomics. Hepatic triglycerides and cholesterol were further assayed. The expression of ceramide metabolism-related genes was measured by quantitative PCR. Compared with control mice, HHcy mice exhibited hepatic steatosis with a notable increase in ceramide-related metabolites and subsequent upregulation of ceramide synthesis genes such as Sptlc3, Degs2, Cer4 and Smpd4. Omega-3 PUFA was simultaneously administered in HHcy mice through chow diet containing 3.3% omega-3 PUFA supplement for 6 weeks, which significantly ameliorated Hcy-induced hepatic steatosis. The decrease in hepatic lipid accumulation was mainly due to reduced hepatic levels of ceramides, which was partly the result of the lower expression of ceramide synthesis genes, Sptlc3 and Degs2. Similar beneficial effects of DHA were observed in Hcy-stimulated primary hepatocytes in vitro. In summary, Hcy-induced ceramide elevation in hepatocytes might contribute to the development of hepatic steatosis. Furthermore, downregulation of ceramide levels through omega-3 PUFA supplementation ameliorates hepatic lipid accumulation. Thus, ceramide is a potential therapeutic target for the treatment of hepatic steatosis.


Assuntos
Ceramidas/biossíntese , Ácidos Graxos Ômega-3/farmacologia , Ácidos Graxos Ômega-3/uso terapêutico , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/etiologia , Hepatócitos/efeitos dos fármacos , Hiper-Homocisteinemia/complicações , Animais , Células Cultivadas , Hepatócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
12.
Nanoscale ; 9(3): 1028-1032, 2017 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-28054701

RESUMO

A one-pot hydrothermal method was proposed for the synthesis of carbon based dots (CDs) with high quantum yield and controllable long-wavelength photoluminescence (PL). The PL mechanisms of the CDs were discussed, and a common model has been proposed. Furthermore, the obtained CDs showed excellent biocompatibility and high PLQYs (more than 20%), and presented great potential bio-applications.


Assuntos
Carbono/química , Pontos Quânticos/química , Materiais Biocompatíveis/síntese química , Cor , Humanos , Células MCF-7
13.
Biosens Bioelectron ; 92: 695-701, 2017 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27829561

RESUMO

A novel g-C3N4 nanosheets embedded with C3N4 QDs nanocomposites (QD@CNNS) was prepared by simple oxidation using hydrogen peroxide and UV light irradiation. This nanocomposite exhibits more stable and stronger electrochemiluminescent (ECL) behavior compared with CNNS. Coupling this nanocomposite with Fc-labeled aptamer, a signal-on aptasensor for platelet derived growth factor BB (PDGF-BB) is fabricated. Initially, the Fc-labeled aptamer binds onto QD@CNNS via π-π conjugation and electrostatic interaction, quenching ECL emission from QD@CNNS. The introduction of target efficiently recovers the ECL signal by the formation of PDGF-BB/aptamer complex. The ECL intensity is proportion to the concentration of PDGF-BB in the range of 0.02-80nM with a detection limit of 0.013nM. This work demonstrates a simple synthesis method to obtain QD@CNNS with excellent ECL behavior, and opens up the application of g-C3N4 nanocomposite in signal-on aptasensing.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Nanoestruturas/química , Nitrilos/química , Proteínas Proto-Oncogênicas c-sis/sangue , Pontos Quânticos/química , Becaplermina , Técnicas Eletroquímicas/métodos , Humanos , Limite de Detecção , Medições Luminescentes/métodos , Nanocompostos/química , Nanocompostos/ultraestrutura , Nanoestruturas/ultraestrutura , Pontos Quânticos/ultraestrutura
14.
Small ; 12(39): 5376-5393, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27611869

RESUMO

Graphitic carbon nitrides (g-C3 N4 ) are a class of 2D polymeric materials mainly composed of carbon and nitrogen atoms. g-C3 N4 are attracting dramatically increasing interest in the areas of sensing, imaging, and therapy, due to their unique optical and electronic properties. Here, the luminescent properties (mainly includes photoluminescence and electrochemiluminescence), and catalytic and photoelectronic properties related to sensing and therapy applications of g-C3 N4 materials are reviewed. Furthermore, the fabrication and advantages of sensing, imaging and therapy systems based on g-C3 N4 materials are summarized. Finally, the future perspectives for developing the sensing, imaging and therapy applications of the g-C3 N4 materials are discussed.


Assuntos
Técnicas Biossensoriais , Diagnóstico por Imagem , Grafite/uso terapêutico , Nitrilos/química , Catálise , Grafite/química , Luminescência
15.
Anal Chem ; 88(3): 1748-52, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26744080

RESUMO

Nitrogen and sulfur codoped carbon-based dots (N,S-CDs) with strong blue light emission are encapsulated into red light-emitting europium metal-organic frameworks (Eu-MOFs) to form two color light-emitting nanohybrids (Eu-MOFs/N,S-CDs). In organic solvents, the encapsulated N,S-CDs are aggregated and confined in the cavities of the Eu-MOFs, exhibiting only a very weak photoluminescence (PL) signal. Therefore, the nanohybrids show red light emission of the Eu-MOFs. Contrarily, when the Eu-MOFs/N,S-CDs are dispersed in water, the encapsulated N,S-CDs are released into solution while the red light emission of the Eu-MOFs is quenched due to the effect of O-H oscillators. The nanohybrids are used as the probe for the water content in organic solvents. Take ethanol as an example; as the water content is increased from 0.2 to 30%, the nanoprobe provides distinguishable PL color change. The ratio of light intensity at 420 nm to that at 623 nm (I420/I623) increases linearly with increasing water content in the range from 0.05 to 4% with a low detection limit of 0.03%.

16.
Zhonghua Zhong Liu Za Zhi ; 37(7): 485-9, 2015 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-26463322

RESUMO

OBJECTIVE: To investigate the inhibitory effect of classic demethylating drug 5-aza-2'-deoxycytidine (5-Aza-CdR) on the growth of human lung adenocarcinoma cells in nude mouse xenograft models, and to observe its effect on methylation status and expression of TFPI-2 gene in the nude mouse xenograft tissues. METHODS: The nude mouse xenograft model was established by subcutaneous inoculation of human lung adenocarcinoma A549 cells. According to different doses of 5-Aza-CdR, the tumor-bearing nude mice were randomly divided into experimental groups (0.5 mg/kg group, 1 mg/kg group, 2 mg/kg group) and control group (0 mg/kg group). The tumor growth in the nude mice was observed. The methylation status and the expression of TFPI-2 gene mRNA and protein were detected by methylation specific polymerase chain reaction, real-time fluorescent quantitative polymerase chain reaction and Western blot assay. RESULTS: The nude mice were euthanized at 28 days after intraperitoneal injection of 5-Aza-CdR. The body weight of tumor-bearing nude mice was (27.12 ± 0.38) g in the 0 mg/kg group, (26.80 ± 0.18) g in the 0.5 mg/kg group, (26.67 ± 0.28) g in the 1 mg/kg group, and (26.50 ± 0.26) g in the 2 mg/kg group, showing no significant difference among them (P > 0.05). The volume of xenograft tumors in the 0 mg/kg group was (709.22 ± 2.87)mm³, (400.67 ± 2.68)mm³ in the 0.5 mg/kg group, (285.71 ± 2.91)mm³ in the 1 mg/kg group, and (230.44 ± 3.15)mm³ in the 2 mg/kg group, showing a significant difference (P < 0.05). There were complete methylation of TFPI-2 gene in the 0 mg/kg group, incomplete methylation in the 0.5 and 1 mg/kg groups, and unmethylation in the 2 mg/kg group. The relative mRNA level in the 0, 0.5, 1, 2 mg/kg groups were 1.00 ± 0.00, 1.67 ± 0.07, 3.40 ± 0.24, and 5.55 ± 0.61, respectively (P < 0.05). The relative expression level of TFPI-2 protein in the 0, 0.5, 1, 2 mg/kg groups was 0.18 ± 0.02, 0.36 ± 0.01, 0.64 ± 0.02, and 0.81 ± 0.20, respectively (P < 0.05). CONCLUSIONS: 5-Aza-CdR suppresses the tumor growth of human lung adenocarcinoma cells in nude mouse xenograft models, and induces expression of TFPI-2 gene in the xenograft tumor cells. The mechanism might be that 5-Aza-CdR induces re-expression of demethylated TFPI-2 gene by demethylation, and thus inhibits the growth and proliferation of human lung adenocarcinoma cells.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Glicoproteínas/genética , Neoplasias Pulmonares/tratamento farmacológico , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Animais , Azacitidina/farmacologia , Proliferação de Células/efeitos dos fármacos , Metilação de DNA , Decitabina , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , RNA Mensageiro/metabolismo , Distribuição Aleatória
17.
Analyst ; 140(22): 7468-86, 2015 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-26396996

RESUMO

Carbon based dots (CDs) including carbon quantum dots and graphene quantum dots exhibit unique luminescence properties, such as photoluminescence (PL), chemiluminescence (CL) and electrochemiluminescence (ECL). This review summarizes the sensing application of the CDs taking advantage of their luminescence properties. The working principle, merits, and prospects of CD based sensors are presented.

18.
Nanoscale ; 7(39): 16366-71, 2015 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-26391198

RESUMO

Hydrazide-modified graphene quantum dots (HM-GQDs) obtained by refluxing GQDs with hydrazine hydrate were hybridized with gold nanoparticles (AuNPs) through a redox reaction between HM-GQDs and AuCl4(-). The obtained nano-hybrids (HM-GQD-AuNPs) possess the unique electrochemiluminescence (ECL) properties of HM-GQDs and the easy self-assembly with some bio-molecules of AuNPs, which have great potential applications in bio-sensors. HM-GQD-AuNPs were modified on a glassy carbon electrode to develop a novel ECL immunosensor of carcinoembryonic antigen (CEA) as a model target analyte. Due to the increment of electron-transfer resistance after immunoreaction, the ECL intensity decreased as the concentration of CEA was increased. The linear response range was between 0.02 and 80 ng mL(-1), and the detection limit was 0.01 ng mL(-1).


Assuntos
Técnicas Biossensoriais/métodos , Antígeno Carcinoembrionário/análise , Técnicas Eletroquímicas/métodos , Ouro/química , Grafite/química , Medições Luminescentes/métodos , Nanopartículas Metálicas/química , Pontos Quânticos/química , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Humanos , Medições Luminescentes/instrumentação , Solubilidade
19.
Sci Rep ; 5: 10037, 2015 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-25944302

RESUMO

For the first time, abundant natural carbon-based dots were found and studied in humic substances (HS). Four soluble HS including three humic acids (HA) from different sources and one fulvic acids (FA) were synthetically studied. Investigation results indicate that all the four HS contain large quantities of Carbon-based dots. Carbon-based dots are mainly small-sized graphene oxide nano-sheets or oxygen-containing functional group-modified graphene nano-sheets with heights less than 1 nm and lateral sizes less than 100 nm. Carbon-based nanomaterials not only contain abundant sp2-clusters but also a large quantity of surface states, exhibiting unique optical and electric properties, such as excitation-dependent fluorescence, surface states-originated electrochemiluminescence, and strong electron paramagnetic resonance. Optical and electric properties of these natural carbon-based dots have no obvious relationship to their morphologies, but affected greatly by their surface states. Carbon-based dots in the three HS have relative high densities of surface states whereas the FA has the lowest density of surface states, resulting in their different fluorescence properties. The finding of carbon-based dots in HS provides us new insight into HS, and the unique optical properties of these natural carbon-based dots may give HS potential applications in areas such as bio-imaging, bio-medicine, sensing and optoelectronics.

20.
J Mol Cell Cardiol ; 81: 96-106, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25680906

RESUMO

Abdominal aortic aneurysm (AAA) is a serious vascular disease with high mortality. Our previous study suggested that hyperhomocysteinemia (HHcy) exaggerates the occurrence of AAA. Here, we investigated whether macrophage inflammasome is involved in HHcy-aggravated AAA formation. Two independent HHcy-aggravated AAA models, perivascular calcium phosphate-treated C57BL/6 mice and angiotensin II (Ang II)-infused apolipoprotein E-deficient (ApoE(-/-)) mice were used. NLPR3, caspase 1, and interleukin-1ß (IL-1ß) levels were higher in aneurysmal lesions of both HHcy models compared to controls, preferentially in macrophages. Similarly, macrophage inflammasome activation was observed in vitro. Folic acid administration reversed the HHcy-accelerated AAA, with ameliorated activation of inflammasome in the tunica adventitia. Lentiviral silencing of NLRP3 significantly ameliorated HHcy-aggravated AAA formation. We observed increased mitochondrial production of reactive oxygen species (ROS) and energy switch from oxidative phosphorylation to glycolysis with excess Hcy in macrophages. Blocking mitochondrial ROS production in macrophages abolished inflammasome activation. Our study highlights the potential importance of macrophage inflammasome in the pathogenesis and development of HHcy-aggravated AAA.


Assuntos
Aneurisma da Aorta Abdominal/metabolismo , Proteínas de Transporte/metabolismo , Hiper-Homocisteinemia/metabolismo , Inflamassomos/metabolismo , Macrófagos/metabolismo , Túnica Adventícia/efeitos dos fármacos , Túnica Adventícia/metabolismo , Túnica Adventícia/patologia , Animais , Aneurisma da Aorta Abdominal/induzido quimicamente , Aneurisma da Aorta Abdominal/complicações , Aneurisma da Aorta Abdominal/prevenção & controle , Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Fosfatos de Cálcio/efeitos adversos , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Caspase 1/genética , Caspase 1/metabolismo , Modelos Animais de Doenças , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Ácido Fólico/farmacologia , Expressão Gênica , Hiper-Homocisteinemia/induzido quimicamente , Hiper-Homocisteinemia/complicações , Hiper-Homocisteinemia/prevenção & controle , Inflamassomos/efeitos dos fármacos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR , Cultura Primária de Células , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo
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