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1.
Virol J ; 18(1): 181, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488793

RESUMO

BACKGROUND: Transmitted drug resistance (TDR) that affects the effectiveness of the first-line antiretroviral therapy (ART) regimen is becoming prevalent worldwide. However, its prevalence and transmission among HIV-1 treatment-naïve patients in Guangdong, China are rarely reported. We aimed to comprehensively analyze the prevalence of TDR and the transmission clusters of HIV-1 infected persons before ART in Guangdong. METHODS: The HIV-1 treatment-naïve patients were recruited between January 2018 and December 2018. The HIV-1 pol region was amplified by reverse transcriptional PCR and sequenced by sanger sequencing. Genotypes, surveillance drug resistance mutations (SDRMs) and TDR were analyzed. Genetic transmission clusters among patients were identified by pairwise Tamura-Nei 93 genetic distance, with a threshold of 0.015. RESULTS: A total of 2368 (97.17%) HIV-1 pol sequences were successfully amplified and sequenced from the enrolled 2437 patients. CRF07_BC (35.90%, 850/2368), CRF01_AE (35.56%, 842/2368) and CRF55_01B (10.30%, 244/2368) were the main HIV-1 genotypes circulating in Guangdong. Twenty-one SDRMs were identified among fifty-two drug-resistant sequences. The overall prevalence of TDR was 2.20% (52/2368). Among the 2368 patients who underwent sequencing, 8 (0.34%) had TDR to protease inhibitors (PIs), 22 (0.93%) to nucleoside reverse transcriptase inhibitors (NRTIs), and 23 (0.97%) to non-nucleoside reverse transcriptase inhibitors (NNRTIs). Two (0.08%) sequences showed dual-class resistance to both NRTIs and NNRTIs, and no sequences showed triple-class resistance. A total of 1066 (45.02%) sequences were segregated into 194 clusters, ranging from 2 to 414 sequences. In total, 15 (28.85%) of patients with TDR were included in 9 clusters; one cluster contained two TDR sequences with the K103N mutation was observed. CONCLUSIONS: There is high HIV-1 genetic heterogeneity among patients in Guangdong. Although the overall prevalence of TDR is low, it is still necessary to remain vigilant regarding some important SDRMs.

2.
Anal Chem ; 93(38): 12944-12953, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34523923

RESUMO

For sensing low abundance of biomarkers, utilizing nanocarriers to load dyes is an efficient method to amplify the detected signal. However, the non-specific leak of the internal dyes in this approach is accompanied by false positive signals, resulting in inaccurate signal acquirement. To address this issue, in this work, we reported a novel signal amplification strategy with dye as a scaffold to construct a self-immolative dye-doped polymeric probe (SDPP). In our proposed approach, the dyes were covalently integrated into the main chain of a polymer, which can avoid the non-specific leak of the dye when used in a rigorous biological environment, thus evading the false positive signal. As a prototype of this concept, a SDPP, which responds to hydroxyl radicals (•OH), was rationally fabricated. Upon being activated by •OH, SDPP will liberate the dye through a self-immolative reaction to bind with protein for amplifying the fluorescence signal. Compared with a dye-loaded nanoprobe, SDPP can precisely track intracellular basal •OH levels and visualize the •OH associated with myocarditis in vivo. More importantly, the attempt in this work not only provides an effective molecular tool to investigate the role of •OH in cardiopathy, but also puts forward a new direction to current signal-amplifying strategies for precisely and reliably acquiring the intracellular molecular information.


Assuntos
Corantes , Radical Hidroxila , Diagnóstico por Imagem , Corantes Fluorescentes , Polímeros , Espectrometria de Fluorescência
3.
Arch Virol ; 166(10): 2853-2857, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34373969

RESUMO

Strains of the HIV-1 circulating recombinant forms (CRFs) 06_cpx and 56_cpx were identified for the first time in Guangzhou, China. The nearly full-length genome (NFLG) sequence was amplified, and the PCR products were sequenced by the Sanger method. The CRF06_cpx and CRF56_cpx strains were identified using the Basic Local Alignment Search Tool (BLAST) and confirmed by neighbour-joining (NJ) phylogenetic analysis. Additionally, these strains were found to contain transmitted drug resistance mutations that have little effect on first-line efavirenz (EFV)-based treatment. Genetic analysis of the detailed sequence data will provide more information on the HIV-1 epidemic in China.


Assuntos
Infecções por HIV/virologia , HIV-1/genética , Adulto , China/epidemiologia , Cidades/epidemiologia , Farmacorresistência Viral/genética , Feminino , Genoma Viral/genética , Genótipo , Infecções por HIV/epidemiologia , HIV-1/classificação , HIV-1/isolamento & purificação , Humanos , Masculino , Mutação , Filogenia , Recombinação Genética , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genética
4.
Angew Chem Int Ed Engl ; 60(22): 12569-12576, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-33739576

RESUMO

The novel theranostic nanosystems based on two-photon fluorescence can achieve higher spatial resolution of deep tissue imaging for simultaneous diagnosis and therapy of a variety of cancers. Herein, we have designed and prepared FRET-based two-photon mesoporous silica nanoparticles (MTP-MSNs) for single-excitation multiplexed intracellular imaging and targeted cancer therapy for the first time. This nanosystem includes two constituents, containing (1) multicolor two-photon mesoporous silica nanoparticles and (2) cancer cell-targeting aptamers that act as gatekeepers for MTP-MSNs. After incubation with cancer cells, the Dox-loaded and aptamer-capped MTP-MSNs could be internalized into the cells, opening the pores and releasing the drug. Furthermore, using two-photon multicolor fluorescence, MTP-MSNs could serve as good contrast agents for multicolor two-photon intracellular imaging with increased imaging depth and improved spatial localization of tissue. In sum, these multicolor MTP-MSNs provide a promising system for traceable targeted cancer therapy with further applications in multiplex intracellular imaging and the screening of drug.


Assuntos
Microscopia de Fluorescência por Excitação Multifotônica/métodos , Nanopartículas/química , Neoplasias/diagnóstico , Animais , Aptâmeros de Nucleotídeos/química , Sobrevivência Celular/efeitos dos fármacos , Meios de Contraste/química , Doxorrubicina/química , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Portadores de Fármacos/química , Transferência Ressonante de Energia de Fluorescência , Humanos , Lasers , Fígado/efeitos dos fármacos , Fígado/patologia , Células MCF-7 , Neoplasias/tratamento farmacológico , Oligodesoxirribonucleotídeos/química , Porosidade , Ratos , Dióxido de Silício/química , Nanomedicina Teranóstica
5.
Anal Chem ; 93(8): 3726-3732, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33601885

RESUMO

Long-term specific tracing of the fibroblast activation protein (FAP) has been of great importance because it is heavily expressed by stromal fibroblasts of multiple diseases, and several disorders associated with FAP are chronical. Bioluminescence (BL) imaging has its advantages to detect FAP in vivo since no external excitation is required, but the current FAP-responsive BL probe was constructed by covalently masking the firefly luciferase substrate and easily secreted out from the animal, resulting in transient BL imaging of FAP. To circumvent this problem, a peptide-linked amphiphilic block copolymer-based probe (PABC) was developed and applied to the long-lasting BL image of FAP in vivo. For this purpose, an amphiphilic block copolymer containing an FAP-responsive peptide was fabricated to self-assemble into micelles, which act as a depot to load amounts of d-luciferin for constructing the BL probe. Upon reaction with FAP, the micelle would be destroyed to release the internal d-luciferin for BL emission by a luciferase-catalyzed reaction. By virtue of the high loading capability of micelles, the FAP was determined from 0.5 to 10 ng/mL with a detection limit of 0.105 ng/mL, and the high sensitivity makes the PABC capable of distinguishing cancer cells from normal ones. Importantly, compared with free d-luciferin, PABC can be used to persistently image the FAP in living cells and in vivo. This characteristic of long-lasting specific tracing of the FAP makes us envision that this BL probe could be used for screening of FAP inhibitors and diagnosing various FAP-related diseases in future.


Assuntos
Luciferases de Vaga-Lume , Medições Luminescentes , Animais , Diagnóstico por Imagem , Fibroblastos , Luciferases
6.
Artigo em Inglês | MEDLINE | ID: mdl-33287631

RESUMO

The wide variety of new HIV-1 recombinant variants are a predominant challenge for understanding the molecular epidemiology and preventing the spread of the HIV-1 epidemic. In this study, we confirmed a novel HIV-1 unique B/C recombinant (ZLQ01186) isolated from a male patient infected with HIV-1 through injection drug use in Foshan city, Guangdong Province. The near full-length genome was amplified, and then the polymerase chain reaction products were sequenced by Sanger sequencing. The genomic sequence of the strain, with two subtype B segments inserted into the subtype C backbone, was 8,953 bp in length, extending from 647 to 9,599 bp according to the HXB2 genome. In addition, this B/C recombinant strain contained the non-nucleoside reverse transcriptase inhibitor resistance mutation K103N and the integrase strand transfer inhibitor other resistance mutation L74I according to the Stanford University HIV Drug Resistance Database program. The drug resistance profile indicates high-level resistance against efavirenz and rilpivirine. This study identified a recombinant between the main circulating strains, indicating a more complicated trend of the HIV-1 epidemic in Guangdong, China.

7.
Infect Genet Evol ; 87: 104673, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33309773

RESUMO

Guangzhou city is the political, economic, and cultural center of the Guangdong Province, China. The molecular epidemiological characteristics of HIV-1 in Guangzhou are not widely known. The aim of this study was to explore the characteristics of HIV-1 genotypes among treatment naïve HIV/AIDS patients living in Guangzhou. HIV-1 RNA was extracted from serum specimens. The partial pol gene of the HIV-1 genome was amplified and sequenced. The genotypes were screened using the subtyping tool COMET and further confirmed by phylogenetic analysis, with the exception of the URFs that were analyzed by jpHMM and RIP. The distributions of HIV genotypes in different risk populations were analyzed. Subsequently, pol sequences were used to construct transmission networks and analyze drug resistance. Twelve HIV-1 genotypes including 3 subtypes and 9 CRFs, with several URFs were identified from 1388 HIV-1 sequences, which were derived from 1490 patients. The main genotypes circulating in Guangzhou were CRF07_BC (38.3%), CRF01_AE (32.3%), and CRF55_01B (10.7%). CRF01_AE was the secondary dominant strain and multiple lineages of CRF01_AE had been identified in Guangzhou. The 01B recombinant forms, including CRF55_01B, CRF59_01B and CRF68_01B, have circulated widely in Guangzhou. 42.22% (586/1388) of the study sequences fell into 143 transmission networks, and the three main clusters revealed that sequences from MSM and HET populations were intermixed. 5.40% (75/1388) of patients had pre-treatment drug resistance. The HIV-1 strains that were present in Guangzhou have demonstrated complex genotypes. Particular attention should be given on these genotypes for the further strategy of prevention and intervention of HIV transmission.

8.
ACS Sens ; 5(6): 1726-1733, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32441104

RESUMO

Hyaluronidase 1 (Hyal-1) is an important enzyme involved in intracellular hyaluronic acid (HA) catabolism for performing various physiological functions, and its aberrant level is closely associated with many malignant diseases. Bioluminescence imaging is advantageous for monitoring Hyal-1 activity in vivo, but it remains challenging to design an available probe for differentiating Hyal-1 from other isoforms by a traditional strategy that covalently masks the firefly luciferase substrate. Herein, we, for the first time, present a noncovalently caging approach to construct a Hyal-1-specific bioluminogenic nanosensor by entrapping d-luciferin (d-Luc) inside the cholesterylamine-modified HA (CHA) nanoassembly to inhibit the bioluminescence production. When encountered with intracellular Hyal-1, CHA could be fully dissembled to liberate multiple copies of the loaded d-Luc, thereby emitting light by the luciferase-catalyzed bioluminescence reaction. Because of its cascade signal amplification feature, d-Luc@CHA displayed a remarkable "turn-on" response (248-fold) to 5 µg/mL Hyal-1 with a detection limit of 0.07 ng/mL. Importantly, bioluminescence imaging results validated that d-Luc@CHA could be competent for dynamically visualizing endogenous Hyal-1 changes in living cells and animals and possessed the capability of discriminating between normal and cancer cells, thus offering a promising toolbox to evaluate Hyal-1 roles in biological processes as well as to diagnose Hyal-1-related diseases.


Assuntos
Luciferina de Vaga-Lumes , Neoplasias , Animais , Hialuronoglucosaminidase , Luciferases/genética , Luciferases de Vaga-Lume
9.
Anal Chem ; 91(15): 9682-9689, 2019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31282656

RESUMO

Furin, an important member in the family of proprotein convertases, is a participant in the activation of various precursor proteins. The expression level of furin stays in a very low range in most normal cells, but elevates with a big margin in many cancer cells. More importantly, furin is closely related to tumor formation and migration. Herein, a furin-activatable near-infrared (NIR) fluorescent probe (HD-F) was first developed that allowed for specific, sensitive detection and imaging of furin both in vitro and in vivo. HD-F consists of a classical NIR fluorophore (HD), a furin-particular polypeptide sequence RVRR, and a self-eliminating linker. Without the interaction with furin, no noticeable fluorescence enhancement was detected, even over 3 days, demonstrating the excellent stability of HD-F. Upon conversion by furin, there was a distinct signal increase around 708 nm. It has achieved assay and visualization of endogenous furin in various cells, tumor tissues, and tumor-bearing mouse models. Importantly, HD-F is well-suited for monitoring the change of furin expression level in the process of hypoxia-inducible factor-1 stabilized by CoCl2. Moreover, HD-F could visualize the divergence in the expression level of furin between normal and cancer cells, indicating its potential in specific cancer imaging. Thus, this novel probe is able to serve as a potential tackle for better understanding of the intrinsic link between a hypoxic physiological environment and cellular carcinogenesis and predicting cancer in preclinical applications.


Assuntos
Carcinogênese , Furina/química , Animais , Fluorescência , Corantes Fluorescentes , Furina/metabolismo , Células Hep G2 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais , Transporte Proteico , Análise de Célula Única
10.
Chem Commun (Camb) ; 55(31): 4487-4490, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30912542

RESUMO

In this work, we report the first bioluminescent probe BP-PS for detecting H2Sn with high specificity and sensitivity. Owing to the bioluminescence imaging without requiring an excitation light source, tissue autofluorescence is eliminated and BP-PS shows a high signal-to-noise ratio. Moreover, BP-PS was successfully utilized to visualize endogenous H2Sn in live cells and a murine model of bacterial infection.


Assuntos
Infecções Bacterianas/diagnóstico por imagem , Corantes Fluorescentes/química , Sulfetos/química , Animais , Infecções Bacterianas/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Escherichia coli/patogenicidade , Humanos , Camundongos , Microscopia de Fluorescência , Imagem Óptica , Espectrometria de Fluorescência
11.
Chem Commun (Camb) ; 55(12): 1758-1761, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30664144

RESUMO

A bioluminescent probe, BP-HNO, which exhibits a turn-on response to nitroxyl with high sensitivity and selectivity, is reported for the first time in this work. BP-HNO is free from the interference of biological autofluorescence to afford a high signal-to-noise ratio for bioimaging, and was successfully applied to imaging nitroxyl in live cells and mice.


Assuntos
Corantes Fluorescentes/química , Óxidos de Nitrogênio/química , Animais , Linhagem Celular Tumoral , Humanos , Medições Luminescentes , Camundongos , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Imagem Óptica , Transfecção , Transplante Heterólogo
12.
Trends Chem ; 1(2): 224-234, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-32864595

RESUMO

Small-molecule near-IR (NIR) optical imaging has experienced tremendous advancements over the past two decades, playing important roles in both theory and application in the biomedical field. NIR optical imaging affords improved contrast and depth of tissue penetration by reducing photon scattering, lowering tissue absorption, and minimizing autofluorescence in the NIR window. Moreover, molecular engineering endows small-molecule probes with powerful tunability, providing a valuable means for real-time noninvasive visualization of various biological processes and analytes in vivo with high sensitivity and resolution. In this review, we focus on the most recent advances in the development of small-molecule NIR probes and their applications in bioimaging. We also highlight the challenges and opportunities in this rapidly developing field.

13.
Anal Chem ; 90(19): 11680-11687, 2018 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-30191711

RESUMO

Furin, a kind of trans-Golgi proprotein convertases, plays important role in various physiological processes. It is overexpressed in many cancers and relates to tumor growth and migration. In situ detection and imaging of furin is of great significance for obtaining real-time information about its activity. However, the previously reported fluorescent probes for furin usually failed to realize in situ detection and long-term bioimaging, because these probes are based on water-soluble fluorophores, which tend to diffuse away from the reaction sites after converted by furin. Such a problem can be addressed by designing a probe, which releases a precipitating fluorophore upon furin conversion. Herein, we developed a probe HPQF for in situ detection of endogenous furin activity and long-term bioimaging by integrating a strictly insoluble solid-state fluorophore 6-chloro-2-(2-hydroxyphenyl) quinazolin-4(3H)-one (Cl-HPQ) with a furin specific peptide substrate (RVRR) through a self-immolative linker. The HPQF probe shows high selectivity and sensitivity to furin. Upon converted by furin, HPQF releases free Cl-HPQ, which precipitates near the enzyme active site. The precipitates emit bright solid-state fluorescence for in situ imaging. HPQF could truly visualize the location of intracellular furin, which was further confirmed by colocalization and immunofluorescence experiments. Excitingly, the long-term bioimaging was also achieved benefiting from its outstanding signal-stability and antidiffusion ability. HPQF was further utilized to monitor the level change of furin under stabilizing of hypoxia-inducible factor (HIF) regulated by cobalt chloride (CoCl2) as well as visualization of furin in MDA-MB-468 cell tumor tissues.


Assuntos
Corantes Fluorescentes/química , Furina/metabolismo , Microscopia de Fluorescência , Linhagem Celular Tumoral , Cobalto/química , Complexo de Golgi/metabolismo , Humanos , Fator 1 Induzível por Hipóxia/metabolismo , Peptídeos/química , Peptídeos/metabolismo
14.
Anal Chem ; 90(6): 4167-4173, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29468879

RESUMO

Peroxynitrite (ONOO-), an extremely reactive nitrogen species (RNS), is implicated in diverse pathophysiological conditions, including cancer, neurodegenerative diseases, and inflammation. Sensing and imaging of ONOO- in living systems remains challenging due to the high autofluorescence and the limited light penetration depth. In this work, we developed a bioluminescent probe BP-PN, based on luciferase-luciferin pairs and the ONOO--responded group α-ketoamide, for highly sensitive detection and imaging of endogenous ONOO- in living cells and mice for the first time. Attributed to the BL without external excitation, the probe BP-PN exhibits a high signal-to-noise ratio with relatively low autofluorescence. Furthermore, we examine the application of the probe BP-PN using the mice model of inflammation, and BP-PN shows high sensitivity for imaging endogenous ONOO- in inflamed mice. This newly developed bioluminescent probe would be a potentially useful tool for in vivo imaging of ONOO- in wider physiological and pathological processes.


Assuntos
Substâncias Luminescentes/química , Medições Luminescentes/métodos , Imagem Óptica/métodos , Ácido Peroxinitroso/análise , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Luciferina de Vaga-Lumes/química , Humanos , Luciferases de Vaga-Lume/química , Camundongos , Camundongos Nus , Imagem Corporal Total/métodos
15.
Analyst ; 141(11): 3395-402, 2016 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-27137921

RESUMO

Formaldehyde (FA) plays an important role in living systems as a reactive carbonyl species (RCS). An abnormal degree of FA is known to induce neurodegeneration, cognitive decrease and memory loss owing to the formation of strong cross-link DNA and protein and other molecules. The development of efficient methods for biological FA detection is of great biomedical importance. Although a few one-photon FA fluorescent probes have been reported for imaging in living cells, probes excited by two photons are more suitable for bio-imaging due to their low background fluorescence, less photobleaching, and deep penetration depth. In this study, a two-photon fluorescent probe for FA detection and bio-imaging in living cells and tissues was reported. The detection is based on the 2-aza-Cope sigmatropic rearrangement followed by elimination to release the fluorophore, resulting in both one- and two-photon excited fluorescence increase. The probe showed a high sensitivity to FA with a detection limit of 0.2 µM. Moreover, enabled the two-photon bio-imaging of FA in live HEK-293 cells and tissues with tissue-imaging depths of 40-170 µm. Furthermore, could be applied for the monitoring of endogenous FA in live MCF-7 cells, presaging its practical applications in biological systems.


Assuntos
Corantes Fluorescentes , Formaldeído/análise , Fígado/diagnóstico por imagem , Animais , Células HEK293 , Humanos , Células MCF-7 , Camundongos Nus , Estrutura Molecular , Fótons
16.
Anal Chem ; 88(3): 1639-46, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26744211

RESUMO

Upconversion nanoparticles (UCNPs) possess several unique features, but they suffer from surface quenching effects caused by the interaction between the UCNPs and fluorophore. Thus, the use of UCNPs for target-induced emission changes for biosensing and bioimaging has been challenging. In this work, fluorophore and UCNPs are effectively separated by a silica transition layer with a thickness of about 4 nm to diminish the surface quenching effect of the UCNPs, allowing a universal and efficient luminescence resonance energy transfer (LRET) ratiometric upconversion luminescence nanoplatform for biosensing applications. A pH-sensitive fluorescein derivative and Hg(2+)-sensitive rhodamine B were chosen as fluoroionphores to construct the LRET nanoprobes. Both showed satisfactory target-triggered ratiometric upconversion luminescence responses in both solution and live cells, indicating that this strategy may find wide applications in the design of nanoprobes for various biorelated targets.


Assuntos
Técnicas Biossensoriais/métodos , Luminescência , Medições Luminescentes/métodos , Nanopartículas/análise , Nanopartículas/química , Fluoresceínas/análise , Fluoresceínas/química , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Medições Luminescentes/instrumentação , Mercúrio/análise , Tamanho da Partícula , Rodaminas/análise , Rodaminas/química , Propriedades de Superfície , Células Tumorais Cultivadas
17.
Zhongguo Yi Liao Qi Xie Za Zhi ; 40(6): 413-7, 2016 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-29792601

RESUMO

In order to monitor the physiological condition of the human body in daily life, this study has designed a system of measuring physiological parameters based on cushion, which could detect heart rate and respiration rate when people are sitting. The system can continuously colect signal from cushion with a state of low pressure and without sticking any electrode on people's bodies. The hardware part mainly includes the signal acquisition circuit of the sensor, microcomputer control module and Bluetooth wireless transmission module. For the two physiological signals have the characteristic of the large noise and low-frequency, we use the Butterworth low-pass filter to process the signal according to an optimized Matlab algorithm. The results show that this system can measure heart rate and respiration rate accurately. Thus, the real-time monitoring on body's information can be implemented.


Assuntos
Algoritmos , Frequência Cardíaca , Taxa Respiratória , Humanos , Monitorização Fisiológica , Processamento de Sinais Assistido por Computador
18.
Infect Immun ; 83(4): 1587-97, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25644014

RESUMO

Staphylococcus aureus is a Gram-positive bacterium that is carried by a quarter of the healthy human population and that can cause severe infections. This pathobiosis has been linked to a balance between Toll-like receptor 2 (TLR2)-dependent pro- and anti-inflammatory responses. The relationship between these two types of responses is unknown. Analysis of 16 nasal isolates of S. aureus showed heterogeneity in their capacity to induce pro- and anti-inflammatory responses, suggesting that these two responses are independent of each other. Uncoupling of these responses was corroborated by selective signaling through phosphoinositol 3-kinase (PI3K)-Akt-mTOR and extracellular signal-regulated kinase (ERK) for the anti-inflammatory response and through p38 for the proinflammatory response. Uncoupling was also observed at the level of phagocytosis and phagosomal processing of S. aureus, which were required solely for the proinflammatory response. Importantly, the anti-inflammatory properties of an S. aureus isolate correlated with its ability to modulate T cell immunity. Our results suggest the presence of anti-inflammatory TLR2 ligands in the staphylococcal cell wall, whose identification may provide templates for novel immunomodulatory drugs.


Assuntos
Parede Celular/imunologia , Inflamação/microbiologia , Staphylococcus aureus/imunologia , Linfócitos T/imunologia , Receptor 2 Toll-Like/imunologia , MAP Quinases Reguladas por Sinal Extracelular/imunologia , Humanos , Inflamação/imunologia , Interleucina-10/imunologia , Fagocitose/imunologia , Fosfatidilinositol 3-Quinases/imunologia , Proteínas Proto-Oncogênicas c-akt/imunologia , Transdução de Sinais/imunologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Serina-Treonina Quinases TOR/imunologia , Fator de Necrose Tumoral alfa/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia
19.
Anal Chem ; 86(20): 10389-96, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25242376

RESUMO

Pyrene excimer possesses a large Stokes shift and long fluorescence lifetime and has been widely applied in developing time-resolved biosensing systems to solve the autofluorescence interference problems in biological samples. However, only a few of pyrene excimer-based small molecular probes have been reported so far. Ratiometric probes, on the other hand, can eliminate interferences from environmental factors such as instrumental efficiency and environmental conditions by a built-in correction of the dual emission bands but are ineffective for endogenous autofluorescence in biosystems. In this work, by combining the advantages of time-resolved fluorescence technique with ratiometric probe, we reported a bispyrene-fluorescein hybrid FRET cassette (PF) as a novel ratiometric time-resolved sensing platform for bioanalytical applications, with pH chosen as a biorelated target. The probe PF showed a fast, highly selective, and reversible ratiometric fluorescence response to pH in a wide range from 3.0 to 10.0 in buffered solution. By employing time-resolved fluorescence technique, the pH-induced fluorescence signal of probe PF can be well-discriminated from biological autofluorescence background, which enables us to detect pH in a range of 4.0-8.0 in cell media within a few seconds. It has also been preliminarily applied for ratiometric quantitative monitoring of pH changes in living cells with satisfying results. Since many fluorescein-based fluorescence probes have been developed, our strategy might find wide applications in design ratiometric time-resolved probes for detection of various biorelated targets.


Assuntos
Bioensaio/métodos , Fluoresceína/química , Transferência Ressonante de Energia de Fluorescência , Pirenos/química , Bioensaio/instrumentação , Corantes Fluorescentes/química , Células HeLa , Humanos , Estrutura Molecular
20.
Chem Commun (Camb) ; 50(16): 2040-2, 2014 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-24419273

RESUMO

Thewater-soluble CP was conjugatedwith a rhodamine spirolactam for the first time to develop a new FRET-based ratiometric fluorescence sensing platform(CP 1) for intracellular metal-ion probing. CP 1 exhibits excellent water-solubility with twowell-resolved emission peaks, which benefit ratiometric intracellular imaging applications.


Assuntos
Compostos Férricos/análise , Fluorescência , Corantes Fluorescentes/química , Lactamas/química , Polímeros/química , Rodaminas/química , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Íons/análise , Estrutura Molecular , Solubilidade , Compostos de Espiro/química , Água/química
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