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1.
Int J Biol Macromol ; 280(Pt 1): 135654, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39278452

RESUMEN

In recent years, exosomes, as an important medium of intercellular information transmission, have received extensive attention for their potential in the treatment of liver fibrosis. The purpose of this study was to investigate the role of exosome natural lipid membrane proteins in the treatment of liver fibrosis, with emphasis on the regulatory mechanism through the TGF-ß/SMAD signaling pathway. Exosomes were extracted from healthy human hepatocytes and their membrane protein components were identified by mass spectrometry. Subsequently, the effects of these exosomes and their membrane proteins on the TGF-ß/SMAD signaling pathway were examined using in vitro cell models and mouse liver fibrosis models. Western blot, qPCR and immunofluorescence were used to analyze the expression of fibrosis markers and the activity of signaling pathways. In vitro cell experiments, fibrotic cells showed an obvious reversal trend after treating exosome membrane proteins. In a mouse model of liver fibrosis, the injection of exosome membrane proteins significantly improved the degree of fibrosis in liver tissue.

2.
Mol Hum Reprod ; 30(10)2024 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-39254642

RESUMEN

Studies on DNA methylation alterations associated with pre-eclampsia (PE) have improved our understanding of the mechanisms underlying this disorder. However, differentially methylated cytosines (DMCs) have not been adjusted for cell-type heterogeneity, hampering the identification of alterations that drive disease risk. Using a reference-based, cell-type deconvolution approach, we estimated the nuclear proportions of 335 placental samples based on DNA methylation data. We found that the nuclei of total trophoblast lineages accounted for more than 80% of the placental samples, with a significant increase in PE placentas. The nuclear proportions of stromal and Hofbauer cells decreased in PE placentas. Our nuclear proportion estimation reflected previous histological knowledge on the changes in cell type proportions in PE placentas. We corrected 2125 DMCs associated with early-onset PE for cell-type heterogeneity by adjusting for the nuclear proportions and observed a notable reduction in the association signals, with 145 probes not reaching epigenome-wide significance. After correction, the top 200 significant DMCs were strongly enriched in active enhancers in trophoblast lineages, whereas 145 non-significant probes were enriched in regions with a quiescent state of chromatin. Our results suggest that future epigenetic studies of PE should focus on functional regulatory sequences.


Asunto(s)
Núcleo Celular , Metilación de ADN , Epigénesis Genética , Placenta , Preeclampsia , Preeclampsia/genética , Preeclampsia/metabolismo , Preeclampsia/patología , Humanos , Femenino , Embarazo , Placenta/metabolismo , Placenta/patología , Núcleo Celular/metabolismo , Núcleo Celular/genética , Trofoblastos/metabolismo , Trofoblastos/patología , Adulto
3.
Biosensors (Basel) ; 14(8)2024 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-39194599

RESUMEN

Viral hepatitis is a systemic infectious diseases caused by various hepatitis viruses, primarily leading to liver damage. It is widely prevalent worldwide, with hepatitis viruses categorized into five types: hepatitis A, B, C, D, and E, based on their etiology. Currently, the detection of hepatitis viruses relies on methods such as enzyme-linked immunosorbent assay (ELISA), immunoelectron microscopy to observe and identify viral particles, and in situ hybridization to detect viral DNA in tissues. However, these methods have limitations, including low sensitivity, high error rates in results, and potential false negative reactions due to occult serum infection conditions. To address these challenges, we have designed an AuNPs-DNA walker method that uses gold nanoparticles (AuNPs) and complementary DNA strands for detecting viral DNA fragments through a colorimetric assay and fluorescence detection. The DNA walker, attached to gold nanoparticles, comprises a long walking strand with a probe sequence bound and stem-loop structural strands featuring a modified fluorescent molecule at the 3' end, which contains the DNAzyme structural domain. Upon the addition of virus fragments, the target sequence binds to the probe chains. Subsequently, the long walking strand is released and continuously hybridizes with the stem-loop structural strand. The DNAzyme undergoes hydrolytical cleavage by Mg2+, breaking the stem-loop structural strand into linear single strands. As a result of these structural changes, the negative charge density in the solution decreases, weakening spatial repulsion and rapidly reducing the stability of the DNA walker. This leads to aggregation upon the addition of a high-salt solution, accompanied by a color change. Virus typing can be performed through fluorescence detection. The innovative method can detect DNA/RNA fragments with high specificity for the target sequence, reaching concentrations as low as 1 nM. Overall, our approach offers a more convenient and reliable method for the detection of hepatitis viruses.


Asunto(s)
ADN Viral , Oro , Nanopartículas del Metal , Oro/química , Nanopartículas del Metal/química , ADN Viral/análisis , Virus de Hepatitis , Técnicas Biosensibles , Colorimetría , Humanos , ADN Catalítico/química , Colorantes Fluorescentes/química
4.
J Genet Genomics ; 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-39002897

RESUMEN

Facial morphology, a complex trait influenced by genetics, holds great significance in evolutionary research. However, due to limited fossil evidence, the facial characteristics of Neanderthals and Denisovans have remained largely unknown. In this study, we conducted a large-scale multi-ethnic meta-analysis of the genome-wide association study (GWAS), including 9674 East Asians and 10,115 Europeans, quantitatively assessing 78 facial traits using 3D facial images. We identified 71 genomic loci associated with facial features, including 21 novel loci. We developed a facial polygenic score (FPS) that enables the prediction of facial features based on genetic information. Interestingly, the distribution of FPSs among populations from diverse continental groups exhibited relevant correlations with observed facial features. Furthermore, we applied the FPS to predict the facial traits of seven Neanderthals and one Denisovan using ancient DNA and aligned predictions with the fossil records. Our results suggested that Neanderthals and Denisovans likely shared similar facial features, such as a wider but shorter nose and a wider endocanthion distance. The decreased mouth width was characterized specifically in Denisovans. The integration of genomic data and facial trait analysis provides valuable insights into the evolutionary history and adaptive changes in human facial morphology.

5.
Biol Psychiatry ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38942348

RESUMEN

BACKGROUND: Mosaic chromosomal alterations are implicated in neuropsychiatric disorders, but the contribution to schizophrenia (SCZ) risk for somatic copy number variations (sCNVs) emerging in early developmental stages has not been fully established. METHODS: We analyzed blood-derived genotype arrays from 9715 patients with SCZ and 28,822 control participants of Chinese descent using a computational tool (MoChA) based on long-range chromosomal information to detect mosaic chromosomal alterations. We focused on probable early developmental sCNVs through stringent filtering. We assessed the burden of sCNVs across varying cell fraction cutoffs, as well as the frequency with which genes were involved in sCNVs. We integrated this data with the PGC (Psychiatric Genomics Consortium) dataset, which comprises 12,834 SCZ cases and 11,648 controls of European descent, and complemented it with genotyping data from postmortem brain tissue of 936 participants (449 cases and 487 controls). RESULTS: Patients with SCZ had a significantly higher somatic losses detection rate than control participants (1.00% vs. 0.52%; odds ratio = 1.91; 95% CI, 1.47-2.49; two-sided Fisher's exact test, p = 1.49 × 10-6). Further analysis indicated that the odds ratios escalated proportionately (from 1.91 to 2.78) with the increment in cell fraction cutoffs. Recurrent sCNVs associated with SCZ (odds ratio > 8; Fisher's exact test, p < .05) were identified, including notable regions at 10q21.1 (ZWINT), 3q26.1 (SLITRK3), 1q31.1 (BRINP3) and 12q21.31-21.32 (MGAT4C and NTS) in the Chinese cohort, and some regions were validated with PGC data. Cross-tissue validation pinpointed somatic losses at loci like 1p35.3-35.2 and 19p13.3-13.2. CONCLUSIONS: The study highlights the significant impact of mosaic chromosomal alterations on SCZ, suggesting their pivotal role in the disorder's genetic etiology.

6.
Arthritis Rheumatol ; 75(11): 1947-1957, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37219934

RESUMEN

OBJECTIVE: Previous studies have underlined the genetic susceptibility in the pathogenesis of palindromic rheumatism (PR), but the known PR loci only partially explain the disease's genetic background. We aimed to genetically identify PR by whole-exome sequencing (WES). METHODS: This multicenter prospective study was conducted in 10 Chinese specialized rheumatology centers between September 2015 and January 2020. WES was performed in 185 patients with PR and in 272 healthy controls. PR patients were divided into PR subgroups who were negative for anti-citrullinated protein antibody (ACPA-) and positive for ACPA (ACPA+) according to ACPA titer (cutoff value 20 IU/liter). We conducted whole-exome association analysis for the WES data. We used HLA imputation to type HLA genes. In addition, we used the polygenic risk score to measure the genetic correlations between PR and rheumatoid arthritis (RA) and the genetic correlations between ACPA- PR and ACPA+ PR. RESULTS: Among 185 patients with PR enrolled in our study, 50 patients (27.02%) were ACPA+ and 135 PR patients (72.98%) were ACPA-. We identified 8 novel loci (in the ACPA- PR group: ZNF503, RPS6KL1, HOMER3, HLA-DRA; in the ACPA+ PR group: RPS6KL1, TNPO2, WASH2P, FANK1) and 3 HLA alleles (in the ACPA- PR group: HLA-DRB1*0803 and HLA-DQB1; in the ACPA+ PR group: HLA-DPA1*0401) that were associated with PR and that surpassed genome-wide significance (P < 5 × 10-8 ). Furthermore, polygenic risk score analysis showed that PR and RA were not similar (R2 < 0.025), whereas ACPA+ PR and ACPA- PR showed a moderate genetic correlation (0.38 < R2 < 0.8). CONCLUSION: This study demonstrated the distinct genetic background between ACPA- and ACPA+ PR patients. Additionally, our findings strengthened that PR and RA were not genetically similar.


Asunto(s)
Artritis Reumatoide , Autoanticuerpos , Humanos , Genotipo , Perfil Genético , Secuenciación del Exoma , Estudios Prospectivos , Péptidos Cíclicos , Artritis Reumatoide/genética , Predisposición Genética a la Enfermedad , Cadenas HLA-DRB1/genética , Alelos
7.
Adv Sci (Weinh) ; 10(8): e2204177, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36658726

RESUMEN

Repopulation of residual tumor cells impedes curative radiotherapy, yet the mechanism is not fully understood. It is recently appreciated that cancer cells adopt a transient persistence to survive the stress of chemo- or targeted therapy and facilitate eventual relapse. Here, it is shown that cancer cells likewise enter a "radiation-tolerant persister" (RTP) state to evade radiation pressure in vitro and in vivo. RTP cells are characterized by enlarged cell size with complex karyotype, activated type I interferon pathway and two gene patterns represented by CST3 and SNCG. RTP cells have the potential to regenerate progenies via viral budding-like division, and type I interferon-mediated antiviral signaling impaired progeny production. Depleting CST3 or SNCG does not attenuate the formation of RTP cells, but can suppress RTP cells budding with impaired tumor repopulation. Interestingly, progeny cells produced by RTP cells actively lose their aberrant chromosomal fragments and gradually recover back to a chromosomal constitution similar to their unirradiated parental cells. Collectively, this study reveals a novel mechanism of tumor repopulation, i.e., cancer cell populations employ a reversible radiation-persistence by poly- and de-polyploidization to survive radiotherapy and repopulate the tumor, providing a new therapeutic concept to improve outcome of patients receiving radiotherapy.


Asunto(s)
Neoplasias , Humanos , Línea Celular Tumoral , Neoplasias/radioterapia
8.
Psychiatr Genet ; 32(5): 188-193, 2022 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-36125369

RESUMEN

BACKGROUND: Schizophrenia is a chronic brain disorder. Previously, the Schizophrenia Exome Sequencing Meta-analysis consortium identified 10 highest risk genes related to schizophrenia. This study aimed to analyze the relationship between the 10 highest risk genes identified by the SCHEMA and schizophrenia in a Chinese population. METHODS: A total of 225 variants in 10 genes were screened in a Chinese population of 6836 using a customized array. All variants were annotated through the Variant Effect Predictor tool, and the functional impacts of missense variants were assessed based on sorting intolerant from tolerant and PolyPhen-2 scores. The SHEsisPlus tool was used to analyze the association between risk genes and schizophrenia at the locus and gene levels. RESULTS: At the locus level, no missense variants significantly related to schizophrenia were found, but we detected three missense variants that appeared only in cases, including TRIO p. Arg1185Gln, RB1CC1 p. Arg1514Cys, and HERC1 p. Val4517Leu. At the gene level, five genes (TRIO, RB1CC1, HERC1, GRIN2A, and CACAN1G) with more than one variant analyzed were kept for the gene-level association analysis. Only the association between RB1CC1 and schizophrenia reached a significant level (OR = 1.634; 95% CI, 1.062-2.516; P = 0.025). CONCLUSION: In this study, we determined that RB1CC1 might be a risk gene for schizophrenia in the Chinese population. Our results provide new evidence for recognizing the correlation of these risk genes with the Chinese schizophrenia population.


Asunto(s)
Esquizofrenia , Pueblo Asiatico/genética , China , Predisposición Genética a la Enfermedad , Humanos , Polimorfismo de Nucleótido Simple/genética , Esquizofrenia/genética
9.
Research (Wash D C) ; 2022: 9781758, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35198984

RESUMEN

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has evolved many variants with stronger infectivity and immune evasion than the original strain, including Alpha, Beta, Gamma, Delta, Epsilon, Kappa, Iota, Lambda, and 21H strains. Amino acid mutations are enriched in the spike protein of SARS-CoV-2, which plays a crucial role in cell infection. However, the impact of these mutations on protein structure and function is unclear. Understanding the pathophysiology and pandemic features of these SARS-CoV-2 variants requires knowledge of the spike protein structures. Here, we obtained the spike protein structures of 10 main globally endemic SARS-CoV-2 strains using AlphaFold2. The clustering analysis based on structural similarity revealed the unique features of the mainly pandemic SARS-CoV-2 Delta variants, indicating that structural clusters can reflect the current characteristics of the epidemic more accurately than those based on the protein sequence. The analysis of the binding affinities of ACE2-RBD, antibody-NTD, and antibody-RBD complexes in the different variants revealed that the recognition of antibodies against S1 NTD and RBD was decreased in the variants, especially the Delta variant compared with the original strain, which may induce the immune evasion of SARS-CoV-2 variants. Furthermore, by virtual screening the ZINC database against a high-accuracy predicted structure of Delta spike protein and experimental validation, we identified multiple compounds that target S1 NTD and RBD, which might contribute towards the development of clinical anti-SARS-CoV-2 medicines. Our findings provided a basic foundation for future in vitro and in vivo investigations that might speed up the development of potential therapies for the SARS-CoV-2 variants.

11.
Transl Psychiatry ; 11(1): 343, 2021 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-34083506

RESUMEN

BACKGROUND: Clozapine is considered to be the most effective antipsychotic medication for schizophrenia. However, it is associated with several adverse effects such as leukopenia, and the underlying mechanism has not yet been fully elucidated. The authors performed a genome-wide association study (GWAS) in a Chinese population to identify genetic markers for clozapine-induced leukopenia (CIL) and clozapine-induced neutropenia (CIN). METHODS: A total of 1879 patients (225 CIL cases, including 43 CIN cases, and 1,654 controls) of Chinese descent were included. Data from common and rare single nucleotide polymorphisms (SNPs) were tested for association. The authors also performed a trans-ancestry meta-analysis with GWAS results of European individuals from the Clozapine-Induced Agranulocytosis Consortium (CIAC). RESULTS: The authors identified several novel loci reaching the threshold of genome-wide significance level (P < 5 × 10-8). Three novel loci were associated with CIL while six were associated with CIN, and two T cell related genes (TRAC and TRAT1) were implicated. The authors also observed that one locus with evidence close to genome-wide significance (P = 5.08 × 10-8) was near the HLA-B gene in the major histocompatibility complex region in the trans-ancestry meta-analysis. CONCLUSIONS: The associations provide novel and valuable understanding of the genetic and immune causes of CIL and CIN, which is useful for improving clinical management of clozapine related treatment for schizophrenia. Causal variants and related underlying molecular mechanisms need to be understood in future developments.


Asunto(s)
Antipsicóticos , Clozapina , Neutropenia , Esquizofrenia , Antipsicóticos/efectos adversos , Clozapina/efectos adversos , Estudio de Asociación del Genoma Completo , Humanos , Neutropenia/inducido químicamente , Neutropenia/tratamiento farmacológico , Neutropenia/genética , Esquizofrenia/tratamiento farmacológico , Esquizofrenia/genética
12.
World J Biol Psychiatry ; 22(1): 27-33, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32129128

RESUMEN

OBJECTIVES: Chromosome 8p12 was first identified as a schizophrenia (SCZ) risk locus in Chinese populations and replicated in European populations. However, the underlying functional variants still need to be further explored. In this study, we sought to identify plausible causal variants within this locus. METHODS: A total of 386 potentially functional variants from 29 genes within the 8p12 locus were analysed in 2403 SCZ cases and 2594 control subjects in the Han Chinese population using Affymetrix customised genotyping assays. SHEsisplus was used for association analysis. A multiple testing corrected p value (false discovery rate (FDR)) < .05 was considered significant, and an unadjusted p value < .05 was considered nominal evidence of an association. RESULTS: We did not find significant associations between the tested variants and SCZ. However, nominal associations were found for rs201292574 (unadjusted p = .033, FDR p = .571; 95% confidence interval (CI): 0.265-0.945; TACC1, NP_006274.2:p.Ala211Thr) and rs45563241 (unadjusted p = .039, FDR p = .571; 95% CI: 1.023-1.866; a synonymous mutation in ADRB3). CONCLUSIONS: Our results provide limited evidence for the associations between variants from protein coding regions in 8p12 and SCZ in the Chinese population. Analyses of both coding and regulatory variants in larger sample sizes are required to further clarify the causal variants for SCZ with this risk locus.


Asunto(s)
Esquizofrenia , Pueblo Asiatico/genética , Estudios de Casos y Controles , China , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo , Humanos , Polimorfismo de Nucleótido Simple , Receptores Adrenérgicos beta 3 , Esquizofrenia/genética
13.
Artículo en Inglés | MEDLINE | ID: mdl-32450113

RESUMEN

Multiple genetic risk factors have been associated with psychiatric disorders which provides the genetic insight to these disorders; however, the etiology of these disorders is still elusive. 15q13.3 was previously associated with schizophrenia, bipolar and other neurodevelopmental disorders. Whereas, the FAN1 which encodes the Fanconi anemia associated nuclease 1 was suggested to be causal gene for 15q13.3 related psychiatric disorders. This study aimed to investigate the association of FAN1 with three major psychiatric disorders. Herein, we conducted a case-control study with the Chinese Han population. Three single nucleotide polymorphisms (SNPs) of FAN1 were genotyped in 1248 schizophrenia cases, 1344 bipolar disorder cases, 1056 major depressive disorder cases and 1248 normal controls. We found that SNPs rs7171212 was associated with bipolar (pallele = 0.023, pgenotype = 0.022, OR = 0.658) and schizophrenia (pallele = 0.021, pgenotype = 0.019, OR = 0.645). Whereas, rs4779796 was associated with schizophrenia (pgenotype = 0.001, adjusted pgenotype = 0.003, OR = 1.089). In addition, rs7171212 (adjusted pallele = 0.018, adjusted pgenotype = 0.018, OR = 0.652) and rs4779796 (adjusted pgenotype = 0.024, OR = 1.12) showed significantly associated with combined cases of schizophrenia and bipolar disorder. Further, meta-analysis was performed with the case-control data and dataset extracted from previously reported genome-wide association study to validate the promising SNPs. Our results provide the new evidence that FAN1 may be a common susceptibility gene for schizophrenia and bipolar disorder in Han Chinese. These novel findings need further validation with larger sample size and functional characterization to understand the underlying pathogenic mechanism behind FAN1 in the prevalence of schizophrenia and bipolar disorders.


Asunto(s)
Trastorno Bipolar/epidemiología , Trastorno Bipolar/genética , Cromosomas Humanos Par 15/genética , Endodesoxirribonucleasas/genética , Exodesoxirribonucleasas/genética , Enzimas Multifuncionales/genética , Esquizofrenia/epidemiología , Esquizofrenia/genética , Adulto , Pueblo Asiatico , Estudios de Casos y Controles , China/epidemiología , Bases de Datos Factuales , Femenino , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Desequilibrio de Ligamiento , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple/genética , Adulto Joven
14.
Small ; 14(6)2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29283218

RESUMEN

The hepatitis B virus (HBV) genotyping may profoundly affect the accurate diagnosis and antiviral treatment of viral hepatitis. Existing genotyping methods such as serological, immunological, or molecular testing are still suffered from substandard specificity and low sensitivity in laboratory or clinical application. In a previous study, a set of high-efficiency hybridizable DNA origami-based shape ID probes to target the templates through which genetic variation could be determined in an ultrahigh resolution of atomic force microscopy (AFM) nanomechanical imaging are established. Here, as a further confirmatory research to explore the sensitivity and applicability of this assay, differentially predesigned DNA origami shape ID probes are also developed for precisely HBV genotyping. Through the specific identification of visualized DNA origami nanostructure with clinical HBV DNA samples, the genetic variation information of genotypes can be directly identified under AFM. As a proof-of-concept, five genotype B and six genotype C are detected in 11 HBV-infected patients' blood DNA samples of Han Chinese population in the single-blinded test. The AFM image-based DNA origami shape ID genotyping approach shows high specificity and sensitivity, which could be promising for virus infection diagnosis and precision medicine in the future.


Asunto(s)
ADN Viral/sangre , ADN Viral/genética , Genes Virales , Genotipo , Virus de la Hepatitis B/genética , China , ADN Viral/química , Etnicidad , Humanos , Microscopía de Fuerza Atómica , Conformación de Ácido Nucleico , Prueba de Estudio Conceptual
16.
Anal Chem ; 84(18): 7664-9, 2012 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-22928468

RESUMEN

We present a highly sensitive colorimetric method for microRNA (miRNA) detection. This method is based on a rolling-circle amplification (RCA) DNA machine, which integrates RCA, nicking enzyme signal amplification and DNAzyme signal amplification. The DNA machine is triggered by the hybridization of target miRNA with a rational designed padlock DNA template and activated by RCA. The resulting RCA product then autonomously replicates a multiple machinery cutter cycle and generates accumulated amount of products. Specifically, the DNA product in the present work is designed as a horseradish peroxidase (HRP)-mimicking DNAzyme, which could that catalyze a colorimetric reaction and generate colored product. Through these cascade amplifications, microRNA (miRNA) as low as 2 aM could be detected. As an example of in vivo application, miRNA from single Drosophila larva was successfully analyzed. Drosophila is a model organism that provides a powerful genetic tool to study gene functions. Study of Drosophila miRNAs has brought us knowledge of its biogenesis and biological functions. The analysis of miRNA typically requires a pretreatment process of extracting total RNAs from target cells, followed by quantitative analysis of target miRNA in total RNA samples, which nevertheless suffers from laborious total RNA extraction and time-consuming processes and poor limit of detection. Meanwhile, the tiny size of Drosophila makes it difficult to accurately measure trivial changes of its cellular miRNA levels. The ability to detect ultralow concentration of miRNA of the proposed method enables the analysis the expression of mir-1 in single Drosophila larva. We thus expect that the strategy may open new avenues for in situ miRNA analysis in single cell or living animals.


Asunto(s)
ADN Catalítico/metabolismo , Drosophila/metabolismo , MicroARNs/análisis , Técnicas de Amplificación de Ácido Nucleico , Animales , Benzotiazoles/química , Drosophila/crecimiento & desarrollo , Humanos , Peróxido de Hidrógeno/química , Larva/metabolismo , Ácidos Sulfónicos/química
17.
Chem Commun (Camb) ; 48(52): 6490-2, 2012 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-22622438

RESUMEN

A novel graphene-cobalt oxide hybrid needle-like electrode was fabricated for non-enzymatic glucose detection. Taking advantage of its small size, the needle electrode can probe glucose in a micro-droplet with high sensitivity.


Asunto(s)
Cobalto/química , Técnicas Electroquímicas/instrumentación , Glucosa/análisis , Grafito/química , Óxidos/química , Electrodos , Sensibilidad y Especificidad
19.
Chem Commun (Camb) ; 47(22): 6278-80, 2011 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-21503363

RESUMEN

We investigate interactions between graphene oxide and a Pb(2+)-dependent DNAzyme, based on which a Pb(2+) sensor with high sensitivity, selectivity and tunable dynamic range is developed.


Asunto(s)
ADN Catalítico/química , Grafito/química , Plomo/análisis , Metales/química , Nanoestructuras/química , Espectrometría de Fluorescencia/métodos , Carbocianinas/química , Iones/química , Óxidos/química
20.
Anal Bioanal Chem ; 399(10): 3459-64, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20803193

RESUMEN

The operation of DNA nanomachines is generally triggered by either conformational changes of DNA nanostructure or external environmental stimuli. In the present study, we demonstrate an alternative driving force, DNA methylation, to stimulate DNA machine operation. DNA methylation changes neither DNA sequence and conformation nor external environment, however, blocks its cleavage by corresponding methylation-sensitive restriction endonuclease. We thus designed a strand displacement amplification DNA machine, which could be stimulated upon DNA methylation and then autonomously generates accumulated amounts of peroxidase-mimicking DNAzyme signaling machine products in an isothermal manner. The machine product DNAzyme could catalyze the H(2)O(2)-mediated oxidation of 2,2'-azino-bis(3-ethylbenzo thiazoline-6-sulfonic acid) (ABTS(2-)) to a colored product ABTS(·-). This methylation-stimulated DNA machine was further used as a colorimetric assay for analysis of methyltransferases activities and screening of methylation inhibitors. As compared with classical methylation assay, this facile isothermal DNA machine avoids the introduction of methylation-specific polymerase chain reaction and radioactive labels, which might be employed as an effective tool for DNA methylation analysis.


Asunto(s)
ADN-Citosina Metilasas/química , ADN/química , Inhibidores Enzimáticos/farmacología , Metilación de ADN , ADN-Citosina Metilasas/antagonistas & inhibidores , Estabilidad de Enzimas , Cinética
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