Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Acta Pharmacol Sin ; 44(3): 680-692, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36114272

RESUMEN

The growth of solid tumors depends on tumor vascularization and the endothelial cells (ECs) that line the lumen of blood vessels. ECs generate a large fraction of ATP through glycolysis, and elevation of their glycolytic activity is associated with angiogenic behavior in solid tumors. 6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) positively regulates glycolysis via fructose-2/6-bisphosphate, the product of its kinase activity. Partial inhibition of glycolysis in tumor ECs by targeting PFKFB3 normalizes the otherwise abnormal tumor vessels, thereby reducing metastasis and improving the outcome of chemotherapy. Although a limited number of tool compounds exist, orally available PFKFB3 inhibitors are unavailable. In this study we conducted a high-throughput screening campaign against the kinase activity of PFKFB3, involving 250,240 chemical compounds. A total of 507 initial hits showing >50% inhibition at 20 µM were identified, 66 of them plus 1 analog from a similarity search consistently displayed low IC50 values (<10 µM). In vitro experiments yielded 22 nontoxic hits that suppressed the tube formation of primary human umbilical vein ECs at 10 µM. Of them, 15 exhibited binding affinity to PFKFB3 in surface plasmon resonance assays, including 3 (WNN0403-E003, WNN1352-H007 and WNN1542-F004) that passed the pan-assay interference compounds screening without warning flags. This study provides potential leads to the development of new PFKFB3 inhibitors.


Asunto(s)
Ensayos Analíticos de Alto Rendimiento , Neoplasias , Fosfofructoquinasa-2 , Humanos , Glucólisis , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Neoplasias/metabolismo , Neovascularización Patológica , Fosfofructoquinasa-2/antagonistas & inhibidores , Fosfofructoquinasa-2/metabolismo
2.
Angew Chem Int Ed Engl ; 62(12): e202300470, 2023 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-36722622

RESUMEN

Inspired by the signal transduction function of organophosphates in biological systems, bioactive organophosphates were utilized for the first time as chiral nodes to dictate the stereoselective assembly of hydrogen-bonded anionic cages. Phosphonomycin (antibiotics), tenofovir (antivirals), adenosine monophosphate (natural product, AMP) and clindamycin phosphate (antibiotics) were assembled with an achiral bis-monourea ligand, thereby leading to the stereoselective formation of quadruple or triple helicates. The extent of the stereoselectivity could be enhanced by either lowering the temperature or adding stronger-binding cations as templates. With the chiral anionic cages as the host, some enantioselectivity was achieved when binding chiral quaternary ammonium cations.

3.
Angew Chem Int Ed Engl ; 61(41): e202210478, 2022 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-35984093

RESUMEN

Anionocages have been developed as a unique family of hydrogen bonded cages. However, strategies for constructing anionocages are mainly limited to that based on (PO4 3- )-bisurea coordination, neither the ligands nor the anions lack the simplicity and diversity of the maturely developed analogues based on metal coordination (i.e. metallocage). We report herein a more simple strategy for anionocages design based on (RPO3 2- )-monourea coordination, utilizing monourea rather than bisurea as the hydrogen binding donor, and RPO3 2- rather than PO4 3- as the acceptor. Two fluorescent, quadruple helicate anionocages were constructed by a bis-monourea ligand, and dianions PhOPO3 2- (H1 ) or HOPO3 2- (H1A ), respectively, which were capable of encapsulating a series of cation guests. As revealed by molecular modeling, H1 features remarkable guest-adaptive cavity breathing without change of the quadruple helicate topology, which allowed the encapsulation of different sized guests in an "induced fit" manner.


Asunto(s)
Hidrógeno , Metales , Aniones/química , Ligandos , Metales/química , Modelos Moleculares
4.
Cancer Sci ; 112(4): 1402-1416, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33529452

RESUMEN

Human papillomavirus (HPV) is an important etiological factor of head and neck squamous cell carcinoma (HNSCC). HPV+ HNSCC patients usually have a better prognosis, which probably results from the higher infiltration of B lymphocytes. This study was purposed to detect the infiltration of B lymphocyte subsets and the correlation between B lymphocyte subsets and the prognosis in HPV-related HNSCC. In this study, 124 HPV+ and 513 HPV- HNSCC samples were obtained from the Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA) database for transcriptomic analysis. Infiltration of B lymphocytes subsets was detected with 7 HPV+ HNSCC and 13 HPV- HNSCC tissues through immunohistochemistry and immunofluorescence. One HPV- HNSCC sample was detected with single-cell sequencing for chemokine analysis. In the results, the infiltration of plasma cells (CD19+ CD38+ ) and memory B cells (MS4A1+ CD27+ ) was higher in HPV+ HNSCC samples. High infiltration of plasma cells and memory B cells was related to a better prognosis. High density of B lymphocytes was positively correlated with high CXCL13 production mainly from CD4+ T lymphocytes in HNSCC. These results indicated that a high density of plasma cells and memory B cells could predict excellent prognosis. CD4+ T lymphocytes might affect B lymphocytes and their subsets through the CXCL13/CXCR5 axis in HNSCC.


Asunto(s)
Alphapapillomavirus/inmunología , Linfocitos B/inmunología , Carcinoma de Células Escamosas/inmunología , Neoplasias de Cabeza y Cuello/inmunología , Carcinoma de Células Escamosas de Cabeza y Cuello/inmunología , Anciano , Linfocitos T CD4-Positivos/inmunología , Carcinoma de Células Escamosas/virología , Quimiocina CXCL13/inmunología , Femenino , Neoplasias de Cabeza y Cuello/virología , Humanos , Masculino , Persona de Mediana Edad , Infecciones por Papillomavirus/inmunología , Infecciones por Papillomavirus/virología , Pronóstico , Receptores CXCR5/inmunología , Carcinoma de Células Escamosas de Cabeza y Cuello/virología
5.
Int J Cancer ; 147(10): 2879-2890, 2020 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-32638385

RESUMEN

Laryngeal squamous cell carcinoma (LSCC) is a highly malignant tumor originated from respiratory system. Although there have been many improvements in therapy until now, reducing the high mortality remains difficult. Understanding the cellular heterogeneity of LSCC could contribute to improve this problem. Single-cell RNA sequencing was applied to dissect the cell composition and molecular characteristics of LSCC tissues. Immunohistochemistry staining of the LSCC tissues was performed to identify the spatial location of tumor cells. Survival analysis of marker genes was executed in The Cancer Genome Atlas to verify the correlation between each cell clusters and patients' prognosis. The LSCC tissue cells were finely grouped into various clusters, including tumor cells, immune cells, epithelial cells, fibroblasts and endothelial cells. Notably, in tumor cells, keratinocyte-like cells were in the core of tumor while malignant proliferating cells were located at the tumor edge. The malignant proliferating cells were correlated with poor prognosis. In summary, this is the first study to delineate a landscape of the LSCC intratumor heterogeneity. Our work might help researchers have a better understanding for tumor progression.


Asunto(s)
Biomarcadores de Tumor/genética , Carcinoma de Células Escamosas/patología , Neoplasias Laríngeas/patología , Análisis de Secuencia de ARN/métodos , Análisis de la Célula Individual/métodos , Anciano , Carcinoma de Células Escamosas/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Heterogeneidad Genética , Humanos , Neoplasias Laríngeas/genética , Masculino , Persona de Mediana Edad , Pronóstico , Análisis de Supervivencia
6.
Anal Chem ; 91(13): 8244-8251, 2019 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-31134796

RESUMEN

Mechanoelectronic DNA nanoswitches refer to designed oligonucleotide constructs that are composed of conduction-interrupted duplex stems functionally coupled to ligand recognition motifs; they have been shown to undergo remarkable conduction switching upon binding molecular ligands/analytes. Herein we report a divergent pair of such mechanoelectronic DNA switches, the "signal-on" 3'AA-1 switch and the "signal-off" NB-1 switch, both activated by and responded to mercury ions (Hg2+) at nM levels. We first investigated their charge transport efficiency at a biochemical level, by studying how distinct base sequence at the switches' central three-way junction and at the recognition motif (capable of forming T-Hg2+-T metallo-base pairs) influences their overall conductivity. Gel electrophoresis assays revealed that the presence of two unpaired adenines (AA) at the junction led to "signal-on" behavior with increasing Hg2+ concentration; divergently, absence of these adenines led to a "signal-off" behavior. Upon immobilization on gold electrodes, both DNA switches, with enhanced and inhibited conductivity, respectively, showed excellent sensitivity as well as selectivity toward Hg2+ and can be regenerated for multicycle applications. The high performance of these devices, as both nanoswitches and biosensors with robust and reproducible properties, highlights their potential as an outstanding new class of DNA mechanoelectronic components with built-in biosensing capabilities.


Asunto(s)
ADN/metabolismo , Mercurio/metabolismo , Emparejamiento Base , Secuencia de Bases , Técnicas Biosensibles , ADN/química , Conductividad Eléctrica , Electrodos
7.
Virol J ; 16(1): 78, 2019 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-31196108

RESUMEN

BACKGROUND: Human adenoviruses (HAdVs) cause a wide range of diseases. However, the genotype diversity and epidemiological information relating to HAdVs among hospitalized children with respiratory tract infections (RTIs) is limited. Here, we describe the epidemiology and genotype distribution of HAdVs associated with RTIs in Beijing, China. METHODS: Nasopharyngeal aspirates (NPA) were collected from hospitalized children with RTIs from April 2017 to March 2018. HAdVs were detected by a TaqMan-based quantitative real-time polymerase chain reaction (qPCR) assay, and the hexon gene was used for phylogenetic analysis. Epidemiological data were analyzed using statistical product and service solutions (SPSS) 21.0 software. RESULTS: HAdV was detected in 72 (5.64%) of the 1276 NPA specimens, with most (86.11%, 62/72) HAdV-positives cases detected among children < 6 years of age. HAdV-B3 (56.06%, 37/66) and HAdV-C2 (19.70%, 13/66) were the most frequent. Of the 72 HAdV-infected cases, 27 (37.50%) were co-infected with other respiratory viruses, most commonly parainfluenza virus (12.50%, 9/72) and rhinovirus (9.72%, 7/72). The log number of viral load ranged from 3.30 to 9.14 copies per mL of NPA, with no significant difference between the HAdV mono- and co-infection groups. The main clinical symptoms in the HAdV-infected patients were fever and cough, and 62 (86.11%, 62/72) were diagnosed with pneumonia. Additionally, HAdVs were detected throughout the year with a higher prevalence in summer. CONCLUSIONS: HAdV prevalence is related to age and season. HAdV-B and HAdV-C circulated simultaneously among the hospitalized children with RTIs in Beijing, and HAdV-B type 3 and HAdV-C type 2 were the most frequent.


Asunto(s)
Infecciones por Adenovirus Humanos/epidemiología , Hospitalización/estadística & datos numéricos , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/virología , Infecciones por Adenovirus Humanos/virología , Adenovirus Humanos/genética , Adenovirus Humanos/aislamiento & purificación , Adolescente , Beijing/epidemiología , Niño , Preescolar , Femenino , Variación Genética , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Nasofaringe/virología , Filogenia , Prevalencia , Radiografía , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Carga Viral
8.
Nucleic Acids Res ; 45(7): 3738-3751, 2017 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-28062857

RESUMEN

P-TEFb (CDK9/cyclin T) plays a central role in androgen receptor (AR)-mediated transactivation by phosphorylating both RNA polymerase 2 complex proteins and AR at S81. CDK9 dephosphorylation mobilizes P-TEFb from an inhibitory 7SK ribonucleoprotein complex, but mechanisms targeting phosphatases to P-TEFb are unclear. We show that AR recruits protein phosphatase 1α (PP1α), resulting in P-TEFb mobilization and CDK9-mediated AR S81 phosphorylation. This increased pS81 enhances p300 recruitment, histone acetylation, BRD4 binding and subsequent further recruitment of P-TEFb, generating a positive feedback loop that sustains transcription. AR S81 is also phosphorylated by CDK1, and blocking basal CDK1-mediated S81 phosphorylation markedly suppresses AR activity and initiation of this positive feedback loop. Finally, androgen-independent AR activity in castration-resistant prostate cancer (CRPC) cells is driven by increased CDK1-mediated S81 phosphorylation. Collectively these findings reveal a mechanism involving PP1α, CDK9 and CDK1 that is used by AR to initiate and sustain P-TEFb activity, which may be exploited to drive AR in CRPC.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Factor B de Elongación Transcripcional Positiva/metabolismo , Neoplasias de la Próstata/genética , Proteína Fosfatasa 1/metabolismo , Receptores Androgénicos/metabolismo , Antagonistas de Receptores Androgénicos/farmacología , Proteína Quinasa CDC2/metabolismo , Línea Celular Tumoral , Cromatina/metabolismo , Quinasa 9 Dependiente de la Ciclina/metabolismo , Retroalimentación Fisiológica , Humanos , Masculino , Neoplasias de la Próstata/enzimología , Neoplasias de la Próstata/metabolismo , Activación Transcripcional
9.
Virol J ; 14(1): 152, 2017 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-28806976

RESUMEN

BACKGROUND: Human Malawi polyomavirus (MWPyV) was discovered in 2012, but its prevalence and clinical characteristics are largely unknown. METHODS: We used real-time TaqMan-based PCR to detect MWPyV in the feces (n = 174) of children with diarrhea, nasopharyngeal aspirates (n = 887) from children with respiratory infections, and sera (n = 200) from healthy adults, and analyzed its clinical characteristics statistically. All the MWPyV-positive specimens were also screened for other common respiratory viruses. RESULTS: Sixteen specimens were positive for MWPyV, including 13 (1.47%) respiratory samples and three (1.7%) fecal samples. The samples were all co-infected with other respiratory viruses, most commonly with influenza viruses (69.2%) and human coronaviruses (30.7%). The MWPyV-positive children were diagnosed with bronchopneumonia or viral diarrhea. They ranged in age from 12 days to 9 years, and the most frequent symptoms were cough and fever. CONCLUSIONS: Real-time PCR is an effective tool for the detection of MWPyV in different types of samples. MWPyV infection mainly occurs in young children, and fecal-oral transmission is a possible route of its transmission.


Asunto(s)
Heces/virología , Nasofaringe/virología , Infecciones por Polyomavirus/epidemiología , Infecciones por Polyomavirus/virología , Poliomavirus/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa , Suero/virología , Adolescente , Adulto , Beijing/epidemiología , Bronconeumonía/epidemiología , Bronconeumonía/virología , Niño , Preescolar , ADN Viral/análisis , ADN Viral/genética , Diarrea/epidemiología , Diarrea/virología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Prevalencia
10.
J Micromech Microeng ; 27(1)2017 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-28798539

RESUMEN

Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate E. coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells (RBCs) shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care (POC) sepsis diagnostic device.

11.
Cell Mol Biol Lett ; 22: 26, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29213292

RESUMEN

BACKGROUND: Many studies have investigated the characteristics and biological activities of type III interferon (IFN), finding that it has similar features to type I IFN but also unique actions because it is recognized by a different receptor. RESULTS: A full-length recombinant human IFN-λ1 (rhIFN-λ1) cDNA was cloned into the pDF expression vector and stably expressed in Flp-In-CHO cells. After four purification steps (ammonium sulfate precipitation, SP Sepharose chromatography, Blue Sepharose 6 fast flow affinity chromatography and molecular sieve chromatography), the rhIFN-λ1 had a purity of about 90% and was found to have the predicted biological activities. The anti-viral activity of rhIFN-λ1 was determined as 106 IU/mg using the vesicular stomatitis virus (WISH-VSV) assay system. The anti-proliferation activity of rhIFN-λ1 was measured using the MTS method and the growth inhibition ratio was 57% higher than that for recombinant human IFN-α2b (rhIFN-α2b) when the rhIFN-λ1 concentration was 1000 IU/ml. rhIFN-λ1 had lower natural killer cell cytotoxicity than rhIFN-α2b. CONCLUSION: The Flp-In-CHO system is suitable for stably expressing rhIFN-λ1 that possesses the predicted anti-viral, anti-proliferation and natural killer cell cytotoxicity-promoting activities.


Asunto(s)
Interleucinas/metabolismo , Interleucinas/farmacología , Animales , Antivirales/farmacología , Células CHO , Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Clonales , Cricetulus , Vectores Genéticos/metabolismo , Interferones , Interleucinas/aislamiento & purificación , Células Asesinas Naturales/efectos de los fármacos , Células Asesinas Naturales/metabolismo , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacología , Transfección
12.
Am J Physiol Cell Physiol ; 310(4): C305-17, 2016 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26879375

RESUMEN

We previously found hydrogen sulfide (H2S) to be a new proangiogenic factor. However, the mechanisms underlying the cardiovascular effect of this small gas molecule remain largely unknown. The aim of the present study was to identify the essential microRNAs (miRNAs) involved in the transduction of H2S signals in vascular endothelial cells (ECs). The expression of miR-640 and its signaling elements, vascular endothelial growth factor receptor 2 (VEGFR2), hypoxia inducible factor 1-α (HIF1A), and mammalian target of rapamycin (mTOR), was measured using quantitative PCR and Western blotting. Overexpression and inhibition of miR-640 were performed to clarify their roles in mediating the effect of H2S. In addition, knockdown of VEGFR2, HIF1A, and mTOR was performed using siRNAs, dominant negative mutants, or inhibitors to examine their roles in the transduction of the H2S signals. miR-640 levels decreased in vascular ECs that were treated with H2S, whereas overexpression of miR-640 blunted the proangiogenic effect of H2S. Knockdown of either VEGFR2 or mTOR blunted the downregulation of miR-640 and the proangiogenic effect induced by H2S. In addition, miR-640 bound to the 3'-UTR of HIF1A mRNA and then inhibited the expression of HIF1A. The inhibition could be recovered by treating cells with H2S. Thus we concluded that miR-640 plays a pivotal role in mediating the proangiogenic effect of H2S; H2S acts through downregulation of the expression of miR-640 and increasing the levels of HIF1A through the VEGFR2-mTOR pathway.


Asunto(s)
Inductores de la Angiogénesis/farmacología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Sulfuro de Hidrógeno/farmacología , MicroARNs/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Regiones no Traducidas 3' , Sitios de Unión , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Regulación hacia Abajo , Células Endoteliales de la Vena Umbilical Humana/enzimología , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , MicroARNs/genética , Mutación , Interferencia de ARN , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/genética , Transfección , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética
13.
Anal Chem ; 87(8): 4385-93, 2015 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-25735847

RESUMEN

A label free lectin biosensor developed in our laboratory that can quantitatively measure the binding between the lectin immobilized at the carbohydrate sensor surface and the lipopolysaccharide (LPS) on Gram-negative bacteria was demonstrated for an antibiotic susceptibility assay. The biosensor utilizes a polythiophene interface containing fused quinone moieties glycosylated to form a carbohydrate platform for the immobilization of Concanavalin A (Con A) and is capable of LPS binding measurements via orthogonal quartz crystal microbalance and electrochemical readouts (EQCM). Such orthogonal transduction provides cross-validation, better sensor sensitivity, and a large dynamic range of the measurements. We have applied this label free lectin biosensor for a new antibiotic susceptibility assay by characterizing the antimicrobial activities of various antibiotics (i.e., ciprofloxacin, ceftriaxone, and tetracycline) against Escherichia coli W1485 as a model system. The label free biosensor allows both end point and real time measurements of antibiotic effects on the bacterial cell surface LPS, which is shown to correlate to their antibiotic effects. At the end point, after 18 h incubation of bacterial cells with these three antibiotics respectively, the bacterial LPS binding signal was reduced to 23%, 27%, and 38%, respectively, for the three antibiotics, indicating that ciprofloxacin is the most effective against this E. coli strain. Real time measurements at the 1 h time point showed a similar trend with a reduction of binding to 91%, 93%, and 95%, respectively. From the binding kinetics of these measurements, the relaxation time (τ) was obtained, where higher τ value means slow binding interactions between the lectin and the bacterial LPS. The obtained order of τ, (i.e., τciprofloxacin > τceftriaxone > τtetracycline) again indicated that ciprofloxacin has more bactericidal activity than the other two antibiotics with the same concentrations. Thus, we are able to establish that the reduction in the binding of LPS with the lectin Con A sensor upon exposure to various antibiotics has a direct relation with the antibiotic dosages making this label free biosensor assay promising for therapeutic management of these drugs as well as for applications in antibiotic research and development.


Asunto(s)
Antibacterianos/farmacología , Técnicas Biosensibles , Escherichia coli/química , Escherichia coli/efectos de los fármacos , Lectinas/química , Lipopolisacáridos/análisis , Antibacterianos/química
14.
Anal Chem ; 87(3): 1560-8, 2015 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-25569130

RESUMEN

In this report, a new polythiophene interface is fabricated containing fused quinone moieties which are then glycosylated to form a carbohydrate platform for bacterial detection. Very importantly, this interface can be used for label-free and reagentless detection, both by electrochemical and Quartz Crystal Microbalance (QCM) transducers and by using the direct pili-mannose binding as well as Concanavalin A (Con A) mediated lipopolysaccharides (LPS)-mannose binding. The conductive polymer's unique collective properties are very sensitive to very minor perturbations, which result in significant changes of electrical conductivity and providing amplified sensitivity and improved limits of detection (i.e., 25 cell/mL for electrochemical sensor and 50 cells/mL for QCM sensor), a widened logarithmic range of detection (i.e., 3-7 for pili-mannose binding and 2-8 for Con A mediated binding), high specificity and selectivity, and an extraordinary reliability by a mechanism of internal validation. With these analytical performances, the described biosensor is envisaged for being capable of differentiating Gram-negative bacterial strain and species, for many important applications.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Infecciones por Escherichia coli/diagnóstico , Escherichia coli/aislamiento & purificación , Polímeros/química , Tecnicas de Microbalanza del Cristal de Cuarzo , Quinonas/química , Tiofenos/química , Técnicas Biosensibles/métodos , Concanavalina A/química , Técnicas Electroquímicas/métodos , Infecciones por Escherichia coli/microbiología , Glicosilación , Humanos , Manosa/química , Tecnicas de Microbalanza del Cristal de Cuarzo/métodos , Sensibilidad y Especificidad
15.
Virol J ; 12: 166, 2015 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-26463646

RESUMEN

BACKGROUND: HPyV6 is a novel human polyomavirus (HPyV), and neither its natural history nor its prevalence in human disease is well known. Therefore, the epidemiology and phylogenetic status of HPyV6 must be systematically characterized. METHODS: The VP1 gene of HPyV6 was detected with an established TaqMan real-time PCR from nasopharyngeal aspirate specimens collected from hospitalized children with respiratory tract infections. The HPyV6-positive specimens were screened for other common respiratory viruses with real-time PCR assays. RESULTS: The prevalence of HPyV6 was 1.7 % (15/887), and children ≤ 5 years of age accounted for 80 % (12/15) of cases. All 15 HPyV6-positive patients were coinfected with other respiratory viruses, of which influenza virus A (IFVA) (8/15, 53.3 %) and respiratory syncytial virus (7/15, 46.7 %) were most common. All 15 HPyV6-positive patients were diagnosed with lower respiratory tract infections, and their viral loads ranged from 1.38 to 182.42 copies/µl nasopharyngeal aspirate specimen. The most common symptoms were cough (100 %) and fever (86.7 %). The complete 4926-bp genome (BJ376 strain, GenBank accession number KM387421) was amplified and showed 100 % identity to HPyV6 strain 607a. CONCLUSIONS: The prevalence of HPyV6 was 1.7 % in nasopharyngeal aspirate specimens from hospitalized children with respiratory tract infections, as analyzed by real-time PCR. Because the coinfection rate was high and the viral load low, it was not possible to establish a correlation between HPyV6 and respiratory diseases.


Asunto(s)
Filogenia , Infecciones por Polyomavirus/epidemiología , Infecciones por Polyomavirus/virología , Poliomavirus/clasificación , Poliomavirus/aislamiento & purificación , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/virología , Adolescente , Beijing/epidemiología , Niño , Niño Hospitalizado , Preescolar , Análisis por Conglomerados , ADN Viral/química , ADN Viral/genética , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Datos de Secuencia Molecular , Nasofaringe/virología , Orthomyxoviridae , Poliomavirus/genética , Prevalencia , Reacción en Cadena en Tiempo Real de la Polimerasa , Virus Sincitiales Respiratorios , Análisis de Secuencia de ADN , Homología de Secuencia
16.
J Biol Chem ; 288(9): 6478-87, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-23306204

RESUMEN

Gene expression profiling has identified breast cancer (BCa) subtypes, including an aggressive basal-like (BL) subtype. The molecular signals underlying the behavior observed in BL-BCa group are largely unknown, although recent results indicate a prevalent increase in Wnt/ß-catenin activity. Our immunohistochemistry study confirmed that SOX9, one of the BL-BCa signature genes, was expressed by most BL-BCa, and its expression correlated with indicators of poor prognosis. Importantly, BCa gene expression profiling strongly associated SOX9 with the expression of Wnt/ß-catenin pathway components, LRP6 and TCF4. In cancer cell lines, SOX9 silencing reduced cell proliferation and invasion, LRP6 and TCF4 transcription, and decreased Wnt/ß-catenin activation. SOX9 expression was also increased by Wnt, indicating that SOX9 is at the center of a positive feedback loop that enhances Wnt/ß-catenin signaling. Consistently, SOX9 overexpression in BCa cell lines and transgenic SOX9 expression in breast epithelium caused increased LRP6 and TCF4 expression and Wnt/ß-catenin activation. These results identify SOX9-mediated Wnt/ß-catenin activation as one of the molecular mechanisms underlying aberrant Wnt/ß-catenin activity in BCa, especially in the BL-BCa subgroup.


Asunto(s)
Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/biosíntesis , Neoplasias de la Mama/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/biosíntesis , Neoplasias Mamarias Animales/metabolismo , Proteínas de Neoplasias/metabolismo , Factor de Transcripción SOX9/metabolismo , Factores de Transcripción/biosíntesis , Vía de Señalización Wnt , Animales , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Femenino , Humanos , Inmunohistoquímica , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/genética , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología , Glándulas Mamarias Humanas/metabolismo , Glándulas Mamarias Humanas/patología , Neoplasias Mamarias Animales/genética , Neoplasias Mamarias Animales/patología , Ratones , Ratones Transgénicos , Proteínas de Neoplasias/genética , Factor de Transcripción SOX9/genética , Factor de Transcripción 4 , Factores de Transcripción/genética , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
17.
Int J Biol Macromol ; 269(Pt 1): 132097, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38710249

RESUMEN

Biodegradable polymer blends filled with rod-like polysaccharide nanocrystals have attracted much attention because each component in this type of ternary composites is biodegradable, and the final properties are more easily tailored comparing to those of binary composites. In this work, chitin nanocrystals (ChNCs) were used as nanofiller for the biodegradable poly(ε-caprolactone) (PCL)/polylactide (PLA) immiscible blend to prepare ternary composites for a crystallization study. The results revealed that the crystallization behavior of PCL/PLA blend matrices strongly depended on the surface properties of ChNCs. Non-modified ChNCs and modified ChNCs played completely different roles during crystallization of the ternary systems: the former was inert filler, while the latter acted as anti-nucleator to the PCL phase. This alteration was resulted from the improved ChNC-PCL affinity after modification of ChNCs, which was due to the 'interfacial dilution effect' and the preferential dispersion of ChNCs. This work presents a unique perspective on the nucleation role of ChNCs in the crystallization of immiscible PCL/PLA blends, and opens up a new application scenario for ChNCs as anti-nucleator.


Asunto(s)
Quitina , Cristalización , Interacciones Hidrofóbicas e Hidrofílicas , Nanopartículas , Poliésteres , Poliésteres/química , Quitina/química , Nanopartículas/química
18.
Chin J Nat Med ; 22(4): 329-340, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38658096

RESUMEN

The management of colorectal cancer (CRC) poses a significant challenge, necessitating the development of innovative and effective therapeutics. Our research has shown that notoginsenoside Ft1 (Ng-Ft1), a small molecule, markedly inhibits subcutaneous tumor formation in CRC and enhances the proportion of CD8+ T cells in tumor-bearing mice, thus restraining tumor growth. Investigation into the mechanism revealed that Ng-Ft1 selectively targets the deubiquitination enzyme USP9X, undermining its role in shielding ß-catenin. This leads to a reduction in the expression of downstream effectors in the Wnt signaling pathway. These findings indicate that Ng-Ft1 could be a promising small-molecule treatment for CRC, working by blocking tumor progression via the Wnt signaling pathway and augmenting CD8+ T cell prevalence within the tumor environment.


Asunto(s)
Linfocitos T CD8-positivos , Neoplasias Colorrectales , Ubiquitina Tiolesterasa , Vía de Señalización Wnt , Animales , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/metabolismo , Linfocitos T CD8-positivos/efectos de los fármacos , Ratones , Humanos , Vía de Señalización Wnt/efectos de los fármacos , Ubiquitina Tiolesterasa/metabolismo , Ubiquitina Tiolesterasa/genética , Ginsenósidos/farmacología , Ginsenósidos/uso terapéutico , Línea Celular Tumoral , Transducción de Señal/efectos de los fármacos , beta Catenina/metabolismo , Ratones Endogámicos BALB C
19.
MedComm (2020) ; 5(5): e521, 2024 May.
Artículo en Catalán | MEDLINE | ID: mdl-38660687

RESUMEN

This study systematically analyzed the molecular mechanism and function of nuclear factor kappa B subunit 2 (NFKB2) in colorectal cancer (CRC) to investigate the potential of NFKB2 as a therapeutic target for CRC. Various experimental techniques, including RNA sequencing, proteome chip assays, and small molecule analysis, were used to obtain a deeper understanding of the regulation of NFKB2 in CRC. The results revealed that NFKB2 was upregulated in a significant proportion of patients with advanced hepatic metastasis of CRC. NFKB2 played an important role in promoting tumor growth through CD8+ T-cell exhaustion. Moreover, NFKB2 directly interacted with signal transducer and activator of transcription 2 (STAT2), leading to increased phosphorylation of STAT2 and the upregulation of programmed death ligand 1 (PD-L1). Applying a small molecule inhibitor of NFKB2 (Rg5) led to a reduction in PD-L1 expression and improved response to programmed death-1 blockade-based immunotherapy. In conclusion, the facilitated NFKB2-STAT2/PD-L1 axis may suppress immune surveillance in CRC and targeting NFKB2 may enhance the efficacy of immunotherapeutic strategies. Our results provide novel insights into the molecular mechanisms underlying the contribution of NFKB2 in CRC immune escape.

20.
Cancer Lett ; 597: 217047, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38871245

RESUMEN

Bone metastasis is common in breast cancer and more effective therapies are required, however, its molecular mechanism is poorly understood. Additionally, the role of the m6A reader YTHDF1 in bone metastasis of breast cancer has not been reported. Here, we reveal that the increased expression of YTHDF1 is clinically correlated with breast cancer bone metastases. YTHDF1 promotes migration, invasion, and osteoblast adhesion and induces osteoclast differentiation of cancer cells in vitro and vivo. Mechanically, RNA-seq, MeRIP-seq and RIP-seq analysis, and molecular biology experiments demonstrate that YTHDF1 translationally enhances EZH2 and CDH11 expression by reading m6A-enriched sites of their transcripts. Moreover, adeno-associated virus (AAV) was used to deliver shYTHDF1 (shYTHDF1-AAV) in intratibial injection models, eliciting a significant suppressive effect on breast cancer bone metastatic formation and osteolytic destruction. Overall, we uncovered that YTHDF1 promotes osteolytic bone metastases of breast cancer by inducing EZH2 and CDH11 translation.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA