Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Genes Dev ; 30(7): 827-39, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26988418

RESUMO

Telomeric regions contain prominent sites of heterochromatin, which is associated with unique histone modification profiles such as the methylation of histone H3 at Lys9 (H3K9me). In fission yeast, the conserved telomeric shelterin complex recruits the histone H3K9 methyltransferase complex CLRC to establish subtelomeric heterochromatin. Although many shelterin mutations affect subtelomeric heterochromatin assembly, the mechanism remains elusive due to the diverse functions of shelterin. Through affinity purification, we found that shelterin directly associates with CLRC through the Ccq1 subunit. Surprisingly, mutations that disrupt interactions between shelterin subunits compromise subtelomeric heterochromatin without affecting CLRC interaction with shelterin component Pot1, located at chromosome ends. We further discovered that telomeric repeats are refractory to heterochromatin spreading and that artificial restoration of shelterin connections or increased heterochromatin spreading rescued heterochromatin defects in these shelterin mutants. Thus, subtelomeric heterochromatin assembly requires both the recruitment of CLRC by shelterin to chromosome ends and the proper connection of shelterin components, which allows CLRC to skip telomeric repeats to internal regions.


Assuntos
Montagem e Desmontagem da Cromatina/fisiologia , Heterocromatina/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/fisiologia , Proteínas de Ligação a Telômeros/metabolismo , Telômero/metabolismo , Montagem e Desmontagem da Cromatina/genética , Heterocromatina/genética , Histona Metiltransferases , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Mutação , Ligação Proteica , Schizosaccharomyces/enzimologia , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética , Complexo Shelterina , Telômero/genética , Proteínas de Ligação a Telômeros/genética
2.
J Biol Chem ; 298(3): 101679, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35124008

RESUMO

In the past decade, the cleavage protein irisin derived from fibronectin type III domain-containing protein 5 (FNDC5) in exercise-stimulated skeletal muscle has increasingly become a biomarker associated with metabolic syndrome and osteoporosis in humans. However, it is unclear how this protein facilitates muscle-adipose-bone connectivity in metabolic and skeletal homeostasis. In this study, we unexpectedly observed that the FNDC5 gene can be markedly activated during the differentiation of brown adipocytes but not white adipocytes, and that FNDC5 is specifically expressed in mouse brown adipose tissues (BATs). But unlike it in the skeletal muscles, the expression of FNDC5/irisin in BAT is promoted by cold exposure rather than exercise in mice. Analysis of promoter activity and chromatin immunoprecipitation further showed that peroxisome proliferator-activated receptor γ coactivator-1α and thyroid hormone receptors cooperate on the FNDC5 gene promoter to induce its transcription. We found that FNDC5/irisin stimulates the runt-related transcriptional factors RUNX1/2 via a focal adhesion kinase-dependent pathway in both bone and subcutaneous white adipose tissues. Mechanistically, focal adhesion kinase is stimulated by FNDC5/irisin and then facilitates E3 ubiquitin-protein ligase WW domain-containing protein 2 to ubiquitinate and subsequently activate RUNX1/2, culminating in the activation of osteoblast-related or thermogenesis-related genes. Interestingly, the PR domain containing protein 16 that is crucial for subcutaneous white adipose "browning" and skeletal development was found to form a complex with RUNX1/2 in a WW domain-containing protein 2-dependent manner. These findings elucidate a signaling mechanism by which FNDC5/irisin supports the muscle-adipose-bone connectivity, especially BAT-bone connectivity.


Assuntos
Subunidade alfa 1 de Fator de Ligação ao Core , Subunidade alfa 2 de Fator de Ligação ao Core , Fibronectinas , Proteína-Tirosina Quinases de Adesão Focal , Animais , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Fibronectinas/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Camundongos , Músculo Esquelético/metabolismo , Ubiquitinação
3.
Strahlenther Onkol ; 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37603050

RESUMO

PURPOSE: The goal of this study was to propose a knowledge-based planning system which could automatically design plans for lung cancer patients treated with intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS: From May 2018 to June 2020, 612 IMRT treatment plans of lung cancer patients were retrospectively selected to construct a planning database. Knowledge-based planning (KBP) architecture named αDiar was proposed in this study. It consisted of two parts separated by a firewall. One was the in-hospital workstation, and the other was the search engine in the cloud. Based on our previous study, A­Net in the in-hospital workstation was used to generate predicted virtual dose images. A search engine including a three-dimensional convolutional neural network (3D CNN) was constructed to derive the feature vectors of dose images. By comparing the similarity of the features between virtual dose images and the clinical dose images in the database, the most similar feature was found. The optimization parameters (OPs) of the treatment plan corresponding to the most similar feature were assigned to the new plan, and the design of a new treatment plan was automatically completed. After αDiar was developed, we performed two studies. The first retrospective study was conducted to validate whether this architecture was qualified for clinical practice and involved 96 patients. The second comparative study was performed to investigate whether αDiar could assist dosimetrists in improving the quality of planning for the patients. Two dosimetrists were involved and designed plans for only one trial with and without αDiar; 26 patients were involved in this study. RESULTS: The first study showed that about 54% (52/96) of the automatically generated plans would achieve the dosimetric constraints of the Radiation Therapy Oncology Group (RTOG) and about 93% (89/96) of the automatically generated plans would achieve the dosimetric constraints of the National Comprehensive Cancer Network (NCCN). The second study showed that the quality of treatment planning designed by junior dosimetrists was improved with the help of αDiar. CONCLUSIONS: Our results showed that αDiar was an effective tool to improve planning quality. Over half of the patients' plans could be designed automatically. For the remaining patients, although the automatically designed plans did not fully meet the clinical requirements, their quality was also better than that of manual plans.

4.
J Opt Soc Am A Opt Image Sci Vis ; 40(10): 1940-1946, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37855550

RESUMO

Rigorous coupled-wave analysis (RCWA) has become one of the most efficient electromagnetic solvers to cope with the diffractions of large-scale periodic nanostructures. Conventional RCWAs focus on planar diffractions and their iterative stabilities. Conical diffractions, as more general incidence cases, are paid little attention in developing their universal and stable implementations for multilayered gratings. Here, we reformulate RCWA algorithms step by step for conical diffractions in a global Cartesian coordinate system. By applying some mathematics tricks, it is found that boundary conditions in conical diffractions can be reduced to the same forms as that of planar diffractions. Conventional stable algorithms including enhanced transmittance matrices and scattering matrices can be directly implemented to attain robust diffraction efficiencies as well as electromagnetic fields for multilayered gratings. An exemplary application in diffractive-waveguide-based augmented reality verified our algorithms.

5.
J Opt Soc Am A Opt Image Sci Vis ; 40(3): A178-A182, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37133035

RESUMO

Emerging high brightness of color displays and high signal-to-noise ratio of camera sensors require an addition of white (W) subpixels to ordinary red, green, and blue (RGB) subpixels. Conventional algorithms converting RGB signals to RGBW signals suffer from reduced chroma of highly saturated colors and complicated coordinate transformations between RGB color spaces and color spaces defined by the Commission internationale de l'éclairage (CIE). In this work, we developed a complete set of RGBW algorithms to digitally code a color in the CIE-based color spaces, making complicated processes including color space transformations and white balancing become largely unnecessary. The analytic three-dimensional gamut can be obtained so that the maximal hue and luminance of a digital frame could be simultaneously obtained. Exemplary applications in adaptive controls of the colors of an RGB display in accordance with the W component of background light validate our theory. The algorithm opens an avenue toward accurate manipulations of digital colors for RGBW sensors and displays.

6.
Bioorg Chem ; 124: 105800, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35468415

RESUMO

Icariside II, a flavonol glycoside, one of the major components of Traditional Chinese Medicine Herba epimedii. In the present study, we found that Icariside II suppressed the proliferation of CRC by inducing cell cycle arrest and apoptosis in vitro and inhibited tumor growth in vivo. The further mechanism investigation showed that Icariside II suppressed the expression of ß-catenin and led to the functional inactivation of Wnt/ß-catenin signaling. Circß-catenin was considered as a promising candidate for mediating the tumorigenesis and the activation of Wnt/ß-catenin signaling in CRC cells. Furthermore, Icariside II has been proven to suppress the biogenesis of circß-catenin via epigenetically targeting DNA methyltransferases (DNMTs) to decrease global DNA methylation levels in CRC cells. Taken together, our results indicated that Icariside II suppressed tumorigenesis by epigenetically silencing the activation of circß-catenin-Wnt/ß-catenin axis in colorectal cancer. More importantly, the information gained from this study suggest that Icariside II may have great potential to be developed as a therapeutic drug for CRC patients.


Assuntos
Cateninas , Neoplasias Colorretais , Flavonoides , Via de Sinalização Wnt , beta Catenina , Carcinogênese , Cateninas/metabolismo , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Epigênese Genética/efeitos dos fármacos , Flavonoides/farmacologia , Humanos , Via de Sinalização Wnt/efeitos dos fármacos , Via de Sinalização Wnt/genética , beta Catenina/genética , beta Catenina/metabolismo
7.
J Chem Phys ; 154(7): 074701, 2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-33607882

RESUMO

Avalanche multiphoton photoluminescence (AMPL) is observed from coupled Au-Al nanoantennas under intense laser pumping, which shows more than one order of magnitude emission intensity enhancement and distinct spectral features compared with ordinary metallic photoluminescence. The experiments are conducted by altering the incident laser intensity and polarization using a home-built scanning confocal optical microscope. The results show that AMPL originates from the recombination of avalanche hot carriers that are seeded by multiphoton ionization. Notably, at the excitation stage, multiphoton ionization is shown to be assisted by the local electromagnetic field enhancement produced by coupled plasmonic modes. At the emission step, the giant AMPL intensity can be evaluated as a function of the local field environment and the thermal factor for hot carriers, in accordance with a linear relationship between the power law exponent coefficient and the emitted photon energy. The dramatic change in the spectral profile is explained by spectral linewidth broadening mechanisms. This study offers nanospectroscopic evidence of both the potential optical damages for plasmonic nanostructures and the underlying physical nature of light-matter interactions under a strong laser field; it illustrates the significance of the emerging topics of plasmonic-enhanced spectroscopy and laser-induced breakdown spectroscopy.

8.
Nano Lett ; 20(12): 8841-8846, 2020 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-33185450

RESUMO

Advances in electron-beam lithography (EBL) have fostered the prominent development of functional micro/nanodevices. Nonetheless, traditional EBL is predominantly applicable to large-area planar substrates and often suffers from chemical contamination and complex processes for handling resists. This paper reports a streamlined and ecofriendly approach to implement e-beam patterning on arbitrary shaped substrates, exemplified by solvent-free nanofabrication on optical fibers. The procedure starts with the vapor deposition of water ice as an electron resist and ends in the sublimation of the ice followed by a "blow-off" process. Without damage and contamination from chemical solvents, delicate nanostructures and quasi-3D structures are easily created. A refractive index sensor is further demonstrated by decorating plasmonic nanodisk arrays on the end face of a single-mode fiber. Our study provides a fresh perspective in EBL-based processing, and more exciting research exceeding the limits of traditional approaches is expected.

9.
Genes Dev ; 27(17): 1886-902, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24013502

RESUMO

Heterochromatin spreading leads to the silencing of genes within its path, and boundary elements have evolved to constrain such spreading. In fission yeast, heterochromatin at centromeres I and III is flanked by inverted repeats termed IRCs, which are required for proper boundary functions. However, the mechanisms by which IRCs prevent heterochromatin spreading are unknown. Here, we identified Bdf2, which is homologous to the mammalian bromodomain and extraterminal (BET) family double bromodomain proteins involved in diverse types of cancers, as a factor required for proper boundary function at IRCs. Bdf2 is enriched at IRCs through its interaction with the boundary protein Epe1. The bromodomains of Bdf2 recognize acetylated histone H4 tails and antagonize Sir2-mediated deacetylation of histone H4K16. Furthermore, abolishing H4K16 acetylation (H4K16ac) with an H4K16R mutation promotes heterochromatin spreading, and mimicking H4K16ac by an H4K16Q mutation blocks heterochromatin spreading at IRCs. Our results thus illustrate a mechanism of establishing chromosome boundaries at specific sites through the recruitment of a factor that protects euchromatic histone modifications. They also reveal a previously unappreciated function of H4K16ac in cooperation with H3K9 methylation to regulate heterochromatin spreading.


Assuntos
Heterocromatina/metabolismo , Elementos Isolantes/genética , Proteínas Nucleares/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Fatores de Transcrição/metabolismo , Inativação Gênica/fisiologia , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Histonas/metabolismo , Proteínas Nucleares/genética , Ligação Proteica , Estrutura Terciária de Proteína , Fatores de Transcrição/genética
10.
Genes Dev ; 27(22): 2489-99, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24240238

RESUMO

The RNAi pathway is required for heterochromatin assembly at repetitive DNA elements in diverse organisms. In fission yeast, loss of RNAi causes pericentric heterochromatin defects, compromising gene silencing and chromosome segregation. Here we show that deletion of telomere shelterin components restores pericentric heterochromatin and its functions in RNAi mutants. We further isolated a separation-of-function mutant of Poz1 and revealed that defective telomere silencing, but not telomere length control, is critical for bypassing RNAi. Further analyses demonstrated that compromising shelterin-mediated heterochromatin assembly in RNAi mutants releases heterochromatin protein Swi6, which is redistributed to pericentric regions through RNAi-independent heterochromatin assembly pathways. Given the high mobility of Swi6 protein and that increased levels of Swi6 facilitates heterochromatin spreading as well as ectopic heterochromatin assembly, our results suggest that constitutive heterochromatin domains use multiple pathways to form high-affinity platforms to restrain Swi6, thus limiting its availability and avoiding promiscuous heterochromatin formation.


Assuntos
Montagem e Desmontagem da Cromatina/genética , Heterocromatina/metabolismo , Interferência de RNA , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Ligação a Telômeros/genética , Proteínas Cromossômicas não Histona/metabolismo , Mutação , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Ligação a Telômeros/metabolismo
11.
J Biol Chem ; 293(51): 19710-19724, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30361437

RESUMO

Upon binding to the canonical WNT glycoproteins, Frizzled family receptors (FZDs) and low-density lipoprotein receptor-related protein 5/6 (LRP5/6) undergo a series of polymerizations on the cell surface that elicit canonical WNT/ß-catenin signaling. The hyperactivation of WNT/ß-catenin signaling is the major cause of tumorigenesis, but the mechanism in tumors such as hepatoma remains unclear. Here, we observed that WNT3A manifested the hyperactivity in ß-catenin-dependent signaling after binding to FZD's competitive inhibitory molecule secreted Frizzled-related protein 2 (SFRP2). To understand the mechanism of FZDs in the presence of SFRP2, we explored how FZDs can bind and activate the LRP5/6 signalosome independently of WNT glycoproteins. Our findings further revealed that oligomerizations of FZDs and LRP5/6 can integrate the cytoplasmic protein Dishevelled into the LRP5/6 signalosome, resulting in a robust activation of ligand-independent ß-catenin signaling. We propose that besides WNT-bridged FZD-WNT-LRP5/6 protein complexes, the homo- and hetero-oligomerizations of WNT receptors may contribute to the formation of the LRP5/6 signalosome on the cell surface. Of note, we identified four highly expressed FZDs in the hepatoma cell line HepG2, all of which significantly promoted ligand-independent LRP5/ß-catenin signaling. As FZDs are ectopically expressed in numerous tumors, our findings may provide a new perspective on tumor pathologies. Furthermore, the results in our study suggest that the composition and stoichiometry of FZDs and LRP5/6 within the LRP5/6 signalosome may tune the selection of bound WNT glycoproteins and configure downstream WNT/ß-catenin signaling.


Assuntos
Receptores Frizzled/química , Espaço Intracelular/metabolismo , Proteína-5 Relacionada a Receptor de Lipoproteína de Baixa Densidade/química , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/química , Multimerização Proteica , Proteína Wnt3A/metabolismo , beta Catenina/metabolismo , Ligação Competitiva , Carcinogênese , Linhagem Celular , Humanos , Ligantes , Proteínas de Membrana/metabolismo , Comunicação Parácrina , Estrutura Quaternária de Proteína , Transdução de Sinais
12.
Trends Genet ; 32(5): 284-294, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27005444

RESUMO

All living organisms are constantly exposed to stresses from internal biological processes and surrounding environments, which induce many adaptive changes in cellular physiology and gene expression programs. Unexpectedly, constitutive heterochromatin, which is generally associated with the stable maintenance of gene silencing, is also dynamically regulated in response to stimuli. In this review we discuss the mechanism of constitutive heterochromatin assembly, its dynamic nature, and its responses to environmental changes.


Assuntos
Montagem e Desmontagem da Cromatina/genética , Interação Gene-Ambiente , Heterocromatina/genética , Transcrição Gênica , Regulação da Expressão Gênica , Inativação Gênica , Histonas/genética , Humanos
14.
Molecules ; 24(10)2019 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-31109095

RESUMO

Licorice, the root and rhizome of Glycyrrhiza uralansis Fisch, is one of the most frequently used Traditional Chinese Medicines in rigorous clinical trials to remove toxins and sputum, and to relieve coughing. However, the aerial parts are not used so widely at present. It has been reported that the aerial parts have many bioactivities such as anti-microbial and anti-HIV activities. In this study, we aimed to discover the bioactive compounds from the leaves of G. uralensis. Four new compounds, licostilbene A-B (1-2) and licofuranol A-B (3-4), together with eight known flavonoids (5-12), were isolated and identified from the leaves of G. uralensis. Their structures were elucidated mainly by the interpretation of high-resolution electrospray mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR) spectroscopic data. Compared with quercetin, which showed a 50% inhibitory concentration (IC50) value of 4.08 µg/mL, compounds 1-9 showed significant anti-inflammatory activities by inhibiting lipopolysaccharide (LPS)-induced nitric oxide (NO) production with IC50 values of 2.60, 2.15, 3.21, 3.25, 2.00, 3.45, 2.53, 3.13 and 3.17 µg/mL, respectively. The discovery of these active compounds is important for the prevention and treatment of inflammation.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Glycyrrhiza/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Lipopolissacarídeos/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Óxido Nítrico/metabolismo , Células RAW 264.7 , Espectrometria de Massas por Ionização por Electrospray
15.
Zhongguo Zhong Yao Za Zhi ; 44(5): 975-982, 2019 Mar.
Artigo em Zh | MEDLINE | ID: mdl-30989858

RESUMO

This study aims to establish a combinative method based on fingerprint,assay of multi-component and chemometrics for quality evaluation of Magnoliae Officinalis Cortex. Twenty batches of samples were determined by UPLC and a common mode of fingerprint was established. The similarities between fingerprints of 20 batches of samples were over 0. 90 and the common mode were evaluated. Eight components were identified as syringing, magnocurarine, magnoflorine, magnoloside B, magnoloside A, honokiol,magnolol,and piperitylmagnolol by comparison with reference substances and their content in samples were simultaneously determined.Based on the results,the fingerprint had good consistency between the same origin and minor diversity between the different sources.Piperitylmagnolol and peak 13 could be used as a distinction with the different sources. According to content of 8 components,Fisher discriminant analysis model was established and different source sample was classified pursuant to the discriminant fraction. It is indicated that simultaneous quantification of multi components coupled with chemometrics analysis could be a well-acceptable strategy to identify and evaluate the quality of Magnoliae Officinalis Cortex.


Assuntos
Medicamentos de Ervas Chinesas/normas , Magnolia/química , Compostos Fitoquímicos/análise , Controle de Qualidade , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Compostos Fitoquímicos/normas
16.
J Biol Chem ; 292(27): 11178-11188, 2017 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-28500134

RESUMO

Poly-ubiquitination-mediated RUNX2 degradation is an important cause of age- and inflammation-related bone loss. NEDD4 family E3 ubiquitin protein ligases are thought to be the major regulators of RUNX2 poly-ubiquitination. However, we observed a mono-ubiquitination of RUNX2 that was catalyzed by WWP2, a member of the NEDD4 family of E3 ubiquitin ligases. WWP2 has been reported to catalyze the mono-ubiquitination of Goosecoid in chondrocytes, facilitating craniofacial skeleton development. In this study, we found that osteogenic differentiation of mesenchymal stem cells promoted WWP2 expression and nuclear accumulation. Knockdown of Wwp2 in mesenchymal stem cells and osteoblasts led to significant deficiencies of osteogenesis, including decreased mineral deposition and down-regulation of osteogenic marker genes. Co-immunoprecipitation experiments showed the interaction of WWP2 with RUNX2 in vitro and in vivo Mono-ubiquitination by WWP2 leads to RUNX2 transactivation, as evidenced by the wild type of WWP2, but not its ubiquitin ligase-dead mutant, augmenting RUNX2-reponsive reporter activity. Moreover, deletion of WWP2-dependent mono-ubiquitination resulted in striking defects of RUNX2 osteoblastic activity. In addition, ectopic expression of the constitutively active type 1A bone morphogenetic protein receptor enhanced WWP2-dependent RUNX2 ubiquitination and transactivation, demonstrating a regulatory role of bone morphogenetic protein signaling in the WWP2-RUNX2 axis. Taken together, our results provide evidence that WWP2 serves as a positive regulator of osteogenesis by augmenting RUNX2 transactivation in a non-proteolytic mono-ubiquitination manner.


Assuntos
Diferenciação Celular/fisiologia , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/metabolismo , Osteogênese/fisiologia , Ativação Transcricional/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/fisiologia , Animais , Linhagem Celular , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Proteína Goosecoid/genética , Proteína Goosecoid/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Camundongos , Osteoblastos/citologia , Transdução de Sinais/fisiologia , Ubiquitina-Proteína Ligases/genética
17.
Eur J Anaesthesiol ; 35(10): 792-798, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29847363

RESUMO

BACKGROUND: Postoperative supraventricular arrhythmias are common in patients after thoracoscopic lobectomy. Inadequate pain control has long been recognised as a significant risk factor for arrhythmias. The performance of ultrasound-guided (USG) thoracic paravertebral block (PVB) is increasing as an ideal technique for postoperative analgesia. OBJECTIVE: We conducted this study to evaluate whether a single-shot USG thoracic PVB would result in fewer postoperative supraventricular tachycardias (SVT) than intercostal nerve blocks (ICNBs) after thoracoscopic pulmonary resection. DESIGN: A randomised controlled study. SETTING: A single university hospital. PATIENTS: Sixty-eight patients undergoing thoracoscopic lobectomy were randomised into two equal groups of 34. INTERVENTIONS: For postoperative pain control, all patients received a total of 0.3 ml kg of a mixture containing 0.5% ropivacaine and 1/200 000 epinephrine after placement of needles for either a single thoracic PVB or two individual ICNBs, both guided by ultrasound. Data were obtained during the first 48 postoperative hours. MAIN OUTCOME MEASURES: The primary outcome was the incidence of SVT after thoracoscopic pulmonary resection. RESULTS: During the first 48 postoperative hours, the incidences of SVT and atrial fibrillation were lower in the USG thoracic PVB group (14.7 vs. 46.9%, P = 0.004 and 3.0 vs. 18.8%, P = 0.037, respectively). The requirement for ß-receptor blockade was more frequent in the ICNBs group than in the PVB group (5.9 vs. 25%, P = 0.033). CONCLUSION: After placement of the needle using ultrasound guidance, a single-shot thoracic PVB is a well tolerated and effective technique to reduce the incidences of postoperative SVT and atrial fibrillation in patients undergoing thoracoscopic pulmonary resection. TRIAL REGISTRATION: http://www.chictr.org/cn/, registration number: ChiCTR-IOR-17010952.


Assuntos
Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/epidemiologia , Bloqueio Nervoso Autônomo/efeitos adversos , Injeções Espinhais/efeitos adversos , Nervos Intercostais/diagnóstico por imagem , Cirurgia Torácica Vídeoassistida/métodos , Idoso , Anestésicos Locais/administração & dosagem , Bloqueio Nervoso Autônomo/métodos , Feminino , Humanos , Incidência , Injeções Espinhais/métodos , Nervos Intercostais/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Vértebras Torácicas/diagnóstico por imagem , Ultrassonografia de Intervenção/métodos
18.
Nucleic Acids Res ; 42(18): 11419-32, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25245948

RESUMO

Heterochromatin preferentially forms at repetitive DNA elements through RNAi-mediated targeting of histone-modifying enzymes. It was proposed that splicing factors interact with the RNAi machinery or regulate the splicing of repeat transcripts to directly participate in heterochromatin assembly. Here, by screening the fission yeast deletion library, we comprehensively identified factors required for telomeric heterochromatin assembly, including a novel gene tls1+. Purification of Tls1 and mass spectrometry analysis of its interacting proteins show that Tls1 associates with the spliceosome subunit Brr2. RNA sequencing analysis shows that the splicing of a subset of mRNAs are affected in tls1Δ cells, including mRNAs of shelterin components rap1+ and poz1+. Importantly, replacing rap1+ and poz1+ with their cDNAs significantly alleviated heterochromatin defects of tls1Δ cells, suggesting that the missplicing of shelterin components is the cause of such defects, and that splicing factors regulate telomeric heterochromatin through the proper splicing of heterochromatin factors. In addition to its role in telomeric heterochromatin assembly, Tls1-mediated splicing of shelterin mRNAs also regulates telomere length. Given that its human homologue C9ORF78 also associates with the spliceosome and is overexpressed in multiple cancer cell lines, our results suggest that C9ORF78 overexpression might alter the proper splicing of genes during cancer progression.


Assuntos
Heterocromatina/metabolismo , Proteínas Nucleares/metabolismo , Splicing de RNA , Proteínas de Schizosaccharomyces pombe/metabolismo , Homeostase do Telômero , Proteínas de Ligação a Telômeros/genética , Telômero/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/fisiologia , Fatores de Processamento de RNA , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/fisiologia , Spliceossomos/metabolismo , Proteínas de Ligação a Telômeros/metabolismo
19.
Cell Mol Life Sci ; 71(24): 4841-52, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25192661

RESUMO

Chromatin is generally classified as euchromatin or heterochromatin, each with distinct histone modifications, compaction levels, and gene expression patterns. Although the proper formation of heterochromatin is essential for maintaining genome integrity and regulating gene expression, heterochromatin can also spread into neighboring regions in a sequence-independent manner, leading to the inactivation of genes. Because the distance of heterochromatin spreading is stochastic, the formation of boundaries, which block the spreading of heterochromatin, is critical for maintaining stable gene expression patterns. Here we review the current understanding of the mechanisms underlying heterochromatin spreading and boundary formation.


Assuntos
Inativação Gênica , Heterocromatina/genética , Modelos Genéticos , Sequências Reguladoras de Ácido Nucleico/genética , Animais , Eucromatina/genética , Eucromatina/metabolismo , Heterocromatina/metabolismo , Histonas/metabolismo , Humanos
20.
Zhongguo Zhong Yao Za Zhi ; 39(12): 2318-21, 2014 Jun.
Artigo em Zh | MEDLINE | ID: mdl-25244767

RESUMO

OBJECTIVE: To discuss the effect of matrine on nitric oxide (NO) and asymmetric methylarginine (ADMA) metabolism pathways in serum and tissues of mice with lipopolysaccharide (LPS) -induced intestine tissue inflammation. METHOD: Kunming mice were randomly divided into five groups: the normal control group, the LPS group and matrine (80, 40, 20 mg x kg(-1) x d(-1)) groups. The mice were intragastrically administered with drugs for 3 d (distilled water of the same volume for the normal control group and the LPS group). One hour after the last intragastrical administration, normal saline or LPS (1 mg x kg(-1)) were intraperitoneally injected. Twelve hours later, serum and tissues were collected to determine NO and ADMA levels and observe the pathological changes of intestinal tissues. The Western blot method was adopted to detect the protein expressions of arginine methyltransferases 1 (PRMT1) and dimethylarginine dimethylaminohydrolase 2 (DDAH2) in intestinal tissues. RESULT: Compared with the model group, matrine (80, 40, 20 mg x kg(-1) x d(-1)) groups showed lower NO content in serum and tissues, higher ADMA level in serum and increased PRMT1 expression in intestinal tissues, but without effect on DDAH2 expression. CONCLUSION: Matrine could inhibit LPS-induced intestine tissue inflammation in mice. Its action mechanism is related to the decreased NO content in serum and tissues and increased ADMA level in serum and PRMT1 expression in intestinal tissues.


Assuntos
Alcaloides/administração & dosagem , Arginina/análogos & derivados , Enteropatias/tratamento farmacológico , Intestinos/imunologia , Lipopolissacarídeos/efeitos adversos , Óxido Nítrico/metabolismo , Quinolizinas/administração & dosagem , Animais , Arginina/sangue , Arginina/metabolismo , Humanos , Inflamação , Enteropatias/enzimologia , Enteropatias/imunologia , Enteropatias/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Intestinos/enzimologia , Masculino , Camundongos , Óxido Nítrico/sangue , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Matrinas
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa