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1.
J Biomater Sci Polym Ed ; : 1-21, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630632

RESUMO

In recent years, mouse nerve growth factor (mNGF) has emerged as an important biological regulator to repair peripheral nerve injury, but its systemic application is restricted by low efficiency and large dosage requirement. These limitations prompted us to search for biomaterials that can be locally loaded. Oxidized sodium alginate hydrogel (OSA) exhibits good biocompatibility and physicochemical properties, and can be loaded with drugs to construct a sustained-release system that can act locally on nerve injury. Here, we constructed a sustained-release system of OSA-mouse nerve growth factor (mNGF), and investigated the loading and release of the drug through Fourier transform infrared spectroscopy and drug release curves. In vitro and in vivo experiments showed that OSA-mNGF significantly promoted the biological activities of RSC-96 cells and facilitated the recovery from sciatic nerve crush injury in rats. This observation may be attributed to the additive effect of OSA on promoting Schwann cell biological activities or its synergistic effect of cross-activating phosphoinositide 3-kinase (PI3K) through extracellular signal regulated kinase (ERK) signaling. Although the specific mechanism of OSA action needs to be explored in the future, the current results provide a valuable preliminary research basis for the clinical application of the OSA-mNGF sustained-release system for nerve repair.

2.
Anal Chim Acta ; 1287: 342110, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38182347

RESUMO

BACKGROUND: Liposomal formulations have traditionally been considered the most therapeutically effective drug delivery systems (DDS). However, their pharmacokinetics study and efficacy assessment are still challenging given size heterogeneity and unknown forms in vivo. The pharmacodynamic evaluation that solely analyzes total drug concentration is unfit for the liposomal formulation study. Hence, it is crucial to develop effective strategies for the separation and analysis of different forms of liposomal formulations in order to contribute to the study of pharmacokinetic profiles associated with both liposome-incorporated and non-liposomal drugs. (84) RESULTS: A laboratory-built circular nonuniform electric field gel electrophoresis (CNEFGE) system was developed in this study for simultaneous separation and analysis of various forms of doxorubicin hydrochloride (DOX•HCl) liposomes. Liposomes were effectively fractionized based on their size and higher concentration in situ in the concentration zone, obtaining liposome recovery >95 % and a 3.04 concentration factor. It was found that the technique could be used to evaluate not only the size distribution of liposomes but also the drug loading capacity related to size. The charge-to-size-based separation mechanism has also allowed the simultaneous separation of liposome-entrapped drugs, protein-bound drugs, and free drugs in various forms, and the technique has been successfully employed in serum. Moreover, the quantification analysis of liposomes incubated with serum for 72 h showed that the proportion of the ratio of DOX•HCl in liposome-entrapped drugs, protein-bound drugs, and free drugs is approximately 97:2:1. (143) SIGNIFICANCE: Using the separation principle of gel electrophoresis and the electrification characteristics of drug carriers, this study developed and implemented an efficient approach for the simultaneous separation and concentration of multiple forms of drug liposomes in vivo. This approach offers a wide range of applications in the pharmacokinetics, efficacy, and safety evaluation of drug carriers and liposomes. (56).


Assuntos
Portadores de Fármacos , Lipossomos , Sistemas de Liberação de Medicamentos , Doxorrubicina , Eletroforese
3.
Nat Biotechnol ; 42(1): 52-64, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37037903

RESUMO

Intrinsically disordered regions (IDRs) in DNA-associated proteins are known to influence gene regulation, but their distribution and cooperative functions in genome-wide regulatory programs remain poorly understood. Here we describe DisP-seq (disordered protein precipitation followed by DNA sequencing), an antibody-independent chemical precipitation assay that can simultaneously map endogenous DNA-associated disordered proteins genome-wide through a combination of biotinylated isoxazole precipitation and next-generation sequencing. DisP-seq profiles are composed of thousands of peaks that are associated with diverse chromatin states, are enriched for disordered transcription factors (TFs) and are often arranged in large lineage-specific clusters with high local concentrations of disordered proteins and different combinations of histone modifications linked to regulatory potential. We use DisP-seq to analyze cancer cells and reveal how disordered protein-associated islands enable IDR-dependent mechanisms that control the binding and function of disordered TFs, including oncogene-dependent sequestration of TFs through long-range interactions and the reactivation of differentiation pathways upon loss of oncogenic stimuli in Ewing sarcoma.


Assuntos
Cromatina , DNA , Análise de Sequência de DNA
4.
J Plant Physiol ; 292: 154149, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38064888

RESUMO

Drought poses a serious challenge to sustained plant growth and crop yields in the context of global climate change. Drought tolerance in poplars and their underlying mechanisms still remain largely unknown. In this article, we investigated the overexpression of PtoMYB99 - both a drought and abscisic acid (ABA) induced gene constraining drought tolerance in poplars (as compared with wild type poplars). First, we found that PtoMYB99-OE lines exhibited increased stomatal opening and conductance, higher transpiration and photosynthetic rates, as well as reduced levels of ABA and jasmonic acid (JA). Second, PtoMYB99-OE lines accumulated more reactive oxygen species (ROS), including H2O2 and O2-, as well as malonaldehyde (MDA), proline, and soluble sugar under osmotic stress; conversely, the activity of antioxidant enzymes (SOD, POD, and CAT), was weakened in the PtoMYB99-OE lines. Third, the expression of ABA biosynthetic genes, PtoNCED3.1 and PtoNCED3.2, as well as JA biosynthetic genes, PtoOPR3.1 and PtoOPR3.2, was significantly reduced in the PtoMYB99-OE lines under both normal conditions and osmotic stress. Based on our results, we conclude that the overexpression of PtoMYB99 compromises tolerance to osmotic stress in poplar. These findings contribute to the understanding of the role of the MYB genes in drought stress and the biosynthesis of ABA and JA.


Assuntos
Ácido Abscísico , Peróxido de Hidrogênio , Ácido Abscísico/metabolismo , Pressão Osmótica , Peróxido de Hidrogênio/metabolismo , Antioxidantes/metabolismo , Transporte Biológico , Secas , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
5.
Hypertens Pregnancy ; 42(1): 2285757, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38017693

RESUMO

OBJECTIVE: The aim of this study was to investigate the possible causal relationship between COVID-19 and the risk of pre-eclampsia/eclampsia using a Mendelian randomized (MR) design. METHODS: We estimated their genetic correlations and then performed two-sample Mendelian randomization analyses using pooled statistics from the COVID-19 susceptibility/hospitalization genome-wide association study and the pre-eclampsia/eclampsia datasets. The main analyses were performed using the inverse variance weighting method, supplemented by the weighted median method and the MR-Egger method. RESULTS: We identified a significant and positive genetic correlation between COVID-19 susceptibility and pre-eclampsia/eclampsia [OR = 1.23 (1.01-1.51), p = 0.043]. Meanwhile, hospitalization of COVID-19 was significantly associated with a higher risk of pre-eclampsia/eclampsia [OR = 1.15 (1.02-1.30), p = 0.024]. Consistently, hospitalization of COVID-19 were nominally associated with higher risk of pre-eclampsia [OR = 1.14, (1.01-1.30), p = 0.040]. The results were robust under all sensitivity analyses. CONCLUSION: These results suggest that COVID-19 may increase the risk of pre-eclampsia/eclampsia. Future development of preventive or therapeutic interventions should emphasize this to mitigate the complications of COVID-19. [Figure: see text].


Assuntos
COVID-19 , Eclampsia , Pré-Eclâmpsia , Feminino , Gravidez , Humanos , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Pré-Eclâmpsia/genética
6.
J Minim Access Surg ; 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37706414

RESUMO

Introduction: The aim of this study was to analyse the effect of perioperative dexmedetomidine (DEX) application on stress response, post-operative pain and prognosis in patients undergoing gynaecologic laparoscopy. Patients and Methods: One hundred and sixty-eight patients admitted for gynaecologic laparoscopic surgery from May 2020 to November 2022 were included in the study. The patients were randomly divided into pre-operative DEX group (n = 56), intraoperative DEX group (n = 56) and post-operative DEX group (n = 56) according to the application of DEX in the perioperative period. The visual analogue scale (VAS), time awake, extubation time, pneumoperitoneum time, post-anaesthesia care unit (PACU) stay time and Richmond agitation-sedation scale score (RASS) were recorded. Results: Patients in both the pre-operative and intraoperative DEX groups had substantially shorter wakeup and extubation times than those in the post-operative DEX group. Patients in the pre-operative DEX group had considerably shorter wakeup and extubation times than those in the intraoperative DEX group, and their pneumoperitoneum time was significantly shorter than that of the post-operative DEX group (P < 0.001). The RASS scores of the pre-operative DEX group and intraoperative DEX group were significantly lower than those of the post-operative DEX group at 1 h, 6 h and 12 h after surgery. Meanwhile, at all time periods, the RASS scores of patients in the pre-operative DEX group were considerably lower than those in the intraoperative DEX group (P < 0.01). The VAS scores of patients in the pre-operative DEX group and intraoperative DEX group were evidently lower than those in the post-operative DEX group at 0.5 h, 2 h and 12 h postoperatively, and the VAS scores of patients in the pre-operative DEX group were markedly lower than those in the intraoperative DEX group (P < 0.001). The incidence of nausea and vomiting was significantly lower in the pre-operative DEX group than in the intraoperative DEX group and the post-operative DEX group at 0-2 h, >2-12 h and >12-24 h postoperatively (P < 0.001). The incidence of nausea and vomiting in the intraoperative DEX group was significantly lower than that in the post-operative DEX group from 0 to 2 h after surgery (P < 0.05). The incidence of adverse reactions was not significantly different amongst the three groups of patients (P > 0.05). Conclusion: Pre-operative and intraoperative application of DEX can help reduce post-operative pain and stress responses, help patients recover quickly after surgery and improve patient prognosis, especially the pre-operative application of DEX.

7.
J Colloid Interface Sci ; 644: 73-80, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37094474

RESUMO

Mineral-solution interface is of great importance in many soil and geochemical processes as well as industrial applications. Most relevant studies were based on saturated condition and given the corresponding theory, model, and mechanism. However, soils are usually in the non-saturation with different capillary suction. Our study presents substantially different scenery for ions interacting with mineral surface under unsaturated condition using molecular dynamics method. Under partially hydrated state, both cations (Ca2+) and anions (Cl-) can be adsorbed as outer-sphere complexes at the montmorillonite surface, and the number significantly increased with the increase of unsaturated degree. Ions preferred to interact with clay mineral instead of water molecules under unsaturated state, and the mobility of both cations and anions substantially decreased with the increase of capillary suction as reflected by the diffusion coefficient analysis. Potential of mean force calculations further clearly revealed that the adsorption strength of both Ca2+ and Cl- increased with capillary suction. Such an increase was more obvious for Cl- compared to Ca2+, despite the adsorption strength of Cl- was much weaker than Ca2+ at a certain capillary suction. Therefore, it is the capillary suction under unsaturated condition that drives the strong specific affinity of ions at the surface of clay mineral, which was tightly related to the steric effect of confined water film, the destruction of EDL structure, and the cation-anion pair interaction. This suggests that our common understanding of mineral-solution interaction should be largely improved.

8.
Sci Adv ; 9(13): eabo3789, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-37000878

RESUMO

Cell fate transitions observed in embryonic development involve changes in three-dimensional genomic organization that provide proper lineage specification. Whether similar events occur within tumor cells and contribute to cancer evolution remains largely unexplored. We modeled this process in the pediatric cancer Ewing sarcoma and investigated high-resolution looping and large-scale nuclear conformation changes associated with the oncogenic fusion protein EWS-FLI1. We show that chromatin interactions in tumor cells are dominated by highly connected looping hubs centered on EWS-FLI1 binding sites, which directly control the activity of linked enhancers and promoters to establish oncogenic expression programs. Conversely, EWS-FLI1 depletion led to the disassembly of these looping networks and a widespread nuclear reorganization through the establishment of new looping patterns and large-scale compartment configuration matching those observed in mesenchymal stem cells, a candidate Ewing sarcoma progenitor. Our data demonstrate that major architectural features of nuclear organization in cancer cells can depend on single oncogenes and are readily reversed to reestablish latent differentiation programs.


Assuntos
Sarcoma de Ewing , Criança , Humanos , Sarcoma de Ewing/genética , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/patologia , Cromatina/genética , Linhagem Celular Tumoral , Proteína EWS de Ligação a RNA/genética , Proteína EWS de Ligação a RNA/metabolismo , Sítios de Ligação , Diferenciação Celular , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Regulação Neoplásica da Expressão Gênica
9.
Phys Chem Chem Phys ; 25(11): 7951-7964, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36866749

RESUMO

Soluble inorganic carbon is an important component of a soil carbon pool, and its fate in soils, sediments, and underground water environments has great effects on many physiochemical and geological processes. However, the dynamical processes, behaviors and mechanism of their adsorption by soil active components, such as quartz, are still unclear. The aim of this work is to systematically address the anchoring mechanism of CO32- and HCO3- on a quartz surface at different pH values. Three pH values (pH 7.5, pH 9.5 and pH 11) and three carbonate salt concentrations (0.07, 0.14 and 0.28 M) are considered, and molecular dynamics methods are used. The results indicate that the pH value regulates the adsorption behavior of CO32- and HCO3- on the quartz surface by affecting the CO32-/HCO3- ratio and the surface charge of quartz. In general, both HCO3- and CO32- ions were able to adsorb on the quartz surface and the adsorption capacity of CO32- is higher than that of HCO3-. HCO3- ions tended to uniformly distribute in an aqueous solution and contact the quartz surface in the form of single molecules instead of clusters. In contrast, CO32- ions were mainly adsorbed as clusters which became larger as the concentration increased. Na+ ions were essential for the adsorption of HCO3- and CO32-, because some of the Na+ and CO32- ions spontaneously associated together to form clusters, promoting the clusters to be adsorbed on the quartz surface through cationic bridges. The local structures and dynamics trajectory of CO32- and HCO3- showed that the anchoring mechanism of carbonate solvates on quartz involved H-bonds and cationic bridges, which changed in relation to the concentration and pH values. However, the HCO3- ions mainly adsorbed on the quartz surface via H-bonds while the CO32- ions tended to be adsorbed through cationic bridges. These results may help in understanding the geochemical behavior of soil inorganic carbon and further the processes of the Earth's carbon chemical cycle.

10.
Food Chem ; 398: 133953, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35998486

RESUMO

The aim of this study was to evaluate the influence of l-ascorbyl palmitate (LAP) as an additive to liposome formulations by self-assembling with soy lecithin to form hybrid liposomes, in order to enhance the physical stability and bioactivator-loaded retention ratio of the LAP incorporated liposomes (LAP-LP). The addition of LAP significantly increased its surface negative charge and strong hydrophobic interactions occurred between the hydrophobic tails of LAP and phospholipids resulting in more compactly ordered, rigid and hydrophobic phospholipid bilayers as indicated by surface tension, fluorescence probes and DSC. These changes enhanced the stability of hydrophobic polyphenol loaded LAP-LP during storage. Particularly, after four weeks storage at 37 °C for naringenin loaded liposomes, the retention ratio of pure liposome decreased dramatically to 12.5 %, while the LAP-LP remained above 74.5 %. This study opens up the potential for the LAP-LP to be developed as a food-grade multifunctional formulation for encapsulating and delivering bioactivators.


Assuntos
Lipossomos , Fosfolipídeos , Ácido Ascórbico/análogos & derivados , Estabilidade de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Lipossomos/química , Fosfolipídeos/química , Polifenóis
11.
Mol Cell ; 82(15): 2738-2753.e6, 2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35662392

RESUMO

The proper function of the genome relies on spatial organization of DNA, RNA, and proteins, but how transcription contributes to the organization is unclear. Here, we show that condensates induced by transcription inhibition (CITIs) drastically alter genome spatial organization. CITIs are formed by SFPQ, NONO, FUS, and TAF15 in nucleoli upon inhibition of RNA polymerase II (RNAPII). Mechanistically, RNAPII inhibition perturbs ribosomal RNA (rRNA) processing, releases rRNA-processing factors from nucleoli, and enables SFPQ to bind rRNA. While accumulating in CITIs, SFPQ/TAF15 remain associated with active genes and tether active chromatin to nucleoli. In the presence of DNA double-strand breaks (DSBs), the altered chromatin compartmentalization induced by RNAPII inhibition increases gene fusions in CITIs and stimulates the formation of fusion oncogenes. Thus, proper RNAPII transcription and rRNA processing prevent the altered compartmentalization of active chromatin in CITIs, suppressing the generation of gene fusions from DSBs.


Assuntos
Cromatina , Transcrição Gênica , Nucléolo Celular/genética , Nucléolo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Quebras de DNA de Cadeia Dupla , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , RNA Ribossômico/genética , RNA Ribossômico/metabolismo
12.
Nat Commun ; 13(1): 2267, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35477713

RESUMO

Oncogenic fusion proteins generated by chromosomal translocations play major roles in cancer. Among them, fusions between EWSR1 and transcription factors generate oncogenes with powerful chromatin regulatory activities, capable of establishing complex gene expression programs in permissive precursor cells. Here we define the epigenetic and 3D connectivity landscape of Clear Cell Sarcoma, an aggressive cancer driven by the EWSR1-ATF1 fusion gene. We find that EWSR1-ATF1 displays a distinct DNA binding pattern that requires the EWSR1 domain and promotes ATF1 retargeting to new distal sites, leading to chromatin activation and the establishment of a 3D network that controls oncogenic and differentiation signatures observed in primary CCS tumors. Conversely, EWSR1-ATF1 depletion results in a marked reconfiguration of 3D connectivity, including the emergence of regulatory circuits that promote neural crest-related developmental programs. Taken together, our study elucidates the epigenetic mechanisms utilized by EWSR1-ATF1 to establish regulatory networks in CCS, and points to precursor cells in the neural crest lineage as candidate cells of origin for these tumors.


Assuntos
Sarcoma de Células Claras , Neoplasias de Tecidos Moles , Carcinogênese/genética , Cromatina/genética , Humanos , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Oncogenes , Proteína EWS de Ligação a RNA/genética , Sarcoma de Células Claras/genética , Sarcoma de Células Claras/patologia , Neoplasias de Tecidos Moles/genética
13.
Front Chem ; 9: 744099, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34631665

RESUMO

To assist or replace the traditional suture techniques for wound closure, soft-tissue adhesives with excellent adhesion strength and favorable biocompatibility are of great significance in biomedical applications. In this study, an injectable hydrogel tissue adhesive containing adipic acid dihydrazide-modified gelatin (Gel-ADH) and oxidized sodium alginate (OSA) was developed. It was found that this tissue adhesive possessed a uniform structure, appropriate swelling ratio, good injectability, and excellent hemocompatibility and cytocompatibility. The adhesion capacity of the developed adhesive with optimized component and concentration was stronger than that of the commercial adhesive Porcine Fibrin Sealant Kit. All these results suggested that the developed hydrogel was a promising candidate for a soft-tissue adhesive.

14.
Science ; 373(6554): 547-555, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34326237

RESUMO

RNA polymerase I (Pol I) transcription takes place at the border of the fibrillar center (FC) and the dense fibrillar component (DFC) in the nucleolus. Here, we report that individual spherical FC/DFC units are coated by the DEAD-box RNA helicase DDX21 in human cells. The long noncoding RNA (lncRNA) SLERT binds to DDX21 RecA domains to promote DDX21 to adopt a closed conformation at a substoichiometric ratio through a molecular chaperone-like mechanism resulting in the formation of hypomultimerized and loose DDX21 clusters that coat DFCs, which is required for proper FC/DFC liquidity and Pol I processivity. Our results suggest that SLERT is an RNA regulator that controls the biophysical properties of FC/DFCs and thus ribosomal RNA production.


Assuntos
Nucléolo Celular/metabolismo , RNA Helicases DEAD-box/metabolismo , RNA Polimerase I/metabolismo , RNA Longo não Codificante/metabolismo , Linhagem Celular , RNA Helicases DEAD-box/química , DNA Ribossômico/metabolismo , Humanos , Chaperonas Moleculares/metabolismo , Conformação Proteica , Domínios Proteicos , Multimerização Proteica , Transcrição Gênica
15.
Life Sci Alliance ; 4(2)2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33361335

RESUMO

Synovial sarcoma (SyS) is an aggressive mesenchymal malignancy invariably associated with the chromosomal translocation t(X:18; p11:q11), which results in the in-frame fusion of the BAF complex gene SS18 to one of three SSX genes. Fusion of SS18 to SSX generates an aberrant transcriptional regulator, which, in permissive cells, drives tumor development by initiating major chromatin remodeling events that disrupt the balance between BAF-mediated gene activation and polycomb-dependent repression. Here, we developed SyS organoids and performed genome-wide epigenomic profiling of these models and mesenchymal precursors to define SyS-specific chromatin remodeling mechanisms and dependencies. We show that SS18-SSX induces broad BAF domains at its binding sites, which oppose polycomb repressor complex (PRC) 2 activity, while facilitating recruitment of a non-canonical (nc)PRC1 variant. Along with the uncoupling of polycomb complexes, we observed H3K27me3 eviction, H2AK119ub deposition and the establishment of de novo active regulatory elements that drive SyS identity. These alterations are completely reversible upon SS18-SSX depletion and are associated with vulnerability to USP7 loss, a core member of ncPRC1.1. Using the power of primary tumor organoids, our work helps define the mechanisms of epigenetic dysregulation on which SyS cells are dependent.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/genética , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Sarcoma Sinovial/genética , Sítios de Ligação , Cromatina/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Perfilação da Expressão Gênica , Histonas/metabolismo , Humanos , Complexos Multiproteicos/metabolismo , Organoides , Ligação Proteica , Transporte Proteico , Sarcoma Sinovial/metabolismo , Transcriptoma
16.
Cell ; 181(3): 621-636.e22, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32259487

RESUMO

Long noncoding RNAs (lncRNAs) evolve more rapidly than mRNAs. Whether conserved lncRNAs undergo conserved processing, localization, and function remains unexplored. We report differing subcellular localization of lncRNAs in human and mouse embryonic stem cells (ESCs). A significantly higher fraction of lncRNAs is localized in the cytoplasm of hESCs than in mESCs. This turns out to be important for hESC pluripotency. FAST is a positionally conserved lncRNA but is not conserved in its processing and localization. In hESCs, cytoplasm-localized hFAST binds to the WD40 domain of the E3 ubiquitin ligase ß-TrCP and blocks its interaction with phosphorylated ß-catenin to prevent degradation, leading to activated WNT signaling, required for pluripotency. In contrast, mFast is nuclear retained in mESCs, and its processing is suppressed by the splicing factor PPIE, which is highly expressed in mESCs but not hESCs. These findings reveal that lncRNA processing and localization are previously under-appreciated contributors to the rapid evolution of function.


Assuntos
Espaço Intracelular/genética , RNA Longo não Codificante/metabolismo , Células-Tronco/metabolismo , Animais , Diferenciação Celular/genética , Linhagem Celular , Células Cultivadas , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Splicing de RNA/genética , RNA Longo não Codificante/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/genética , Células-Tronco/patologia
17.
Mol Cell ; 76(5): 767-783.e11, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31540874

RESUMO

Fibrillar centers (FCs) and dense fibrillar components (DFCs) are essential morphologically distinct sub-regions of mammalian cell nucleoli for rDNA transcription and pre-rRNA processing. Here, we report that a human nucleolus consists of several dozen FC/DFC units, each containing 2-3 transcriptionally active rDNAs at the FC/DFC border. Pre-rRNA processing factors, such as fibrillarin (FBL), form 18-24 clusters that further assemble into the DFC surrounding the FC. Mechanistically, the 5' end of nascent 47S pre-rRNA binds co-transcriptionally to the RNA-binding domain of FBL. FBL diffuses to the DFC, where local self-association via its glycine- and arginine-rich (GAR) domain forms phase-separated clusters to immobilize FBL-interacting pre-rRNA, thus promoting directional traffic of nascent pre-rRNA while facilitating pre-rRNA processing and DFC formation. These results unveil FC/DFC ultrastructures in nucleoli and suggest a conceptual framework for considering nascent RNA sorting using multivalent interactions of their binding proteins.


Assuntos
Nucléolo Celular/metabolismo , Precursores de RNA/metabolismo , Processamento Pós-Transcricional do RNA , RNA Ribossômico/metabolismo , Transporte Ativo do Núcleo Celular , Antígenos Nucleares/genética , Antígenos Nucleares/metabolismo , Nucléolo Celular/genética , Nucléolo Celular/ultraestrutura , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Feminino , Células HEK293 , Células HeLa , Humanos , Conformação de Ácido Nucleico , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Precursores de RNA/genética , Precursores de RNA/ultraestrutura , RNA Ribossômico/genética , RNA Ribossômico/ultraestrutura
18.
J Oral Facial Pain Headache ; 33(2): 165­173, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30726862

RESUMO

AIMS: To evaluate the efficacy of sucrose in the prevention of migraine attacks. METHODS: Two randomized double-blinded pilot trials were conducted, one in college students and one in adults. Migraineurs were randomized into two groups that each received an oral liquid: for students, sucrose 5 g/day (s-group; n = 12) or glucose 2.5 g/day (g-group; n = 10) for 3 months; and for adults, sucrose 5 g/day (s-group; n = 10) or fructose 2.5 g/day (f-group; n = 9) for 6 months. The primary endpoint was the frequency of migraine attacks per month, and the secondary endpoints were mean duration and severity of migraine per attack. Continuous measurements were described as mean ± standard deviation (SD). The overall significance of the effects between different groups was tested using repeated measures analysis of variance (RANOVA), and the efficacy was evaluated using an intent-to-treat analysis. RESULTS: Migraine frequency in the students declined significantly in the g-group (mean reduction ± SD: 0.65 ± 0.71; P < .01), but not in the s-group (0.33 ± 2.02; P = .58). RANOVA results suggested that the secondary endpoints significantly declined over time (all P < .01) with no differences between the groups. In the adult trial, mixed-effects model analysis showed that both the primary and secondary endpoints significantly declined over time with no significant differences between the groups. CONCLUSION: Long-term consumption of a 5-g dose of sucrose for adult migraineurs or a 2.5-g dose of glucose for college student migraineurs may be as effective as preventive treatments.


Assuntos
Transtornos de Enxaqueca , Sacarose , Adulto , Método Duplo-Cego , Humanos , Projetos Piloto , Topiramato , Resultado do Tratamento
19.
Crit Rev Biochem Mol Biol ; 53(6): 596-606, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30252509

RESUMO

Small nucleolar RNAs (snoRNAs) are a family of conserved nuclear RNAs that function in the modification of small nuclear RNAs (snRNAs) or ribosomal RNAs (rRNAs), or participate in the processing of rRNAs during ribosome subunit maturation. Eukaryotic DNA transcription and RNA processing produce many long noncoding RNA (lncRNA) species. Although most lncRNAs are processed like typical mRNAs to be 5' capped and 3' polyadenylated, other types of lncRNAs are stabilized from primary Pol II transcripts by alternative mechanisms. One way to generate stable lncRNAs is to co-operate with snoRNA processing to produce snoRNA-ended lncRNAs (sno-lncRNAs) and 5' snoRNA-ended and 3'-polyadenylated lncRNAs (SPAs). Rather than silently accumulating in the nucleus, some sno-lncRNAs and SPAs are involved in the regulation of pre-rRNA transcription and alternative splicing of pre-mRNAs. Here we provide a mini-review to discuss the biogenesis and functions of these unusually processed lncRNAs.


Assuntos
Processamento Pós-Transcricional do RNA/fisiologia , Estabilidade de RNA/fisiologia , RNA Longo não Codificante/biossíntese , RNA Nucleolar Pequeno/biossíntese , Transcrição Gênica/fisiologia , Animais , Humanos , RNA Longo não Codificante/genética , RNA Nucleolar Pequeno/genética
20.
Gut Liver ; 12(2): 173-182, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29291617

RESUMO

BACKGROUND/AIMS: Methylation status plays a causal role in carcinogenesis in targeted tissues. However, the relationship between the DNA methylation status of multiple genes in blood leukocytes and colorectal cancer (CRC) susceptibility as well as interactions between dietary factors and CRC risks are unclear. METHODS: We performed a case-control study with 466 CRC patients and 507 cancer-free controls to investigate the association among the methylation status of individual genes, multiple CpG site methylation (MCSM), multiple CpG site heterogeneous methylation and CRC susceptibility. Peripheral blood DNA methylation levels were detected by performing methylation-sensitive high-resolution melting. RESULTS: Total heterogeneous methylation of CA10 and WT1 conferred a significantly higher risk of CRC (adjusted odds ratio [ORadjusted], 5.445; 95% confidence interval [CI], 3.075 to 9.643; ORadjusted, 1.831; 95% CI, 1.100 to 3.047; respectively). Subjects with high-level MCSM (MCSM-H) status demonstrated a higher risk of CRC (ORadjusted, 4.318; 95% CI, 1.529 to 12.197). Additionally, interactions between the high-level intake of fruit and CRH, WT1, and MCSM on CRC were statistically significant. CONCLUSIONS: The gene methylation status of blood leukocytes may be associated with CRC risk. MCSM-H of blood leukocytes was associated with CRC, especially in younger people. Some dietary factors may affect hypermethylation status and influence susceptibility to CRC.


Assuntos
Neoplasias Colorretais , Metilação de DNA/genética , Leucócitos/metabolismo , Proteínas Mitocondriais/genética , Proteínas do Tecido Nervoso/genética , Proteínas WT1/genética , Idoso , Biomarcadores Tumorais/genética , Carcinogênese/genética , Carcinogênese/metabolismo , Estudos de Casos e Controles , China , Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Ilhas de CpG/fisiologia , Feminino , Regulação Neoplásica da Expressão Gênica , Interação Gene-Ambiente , Humanos , Leucócitos/patologia , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas
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