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1.
Mol Cell ; 76(4): 646-659.e6, 2019 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-31543422

RESUMEN

Eukaryotic chromosomes contain compartments of various functions, which are marked by and enriched with specific histone modifications. However, the molecular mechanisms by which these histone marks function in chromosome compartmentalization are poorly understood. Constitutive heterochromatin is a largely silent chromosome compartment characterized in part by H3K9me2 and 3. Here, we show that heterochromatin protein 1 (HP1), an H3K9me2 and 3 "reader," interacts with SUV39H1, an H3K9me2 and 3 "writer," and with TRIM28, an abundant HP1 scaffolding protein, to form complexes with increased multivalent engagement of H3K9me2 and 3-modified chromatin. H3K9me2 and 3-marked nucleosomal arrays and associated complexes undergo phase separation to form macromolecule-enriched liquid droplets. The droplets are reminiscent of heterochromatin as they are highly dense chromatin-containing structures that are resistant to DNase and exclude the general transcription factor TFIIB. Our data suggest a general mechanism by which histone marks regulate chromosome compartmentalization by promoting phase separation.


Asunto(s)
Ensamble y Desensamble de Cromatina , Heterocromatina/metabolismo , Histonas/metabolismo , Gotas Lipídicas/metabolismo , Nucleosomas/metabolismo , Procesamiento Proteico-Postraduccional , Homólogo de la Proteína Chromobox 5 , Proteínas Cromosómicas no Histona/genética , Proteínas Cromosómicas no Histona/metabolismo , Células HEK293 , Heterocromatina/genética , Humanos , Metilación , Metiltransferasas/genética , Metiltransferasas/metabolismo , Complejos Multiproteicos , Nucleosomas/genética , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Factores de Tiempo , Proteína 28 que Contiene Motivos Tripartito/genética , Proteína 28 que Contiene Motivos Tripartito/metabolismo
2.
Trends Biochem Sci ; 45(6): 457-458, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32413321

RESUMEN

Chromatin readers are important intermediaries linking epigenetic information and biological phenotypes. Many diseases are caused by mutations in epigenetic readers. Recently, a study by Wan et al. uncovered that cancer-associated mutations promote self-association of eleven-nineteen-leukemia protein (ENL), leading to abnormal condensates, elevated gene expression, and impaired cell fate determination.


Asunto(s)
Cromatina , Mutación con Ganancia de Función , Diferenciación Celular , Mutación
3.
Nat Chem Biol ; 18(12): 1307-1318, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36400991

RESUMEN

Cells are exquisitely compartmentalized to achieve precise spatiotemporal regulation of myriad processes and pathways. Phase separation offers one way to achieve territorial organization in the cellular context, via the creation of membrane-less organelles (MLOs). MLOs formed through phase separation are associated with numerous critical biological functions. Although hundreds of publications on related topics are produced each year, robust criteria for the determination of biologically meaningful phase separation are yet to be well established. Here we present some principles and propose a few guidelines for phase-separation studies in biology. Specifically, we provide an in-depth experiment pipeline for phase-separation studies, including mechanisms of the molecular driving forces, ways to correlate in vivo and in vitro observations, and strategies to relate the phase-separation phenomenon to biological functions. We also intend to contribute to streamlining the aforementioned diagnostic criteria by further stressing a few common caveats in the field.


Asunto(s)
Condensados Biomoleculares , Transición de Fase , Guías como Asunto
4.
Langmuir ; 40(24): 12755-12766, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38848303

RESUMEN

Coke oven gas (COG) is considered to be one of the most likely raw materials for large-scale H2 production in the near or medium term, with membrane separation technologies standing out from traditional technologies due to their less energy-intensive structures as well as simple operation and occupation. Based on the "MOF-in/on-COF" pore modification strategy, the COF membrane (named the PBD membrane) and ZIF-67 were used as assembly elements to design advanced molecular sieving membranes for hydrogen separation. The composition and microstructure of membranes before and after ZIF-67 loading as well as ZIF-67-in-PBD membranes under different preparation conditions (metal ion concentration, metal-ligand ratio, and reaction time) were investigated by various characterizations to reveal the synthesis regularity and microstructure regulation. Furthermore, H2/CH4 separation performances and separation mechanisms were also analyzed and compared. Finally, a dense, continuous, ultrathin, and self-supporting ZIF-67-in-PBD membrane with a Co2+ concentration of 0.02 mol/L, a metal-ligand ratio of 1:4, and a reaction time of 6 h exhibited the largest specific surface area, micropore proportion, and the best H2/CH4 separation selectivity (α = 33.48), which was significantly higher than the Robeson upper limit and was in a leading position among reported MOF membranes. The separation mechanism was mainly size screening, and adsorption selectivity also contributed a little.

5.
Environ Sci Technol ; 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38319870

RESUMEN

As an emerging type of pollutant, microplastics have become a global environmental problem. Approximately, a fifth of the global burden of type 2 diabetes can be attributed to air particulate pollution. However, scientific knowledge remains limited about the effects of airborne nanoplastics (NPs) exposure on metabolic diseases. In this experiment, a whole-body exposure system was used to simulate the real atmospheric environment, and three exposure concentrations combined with the actual environmental concentration were selected to explore the effects of airborne NPs on metabolic diseases. Based on histological analyses, metabolic studies, gene expression, metabolites, and molecular signaling analyses, mice exposed to airborne NPs were observed to show a phenotype of systemic inflammation and complete insulin resistance featuring excessive drinking and eating, weight loss, elevated blood glucose, and decreased triglyceride levels. After airborne NPs exposure, mice were intolerant to glucose and tolerant to insulin. In addition, airborne NPs exposure could result in long-term irreversible hyperglycemia. Together, the research findings provide a strong basis for understanding the hazards of airborne nanopollution on metabolic disorders.

6.
Sensors (Basel) ; 24(13)2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-39001094

RESUMEN

Breathing is one of the body's most basic functions and abnormal breathing can indicate underlying cardiopulmonary problems. Monitoring respiratory abnormalities can help with early detection and reduce the risk of cardiopulmonary diseases. In this study, a 77 GHz frequency-modulated continuous wave (FMCW) millimetre-wave (mmWave) radar was used to detect different types of respiratory signals from the human body in a non-contact manner for respiratory monitoring (RM). To solve the problem of noise interference in the daily environment on the recognition of different breathing patterns, the system utilised breathing signals captured by the millimetre-wave radar. Firstly, we filtered out most of the static noise using a signal superposition method and designed an elliptical filter to obtain a more accurate image of the breathing waveforms between 0.1 Hz and 0.5 Hz. Secondly, combined with the histogram of oriented gradient (HOG) feature extraction algorithm, K-nearest neighbours (KNN), convolutional neural network (CNN), and HOG support vector machine (G-SVM) were used to classify four breathing modes, namely, normal breathing, slow and deep breathing, quick breathing, and meningitic breathing. The overall accuracy reached up to 94.75%. Therefore, this study effectively supports daily medical monitoring.


Asunto(s)
Algoritmos , Redes Neurales de la Computación , Radar , Respiración , Procesamiento de Señales Asistido por Computador , Máquina de Vectores de Soporte , Humanos , Monitoreo Fisiológico/métodos , Monitoreo Fisiológico/instrumentación
7.
Int J Mol Sci ; 25(15)2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-39125729

RESUMEN

Epstein-Barr virus (EBV), a member of the γ-herpesvirus family, is one of the most prevalent and persistent human viruses, infecting up to 90% of the adult population globally. EBV's life cycle includes primary infection, latency, and lytic reactivation, with the virus primarily infecting B cells and epithelial cells. This virus has evolved sophisticated strategies to evade both innate and adaptive immune responses, thereby maintaining a lifelong presence within the host. This persistence is facilitated by the expression of latent genes such as EBV nuclear antigens (EBNAs) and latent membrane proteins (LMPs), which play crucial roles in viral latency and oncogenesis. In addition to their well-known roles in several types of cancer, including nasopharyngeal carcinoma and B-cell lymphomas, recent studies have identified the pathogenic roles of EBV in autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus. This review highlights the intricate interactions between EBV and the host immune system, underscoring the need for further research to develop effective therapeutic and preventive strategies against EBV-associated diseases.


Asunto(s)
Enfermedades Autoinmunes , Infecciones por Virus de Epstein-Barr , Herpesvirus Humano 4 , Evasión Inmune , Humanos , Herpesvirus Humano 4/inmunología , Herpesvirus Humano 4/patogenicidad , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/virología , Infecciones por Virus de Epstein-Barr/inmunología , Infecciones por Virus de Epstein-Barr/virología , Animales , Latencia del Virus/inmunología
8.
Inflammopharmacology ; 32(4): 2555-2574, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38767761

RESUMEN

Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disease with a relapsing-remitting course. Although its etiology remains unknown, excessive oxidative stress in colon is a major intermediate factor that can promote the progression of UC. In the present study, we investigated the effect and the underlying mechanisms of 4-Octyl itaconate (OI) on dextran sulfate sodium (DSS)-induced UC in mice. Our work identified that OI alleviated the colitis by reducing the oxidative stress and the apoptosis in colon tissue, then increasing the tight junction proteins expression and in turn enhancing the intestinal barrier function, thereby creating less severe inflammatory responses. Moreover, our results demonstrated that OI reduced the Kelch-like ECH-associated protein 1 (KEAP1) expression and subsequent upregulated nuclear factor E2-related factor (NRF2) expression and its nuclear translocation which in turn induced the expression of glutathione S-transferase (GST) and NAD(P)H: quinone oxidoreductase 1 (NQO1). In addition, ML385, a NRF2 antagonist, can inhibit the protective effects of OI on UC, indicating that the role of OI in this colitis model could be dependent on the activation of KEAP1-NRF2 pathway. Notably, OI co-administration significantly enhanced the therapeutic effects of mesalazine or 1400W on UC. Collectively, itaconate may have a great potential for use in the treatment of IBD.


Asunto(s)
Colitis Ulcerosa , Sulfato de Dextran , Proteína 1 Asociada A ECH Tipo Kelch , Factor 2 Relacionado con NF-E2 , Estrés Oxidativo , Transducción de Señal , Succinatos , Animales , Factor 2 Relacionado con NF-E2/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/metabolismo , Ratones , Estrés Oxidativo/efectos de los fármacos , Succinatos/farmacología , Masculino , Transducción de Señal/efectos de los fármacos , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Apoptosis/efectos de los fármacos
9.
Sensors (Basel) ; 24(1)2023 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-38203004

RESUMEN

Gait recognition, crucial in biometrics and behavioral analytics, has applications in human-computer interaction, identity verification, and health monitoring. Traditional sensors face limitations in complex or poorly lit settings. RF-based approaches, particularly millimeter-wave technology, are gaining traction for their privacy, insensitivity to light conditions, and high resolution in wireless sensing applications. In this paper, we propose a gait recognition system called Multidimensional Point Cloud Gait Recognition (PGGait). The system uses commercial millimeter-wave radar to extract high-quality point clouds through a specially designed preprocessing pipeline. This is followed by spatial clustering algorithms to separate users and perform target tracking. Simultaneously, we enhance the original point cloud data by increasing velocity and signal-to-noise ratio, forming the input of multidimensional point clouds. Finally, the system inputs the point cloud data into a neural network to extract spatial and temporal features for user identification. We implemented the PGGait system using a commercially available 77 GHz millimeter-wave radar and conducted comprehensive testing to validate its performance. Experimental results demonstrate that PGGait achieves up to 96.75% accuracy in recognizing single-user radial paths and exceeds 94.30% recognition accuracy in the two-person case. This research provides an efficient and feasible solution for user gait recognition with various applications.


Asunto(s)
Algoritmos , Radar , Humanos , Biometría , Marcha , Redes Neurales de la Computación
10.
Int J Mol Sci ; 24(18)2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37762435

RESUMEN

The SARS-CoV-2 virus, causing the devastating COVID-19 pandemic, has been reported to affect platelets and cause increased thrombotic events, hinting at the possible bidirectional interactions between platelets and the virus. In this review, we discuss the potential mechanisms underlying the increased thrombotic events as well as altered platelet count and activity in COVID-19. Inspired by existing knowledge on platelet-pathogen interactions, we propose several potential antiviral strategies that platelets might undertake to combat SARS-CoV-2, including their abilities to internalize the virus, release bioactive molecules to interfere with viral infection, and modulate the functions of immune cells. Moreover, we discuss current and potential platelet-targeted therapeutic strategies in controlling COVID-19, including antiplatelet drugs, anticoagulants, and inflammation-targeting treatments. These strategies have shown promise in clinical settings to alleviate the severity of thrombo-inflammatory complications and reduce the mortality rate among COVID-19 patients. In conclusion, an in-depth understanding of platelet-SARS-CoV-2 interactions may uncover novel mechanisms underlying severe COVID-19 complications and could provide new therapeutic avenues for managing this disease.

11.
Environ Microbiol ; 22(7): 2514-2535, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-31894607

RESUMEN

Adaptation to low-oxygen (LO) environment in host tissues is crucial for microbial pathogens, particularly fungi, to successfully infect target hosts. However, the underlying mechanisms responsible for hypoxia tolerance in most pathogens are poorly understood. A mitochondrial protein, BbOhmm, is demonstrated to limit oxidative stress resistance and virulence in the insect fungal pathogen, Beauveria bassiana. Here, we found that BbOhmm negatively affected hypoxic adaptation in the insect haemocoel while regulating respiration-related events, heme synthesis and mitochondrial iron homeostasis. A homologue of the mammalian sterol regulatory element-binding proteins (SREBPs), BbSre1, was shown to be involved in BbOhmm-mediated LO adaptation. Inactivation of BbSre1 resulted in a significant increase in sensitivity to hypoxic and oxidative stress. Similar to ΔBbOhmm, ΔBbSre1 or the ΔBbOhmmΔBbSre1 double mutant accumulated high levels of heme and mitochondrial iron, regulating the similar pathways during hypoxic stress. BbSre1 transcriptional activity and nuclear import were repressed in ΔBbOhmm cells and affected by intracellular reactive oxygen species (ROS) and oxygen levels. These findings have led to a new model in which BbOhmm affects ROS homeostasis in combination with available oxygen to control the transcriptional activity of BbSre1, which in turn mediates LO adaptation by regulating mitochondrial iron homeostasis, heme synthesis and respiration-implicated genes.


Asunto(s)
Beauveria/patogenicidad , Proteínas Fúngicas/metabolismo , Proteínas de la Membrana/metabolismo , Membranas Mitocondriales/metabolismo , Estrés Oxidativo/fisiología , Acetiltransferasas/metabolismo , Adaptación Fisiológica/genética , Adaptación Fisiológica/fisiología , Animales , Beauveria/genética , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Hipoxia/metabolismo , Insectos/microbiología , Proteínas de la Membrana/genética , Mitocondrias/metabolismo , Oxígeno/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Virulencia/genética
12.
Biosci Biotechnol Biochem ; 84(9): 1958-1965, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32450767

RESUMEN

The role of exogenous methyl jasmonate (MeJA) in alleviating drought stress was investigated on Huangguogan. Except for intercellular CO2 concentration, MeJA had little effect on net photosynthetic rate, stomatal conductance, and transpiration rate under drought stress. Compared with drought stress, MeJA significantly alleviated the decrease of chlorophyll content. However, chlorophyll a/b ratio was significantly increased. MeJA significantly increased proline and soluble sugar contents, significantly decreased the O2 -· and H2O2 levels, and increased SOD and POD activities. In addition, the MDA content of drought stress was the highest of all treatments. MeJA significantly reduced MDA content in drought-stressed Huangguogan leaves. Although the Ascorbic acid (AsA) contents of 500 and 1000 mg L-1 MeJA treatments were lower than that of 250 mg L-1 MeJA, but all concentration of MeJA treatments delayed the decline of AsA content. Therefore, MeJA could induce drought stress tolerance by increasing the osmotic adjustment substances and antioxidant activities.


Asunto(s)
Acetatos/farmacología , Citrus/efectos de los fármacos , Citrus/fisiología , Ciclopentanos/farmacología , Sequías , Oxilipinas/farmacología , Estrés Fisiológico/efectos de los fármacos , Ácido Ascórbico/metabolismo , Dióxido de Carbono/metabolismo , Citrus/citología , Peróxido de Hidrógeno/metabolismo , Espacio Intracelular/efectos de los fármacos , Espacio Intracelular/metabolismo , Malondialdehído/metabolismo , Transducción de Señal/efectos de los fármacos
13.
Clin Sci (Lond) ; 133(18): 1977-1992, 2019 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-31519790

RESUMEN

Inflammatory bowel disease (IBD) is a chronic intestinal inflammation, but the accurate etiology remains to be elucidated. Increasing evidence has shown that macrophages polarize to different phenotypes depending on the intestinal microenvironment and are associated with the progression of IBD. In the present study, we investigated the effect of oxytocin, a neuroendocrinal, and pro-health peptide, on the modulation of macrophages polarization and the progression of experimental colitis. Our data demonstrated that oxytocin decreased the sensitivity of macrophages to lipopolysaccharide stimulation with lower expression of inflammatory cytokines, like IL-1ß, IL-6, and TNF-α, but increased the sensitivity to IL-4 stimulation with enhanced expression of M2-type genes, arginase I (Arg1), CD206, and chitinase-like 3 (Chil3). This bidirectional modulation was partly due to the up-regulation of ß-arrestin2 and resulted in the inhibition of NF-κB signaling and reinforcement of Signal transducer and activator of transcription (STAT) 6 phosphorylation. Moreover, oxytocin receptor (OXTR) myeloid deficiency mice were more susceptible to dextran sulfate sodium (DSS) intervention compared with the wild mice. For the first time, we reveal that oxytocin-oxytocin receptor system participates in modulating the polarization of macrophages to an anti-inflammatory phenotype and alleviates experimental colitis. These findings provide new potential insights into the pathogenesis and therapy of IBD.


Asunto(s)
Colitis/patología , Inflamación/patología , Intestinos/patología , Macrófagos/patología , Oxitocina/farmacología , Adulto , Anciano , Animales , Polaridad Celular/efectos de los fármacos , Sulfato de Dextran , Femenino , Humanos , Mediadores de Inflamación/metabolismo , Interleucina-4/metabolismo , Lipopolisacáridos , Macrófagos/efectos de los fármacos , Masculino , Ratones , Ratones Noqueados , Persona de Mediana Edad , Modelos Biológicos , FN-kappa B/metabolismo , Fosforilación/efectos de los fármacos , Células RAW 264.7 , Receptores de Oxitocina/metabolismo , Factor de Transcripción STAT6/metabolismo , Células THP-1 , beta-Arrestinas/metabolismo
14.
Inorg Chem ; 58(14): 9290-9302, 2019 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-31247832

RESUMEN

Four [Pt(PNP)(L)]+ pincer complexes (PNP = 4,5-bis(diphenylphosphino)acridine; L = Cl- (1), CN- (2), benzenethiolate -SPh (3), and 4-thiolatobenzoic acid -SPhCO2H (4)) were synthesized and structurally characterized. The oxidation of 3 and 4 by HOCl gave the corresponding sulfinate complexes 3″ (L = -SO2Ph) and 4″ (L = -SO2PhCO2H), which were characterized by X-ray crystallography. All of the complexes show intense acridine-based π → π* absorption at λmax = 398-430 nm, but the spectra of 3 and 4 display low-energy absorptions at 525 and 482 nm, respectively, which are predominantly ligand (3p of S)-to-ligand (π* of acridine) charge transfer (CT) in nature. 1, 2, 3″, and 4″ exhibit 1ππ* fluorescence, which is quenched by internal conversion to the dark CT excited state in 3 and 4. This photophysical property of 3 and 4 was harnessed for the detection of hypochlorous acid HOCl and peroxynitrite ion (ONOO-). The cyclic voltammetry (CV) of the complexes is consistent with the notion that 3 is more prone to oxidation than 4, as the CV of the former exhibits an irreversible S oxidation at +0.68 V vs Fc+/Fc, which is anodically shifted to +0.79 V in the CV of 4. The addition of HOCl or ONOO- to a solution of 3 promptly switches on its emission as the complex is oxidized to 3″. The emission intensity reaches its maximum at a [HOCl]/[3] ratio of 2. On the contrary, 4, because its thiolate S atom is less electron-rich, responds only to HOCl, indicating that electronic tuning of the auxiliary ligand can lead to different selectivities. Our findings show that 3 and 4 are fast responding probes for HOCl or ONOO- with reasonably good detection limits.

15.
Anal Bioanal Chem ; 411(1): 171-179, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30390111

RESUMEN

Bisphenol A (BPA) is one of the endocrine-disrupting chemicals which might cause reproductive and endocrine system diseases, and poses a serious threat to the ecosystem and human health. This paper reports an ultrasensitive sensor for trace BPA detection employing fluorescence resonance energy transfer (FRET) between modified upconversion nanoparticles (UCNPs) and tetramethylrhodamine. To circumvent the problems of low luminous efficiency of FRET and low sensitivity of sensor, the upconversion nanoparticles with very strong fluorescence efficiency were prepared and quantitatively modified. Results showed that the concentrations of amino groups and streptavidin were 43 nmol/mg and 6.12 µg/mg on the surface of the UCNPs, respectively. Under the optimal detection conditions, the peak intensity of UCNPs at 547 nm was linear with the logarithm of the BPA concentration with the detection limit of 0.05 ng/mL. Without complicated pre-processing, the recoveries were in general between 91.0 and 115.0% in tap water, river water, and disposable paper cup water. Therefore, the proposed sensor is suitable for effective sensing of trace BPA in water samples. Graphical abstract ᅟ.

16.
Stem Cells ; 33(5): 1589-600, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25641499

RESUMEN

Several miRNAs have recently been identified to regulate adipocyte or osteoblast differentiation or both. In this study, miR-223 was found to be involved in the reciprocal regulation of adipocyte and osteoblast differentiation. miR-223 was induced in primary cultured mouse marrow stromal cell, mesenchymal line C3H10T1/2 and stromal line ST2 after adipogenic treatment. Conversely, it was reduced in preosteoblast MC3T3-E1 after osteogenic treatment. Supplementing miR-223 levels using synthetic miR-223 mimics significantly suppressed the growth of the C3H10T1/2 and ST2 cells and induced the progenitor cells to fully differentiate into adipocytes, along with induction of adipocyte-specific transcription factors peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein-α (C/EBPα), and marker genes aP2 and adipsin. By contrast, depletion of the endogenous miR-223 using synthetic miR-223 inhibitor repressed the progenitor cells to differentiate. The effects of miR-223 on adipocyte formation from ST2 cells were also demonstrated by using lentivirus that overexpresses miR-223. Conversely, supplementing miR-223 blocked ST2 to differentiate into osteoblasts. Fibroblast growth factor receptor 2 (Fgfr2), a critical regulator of osteoblast, was shown to be a direct target of miR-223 by using dual luciferase reporter assay. Knockdown of Fgfr2 in C3H10T1/2 downregulated phosphorylation of ERK1/2 and upregulated expression of C/EBPα and dramatically enhanced the differentiation of the cells into adipocytes. Further investigation of mechanisms that control miR-223 expression demonstrated that C/EBPs induced miR-223 expression through binding to the promoter regions of the miR-223. Taken together, our study provides evidences that miR-223 regulates adipocyte and osteoblast differentiation through a novel C/EBPs/miR-223/FGFR2 regulatory feedback loop.


Asunto(s)
Adipogénesis/genética , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Retroalimentación Fisiológica , Células Madre Mesenquimatosas/metabolismo , MicroARNs/metabolismo , Osteogénesis , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Adipocitos/citología , Adipocitos/metabolismo , Animales , Secuencia de Bases , Línea Celular , Proliferación Celular , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Células Madre Mesenquimatosas/citología , Ratones Endogámicos C57BL , MicroARNs/genética , Datos de Secuencia Molecular , Osteogénesis/genética , Regiones Promotoras Genéticas/genética , Activación Transcripcional/genética
17.
Int J Biol Macromol ; 259(Pt 2): 129265, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38218292

RESUMEN

The flame retardants and electromagnetic interference (EMI) shielding performance were enhanced by using imidazolium-functionalized polyurethane (IPU) modified multi-walled carbon nanotubes (CNTs) and ammonium polyphosphate (APP) for polylactic acid (PLA)/polycaprolactone (PCL) composites. The PLA/PCL/10APP/8CNT/1.6IPU composite containing 10 wt% APP and 8 wt% imidazolium modified CNTs reached the limiting oxygen index (LOI) value of 30.3 % and passed the V-0 rating in UL-94 tests. Moreover, the peak of the heat release rate (pHRR) and total heat release (THR) for this composite reached around 302 kW/m2 and 64 KJ/m2, which were decreased by 39.1 % and 15.8 % compared with that of PLA/PCL/10APP composite. The improved flame retardancy was attributed to the interplay of catalytic, barrier, and condensed char forming of imidazolium-modified CNTs and APP. IPU catalyzed the charring effect of the polymer matrix during combustion and regulated the migration of more CNTs to disperse at the two-phase interface. The dispersion of imidazolium-modified CNTs and co-continuous phase structure of the composites can establish continuous conductive pathways. The PLA/PCL/APP/CNT/IPU composite obtained a higher conductivity compared to the PLA/PCL/APP/CNT composite and whose EMI SE reached 33.9 dB, which is a promising candidate for next-generation sustainable and protective plastics.


Asunto(s)
Caproatos , Retardadores de Llama , Lactonas , Nanotubos de Carbono , Poliésteres , Catálisis , Conductividad Eléctrica , Polifosfatos
18.
Dalton Trans ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39229906

RESUMEN

Two isoelectronic and isostructural W(0) and Re(I) complexes mer-W(CO)3(PNP) (1) and [mer-Re(CO)3(PNP)]Cl (2) (PNP = 4,5-bis(diphenylphosphino)acridine) were synthesized and characterized by X-ray diffraction, infrared, electronic absorption and emission spectroscopy, and cyclic voltammetry. Structures of these complexes show a metal center bonded to the pincer ligand and two axial CO and one equatorial CO ligands. DFT calculations showed that the LUMOs of both complexes are the lowest energy π* orbitals localized in the acridine part of the ligand. The HOMO of 1 is dominated by the dπ orbital of W(0) while the HOMO of 2 has a substantial contribution from the highest energy π orbital of the acridine ring. TD-DFT calculations were performed to assist assignment of the UV-vis absorption spectra. The UV-vis absorption spectrum of 1 shows a very low energy W → π* (acridine) metal-to-ligand-charge-transfer (MLCT) absorption band that ranges from visible (500 nm) to near-infrared (>900 nm) regions and an intense acridine π → π* absorption band at 410 nm. There is a blue-green window in the ∼450-500 nm range between the π → π* and W → π*(acridine) MLCT absorptions. The absorption spectrum of 2, dominated by intense π → π* absorptions, shows no distinct low energy MLCT band. Complex 1 is luminescent, displaying acridine-based ππ* fluorescence at 501 nm which is anti-Kasha as it is higher in energy than the lowest energy excited state.

19.
Sci Total Environ ; 946: 174305, 2024 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-38936714

RESUMEN

For the first time, combined detection and simulation was performed on microplastic (MP) debris in surface water, sediment, and oyster samples at ten coastal sites of Shing Mun River estuary, Hong Kong at different tidal conditions. The MP debris were extracted and detected using Fourier transform infrared (FT-IR) spectroscopy, and the simulation was conducted using Weather Research & Forecasting Model (WRF) / Regional Ocean Modelling System (ROMS) coupled hydro-dynamic modelling and the subsequent Lagrangian particle tracking. The results demonstrated the majority of polyethylene (with partial chlorine substitution) debris among all the MPs found, and great spatial and tidal variabilities of MP concentrations were observed. The combination of MP observation and simulations referred to the interpretation that a considerable percentage of MPs found in this study originated from South China Sea. Those MPs were probably transported to Tolo Harbour through sea currents and drifted inshore and offshore with tides. This study provided baseline measures of MP concentrations in Shing Mun River estuary and comprehensive understanding for how MPs transport and distribute within a dynamic estuarine system.

20.
Food Funct ; 15(2): 625-646, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38099724

RESUMEN

Delayed mucosal healing and impaired intestinal epithelial barrier function have been implicated in the pathogenesis of ulcerative colitis (UC). Accordingly, restoration of epithelial barrier function as a means to reshape mucosal homeostasis represents an important strategy for use in the treatment of UC. In this study, we examined the role and mechanisms of D-mannose in the recovery of colitis as assessed in both animal and cell models. We found that D-mannose ameliorated inflammation, promoted mucosal healing in the colon and therefore was able to induce the recovery of UC. Furthermore, D-mannose increased the expression of tight junction (TJ) proteins and reduced the intestinal permeability during the recovery of colitis. Moreover, D-mannose inhibited M1 macrophage polarization and promoted M2 macrophage polarization via inducing AMPK phosphorylation while reducing mTOR phosphorylation in both models. In addition, increased TJ protein expression and decreased paracellular permeability were observed in NCM460 cells when incubated with the supernatants of D-mannose-treated RAW264.7 cells, suggesting that M1/M2 polarization induced by D-mannose modulates the expression of TJ proteins. Further study showed that D-mannose significantly upregulated the expression of TJ proteins in DSS-treated NCM460 cells by inducing AMPK phosphorylation, indicating a direct protective effect on epithelial cells. Finally, the protective effects of D-mannose were significantly abrogated by the presence of compound C, an AMPK inhibitor. Taken together, our data indicate that D-mannose can alleviate inflammation and foster epithelial restitution in UC recovery by inducing the TJ protein expression, which are achieved by inducing AMPK phosphorylation in the epithelium and/or macrophages.


Asunto(s)
Colitis Ulcerosa , Colitis , Animales , Ratones , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Manosa/metabolismo , Fosforilación , Mucosa Intestinal/metabolismo , Colitis/inducido químicamente , Colitis Ulcerosa/inducido químicamente , Inflamación/metabolismo , Proteínas de Uniones Estrechas/genética , Proteínas de Uniones Estrechas/metabolismo , Sulfato de Dextran/efectos adversos , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Colon/metabolismo
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