Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Am J Transl Res ; 15(3): 2122-2139, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37056832

RESUMEN

OBJECTIVE: Endometrial cancer is one of the most common tumors of the female reproductive system, and the existing treatment options for advanced and metastatic endometrial cancer have certain limitations. The antitumor activity of luteolin has been gradually discovered. The purpose of this study was to predict the potential of luteolin in the treatment of endometrial cancer and to provide reference for future clinical drug use. METHODS: The target gene database of luteolin and differential gene dataset of uterine corpus endometrial carcinoma (UCEC) have been constructed to obtain the differential genes (DR-DEGs) for luteolin and UCEC. The Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis are performed at the same time. Genes associated with prognosis in DR-DEGs were screened and validated using univariate and multivariate COX risk regression analysis so as to construct a prognostic model. Genes are divided into high-risk and low-risk groups according to risk scores for survival analysis and the predictive effect of the model is evaluated. The role of immune function in UCEC is investigated by immune infiltration and immune checkpoint analysis Finally, Transwell experiment was conducted to investigate the effect of luteolin on the migration ability of endometrial cancer cells, and the expression changes of MMP1, IL-17 and VEGF were detected by q-PCR. RESULTS: Through the GO, KEGG and GSEA enrichment analysis, we have found a significant enrichment in "IL 17 signaling (IL-17) pathway", "oxidative stress response" and "HOMOLOGOUS_RECOMBINATION". Through multivariate COX risk regression analysis, four genes associated with the prognosis are harvested, including "PRSS1, MMP1, ERBB2 and NUF2" which belong to high-risk genes. Kaplan-Meier analysis shows that the survival rate in the high risk group is lower than that in the low risk group, and the receiver operating characteristic (ROC) curve reveals that the predictive effect of the model is good and stable (area under 1-year curve (AUC) 0.569, two-year AUC 0.628 and three-year AUC 0.653). Immune infiltration and immune checkpoint analysis suggest that "CD40", "T cells regulatory (Tregs)", "dendritic cells resting" and "dendritic cells activated" are correlated with survival and prognosis in UCEC patients. In in vitro experiments, we found that the migration ability of endometrial cancer cells was significantly reduced after luteolin treatment, and the expressions of MMP1, IL-17 and VEGF were all decreased. CONCLUSION: Through bioinformatic analysis, we found that luteolin could slow down the progression of UCEC by inhibiting the production of inflammatory mediators such as IL-17 and oxidative stress, and constructed genetic prognostic models associated with them: PRSS1, MMP1, ERBB2 and NUF2, respectively. In addition, we found that luteolin has an inhibitory effect on the migration of endometrial cancer cells and can reduce the expressions of MMP1, IL-17 and VEGF, thus easing the progression of endometrial cancer.

2.
Oncogenesis ; 12(1): 22, 2023 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-37080999

RESUMEN

Anti-PD-1 therapy has shown promising outcomes in the treatment of different types of cancer. It is of fundamental interest to analyze the efficacy of anti-PD-1 therapy in cancer patients infected with hepatitis B virus (HBV) since the comorbidity of HBV and cancer is widely documented. We designed a multicenter retrospective study to evaluate the efficacy of anti-PD-1 therapy on non-liver cancer patients infected with HBV. We found anti-PD-1 therapy achieved much better outcomes in HBV+ non-liver cancer patients than their HBV- counterparts. We performed single-cell RNA sequencing (scRNA-seq) on peripheral blood mononuclear cells (PBMCs) from esophageal squamous cell carcinoma (ESCC) patients. We found both cytotoxicity score of T cells and MHC score of B cells significantly increased after anti-PD-1 therapy in HBV+ ESCC patients. We also identified CX3CR1high TEFF, a subset of CD8+ TEFF, associated with better clinical outcome in HBV+ ESCC patients. Lastly, we found CD8+ TEFF from HBV+ ESCC patients showing higher fraction of Exhaustionhi T than their HBV- counterpart. In summary, anti-PD-1 therapy on HBV+ non-liver cancer patients is safe and achieves better outcomes than that on HBV- non-liver cancer patients, potentially because HBV+ patients had higher fraction of Exhaustionhi T, which made them more efficiently respond to anti-PD-1 therapy.

3.
Front Genet ; 14: 1075347, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36816040

RESUMEN

Hepatocellular carcinoma (HCC) is a clinically and genetically heterogeneous disease. To better describe the clinical value of the main driver gene mutations of HCC, we analyzed the whole exome sequencing data of 125 patients, and combined with the mutation data in the public database, 14 main mutant genes were identified. And we explored the correlation between the main mutation genes and clinical features. Consistent with the results of previous data, we found that TP53 and LRP1B mutations were related to the prognosis of our patients by WES data analysis. And we further explored the associated characteristics of TP53 and LRP1B mutations. However, it is of great clinical significance to tailor a unique prediction method and treatment plan for HCC patients according to the mutation of TP53. For TP53 wild-type HCC patients, we proposed a prognostic risk model based on 11 genes for better predictive value. According to the median risk score of the model, HCC patients with wild-type TP53 were divided into high-risk and low-risk groups. We found significant transcriptome changes in the enrichment of metabolic-related pathways and immunological characteristics between the two groups, suggesting the predictability of HCC immunotherapy by using this model. Through the CMap database, we found that AM580 had potential therapeutic significance for high-risk TP53 wild-type HCC patients.

4.
Sci Rep ; 12(1): 18813, 2022 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-36335189

RESUMEN

N-7 methylguanine (m7G) is one of the most common RNA base modifications in post-transcriptional regulation, which participates in multiple processes such as transcription, mRNA splicing and translation during the mRNA life cycle. However, its expression and prognostic value in uterine corpus endometrial carcinoma (UCEC) have not been systematically studied. In this paper, the data such as gene expression profiles, clinical data of UCEC patients, somatic mutations and copy number variants (CNVs) are obtained from the cancer genome atlas (TCGA) and UCSC Xena. By analyzing the expression differences of m7G-related mRNA in UCEC and plotting the correlation network maps, a risk score model composed of four m7G-related mRNAs (NSUN2, NUDT3, LARP1 and NCBP3) is constructed using least absolute shrinkage and selection operator (LASSO), univariate and multivariate Cox regression in order to identify prognosis and immune response. The correlation of clinical prognosis is analyzed between the m7G-related mRNA and UCEC via Kaplan-Meier method, receiver operating characteristic (ROC) curve, principal component analysis (PCA), t-SNE, decision curve analysis (DCA) curve and nomogram etc. It is concluded that the high risk is significantly correlated with (P < 0.001) the poorer overall survival (OS) in patients with UCEC. It is one of the independent risk factors affecting the OS. Differentially expressed genes are identified by R software in the high and low risk groups. The functional analysis and pathway enrichment analysis have been performed. Single sample gene set enrichment analysis (ssGSEA), immune checkpoints, m6A-related genes, tumor mutation burden (TMB), stem cell correlation, tumor immune dysfunction and rejection (TIDE) scores and drug sensitivity are also used to study the risk model. In addition, we have obtained 3 genotypes based on consensus clustering, which are significantly related to (P < 0.001) the OS and progression-free survival (PFS). The deconvolution algorithm (CIBERSORT) is applied to calculate the proportion of 22 tumor infiltrating immune cells (TIC) in UCEC patients and the estimation algorithm (ESTIMATE) is applied to work out the number of immune and matrix components. In summary, m7G-related mRNA may become a potential biomarker for UCEC prognosis, which may promote UCEC occurrence and development by regulating cell cycles and immune cell infiltration. It is expected to become a potential therapeutic target of UECE.


Asunto(s)
Carcinoma Endometrioide , Neoplasias Endometriales , Femenino , Humanos , Pronóstico , Neoplasias Endometriales/patología , Regulación Neoplásica de la Expresión Génica , Carcinoma Endometrioide/patología , ARN Mensajero/genética , ARN Mensajero/metabolismo
5.
Sci Rep ; 12(1): 16285, 2022 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-36175606

RESUMEN

Necroptosis, a programmed form of necrotic cell death, plays critical regulatory roles in the progression and metastatic spread of cancers such as cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC). However, there are few articles systematically analyzing the necroptosis-related long non-coding RNAs (NRlncRNAs) correlated with CESC patients. Both RNA-sequencing and clinical data of CESC patients are downloaded from TCGA database in this study. Pearson correlation analysis, least absolute shrinkage, operator algorithm selection and Cox regression model are employed to screen and create a risk score model of eleven-NRlncRNAs (MIR100HG, LINC00996, SNHG30, LINC02688, HCG15, TUBA3FP, MIAT, DBH-AS1, ERICH6-AS1SCAT1, LINC01702) prognostic. Thereafter, a series of tests are carried out in sequence to evaluate the model for independent prognostic value. Gene set enrichment analytic paper, Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analytic paper make it clear that immune-related signaling pathways are very rich in the high-risk subgroup. Additionally, the prognostic risk score model is correlated to immune cell infiltration, potential immune checkpoint, immune function, immune micro-environmental and m6A-related gene. Mutation frequency in mutated genes and survival probability trend are higher in the low-risk subgroup in most of test cases when compared to the high-risk subgroup. This study constructs a renewed prognostic model of eleven-NRlncRNAs, which may make some contribution to accurately predicting the prognosis and the immune response from CESC patients, and improve the recognition of CESC patients and optimize customized treatment regimens to some extent.


Asunto(s)
Adenocarcinoma , Carcinoma de Células Escamosas , ARN Largo no Codificante , Neoplasias del Cuello Uterino , Femenino , Humanos , Carcinoma de Células Escamosas/genética , Inmunidad , Necroptosis/genética , Pronóstico , ARN Largo no Codificante/genética , Neoplasias del Cuello Uterino/genética
6.
Soft Matter ; 18(35): 6582-6591, 2022 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-35968884

RESUMEN

Recent advances in the functional material and biomedical applications of nanorods call for a fundamental understanding of the active motion of nanorods in a viscoelastic medium. Molecular dynamics simulations are performed to investigate a model system consisting of force-driven active thin nanorods in a melt of unentangled polymers. The activeness of a thin nanorod arises from a constant external force applied uniformly along the rod. The simulations demonstrate that the active force overcomes the randomness of the diffusive motion and results in a ballistic motion along the direction of the applied force at long timescales. The constant speed of the force-driven ballistic motion is determined by the balance of the active force and the friction from the coupling of the nanorod with the polymer viscosity. The friction coefficient, which is computed as the ratio of the active force and the speed, decreases as the active force increases. The origin of the reduction in the friction coefficient is the high speed that allows the nanorod to renew its local environment faster than the relaxation time of melt chains. A scaling theory is developed to quantify the dependence of the friction coefficient on the strength of the active force. The simulations also demonstrate that the force-driven ballistic motion suppresses the rotational diffusion of the rod and cuts off the de-correlation of the rod axis with time. On the scaling level, the long-time trajectory of a force-driven active nanorod piercing through unentangled polymers may be described as a stretched array of "active blobs", where the short-time random-walk trajectory within an active blob is unperturbed by the active force.

7.
Phys Rev Lett ; 128(23): 237801, 2022 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35749195

RESUMEN

The stretchability of polymeric materials is critical to many applications such as flexible electronics and soft robotics, yet the stretchability of conventional cross-linked linear polymers is limited by the entanglements between polymer chains. We show using molecular dynamics simulations that cross-linked ring polymers are significantly more stretchable than cross-linked linear polymers. Compared to linear polymers, the entanglements between ring polymers do not act as effective cross-links. As a result, the stretchability of cross-linked ring polymers is determined by the maximum extension of polymer strands between cross-links, rather than between trapped entanglements as in cross-linked linear polymers. The more compact conformation of ring polymers before deformation also contributes to the increase in stretchability.


Asunto(s)
Elastómeros , Polímeros , Conformación Molecular , Simulación de Dinámica Molecular
8.
Phytochemistry ; 184: 112649, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33440297

RESUMEN

Euphorbia helioscopia L. which is called "Zeqi" in China, is a medicinal plant extensively distributed worldwide, especially in China, and has been widely used for decades to treat various diseases including edema, phlegm and cough, malaria, dysentery, scab, tuberculous fistula, osteomyelitis, and cancer. The present review aims to provide up-to-date information on E. helioscopia, including its traditional uses, phytochemistry, quality control, pharmacological research, toxicology, and human studies in exploring future scientific and therapeutic potentials in disease treatment. So far, a total of 173 terpenoids, as well as polyphenols, steroids, lipids, and volatile oils have been isolated and identified from E. helioscopia. Among them, diterpenoids and flavonoids are the most important and abundant bioactive constituents. Modern pharmacological studies have demonstrated that E. helioscopia has outstanding bioactivities especially on antiproliferative and multidrug resistance modulating. Nevertheless, most of these studies were carried out in vitro. The quality control, metabolites identification, in-depth in-vivo studies as well as toxicology and human studies for the crude extracts and active components are still very limited. Consequently, more well-designed pre-clinical and clinical studies are required to justify their reported therapeutic potential.


Asunto(s)
Euphorbia , Plantas Medicinales , China , Etnofarmacología , Fitoquímicos/farmacología , Fitoterapia , Extractos Vegetales/farmacología
9.
Macromolecules ; 54(15): 7051-7059, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-35935463

RESUMEN

The diffusion of monomerically thin nanorods in polymer melts is studied by molecular dynamics simulations. We focus on the systems where chains are long enough to screen the hydrodynamic interactions such that the diffusion coefficient D ∥ for the direction parallel to the rod decreases linearly with increasing rod length l. In unentangled polymers, the diffusion coefficient for the direction normal to the rod exhibits a crossover from D ⊥ ~ l -2 to D ⊥ ~ l -1 with increasing l, corresponding to a progressive coupling of nanorod motion to the polymers. Accordingly, the rotational diffusion coefficient D R ≈ D ⊥ l -2 ~ l -4 and then D R ~ l -3 as l increases. In entangled polymers, D ⊥ and D R are suppressed for l larger than the entanglement mesh size a. D ⊥ ~ l -3 and D R ~ l -5 for l sufficiently above a in agreement with de Gennes' rod reptation model.

10.
Mol Cell Biol ; 40(13)2020 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-32312884

RESUMEN

RNA helicase DHX33 was found to regulate the transcription of multiple genes involved in cancer development. But the underlying molecular mechanism remains unclear. Here, we found DHX33 associated extensively with gene promoters at CG-rich region. Its deficiency reduced the loading of active RNA polymerase II at gene promoters. Furthermore, we observed a functional interaction between DHX33, AP-2ß, and DNA demethylation protein Gadd45a (growth arrest and DNA damage inductile protein 45a) at specific gene promoters. DHX33 is required to recruit GADD45a, thereby causing local DNA demethylation through further recruiting ten-eleven-translocation (Tet) methylcytosine dioxygenase enzyme, as manifested by reduced 5-hydroxymethyl cytosine levels for a subset of genes after DHX33 deficiency. This process might involve R-loop formation in GC skew as a guidance signal at promoter sites. Our report provides for the first time, to our knowledge, original evidence that DHX33 alters epigenetic marks and regulates specific gene transcription through interaction with Gadd45a.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , ARN Helicasas DEAD-box/metabolismo , Desmetilación del ADN , Neoplasias/metabolismo , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias/genética , Regiones Promotoras Genéticas , Mapas de Interacción de Proteínas , Activación Transcripcional
11.
Nanoscale ; 12(8): 5091-5102, 2020 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-32068755

RESUMEN

Embedding percolating networks of nanoparticles (NPs) within polymers is a promising approach for mechanically reinforcing polymers and for introducing novel electronic, transport, and catalytic properties into otherwise inert polymers. While such networks may be obtained through kinetic assembly of unary system of NPs, the ensuing structures exhibit limited morphologies. Here, we investigate the possibility of increasing the diversity of NP networks through kinetic assembly of multiple species of NPs. Using lattice Monte Carlo simulations we show that networks obtained from co-assembly of two NP species of different sizes exhibit significantly more diverse morphology than those assembled from a single species. In particular, we achieved considerable variations in the particle spatial distribution, proportions of intra- and interspecies contacts, fractal dimension, and pore sizes of the networks by simply modulating the stoichiometry of the two species and their intra and inter-species affinities. We classified these distinct morphologies into "integrated", "coated", "leaved", and "blocked" phases, and provide relevant phase diagrams for achieving them. Our findings are relevant to controlled and predictable assembly of particle networks for creating multifunctional composites with improved properties.

12.
Sci Rep ; 10(1): 2576, 2020 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-32054865

RESUMEN

Traumatic injury to the spinal cord causes permanent loss of function and major personal, social, and economic problems. Cell-based delivery strategies is a promising approach for treating spinal cord injury (SCI). However, the inhospitable microenvironment in the injured spinal cord results in poor cell survival and uncontrolled differentiation of the transplanted stem cells. The combination of a scaffold with cells has been developed with a tendency for achieving greater survival and integration with the host tissue. We investigated the effect of Matrigel combined with neural stem cells (NSCs) in vitro and in vivo. We compared the effect of different types of scaffold on the survival and differentiation of brain-derived NSCs in an in vitro culture. Subsequently, NSCs were transplanted subcutaneously into nude mice to detect graft survival and differentiation in vivo. Finally, phosphate-buffered saline (PBS), Matrigel alone, or Matrigel seeded with NSCs was injected into 48 subacute, clinically relevant rat models of SCI (16 rats per group). Matrigel supported cell survival and differentiation efficiently in vitro and in vivo. SCI rats transplanted with NSCs in Matrigel showed improved behavioral recovery and neuronal and reactive astrocyte marker expression levels compared to PBS- or Matrigel-transplanted rats. Functional repair and neuronal and reactive astrocyte marker expression was slightly improved in the Matrigel-alone group relative to the PBS group, but not statistically significantly. These data suggest that Matrigel is a promising scaffold material for cell transplantation to the injured spinal cord.


Asunto(s)
Células-Madre Neurales/trasplante , Neurogénesis/efectos de los fármacos , Neuronas/metabolismo , Traumatismos de la Médula Espinal/terapia , Animales , Diferenciación Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Colágeno/farmacología , Modelos Animales de Enfermedad , Combinación de Medicamentos , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Laminina/farmacología , Células-Madre Neurales/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/patología , Proteoglicanos/farmacología , Ratas , Recuperación de la Función , Traumatismos de la Médula Espinal/fisiopatología , Andamios del Tejido
13.
Proc Natl Acad Sci U S A ; 117(8): 3930-3937, 2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32029595

RESUMEN

Intrinsically low lattice thermal conductivity ([Formula: see text]) in superionic conductors is of great interest for energy conversion applications in thermoelectrics. Yet, the complex atomic dynamics leading to superionicity and ultralow thermal conductivity remain poorly understood. Here, we report a comprehensive study of the lattice dynamics and superionic diffusion in [Formula: see text] from energy- and momentum-resolved neutron and X-ray scattering techniques, combined with first-principles calculations. Our results settle unresolved questions about the lattice dynamics and thermal conduction mechanism in [Formula: see text] We find that the heat-carrying long-wavelength transverse acoustic (TA) phonons coexist with the ultrafast diffusion of Ag ions in the superionic phase, while the short-wavelength nondispersive TA phonons break down. Strong scattering of phonon quasiparticles by anharmonicity and Ag disorder are the origin of intrinsically low [Formula: see text] The breakdown of short-wavelength TA phonons is directly related to the Ag diffusion, with the vibrational spectral weight associated to Ag oscillations evolving into stochastic decaying fluctuations. Furthermore, the origin of fast ionic diffusion is shown to arise from extended flat basins in the energy landscape and collective hopping behavior facilitated by strong repulsion between Ag ions. These results provide fundamental insights into the complex atomic dynamics of superionic conductors.

14.
Mol Cell Biol ; 39(17)2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31182639

RESUMEN

The RNA helicase DHX33 has been found to be overexpressed in human cancers, where it promotes cancer development. Previous reports have shown that DHX33 deficiency caused cancer cell apoptosis, but the underlying mechanism remains unknown. In this study, we discovered that DHX33 regulates Bcl-2 family protein expression. In multiple human cancer cell lines, DHX33 was found to stimulate the transcription of Bcl-2 Mechanistically, we found that DHX33 interacts with the AP-2ß transcription factor and acts as a coactivator to stimulate Bcl-2 gene transcription. DHX33 deficiency abolished the loading of AP-2ß onto the promoter of Bcl-2 and thereby reduced the recruitment of active RNA polymerase II during transcription initiation. Acute knockdown of DHX33 in multiple human cancer cells caused decreased Bcl-2 protein level, which ultimately triggered mitochondrion-mediated cellular apoptosis. In addition, we found that normal human lung and mammary epithelial cells were less sensitive to acute DHX33 knockdown, implying that cancer cells are uniquely responsive to DHX33 reduction. These data support the notion that disruption of DHX33 function could be an important application for cancer therapy.


Asunto(s)
Neoplasias de la Mama/patología , ARN Helicasas DEAD-box/genética , ARN Helicasas DEAD-box/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Factor de Transcripción AP-2/metabolismo , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Supervivencia Celular , Femenino , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Ratones , Mitocondrias/metabolismo , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , ARN Polimerasa II/metabolismo
15.
Nat Commun ; 9(1): 2607, 2018 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-29973592

RESUMEN

To optimally penetrate biological hydrogels such as mucus and the tumor interstitial matrix, nanoparticles (NPs) require physicochemical properties that would typically preclude cellular uptake, resulting in inefficient drug delivery. Here, we demonstrate that (poly(lactic-co-glycolic acid) (PLGA) core)-(lipid shell) NPs with moderate rigidity display enhanced diffusivity through mucus compared with some synthetic mucus penetration particles (MPPs), achieving a mucosal and tumor penetrating capability superior to that of both their soft and hard counterparts. Orally administered semi-elastic NPs efficiently overcome multiple intestinal barriers, and result in increased bioavailability of doxorubicin (Dox) (up to 8 fold) compared to Dox solution. Molecular dynamics simulations and super-resolution microscopy reveal that the semi-elastic NPs deform into ellipsoids, which enables rotation-facilitated penetration. In contrast, rigid NPs cannot deform, and overly soft NPs are impeded by interactions with the hydrogel network. Modifying particle rigidity may improve the efficacy of NP-based drugs, and can be applicable to other barriers.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Doxorrubicina/farmacología , Portadores de Fármacos , Nanopartículas/química , Neoplasias Pancreáticas/tratamiento farmacológico , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Administración Oral , Animales , Antibióticos Antineoplásicos/metabolismo , Transporte Biológico , Línea Celular Tumoral , Difusión , Doxorrubicina/metabolismo , Composición de Medicamentos , Elasticidad , Dureza , Humanos , Hidrogeles/química , Masculino , Ratones , Ratones Desnudos , Moco/química , Nanopartículas/administración & dosificación , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Permeabilidad , Ratas , Ratas Sprague-Dawley , Esferoides Celulares/efectos de los fármacos , Esferoides Celulares/metabolismo , Esferoides Celulares/patología , Ensayos Antitumor por Modelo de Xenoinjerto
16.
Small ; : e1801586, 2018 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-29883045

RESUMEN

Supported metal nanoparticles play key roles in nanoelectronics, sensors, energy storage/conversion, and catalysts for the sustainable production of fuels and chemicals. Direct observation of the dynamic processes of nanocatalysts at high temperatures and the confinement of supports is of great significance to investigate nanoparticle structure and functions for practical utilization. Here, in situ high-resolution transmission electron microscopy photos and videos are combined with dynamics simulations to reveal the real-time dynamic behavior of Pt nanocatalysts at operation temperatures. Amorphous Pt surface on moving and deforming particles is the working structure during the high operation temperature rather than a static crystal surface and immobilization on supports as proposed before. The free rearrangement of the shape of Pt nanoparticles allows them to pass through narrow windows, which is generally considered to immobilize the particles. The Pt particles, no matter what their sizes, prefer to stay inside nanopores even when they are fast moving near an opening at temperatures up to 900 °C. The porous confinement also blocks the sintering of the particles under the confinement size of pores. These contribute to the continuous high activity and stability of Pt nanocatalysts inside nanoporous supports during a long-term evaluation of catalytic reforming reaction.

17.
Biochem Biophys Res Commun ; 502(4): 501-507, 2018 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-29864424

RESUMEN

DHX33 has been shown to play key roles in promoting cell proliferation. We have previously found that DHX33 protein is a doublet. In this report, we discovered that DHX33 doublet is due to alternative translation initiation by two in-frame initiation codons. This is supported by studies from both cell lines and mouse models. DHX33 translation initiation from either AUG codon happens at equal efficiency. Short DHX33 protein has similar cellular location and functions with full-length DHX33. Our results suggest that leaky scanning normally occur in DHX33 mRNA translation, which may serve as a safeguard mechanism to ensure optimal DHX33 translation efficiency. This is the first report of DEAD/DEAH box proteins that can be regulated by alternative translation initiation.


Asunto(s)
Codón Iniciador , ARN Helicasas DEAD-box/biosíntesis , ARN Helicasas DEAD-box/genética , Iniciación de la Cadena Peptídica Traduccional , Animales , Células Cultivadas , ARN Helicasas DEAD-box/química , Humanos , Isoenzimas/biosíntesis , Isoenzimas/química , Isoenzimas/genética , Ratones , Ratones Noqueados , Células 3T3 NIH , ARN Guía de Kinetoplastida/genética , Sistemas de Lectura
18.
Spine J ; 18(5): 845-856, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29355788

RESUMEN

BACKGROUND CONTEXT: Lung injury is a major cause of respiratory complications following an acute spinal cord injury (ASCI), which are associated with a high mortality rate. Autophagy has been shown to be involved in a variety of lung diseases; however, whether autophagy is activated in the lung following ASCI remains unknown. PURPOSE: The objective of this study was to investigate the induction of autophagy in the lung after ASCI. STUDY DESIGN: This is an experimental animal study of ASCI investigating kinetics of autophagy in the lung following ASCI. METHODS: One hundred and forty-four rats (N=144) were divided into two groups: (1) a sham (n=72) and (2) an injury group (n=72). Allen's method was used to induce an injury at the level of the 10th thoracic vertebra. Rats were sacrificed at 6, 12, 24, 48, and 72 hours, 1 week, and 2 weeks after surgery. Lung pathology and apoptosis were assessed to determine the level of damage in the lung. LC3, RAB7, P62, and Beclin 1 were used to detect the induction of autophagy. The study was funded by the Natural Science Foundation of China (NSFC,81272172); National Key Specialty Construction of Clinical Projects of China (#2013-544). The funder of the present study had no capacity to influence the scholarly conduct of the research, interpretation of results, or dissemination of study outcomes. RESULTS: In the injury group, pathologic changes (i.e., pulmonary congestion, hemorrhage, inflammatory exudation, and alveolar collapse) occurred within the lung tissue within 72 hours after ASCI. Apoptosis of the lung cells gradually increased and peaked 72 hours after ASCI. Within 24 hours of ASCI, LC3 expression decreased, recovered, and gradually increased from 24 hours to 72 hours. As RAB7 decreased, P62 increased, and the ratio of RAB7/LC3 significantly decreased. CONCLUSIONS: After ASCI, autophagy in the injured lung underwent dynamic changes, as early autophagosome formation decreased and late autophagosomes accumulated; thus, autophagy is in a state of inhibition.


Asunto(s)
Autofagia , Pulmón/metabolismo , Traumatismos de la Médula Espinal/patología , Animales , Apoptosis , Femenino , Masculino , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/metabolismo
19.
Soft Matter ; 13(26): 4644-4652, 2017 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-28650048

RESUMEN

Understanding the interaction between nanoparticles (NPs) and cell membranes is crucial for the design of NP-based drug delivery systems and for the assessment of the risks exerted by the NPs. Recent experimental and theoretical studies have shown that cell membranes can mediate attraction between NPs and form tubular structures to wrap multiple NPs. However, the cooperative wrapping process is still not well understood, and the shape effect of NPs is not considered. In this article, we use large-scale coarse-grained molecular dynamics (CGMD) simulations to study the cooperative wrapping of NPs when a varying number of NPs adhered to the membrane. Spherical, prolate and oblate NPs of different sizes are considered in this study. We find that, in addition to tubular structures, the membrane can form a pocket-like and a handle-like structure to wrap multiple NPs depending on the size and shape of the NPs. Furthermore, we find that NPs can mediate membrane hemifusion or fusion during this process. Our findings provide new insights into the interaction of NPs with the cell membrane.


Asunto(s)
Membrana Celular/química , Lípidos de la Membrana/química , Tamaño de la Partícula , Conformación Molecular , Simulación de Dinámica Molecular , Nanopartículas
20.
Cell Death Discov ; 3: 16095, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28090355

RESUMEN

DEAD box proteins are multifunctional proteins involved in every aspect in RNA metabolism and have essential roles in many cellular activities. Despite their importance, many DEAD box proteins remain uncharacterized. In this report, we found DDX59 overexpressed in lung adenocarcinoma. DDX59 knockdown reduced cell proliferation, anchorage-independent cell growth, and caused reduction of tumor formation in immunocompromised mice. In multiple lung cancer cells, we found that DDX59 knockdown inhibits DNA synthesis; wild-type DDX59 but not helicase-defective mutant of DDX59 enhances DNA synthesis. DDX59 knockdown caused reduction of MCM protein levels, decreased the loading of MCM ring protein onto chromatin, and therefore inhibited DNA replication. Our study reveals for the first time that DDX59 has an important role in lung cancer development through promoting DNA replication.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...