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1.
Phys Rev Lett ; 132(24): 246501, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38949356

RESUMEN

Electrons residing in a flat-band system can play a vital role in triggering spectacular phenomenology due to relatively large interactions and spontaneous breaking of different degeneracies. In this work, we demonstrate chirally twisted triple bilayer graphene, a new moiré structure formed by three pieces of helically stacked Bernal bilayer graphene, as a highly tunable flat-band system. In addition to the correlated insulators showing at integer moiré fillings, commonly attributed to interaction induced symmetry broken isospin flavors in graphene, we observe abundant insulating states at half-integer moiré fillings, suggesting a longer-range interaction and the formation of charge density wave insulators which spontaneously break the moiré translation symmetry. With weak out-of-plane magnetic field applied, as observed half-integer filling states are enhanced and more quarter-integer filling states appear, pointing toward further quadrupling moiré unit cells. The insulating states at fractional fillings combined with Hartree-Fock calculations demonstrate the observation of a new type of correlated charge density wave insulators in graphene and points to a new accessible twist manner engineering correlated moiré electronics.

2.
Nat Mater ; 21(11): 1263-1268, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36109673

RESUMEN

The production of large-area twisted bilayer graphene (TBG) with controllable angles is a prerequisite for proceeding with its massive applications. However, most of the prevailing strategies to fabricate twisted bilayers face great challenges, where the transfer methods are easily stuck by interfacial contamination, and direct growth methods lack the flexibility in twist-angle design. Here we develop an effective strategy to grow centimetre-scale TBG with arbitrary twist angles (accuracy, <1.0°). The success in accurate angle control is realized by an angle replication from two prerotated single-crystal Cu(111) foils to form a Cu/TBG/Cu sandwich structure, from which the TBG can be isolated by a custom-developed equipotential surface etching process. The accuracy and consistency of the twist angles are unambiguously illustrated by comprehensive characterization techniques, namely, optical spectroscopy, electron microscopy, photoemission spectroscopy and photocurrent spectroscopy. Our work opens an accessible avenue for the designed growth of large-scale two-dimensional twisted bilayers and thus lays the material foundation for the future applications of twistronics at the integration level.

3.
Appl Opt ; 60(3): 662-669, 2021 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-33690435

RESUMEN

In this study, we demonstrate a novel, to the best of our knowledge, integrated indium phosphide (InP) and silicon nitride (Si3N4) waveguide platform, which is based on interlayer coupling, to achieve heterogeneous integration of a photodetector and waveguide ring resonator firstly. In order to improve the gyro bias stability, the Si3N4 and InP waveguides were designed with a high polarization extinction ratio and ultra-low loss. Three-dimensional finite difference time domain methods are used to optimize the InP taper dimensions to provide efficient optical coupling between the Si3N4 and InP waveguides. The optical coupler with a length of 100 µm is designed to achieve optical coupling between the Si3N4 and InP waveguides while maintaining its state of polarization all the way from the taper waveguides. The coupling efficiency of the optimized interlayer coupler has been improved to about 99.5%.

4.
Cancer Sci ; 106(5): 559-66, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25683165

RESUMEN

Sirtuin 6 (SIRT6) can function as a tumor suppressor by suppressing aerobic glycolysis and apoptosis resistance. However, the negative effect of SIRT6 on cellular senescence implies that it may also have the potential to promote tumor development. Here we report that the upregulation of SIRT6 expression was required for transforming growth factor (TGF)-ß1 and H2O2/HOCl reactive oxygen species (ROS) to promote the tumorigenicity of hepatocellular carcinoma (HCC) cells. Transforming growth factor-ß1/H2O2/HOCl could upregulate SIRT6 expression in HCC cells by inducing the sustained activation of ERK and Smad pathways. Sirtuin 6 in turn abrogated the inducing effect of TGF-ß1/H2O2/HOCl on cellular senescence of HCC cells, and was required for the ERK pathway to efficiently suppress the expression of p16 and p21. Sirtuin 6 altered the effect of Smad and p38 MAPK pathways on cellular senescence, and contributed to the inhibitory effect of the ERK pathway on cellular senescence. However, SIRT6 was inefficient in antagonizing the promoting effect of TGF-ß1/H2O2 HOCl on aerobic glycolysis and anoikis resistance. Intriguingly, if SIRT6 expression was inhibited, the promoting effect of TGF-ß1/H2O2/HOCl on aerobic glycolysis and anoikis resistance was not sufficient to enhance the tumorigenicity of HCC cells. Suppressing the upregulation of SIRT6 enabled TGF-ß1/H2O2/HOCl to induce cellular senescence, thereby abrogating the enhancement of HCC cell tumorigenicity by TGF-ß1/H2O2/HOCl. These results suggest that SIRT6 is required for TGF-ß1/H2O2/HOCl to enhance the tumorigenicity of HCC cells, and that targeting the ERK pathway to suppress the upregulation of SIRT6 might be a potential approach in comprehensive strategies for the therapy of HCC.


Asunto(s)
Carcinoma Hepatocelular/patología , Senescencia Celular/efectos de los fármacos , Neoplasias Hepáticas/patología , Sirtuinas/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Animales , Anoicis , Carcinoma Hepatocelular/metabolismo , Línea Celular Tumoral , Glucólisis , Humanos , Peróxido de Hidrógeno/metabolismo , Peróxido de Hidrógeno/farmacología , Ácido Hipocloroso/metabolismo , Ácido Hipocloroso/farmacología , Neoplasias Hepáticas/metabolismo , Sistema de Señalización de MAP Quinasas , Ratones Desnudos , Sirtuinas/genética , Proteínas Smad/metabolismo , Factor de Crecimiento Transformador beta1/farmacología , Regulación hacia Arriba , Ensayos Antitumor por Modelo de Xenoinjerto
5.
J Immunol ; 190(11): 5882-93, 2013 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-23630344

RESUMEN

Neutrophils are known to have antitumor potential. However, in recent years the tumor-promoting effect of neutrophils has been well demonstrated. So far, it remains unclear what causes the conversion of neutrophil function from tumor suppressive to tumor promoting. In this article, we report that the conversion of murine neutrophil function occurs in bone marrow, and that IL-6 cooperation with G-CSF is required for this conversion. IL-6 cooperated with G-CSF to modulate neutrophils in bone marrow, altering the activation potential of signaling pathways in neutrophils, especially that of STAT3. Costimulation with G-CSF and IL-6 induced a higher level of phospho-STAT3 in neutrophils, which was further increased by upregulation of STAT3 expression in neutrophils owing to downregulation of IFN-ß expression in bone marrow macrophages by IL-6. Augmented STAT3 activation was crucial for upregulating the expression of Mmp9 and Bv8 genes and downregulating the expression of Trail and Rab27a genes in neutrophils. Moreover, G-CSF/IL-6-modulated neutrophils could not efficiently release azurophilic granules because of downregulation of Rab27a and inefficient activation of PI3K and p38 MAPK pathways. Because of premodulation by G-CSF and IL-6, neutrophils in response to complex stimuli in tumor released much less myeloperoxidase, neutrophil elastase, and TRAIL, but showed much higher expression of Mmp9 and Bv8 genes. Taken together, these results demonstrate that G-CSF and IL-6, despite their well-known physiological functions, could modulate the activation potential of signaling pathways in neutrophils, resulting in the production or release of the above-mentioned factors in a way that favors tumor angiogenesis and tumor growth.


Asunto(s)
Factor Estimulante de Colonias de Granulocitos/farmacología , Interleucina-6/farmacología , Neoplasias/inmunología , Neoplasias/metabolismo , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo , Animales , Médula Ósea/inmunología , Médula Ósea/metabolismo , Línea Celular Tumoral , Hormonas Gastrointestinales/genética , Hormonas Gastrointestinales/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Interferón beta/metabolismo , Interleucina-6/administración & dosificación , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Neoplasias/genética , Neuropéptidos/genética , Neuropéptidos/metabolismo , Neutrófilos/inmunología , Fosfatidilinositol 3-Quinasas/metabolismo , Factor de Transcripción STAT3/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Proteínas rab27 de Unión a GTP
6.
Breast Cancer Res Treat ; 143(1): 33-45, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24288120

RESUMEN

CH50, a recombinant CBD-HepII polypeptide of human fibronectin, was shown to suppress tumor metastasis in murine hepatocarcinoma and melanoma models. However, the effect of CH50 on human cancer cells is still not clear. Here we evaluated the efficiency of CH50 delivered by recombinant adeno-associated virus (rAAV) vector for breast cancer treatment. Infection of the two human breast cancer cell line MDA-MB-231 and MDA-MB-468 with a rAAV2 vector encoding CH50 resulted in secretion of soluble CH50. In vitro rAAV-CH50 transduction inhibited adhesion to ECM molecules, and transwell migration and invasion of breast cancer cells induced by fibronectin. In both breast cancer cells, rAAV-CH50 targeted αVß3 signaling, namely inhibited the expression of αVß3, the activation of FAK, the upregulation of cdc2, and the production and activation of MMP-9 by ECM molecules stimulation. rAAV-mediated tail vein transfusion and stable expression of CH50 in the liver resulted in the long-term presence of CH50 in sera of nude mice. Sustained CH50 expression mediated by rAAV vector suppressed the growth and spontaneous metastasis of orthotopic breast cancer xenograft, experimental metastasis of circulating breast cancer cells, and improved the long-term survival of breast tumor-bearing mice. These findings suggest for the first time that rAAV-CH50 gene therapy may present a novel and promising strategy for treatment against metastatic breast cancer.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Dependovirus/genética , Fibronectinas/genética , Expresión Génica , Vectores Genéticos/genética , Proteínas Recombinantes/genética , Animales , Adhesión Celular/genética , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Movimiento Celular/genética , Modelos Animales de Enfermedad , Femenino , Fibronectinas/metabolismo , Fibronectinas/farmacología , Vectores Genéticos/administración & dosificación , Humanos , Integrina alfaVbeta3/metabolismo , Integrinas/metabolismo , Ligandos , Hígado/metabolismo , Ratones , Unión Proteica , Proteínas Recombinantes/metabolismo , Transducción de Señal , Carga Tumoral/genética , Ensayos Antitumor por Modelo de Xenoinjerto
7.
Nat Commun ; 15(1): 4130, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38755189

RESUMEN

Compared to transition metal dichalcogenide (TMD) monolayers, rhombohedral-stacked (R-stacked) TMD bilayers exhibit remarkable electrical performance, enhanced nonlinear optical response, giant piezo-photovoltaic effect and intrinsic interfacial ferroelectricity. However, from a thermodynamics perspective, the formation energies of R-stacked and hexagonal-stacked (H-stacked) TMD bilayers are nearly identical, leading to mixed stacking of both H- and R-stacked bilayers in epitaxial films. Here, we report the remote epitaxy of centimetre-scale single-crystal R-stacked WS2 bilayer films on sapphire substrates. The bilayer growth is realized by a high flux feeding of the tungsten source at high temperature on substrates. The R-stacked configuration is achieved by the symmetry breaking in a-plane sapphire, where the influence of atomic steps passes through the lower TMD layer and controls the R-stacking of the upper layer. The as-grown R-stacked bilayers show up-to-30-fold enhancements in carrier mobility (34 cm2V-1s-1), nearly doubled circular helicity (61%) and interfacial ferroelectricity, in contrast to monolayer films. Our work reveals a growth mechanism to obtain stacking-controlled bilayer TMD single crystals, and promotes large-scale applications of R-stacked TMD.

8.
Nat Commun ; 14(1): 6421, 2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37828069

RESUMEN

Controllable growth of two-dimensional (2D) single crystals on insulating substrates is the ultimate pursuit for realizing high-end applications in electronics and optoelectronics. However, for the most typical 2D insulator, hexagonal boron nitride (hBN), the production of a single-crystal monolayer on insulating substrates remains challenging. Here, we propose a methodology to realize the facile production of inch-sized single-crystal hBN monolayers on various insulating substrates by an atomic-scale stamp-like technique. The single-crystal Cu foils grown with hBN films can stick tightly (within 0.35 nm) to the insulating substrate at sub-melting temperature of Cu and extrude the hBN grown on the metallic surface onto the insulating substrate. Single-crystal hBN films can then be obtained by removing the Cu foil similar to the stamp process, regardless of the type or crystallinity of the insulating substrates. Our work will likely promote the manufacturing process of fully single-crystal 2D material-based devices and their applications.

9.
Cancer Sci ; 103(7): 1319-26, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22494046

RESUMEN

The targeting of αvß3 is a promising therapeutic strategy for suppressing tumor metastasis. However, it is unclear whether the therapeutic efficacy could be influenced by metastasis-promoting factor(s) in vivo. Here we report that Toll-like receptor 4 (TLR4) ligand released from damaged tumor cells or bacteria had a negative effect on the therapeutic effect of a recombinant CBD-HepII polypeptide of fibronectin (CH50) that suppresses tumor metastasis by targeting αvß3. The TLR4 ligand could antagonize the inhibitory effect of CH50 on tumor cell adhesion and invasion by promoting the expression and activity of αvß3 in tumor cells. The TLR4 ligand also reduced the antimetastasis effect of CH50 by promoting tumor cell survival in circulation. Moreover, TLR4 ligands released by tumor cells in circulation could increase the survival and proliferation capacity of tumor cells after extravasation, resulting in the formation of more metastatic nodules. The effect of TLR4 signaling was mainly mediated by nuclear factor-κB (NF-κB). Inhibiting NF-κB could abrogate the negative effect of TLR4 ligand, and augment the inhibitory effect of CH50 on tumor metastasis. Consistently, the combination of NF-κB inhibitor and CH50 significantly inhibited metastasis of tumor cells in vivo and prolonged the survival of mice. The findings in this study suggest that the combination of NF-κB inhibitor and αvß3 antagonist would be a novel therapeutic option for the prevention of tumor metastasis.


Asunto(s)
Integrina alfaVbeta3/metabolismo , FN-kappa B/metabolismo , Neoplasias Experimentales/metabolismo , Transducción de Señal/efectos de los fármacos , Receptor Toll-Like 4/metabolismo , Animales , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Western Blotting , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Femenino , Fibronectinas/genética , Fibronectinas/farmacología , Integrina alfaVbeta3/antagonistas & inhibidores , Integrina alfaVbeta3/genética , Lipopolisacáridos/farmacología , Ratones , Ratones Endogámicos C57BL , FN-kappa B/antagonistas & inhibidores , FN-kappa B/genética , Metástasis de la Neoplasia , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Quinazolinas/farmacología , Interferencia de ARN , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Supervivencia , Receptor Toll-Like 4/genética
10.
Cancer Immunol Immunother ; 61(3): 303-12, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21877248

RESUMEN

Mast cells may have either antitumor or tumor-promoting potential. Nevertheless, mast cells in tumor microenvironment have been found to promote tumor growth. So far the mechanisms underlying the modulation of mast cell function in tumor microenvironment remains to be fully elucidated. Here, we report that tumor-promoting potential of mast cells could be augmented by molecules released from damaged tumor cells through cooperative stimulation of stem cell factor (SCF) and ligand for Toll-like receptor 4 (TLR4). Co-simulation with SCF and TLR4 ligand inhibited mast cell degranulation, but efficiently induced the production and secretion of VEGF, PDGF, and IL-10. Although TLR4 ligand alone may induce IL-12 expression in mast cells, co-stimulation with SCF and TLR4 ligand induced the expression of IL-10, but not IL-12, in mast cells. The phosphorylation of GSK3ß was crucial for the effect of SCF and TLR4 ligand. In addition to inducing phosphorylation of GSK3ß at Ser9 through PI3K pathway, SCF and TLR4 ligand cooperated to induce phosphorylation of GSK3ß at Tyr216 by simultaneous activation of ERK and p38MAPK pathways. Both phospho-Ser9 and phospho-Tyr216 of GSK3ß were required for IL-10 expression induced by SCF/TLR4 ligand, whereas suppressive effect of SCF/TLR4 ligand on mast cell degranulation was related to phospho-Tyr216. Importantly, the effect of SCF and TLR4 ligand on mast cells could be abrogated by inhibiting phosphorylation of GSK3ß at Tyr216. These findings disclose the mechanisms underlying the modulation of mast cell function in tumor microenvironment, and suggest that inhibiting GSK3ß in mast cells will be beneficial to the treatment of cancer.


Asunto(s)
Mastocitos/inmunología , Neoplasias Experimentales/inmunología , Factor de Células Madre/inmunología , Receptor Toll-Like 4/inmunología , Animales , Western Blotting , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/inmunología , Células de la Médula Ósea/fisiología , Degranulación de la Célula/efectos de los fármacos , Degranulación de la Célula/inmunología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Movimiento Celular/inmunología , Células Cultivadas , Cromolin Sódico/farmacología , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-12/genética , Interleucina-12/metabolismo , Ligandos , Lipopolisacáridos/farmacología , Mastocitos/efectos de los fármacos , Mastocitos/fisiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Fosforilación/efectos de los fármacos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Células Madre/metabolismo , Factor de Células Madre/farmacología , Receptor Toll-Like 4/metabolismo , Carga Tumoral/efectos de los fármacos , Carga Tumoral/inmunología , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunología
11.
Breast Cancer Res Treat ; 133(3): 853-63, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22042369

RESUMEN

Triggering of Toll-like receptor 4 (TLR4) on tumor cells has been found to promote tumor progression by promoting tumor cell proliferation and survival. So far, however, the effect of TLR4 signaling on tumor metastasis has not been well elucidated. Here, we report that triggering of TLR4 on metastatic breast cancer cells could reciprocally regulate the expression of αvß3 and the expressions of TPM1 and maspin, and promote αvß3-mediated adhesion and invasive migration of the cells. In metastatic breast cancer cells, TLR4 signaling increased the expression of integrin αvß3 by activating NF-κB, resulting in the increased adhesion capacity of tumor cells to the ligand for αvß3, and the increased polymerization of actin and production of MMP-9 in tumor cells in response to ECM. HoxD3 was required for the up-regulation of αv and ß3 expressions by NF-κB. Moreover, TLR4 signaling increased the expression of miR-21 in breast cancer cells by activating NF-κB. Accordingly, the expressions of TPM1 and maspin were decreased at protein level, whereas the transcription activity of these genes was not influenced. Consistent with the promoting effect on αvß3-mediated adhesion and invasive migration, TLR4 signaling promoted the arrest of metastatic breast cancer cells in circulation and following invasion. The effect of TLR4 signaling could be abrogated by inhibiting NF-κB. These findings suggest that metastatic breast cancer cells could acquire higher metastatic potential due to triggering of TLR4 and activation of NF-κB in the cells, and that both TLR4 and NF-κB could be therapeutic targets for preventing metastasis of breast cancer cells.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Integrina alfaVbeta3/genética , Receptor Toll-Like 4/genética , Animales , Neoplasias de la Mama/metabolismo , Adhesión Celular/efectos de los fármacos , Adhesión Celular/genética , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Movimiento Celular/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Proteínas de Homeodominio/metabolismo , Humanos , Integrina alfaVbeta3/metabolismo , Ratones , Ratones Desnudos , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Metástasis de la Neoplasia , Unión Proteica , Inhibidores de Proteínas Quinasas/farmacología , Serpinas/metabolismo , Transducción de Señal/efectos de los fármacos , Receptor Toll-Like 4/metabolismo , Factores de Transcripción , Tropomiosina/metabolismo
12.
J Immunol ; 185(5): 2773-82, 2010 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-20675592

RESUMEN

Gr-1(+)CD11b(+)F4/80(+) cells play important roles in tumor development and have a negative effect on tumor immunotherapy. So far, the mechanisms underlying the regulation of their immunosuppressive phenotype by classical and alternative macrophage activation stimuli are not well elucidated. In this study, we found that molecules from necrotic tumor cells (NTC-Ms) stimulated Gr-1(+)CD11b(+)F4/80(+) cells to induce apoptosis of activated T cells but not nonstimulated T cells. The apoptosis-inducing capacity was determined by higher expression levels of arginase I and IL-10 relative to those of NO synthase 2 and IL-12 in Gr-1(+)CD11b(+)F4/80(+) cells, which were induced by NTC-Ms through TLR4 signaling. The apoptosis-inducing capacity of NTC-Ms-stimulated Gr-1(+)CD11b(+)F4/80(+) cells could be enhanced by IL-10. IFN-gamma may reduce the apoptosis-inducing capacity of Gr-1(+)CD11b(+)F4/80(+) cells only if their response to IFN-gamma was not attenuated. However, the potential of Gr-1(+)CD11b(+)F4/80(+) cells to express IL-12 in response to IFN-gamma could be attenuated by tumor, partially due to the existence of active STAT3 in Gr-1(+)CD11b(+)F4/80(+) cells and NTC-Ms from tumor. In this situation, IFN-gamma could not effectively reduce the apoptosis-inducing capacity of Gr-1(+)CD11b(+)F4/80(+) cells. Tumor immunotherapy with 4-1BBL/soluble programmed death-1 may significantly reduce, but not abolish the apoptosis-inducing capacity of Gr-1(+)CD11b(+)F4/80(+) cells in local microenvironment. Blockade of TLR4 signaling could further reduce the apoptosis-inducing capacity of Gr-1(+)CD11b(+)F4/80(+) cells and enhance the suppressive effect of 4-1BBL/soluble form of programmed death-1 on tumor growth. These findings indicate the relationship of distinct signaling pathways with apoptosis-inducing capacity of Gr-1(+)CD11b(+)F4/80(+) cells and emphasize the importance of blocking TLR4 signaling to prevent the induction of T cell apoptosis by Gr-1(+)CD11b(+)F4/80(+) cells.


Asunto(s)
Apoptosis/inmunología , Antígeno CD11b/biosíntesis , Carcinoma Hepatocelular/metabolismo , Factor de Crecimiento Epidérmico/biosíntesis , Neoplasias Hepáticas/metabolismo , Activación de Linfocitos/inmunología , Receptores de Quimiocina/biosíntesis , Subgrupos de Linfocitos T/inmunología , Receptor Toll-Like 4/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/biosíntesis , Proteínas Reguladoras de la Apoptosis/metabolismo , Proteínas Reguladoras de la Apoptosis/fisiología , Antígeno CD11b/fisiología , Carcinoma Hepatocelular/inmunología , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Células Cultivadas , Factor de Crecimiento Epidérmico/fisiología , Ligandos , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/patología , Ratones , Ratones Endogámicos BALB C , Monocitos/inmunología , Monocitos/metabolismo , Monocitos/patología , Necrosis , Receptores de Quimiocina/fisiología , Transducción de Señal/inmunología , Subgrupos de Linfocitos T/metabolismo , Subgrupos de Linfocitos T/patología , Receptor Toll-Like 4/antagonistas & inhibidores , Receptor Toll-Like 4/fisiología
13.
Biosensors (Basel) ; 12(12)2022 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-36551053

RESUMEN

Sodium alginate (SA) was used to functionalize the surfaces of silver nanoparticles (AgNPs) to form SA-AgNPs for sensing dimethoate with a rapid and sensitive visual readout. UV-Vis spectrophotometry, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and zeta potential measurements were used to characterize SA-AgNPs that were synthesized under the ideal conditions. SA-AgNPs were spherical with an average size of 14.6 nm. The stability of SA-AgNPs was investigated with changes in pH, salinity, and storage time. This colorimetric assay of dimethoate relied on the change in the absorption ratio (A475/A400) of SA-AgNPs, resulting in their aggregation caused by dimethoate, leading to a visual change for SA-AgNPs from yellow to pale yellow. As a result, the absorption ratio (A475/A400) of SA-AgNPs showed good linearity in the range of 0.05 to 2.0 ppm (R2 = 0.9986) with a limit of detection (LOD) of 30 ppb. Adding other pesticides did not significantly change the absorption ratio of SA-AgNPs, indicating its high selectivity as a colorimetric assay. The sensor was successfully used to detect dimethoate in actual water samples.


Asunto(s)
Dimetoato , Nanopartículas del Metal , Colorimetría/métodos , Alginatos , Plata/química , Nanopartículas del Metal/química , Sodio , Espectroscopía Infrarroja por Transformada de Fourier
14.
EMBO Rep ; 10(2): 180-5, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19098714

RESUMEN

Cyclic AMP (cAMP) is a ubiquitous second messenger that regulates diverse cellular functions. It has been found that CD4(+)CD25(+) regulatory T (T(REG)) cells exert their suppressor function by transferring cAMP to responder T cells. Here, we show that miR-142-3p regulates the production of cAMP by targeting adenylyl cyclase (AC) 9 messenger RNA in CD4(+)CD25(-) T cells and CD4(+)CD25(+) T(REG) cells. miR-142-3p limits the level of cAMP in CD4(+)CD25(-) T cells by inhibiting AC9 production, whereas forkhead box P3 (FOXP3) downregulates miR-142-3p to keep the AC9/cAMP pathway active in CD4(+)CD25(+) T(REG) cells. These findings reveal a new molecular mechanism through which CD4(+)CD25(+) T(REG) cells contain a high level of cAMP for their suppressor function, and also suggest that the microRNA controlling AC expression might restrict the final level of cAMP in various types of cells.


Asunto(s)
Adenilil Ciclasas/genética , Linfocitos T CD4-Positivos/metabolismo , AMP Cíclico/biosíntesis , Factores de Transcripción Forkhead/fisiología , MicroARNs/fisiología , ARN Mensajero/antagonistas & inhibidores , Subgrupos de Linfocitos T/metabolismo , Adenilil Ciclasas/biosíntesis , Animales , Antígenos CD4/análisis , Inducción Enzimática/genética , Subunidad alfa del Receptor de Interleucina-2/análisis , Ratones , Ratones Endogámicos BALB C , MicroARNs/genética , ARN Mensajero/genética , Linfocitos T Reguladores/metabolismo , Transfección
15.
J Immunol ; 182(10): 6618-24, 2009 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-19414817

RESUMEN

Pregnant women have both the local immune tolerance at the maternal-fetal interface and the systemic immune defense against pathogens. To date, regardless of the extensive investigation on the maternal-fetal immune tolerance, the maintenance of systemic immune defense in pregnant women still remains poorly understood. In the present study, we demonstrate that the immunoregulatory molecule T cell Ig and mucin domain (Tim)-3 plays important roles in innate and adaptive immunity of human pregnancy. During pregnancy, Tim-3 is strikingly up-regulated in peripheral blood of pregnant women, most by monocytes but not by T or B cells. The increased IL-4/STAT6 signaling may contribute to such up-regulation of Tim-3. In turn, the increased Tim-3 enhances not only innate immunity but also Th1-associated immune responses of pregnant women against pathogens. In contrast, our clinical data show that abnormal Tim-3 expression level might be connected to the pregnancy loss. In conclusion, our data show in this study that an immune regulatory molecule Tim-3, by virtue of its up-regulation in innate immune cells in pregnant women, enhances both innate and adaptive immune responses. Nevertheless, the abnormality of Tim-3 in pregnant woman may be deleterious to normal pregnancy.


Asunto(s)
Aborto Espontáneo/inmunología , Inmunidad Innata , Proteínas de la Membrana/metabolismo , Monocitos/inmunología , Embarazo/inmunología , Femenino , Citometría de Flujo , Receptor 2 Celular del Virus de la Hepatitis A , Humanos , Interleucina-4/inmunología , Interleucina-4/metabolismo , Proteínas de la Membrana/inmunología , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción STAT6/inmunología , Factor de Transcripción STAT6/metabolismo , Transducción de Señal/inmunología , Células TH1/inmunología , Células Th2/inmunología , Regulación hacia Arriba
16.
Cancer Sci ; 101(2): 494-500, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19922502

RESUMEN

Currently available data indicate the potential application of rapamycin and its analogues in the clinic as anticancer therapeutic agents through inhibiting tumor cell growth and tumor angiogenesis. However, whether rapamycin can directly suppress tumor metastasis remains unclear. In the present study, we demonstrated that rapamycin treatment results in reduced formation of metastatic nodules in the lung by B16 cells. This is due to two mechanisms. First, the expression of alphav integrin is down-regulated by rapamycin treatment, and subsequently, the phosphorylation of focal adhesion kinase (FAK) is reduced. Second, rapamycin promotes apoptosis by up-regulating the proapoptotic molecules Bid and Bax and down-regulating Bcl-xL. Blocking the apoptosis pathway by pan-caspase inhibitor zVAD partially reversed the suppression of rapamycin in B16 metastasis. Interestingly, rapamycin up-regulates Bax and Bid in B16 cells via the S6K1 pathway and down-regulates the expression of alphav integrin via other pathway(s). In addition, our data showed that autophagy was not involved in the mechanisms of rapamycin-mediated metastasis suppression. Our findings demonstrate a potential anti-metastatic effect of rapamycin via down-regulating alphav integrin expression and up-regulating apoptosis signaling, suggesting that rapamycin might be worthy of clinical evaluation as an antimetastatic agent.


Asunto(s)
Apoptosis/efectos de los fármacos , Integrina alfaV/fisiología , Neoplasias Pulmonares/prevención & control , Neoplasias Pulmonares/secundario , Melanoma Experimental/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Sirolimus/farmacología , Animales , Línea Celular Tumoral , Péptidos y Proteínas de Señalización Intracelular/fisiología , Melanoma Experimental/patología , Ratones , Ratones Endogámicos C57BL , Proteínas Serina-Treonina Quinasas/fisiología , Proteínas Quinasas S6 Ribosómicas 90-kDa/fisiología , Serina-Treonina Quinasas TOR
17.
Cancer Immunol Immunother ; 59(2): 313-21, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19680649

RESUMEN

The reduction or loss of MHC-I antigen surface expression in human and murine tumor cells is partly attributable to the dysregulation of various components of the MHC-I antigen-processing machinery. Accumulating evidence suggests that autophagy, besides its vital role in maintaining the cellular homeostasis, plays an important role in MHC-II surface expression. Here, we report that autophagy is a negative regulator of MHC-I antigen expression in B16 melanoma cells; however, in the presence of IFN-γ, it is converted to a positive regulator. We show that autophagy not only participates in the degradation of MHC-I antigen but also plays a role in the generation of MHC-I-binding peptides. For these two processes, IFN-γ interferes with MHC-I antigen degradation, rather than affecting peptide generation. Using B16 melanoma mouse model, we further show that autophagy may enhance the cytolysis of CTL to melanoma cells at the early stage of melanoma, but impairs the cytolysis at the late stage. Such different consequences may be explained by the different levels of IFN-γ during tumor progression. Taken together, our findings demonstrate that autophagy is involved in the regulation of MHC-I antigen expression, through which autophagy can play different roles in tumor immunity.


Asunto(s)
Autofagia , Antígenos de Histocompatibilidad Clase I/inmunología , Interferón gamma/inmunología , Melanoma Experimental/inmunología , Neoplasias Cutáneas/inmunología , Animales , Interferón gamma/farmacología , Ratones , Linfocitos T Citotóxicos/inmunología , Regulación hacia Arriba
18.
Blood ; 112(4): 1269-79, 2008 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-18524989

RESUMEN

Despite the evidence for the role of inflammation in cancer initiation, promotion, and progression, the precise mechanism by which the inflammation within tumor is orchestrated by inflammatory cells remains to be determined. Here, we report that tumor-infiltrating mast cells remodel tumor microenvironment and promote tumor growth. Mast cell infiltration and activation in tumors were mainly mediated by tumor-derived stem cell factor (SCF) and its receptor c-Kit on mast cells. Low concentrations of SCF efficiently induced the chemotactic migration of mast cells. Tumor-infiltrating mast cells, activated by higher concentrations of SCF, expressed multiple proinflammatory factors and increased IL-17 expression in tumors. The activity of NF-kappaB and AP-1 in tumor cells was intensified in the mast cell-remodeled inflammatory microenvironment. SCF-activated mast cells also exacerbated tumor immunosuppression by releasing adenosine and increasing T regulatory cells, which augmented the suppression of T cells and natural killer cells in tumors. These findings emphasize that the remodeling of the tumor microenvironment can actually be initiated by tumor cell-released SCF and suggest that mast cells are not only a participator but also a critical regulator of inflammation and immunosuppression in the tumor microenvironment.


Asunto(s)
Quimiotaxis , Inflamación , Mastocitos/inmunología , Neoplasias/inmunología , Factor de Células Madre/fisiología , Animales , Línea Celular Tumoral , Células Cultivadas , Humanos , Mediadores de Inflamación/análisis , Interleucina-17 , Células Asesinas Naturales/patología , Recuento de Linfocitos , Mastocitos/patología , Ratones , Ratones Endogámicos , FN-kappa B/metabolismo , Trasplante de Neoplasias , Neoplasias/patología , Linfocitos T/patología , Linfocitos T Reguladores/patología , Factor de Transcripción AP-1/metabolismo
19.
J Immunol ; 181(9): 6117-24, 2008 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-18941201

RESUMEN

IL-17 is a pivotal proinflammatory molecule in asthmatics. However, the cellular source of IL-17 in asthma has not been identified to date. In this study, we report that macrophages rather than Th17 cells are the main producer of IL-17 in allergic inflammation related to asthma. After OVA challenge in a mouse model mimicking allergic asthma, the increased IL-17(+) cells in the lung were mainly CD11b(+)F4/80(+) macrophages, instead of T cells or others. Importantly, IL-17(+) alveolar macrophages (AMs), but not IL-17(+) interstitial macrophages, were significantly increased after allergen challenge. The increase of IL-17(+) AMs was not due to the influx of IL-17(+) macrophages from circulation or other tissues, but ascribed to the activation of AMs by mediator(s) secreted by IgE/OVA-activated mast cells. Depleting alveolar macrophages or neutralizing IL-17 prevented the initiation of OVA-induced asthma-related inflammation by inhibiting the increase of inflammatory cells and inflammatory factors in bronchoalveolar lavage fluid. Th2 cytokine IL-10 could down-regulate IL-17 expression in alveolar macrophages. The increased IL-17 and the decreased IL-10 in bronchoalveolar lavage fluid were further confirmed in asthmatic patients. These findings suggest that IL-17 is mainly produced by macrophages but not Th17 cells in allergic inflammation related to asthma. Mast cell-released mediators up-regulate the expression of IL-17 by macrophages, whereas IL-10 down-regulates IL-17 expression.


Asunto(s)
Asma/inmunología , Asma/patología , Interleucina-17/biosíntesis , Pulmón/inmunología , Pulmón/patología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Enfermedad Aguda , Adulto , Animales , Antígenos de Diferenciación/biosíntesis , Asma/metabolismo , Antígeno CD11b/biosíntesis , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Humanos , Hipersensibilidad/inmunología , Hipersensibilidad/metabolismo , Hipersensibilidad/patología , Inmunidad Celular , Inflamación/inmunología , Inflamación/metabolismo , Inflamación/patología , Pulmón/metabolismo , Macrófagos Alveolares/patología , Ratones , Ratones Endogámicos BALB C , Persona de Mediana Edad , Regulación hacia Arriba/inmunología
20.
Immunol Lett ; 218: 44-50, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31794800

RESUMEN

Autoimmune hepatitis (AIH) is a chronic liver disease mediated by immunity, and could lead to liver fibrosis and hepatocellular carcinoma. However, the mechanisms for breaking hepatic tolerance and driving AIH still remain elusive. We herein reported that the non-specific liver inflammation triggered by carbon tetrachloride (CCl4) recruited high numbers of CD4+T, CD8+T and B cells, and elevated the expression of proinflammaitory cytokines in Balb/c mice, further breaking liver tolerance and inducing autoimmune response, AIH inflammation and liver fibrosis in the presence of CYP2D6 antigen mimicry. In contrast, adenovirus infection could not break liver tolerance and induce AIH in Balb/c mice even in the presence of CYP2D6 antigen mimicry. These results suggested that genetic predisposition could determine liver tolerance in Balb/c mice. The chemical induced inflammation in the liver breaks tolerance and might be considered important for the initiation and development of AIH in Balb/c mice.


Asunto(s)
Autoinmunidad , Susceptibilidad a Enfermedades , Hepatitis Autoinmune/etiología , Tolerancia Inmunológica , Adenoviridae/inmunología , Animales , Autoantígenos/inmunología , Biomarcadores , Biopsia , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD4-Positivos/patología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/patología , Tetracloruro de Carbono/efectos adversos , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades/inmunología , Femenino , Hepatitis Autoinmune/metabolismo , Hepatitis Autoinmune/patología , Inmunohistoquímica , Ratones , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Subgrupos de Linfocitos T/patología
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