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1.
Pharm Biol ; 60(1): 1198-1206, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35758295

RESUMEN

CONTEXT: Protocatechuic aldehyde (PCA) is a natural product that has various benefits for fibrosis. OBJECTIVE: This study evaluated the effects of PCA on renal fibrosis. MATERIALS AND METHODS: Epithelial-mesenchymal transition (EMT) was induced by 20 ng/mL transforming growth factor-ß1 (TGF-ß1), followed by treatment with 1 and 5 µM PCA, in the rat renal proximal tubular cell line NRK-52E. Cell viability, protein expression, and scratch wound-healing assays were conducted. Sprague-Dawley (SD) rats underwent unilateral ureteral obstruction (UUO) surgery for renal fibrosis indication and were treated with 50 and 100 mg/kg PCA for 14 days. RESULTS: The IC50 of PCA was appropriately 13.75 ± 1.91 µM in NRK-52E cells, and no significant difference at concentrations less than 5 µM. PCA ameliorated TGF-ß1-induced EMT, such as enhanced E-cadherin and decreased vimentin. Fibrotic markers collagen IV and α-smooth muscle actin (α-SMA) increased in TGF-ß1-induced NRK-52E. Moreover, PCA reduced TGF-ß1-induced migration in the wound-healing assay. Analysis of rat kidneys indicated that PCA reduced UUO-induced hydronephrosis (control: 15.11 ± 1.00%; UUO: 39.89 ± 1.91%; UUO + PCA50: 18.37 ± 1.61%; UUO + PCA100: 17.67 ± 1.39%). Protein level demonstrated that PCA not only decreased vimentin expression and enhanced E-cadherin expression, but inhibited UUO-induced collagen IV and α-SMA upregulation, indicating that it could mitigate EMT in a rat model of UUO-induced renal fibrosis. DISCUSSION AND CONCLUSIONS: This study suggested that PCA decreases TGF-ß1-induced fibrosis and EMT in vitro and in vivo. These findings demonstrate pharmacological effects of PCA and might be a potential strategy for the prevention of organ fibrosis in clinics.


Asunto(s)
Enfermedades Renales , Obstrucción Ureteral , Animales , Benzaldehídos , Cadherinas/metabolismo , Catecoles , Colágeno/metabolismo , Modelos Animales de Enfermedad , Transición Epitelial-Mesenquimal , Fibrosis , Riñón/metabolismo , Enfermedades Renales/tratamiento farmacológico , Enfermedades Renales/etiología , Enfermedades Renales/prevención & control , Ratas , Ratas Sprague-Dawley , Factor de Crecimiento Transformador beta1/metabolismo , Obstrucción Ureteral/complicaciones , Obstrucción Ureteral/tratamiento farmacológico , Vimentina/metabolismo , Vimentina/farmacología , Vimentina/uso terapéutico
2.
Small ; 12(7): 939-50, 2016 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-26715383

RESUMEN

Sulfur cathodes have become appealing for rechargeable batteries because of their high theoretical capacity (1675 mA h g(-1)). However, the conventional cathode configuration borrowed from lithium-ion batteries may not allow the pure sulfur cathode to put its unique materials chemistry to good use. The solid(sulfur)-liquid(polysulfides)-solid(sulfides) phase transitions generate polysulfide intermediates that are soluble in the commonly used organic solvents in Li-S cells. The resulting severe polysulfide diffusion and the irreversible active-material loss have been hampering the development of Li-S batteries for years. The present study presents a robust, ultra-tough, flexible cathode with the active-material fillings encapsulated between two buckypapers (B), designated as buckypaper/sulfur/buckypaper (B/S/B) cathodes, that suppresses the irreversible polysulfide diffusion to the anode and offers excellent electrochemical reversibility with a low capacity fade rate of 0.06% per cycle after 400 cycles. Engineering enhancements demonstrate that the B/S/B cathodes represent a facile approach for the development of high-performance sulfur electrodes with a high areal capacity of 5.1 mA h cm(-2), which increases further to approach 7 mA h cm(-2) on coupling with carbon-coated separators.

3.
Small ; 12(2): 174-9, 2016 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-26580705

RESUMEN

A custom single-wall carbon nanotube (SWCNT)-modulated separator is employed to directly suppress the polysulfide migration and indirectly protect the lithium-metal anode from severe polysulfide contamination. The conductive sp(2) -carbon scaffold continuously reactivates and reutilizes the trapped active material, so the SWCNT-modulated separator provides a facile way to facilitate the implementation of pure sulfur cathodes with high sulfur contents and loadings.

4.
Langmuir ; 31(10): 3115-24, 2015 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-25700185

RESUMEN

In situ scanning tunneling microscopy and cyclic voltammetry studies of self-assembled octyl-triazatriangulenium monolayers on Au(111) electrode surfaces in 0.1 M HClO4 reveal a complex surface phase behavior, involving two fast, highly reversible transitions between different ordered adlayer phases: With decreasing potential, the preadsorbed (√19 × âˆš19)R23.4° adlayer first is converted into a (7√3 × 7√3) and then into a (2√3 × 2√3)R30° phase, corresponding to a stepwise increase in the local packing density of the molecules. The (7√3 × 7√3) → (2√3 × 2√3)R30° transition is accompanied by a reorientation of the peripheral octyl chains from a more planar to a close-packed vertical arrangement. This reversible potential-induced switching between a homogeneous adlayer of small vertical extension and a Au surface partially covered by islands of a compact hydrocarbon layer is attributed to changes in the adsorbate charge state and associated changes in the intermolecular interactions.

5.
Analyst ; 139(19): 4846-54, 2014 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-25089836

RESUMEN

Cancer metastasis and drug resistance are important malignant tumor phenotypes that cause roughly 90% mortality in human cancers. Current therapeutic strategies, however, face substantial challenges partially due to a lack of applicable pre-clinical models and drug-screening platforms. Notably, microscale and three-dimensional (3D) tissue culture platforms capable of mimicking in vivo microenvironments to replicate physiological conditions have become vital tools in a wide range of cellular and clinical studies. Here, we present a microfluidic device capable of mimicking a configurable tumor microenvironment to study in vivo-like cancer cell migration as well as screening of inhibitors on both parental tumors and migratory cells. In addition, a novel evaporation-based paper pump was demonstrated to achieve adaptable and sustainable concentration gradients for up to 6 days in this model. This straightforward modeling approach allows for fast patterning of a wide variety of cell types in 3D and may be further integrated into biological assays. We also demonstrated cell migration from tumor spheroids induced by an epidermal growth factor (EGF) gradient and exhibited lowered expression of an epithelial marker (EpCAM) compared with parental cells, indicative of partial epithelial-mesenchymal transition (EMT) in this process. Importantly, pseudopodia protrusions from the migratory cells - critical during cancer metastasis - were demonstrated. Insights gained from this work offer new opportunities to achieve active control of in vitro tumor microenvironments on-demand, and may be amenable towards tailored clinical applications.


Asunto(s)
Modelos Biológicos , Antígenos de Neoplasias/metabolismo , Moléculas de Adhesión Celular/metabolismo , Técnicas de Cultivo de Célula , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Factor de Crecimiento Epidérmico/farmacología , Molécula de Adhesión Celular Epitelial , Transición Epitelial-Mesenquimal/efectos de los fármacos , Humanos , Células MCF-7 , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos , Paclitaxel/farmacología , ARN Mensajero/metabolismo , Esferoides Celulares/citología , Esferoides Celulares/efectos de los fármacos , Microambiente Tumoral
6.
Langmuir ; 29(39): 12075-83, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-24011019

RESUMEN

A series of amphiphilic poly(amidoamine) dendrimers (PAMAM, G2-G5) composed of a hydrophilic core and a hydrophobic shell of aniline pentamer (AP) were synthesized and characterized. The modified dendrimers self-assembled to vesicular aggregates in water with the critical aggregation concentration (CAC) decreased in the order of G2 > G3 > G4 > G5. It was found that the modified dendrimers self-organized into spherical aggregates with a bilayer vesicular structures and that the dendrimers in higher generation have more order structure, which may be attributed to the crystallization induced by the compacted effect of AP segments. In addition, larger spherical vesicles were observed under acidic and alkaline conditions, as compared with sizes of aggregates in neutral medium. At low pH, the tertiary amine groups of PAMAM-AP were transformed to ammonium salts; the polarons were formed from AP units by doping with strong acids, thereby leading to the stability of vesicular aggregates being better than that in double distilled water. Nevertheless, in high pH environment, the deprotonation of PAMAM-AP caused the enhancement of π-π interactions, resulting in generation of twins or multilayered vesicles.


Asunto(s)
Compuestos de Anilina/química , Dendrímeros/síntesis química , Poliaminas/síntesis química , Tensoactivos/síntesis química , Dendrímeros/química , Interacciones Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Estructura Molecular , Tamaño de la Partícula , Poliaminas/química , Propiedades de Superficie , Tensoactivos/química
7.
Acta Pharmacol Sin ; 34(3): 360-6, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23377549

RESUMEN

AIM: To investigate whether sphingosine-1-phosphate (S1P), a potent angiogenic factor, induced vascular endothelial growth factor-C (VEGF-C) expression in endothelial cells in vitro and to examine its underlying mechanisms. METHODS: Human umbilical vein endothelial cells (HUVECs) were examined. VEGF-C mRNA expression in the cells was assessed using real-time PCR. VEGF-C protein and FGFR-1 phosphorylation in the cells were measured with ELISA. RNA interference was used to downregulate the expression of matrix metalloproteinase-2 (MMP-2), fibroblast growth factor-1 (FGF-1) and FGF receptor-1 (FGFR-1). RESULTS: Incubation of HUVECs with S1P (1, 5, and 10 µmol/L) significantly increased VEGF-C expression. The effect was blocked by pretreatment with the MMP inhibitor GM6001 or the FGFR inhibitor SU5402, but not the EGFR inhibitor AG1478. The effect was also blocked in HUVECs that were transfected with FGFR-1 or MMP-2 siRNA. Furthermore, incubation of HUVECs with S1P (5 µmol/L) significantly increased FGFR-1 phosphorylation, which was blocked by GM6001. Moreover, knockdown of FGF-1, not FGF-2, in HUVECs with siRNAs, blocked S1P-induced VEGF-C expression. CONCLUSION: S1P induces VEGF-C expression through a MMP-2/ FGF-1/FGFR-1-dependent pathway in HUVECs.


Asunto(s)
Factor 1 de Crecimiento de Fibroblastos/metabolismo , Lisofosfolípidos/farmacología , Metaloproteinasa 2 de la Matriz/metabolismo , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/metabolismo , Transducción de Señal , Esfingosina/análogos & derivados , Factor C de Crecimiento Endotelial Vascular/biosíntesis , Técnicas de Cultivo de Célula , Regulación hacia Abajo , Ensayo de Inmunoadsorción Enzimática , Factor 1 de Crecimiento de Fibroblastos/genética , Células Endoteliales de la Vena Umbilical Humana , Humanos , Lisofosfolípidos/fisiología , Metaloproteinasa 2 de la Matriz/genética , Fosforilación , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/farmacología , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genética , Transducción de Señal/efectos de los fármacos , Esfingosina/farmacología , Esfingosina/fisiología
8.
Toxicol Mech Methods ; 23(6): 464-70, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23477502

RESUMEN

Dioxins are byproducts from incomplete combustion processes and belong to a group of mostly toxic chemicals known as persistent organic pollutants, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is considered to be the most toxic species of all dioxin-like compounds. Analytical chemical processes are employed to determine the specific dioxin content in environmental samples. However, cost-ineffectiveness and excess time consumption limit their routine utilization. The aryl hydrocarbon receptor (AhR) is the major TCDD receptor. Upon binding to dioxin, the AhR dissociates from Hsp90 and other cofactors. TCDD-bound AhR subsequently translocates to the nucleus and interacts with the AhR nuclear translocator (Arnt) to induce signal transduction. Here, we describe a highly sensitive and cost-effective alternative assay based on detecting stability of bioluminescence signals. We generated cells that stably co-express Renilla luciferase tagged-AhR (AhR-RL), Ah receptor-interacting protein (AIP), p23 and yellow fluorescent protein-tagged Arnt (Arnt-YFP) (AAPA cells) for detection of dioxin-like compounds. Treatment with 3-methylcholanthrene (3MC), AhR agonist, enhanced the interaction between AhR and Arnt and avoided proteosomal degradation. In addition, treatment with 3MC or TCDD stabilized Renilla luminescence from AhR-RL of AAPA cell-free extracts in a concentration-dependent manner. The TCDD detection limit in this cell-free system was as low as 10(-18 )M. These results highlight the potential of AAPAA cell-free extracts to detect dioxin-like pollutants.


Asunto(s)
Translocador Nuclear del Receptor de Aril Hidrocarburo/metabolismo , Bioensayo/métodos , Dioxinas/análisis , Contaminantes Ambientales/análisis , Receptores de Hidrocarburo de Aril/metabolismo , Translocador Nuclear del Receptor de Aril Hidrocarburo/genética , Western Blotting , Colorantes Fluorescentes/metabolismo , Células HEK293 , Humanos , Límite de Detección , Luciferasas de Renilla/genética , Luciferasas de Renilla/metabolismo , Receptores de Hidrocarburo de Aril/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Transfección
9.
Am J Physiol Renal Physiol ; 299(5): F929-41, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20685818

RESUMEN

The protective effect of combination therapy with valsartan and aliskiren against renal fibrosis remains to be defined. This study was undertaken to examine the protective effects of the combination of valsartan and aliskiren against renal fibrosis induced by unilateral ureteral obstruction (UUO). Combination therapy with valsartan (15 mg·kg(-1)·day(-1)) and aliskiren (10 mg·kg(-1)·day(-1)), valsartan monotherapy (30 mg·kg(-1)·day(-1)), and aliskiren monotherapy (20 mg·kg(-1)·day(-1)) all significantly ameliorated the increase in blood urea nitrogen and the degree of hydronephrosis determined by the increase in weight and length of the obstructed kidney. The dose titration study and blood pressure measurement confirmed that the combination therapy provided a greater benefit independent of the vasodilatory effect. There were no significant changes in serum levels of creatinine, sodium, and potassium in UUO rats and any treatment groups. Combination therapy also attenuated UUO-related increases in the scores of tubular dilatation, interstitial volume, interstitial collagen deposition, α-smooth muscle actin, the activation of ERK 1/2, the infiltration of monocytes/macrophages, the mRNA expression of snail-1, and transforming growth factor-ß1 to a greater extent compared with aliskiren or valsartan used alone. The mRNA expression of renin and the (pro)renin receptor significantly increased after UUO. Combination therapy and monotherapy of valsartan and aliskiren had a comparable enhancing effect on the mRNA expression of renin, whereas all these treatments did not affect the expression of the (pro)renin receptor. In conclusion, a direct renin inhibitor in conjunction with an angiotensin II receptor blocker exerts increased renal protection against renal fibrosis and inflammation during obstruction over either agent alone.


Asunto(s)
Amidas/uso terapéutico , Antihipertensivos/uso terapéutico , Fumaratos/uso terapéutico , Enfermedades Renales/tratamiento farmacológico , Enfermedades Renales/etiología , Tetrazoles/uso terapéutico , Obstrucción Ureteral/complicaciones , Obstrucción Ureteral/tratamiento farmacológico , Valina/análogos & derivados , Actinas/biosíntesis , Anatomía Transversal , Animales , Presión Sanguínea/fisiología , Western Blotting , Colágeno/metabolismo , Quimioterapia Combinada , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Fibrosis , Inmunohistoquímica , Riñón/patología , Riñón/fisiopatología , Enfermedades Renales/genética , Pruebas de Función Renal , Masculino , Infiltración Neutrófila , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción de la Familia Snail , Factores de Transcripción/biosíntesis , Obstrucción Ureteral/genética , Valina/uso terapéutico , Valsartán
10.
ACS Appl Mater Interfaces ; 11(19): 17393-17399, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-31012569

RESUMEN

Lithium-sulfur batteries remain a promising next-generation renewable energy storage device due to their high theoretical energy density over the current commercial lithium-ion battery technology. However, to have any practical viability toward reaching the theoretical value, high-loading cathodes with sufficient sulfur content and specifically the effect of nonconductive binders must be investigated. We consider the limitations of conventional binders for high-loading, high-thickness cathodes by integrating a bifunctional binder with a linear polyethylene chain and maleate-capped ends. The linear polymer allows for flexibility within the high-loading cathode whereas the maleate ends improve the polysulfide trapping ability with carbon-sulfur binding. With the strong polysulfide immobilization ability due to the nucleophilic binding, the binder achieves high sulfur loadings of 12 mg cm-2 with a high sulfur content of 80 wt %. The work serves as a proof of concept for exploring the incorporation of polymeric materials into sulfur cathodes to realize practical viability.

11.
ACS Appl Mater Interfaces ; 11(6): 6136-6142, 2019 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-30648863

RESUMEN

Polyethylene hexasulfide (PEHS) is investigated as a cathode material in lithium batteries. By utilizing a condensation reaction, ethylene groups are inserted between six linear sulfurs in a chain to obtain PEHS while simultaneously exercising control over the polysulfur chain length. Additionally, by selecting a low-molecular-weight organic group, PEHS contains 87 wt % sulfur, thus maximizing the material-level specific capacity to 1217 mA h g-1. Furthermore, this synthesis method is validated using a host of materials characterization techniques. In a battery, PEHS prevents the formation of soluble long-chain intermediates that plague traditional sulfur cathodes. This enables a high material-level capacity of 774 mA h g-1 at 1C-rate alongside a stable performance over 350 cycles with a capacity fade rate of only 0.083% per cycle. We also elucidate the unique reaction pathway of our short-chain polysulfur material and provide a useful foundation for further development of sulfur-containing polymer-based cathode materials.

12.
Theranostics ; 9(22): 6443-6465, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31588228

RESUMEN

Forkhead box protein C1 (FOXC1) is known to regulate developmental processes in the skull and brain. Methods: The unique multipotent arachnoid-pia stem cells (APSCs) isolated from human and mouse arachnoid-pia membranes of meninges were grown as 3D spheres and displayed a capacity for self-renewal. Additionally, APSCs also expressed the surface antigens as mesenchymal stem cells. By applying the FOXC1 knockout mice and mouse brain explants, signaling cascade of FOXC1-STI-1-PrPC was investigated to demonstrate the molecular regulatory pathway for APSCs self-renewal. Moreover, APSCs implantation in stroke model was also verified whether neurogenic property of APSCs could repair the ischemic insult of the stroke brain. Results: Activated FOXC1 regulated the proliferation of APSCs in a cell cycle-dependent manner, whereas FOXC1-mediated APSCs self-renewal was abolished in FOXC1 knockout mice (FOXC1-/- mice). Moreover, upregulation of STI-1 regulated by FOXC1 enhanced cell survival and self-renewal of APSCs through autocrine signaling of cellular prion protein (PrPC). Mouse brain explants STI-1 rescues the cortical phenotype in vitro and induces neurogenesis in the FOXC1-/- mouse brain. Furthermore, administration of APSCs in ischemic brain restored the neuroglial microenvironment and improved neurological dysfunction. Conclusion: We identified a novel role for FOXC1 in the direct regulation of the STI-1-PrPC signaling pathway to promote cell proliferation and self-renewal of APSCs.


Asunto(s)
Aracnoides/citología , Factores de Transcripción Forkhead/metabolismo , Proteínas de Choque Térmico/metabolismo , Células Madre/citología , Animales , Aracnoides/embriología , Isquemia Encefálica/sangre , Isquemia Encefálica/patología , Isquemia Encefálica/terapia , Proliferación Celular/genética , Autorrenovación de las Células , Células Cultivadas , Circulación Cerebrovascular , Femenino , Factores de Transcripción Forkhead/genética , Proteínas de Choque Térmico/genética , Humanos , Masculino , Ratones Noqueados , Neurogénesis/fisiología , Técnicas de Cultivo de Órganos , Proteínas PrPC/metabolismo , Ratas Sprague-Dawley , Transducción de Señal , Trasplante de Células Madre , Células Madre/fisiología , Accidente Cerebrovascular/terapia
13.
Eur J Pharmacol ; 854: 282-288, 2019 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-31034822

RESUMEN

Keloids are characterized by excessive proliferation of fibroblasts and invasion of surrounding healthy skin. High levels of Nitric Oxide (NO) are thought to be the crucial factor within the micro-environment in promoting keloid formation. However, the effects and mechanisms of NO on the proliferation of Keloid Fibroblasts (KDFs) remain unclear. In this study, we investigated the effect of NO on KDFs proliferation by Sodium Nitroprusside (SNP), an NO donor. Our results show that SNP significantly enhanced KDFs proliferation. Moreover, with prolonged treatment with SNP after cell confluence, the growth of KDFs escape contact inhibition and experience significant pile up growth. Furthermore, PTIO, an NO scavenger, attenuated SNP-enhanced cell proliferation effectively. The mechanism involved in SNP-induced KDFs proliferation was soluble Guanylyl Cyclase (sGC) and cGMP independent. ODQ, a specific sGC inhibitor, failed to suppress SNP-enhanced KDFs proliferation. 8-Bromo-c GMP, a cell-permeable cGMP analogue, could not stimulate KDFs proliferation. Erk and Akt provide important signaling for cell growth. U0126 and LY294002, inhibitors of Erk and Akt respectively, block SNP-enhanced KDFs proliferation effectively. As expected, a Western blot showed that SNP up-regulated the phosphorylation levels of Erk and Akt. Moreover, it decreased the expression of p27, a cell cycle inhibitor. Our results reveal that SNP induced KDFs proliferation and loss contact inhibition led to pile up growth via activation of the Erk and Akt pathways, as well as a decreased expression of p27. Thus, we speculate that the pathological feature of continuous expansion in keloids is caused by NO-induced KDFs sustained growth.


Asunto(s)
Queloide/metabolismo , Queloide/patología , Óxido Nítrico/metabolismo , Proliferación Celular/efectos de los fármacos , GMP Cíclico/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Fibroblastos/patología , Humanos , Donantes de Óxido Nítrico/farmacología , Nitroprusiato/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos
14.
Cancer Res ; 79(21): 5550-5562, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31431462

RESUMEN

Neuroblastoma is the most common malignant disease of infancy, and amplification of the MYCN oncogene is closely associated with poor prognosis. Recently, expression of MYCN was shown to be inversely correlated with aryl hydrocarbon receptor (AHR) expression in neuroblastoma, and overexpression of AHR downregulated MYCN expression, promoting cell differentiation. Therefore, we further investigated the potential of AHR to serve as a prognostic indicator or a therapeutic target in neuroblastoma. First, the clinical significance of AHR in neuroblastoma was examined. Positive AHR immunostaining strongly correlated with differentiated histology of neuroblastoma and predicted better survival for patients. The mouse xenograft model showed that overexpression of AHR significantly suppressed neuroblastoma tumor growth. In addition, activation of AHR by the endogenous ligand kynurenine inhibited cell proliferation and promoted cell differentiation in vitro and in vivo. kynurenine treatment also upregulated the expression of KISS1, a tumor metastasis suppressor, and attenuated metastasis in the xenograft model. Finally, analysis of KISS1 levels in neuroblastoma patient tumors using the R2: Genomics Analysis and Visualization Platform revealed that KISS1 expression positively correlated with AHR, and high KISS1 expression predicted better survival for patients. In conclusion, our results indicate that AHR is a novel prognostic biomarker for neuroblastoma, and that overexpression or activation of AHR offers a new therapeutic possibility for patients with neuroblastoma. SIGNIFICANCE: These findings show that AHR may function as a tumor suppressor in childhood neuroblastoma, potentially influencing the aetiologic and therapeutic targeting of the disease.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Quinurenina/genética , Neuroblastoma/genética , Neuroblastoma/patología , Receptores de Hidrocarburo de Aril/genética , Animales , Diferenciación Celular/genética , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Niño , Preescolar , Progresión de la Enfermedad , Femenino , Amplificación de Genes/genética , Regulación Neoplásica de la Expresión Génica/genética , Genes Supresores de Tumor/fisiología , Humanos , Lactante , Recién Nacido , Kisspeptinas/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Proteína Proto-Oncogénica N-Myc/genética
15.
Org Lett ; 20(7): 1949-1952, 2018 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-29537274

RESUMEN

This study explores a Pd-catalyzed decarboxylative Heck-type Csp3-Csp2 coupling reaction of 2,5-cyclohexadiene-1-carboxylic acid derivatives with vinyl halides to provide γ-olefination products. The olefinated 1,3-cyclohexadienes can be further oxidized to produce meta-alkylated stilbene derivatives. Additionally, the conjugated diene products can also undergo a Diels-Alder reaction to produce a bicyclo[2.2.2]octadiene framework.

16.
ACS Nano ; 10(11): 10462-10470, 2016 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-27783490

RESUMEN

Sulfur exhibits a high theoretical capacity of 1675 mA h g-1 via a distinct conversion reaction, which is different from the insertion reactions in commercial lithium-ion batteries. In consideration of its conversion-reaction battery chemistry, a custom design for electrode materials could establish the way for attaining high-loading capability while simultaneously maintaining high electrochemical utilization and stability. In this study, this process is undertaken by introducing carbon cotton as an attractive electrode-containment material for enhancing the dynamic and static stabilities of lithium-sulfur (Li-S) batteries. The carbon cotton possessing a hierarchical macro-/microporous architecture exhibits a high surface area of 805 m2 g-1 and high microporosity with a micropore area of 557 m2 g-1. The macroporous channels allow the carbon cotton to load and stabilize a high amount of active material. The abundant microporous reaction sites spread throughout the carbon cotton facilitate the redox chemistry of the high-loading/content Li-S system. As a result, the high-loading carbon-cotton cathode exhibits (i) enhanced cycle stability with a good dynamic capacity retention of 70% after 100 cycles and (ii) improved cell-storage stability with a high static capacity retention of above 93% and a low time-dependent self-discharge rate of 0.12% per day after storing for a long period of 60 days. These carbon-cotton cathodes with the remarkably highest values reported so far of both sulfur loading (61.4 mg cm-2) and sulfur content (80 wt %) demonstrate enhanced electrochemical utilization with the highest areal, volumetric, and gravimetric capacities simultaneously.

17.
Oncotarget ; 6(3): 1478-89, 2015 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-25596749

RESUMEN

Urothelial carcinoma is the most common type of malignancy in long-term dialysis patients and kidney transplant recipients in Taiwan. mTORCs (mammalian target of rapamycin complexes) and EGF are important in urothelial carcinoma. To identify the regulation of mTORCs upon EGF stimulation is necessary. mTOR integrates signals from growth factors via mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2). The mechanism of mTORC1 action has been widely studied; however, the regulation of mTORC2 has not been well studied. Here, we demonstrate that Gab1 is an important upstream regulator in EGF-mediated activation of mTORCs. In our study, we confirm that mTORCs translocate from the cytoplasm to the plasma membrane via the PH domain of Gab1 upon EGF stimulation. Moreover, Gab1 associates with mTORCs. This association stabilizes the integrity of mTORCs and induces mTORC activity. Compared to normal bladder tissue, the expression of Gab1 and activity of mTORCs are elevated in urothelial carcinoma. Collectively, our results suggest that Gab1 is an essential regulator of the EGF-mediated mTORC pathways and may potentially be used as a biomarker for urothelial carcinoma to predict diagnosis and drug response.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Factor de Crecimiento Epidérmico/farmacología , Complejos Multiproteicos/metabolismo , Fosfoproteínas/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismo , Proteínas Adaptadoras Transductoras de Señales/biosíntesis , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Línea Celular Tumoral , Femenino , Humanos , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina , Diana Mecanicista del Complejo 2 de la Rapamicina , Complejos Multiproteicos/genética , Fosfoproteínas/biosíntesis , Fosfoproteínas/genética , Fosforilación/efectos de los fármacos , Ratas , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/genética , Transfección , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología
18.
Biomaterials ; 35(5): 1562-71, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24269156

RESUMEN

Three-dimensional (3D) tissue culture platforms that are capable of mimicking in vivo microenvironments to replicate physiological conditions are vital tools in a wide range of cellular and clinical studies. Here, learning from the nature of cilia in lungs - clearing mucus and pathogens from the airway - we develop a 3D culture approach via flexible and kinetic copolymer-based chains (nano-cilia) for diminishing cell-to-substrate adhesion. Multicellular spheroids or colonies were tested for 3-7 days in a microenvironment consisting of generated cells with properties of putative cancer stem cells (CSCs). The dynamic and reversible regulation of epithelial-mesenchymal transition (EMT) was examined in spheroids passaged and cultured in copolymer-coated dishes. The expression of CSC markers, including CD44, CD133, and ABCG2, and hypoxia signature, HIF-1α, was significantly upregulated compared to that without the nano-cilia. In addition, these spheroids exhibited chemotherapeutic resistance in vitro and acquired enhanced metastatic propensity, as verified from microfluidic chemotaxis assay designed to replicate in vivo-like metastasis. The biomimetic nano-cilia approach and microfluidic device may offer new opportunities to establish a rapid and cost-effective platform for the study of anti-cancer therapeutics and CSCs.


Asunto(s)
Biomimética , Cilios/fisiología , Resistencia a Antineoplásicos , Microfluídica , Modelos Biológicos , Nanoestructuras , Metástasis de la Neoplasia , Línea Celular Tumoral , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/patología
19.
PLoS One ; 8(9): e74300, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24023933

RESUMEN

Obstructive nephropathy is the most common presentation of urothelial carcinoma. The role of the urine in the obstructed kidney namely "hydronephrotic urine" in urothelial carcinoma has not been extensively explored. This study aims to evaluate whether hydronephrotic urine in the obstructed kidney could promote urothelial carcinoma. The hydronephrotic urine was collected from the obstructed kidneys of Sprague-Dawley rats induced by different periods of unilateral ureteral obstruction (UUO). By the inhibition of LY294002 and PD184352, we confirm that hydronephrotic urine promotes urothelial carcinoma cell (T24) and immortalized normal urothelial cells (E6) proliferation, migration and invasion in a dose-dependent manner through the activation of the mTORC2-AKT and ERK signaling pathways. Hydronephrotic urine also increases the expression of cyclin-D2, cyclin-B and CDK2. It also decreases the expression of p27 and p21 in both urothelial carcinoma cells and normal urothelial cells. By the protein array study, we demonstrate that many growth factors which promote tumor cell survival and metastasis are over-expressed in a time-dependent manner in the hydronephrotic urine, including beta-FGF, IFN-γ, PDGF-BB, PIGF, TGF-ß, VEGF-A, VEGF-D and EGF. These results suggest that hydronephrotic urine promotes normal and malignant urothelial cells proliferation, migration and invasion, through the activation of the mTORC2-AKT and ERK signaling pathways. Further investigation using live animal models of tumor growth may be needed to clarify aspects of these statements.


Asunto(s)
Movimiento Celular , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Hidronefrosis/orina , Complejos Multiproteicos/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Neoplasias Urológicas/patología , Urotelio/patología , Animales , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular , Supervivencia Celular/efectos de los fármacos , Factor de Crecimiento Epidérmico/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Hidronefrosis/terapia , Masculino , Diana Mecanicista del Complejo 2 de la Rapamicina , Invasividad Neoplásica , Neovascularización Patológica , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Neoplasias Urológicas/irrigación sanguínea
20.
J Mater Chem B ; 1(38): 4983-4991, 2013 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-32261088

RESUMEN

Electroactive mesoporous organosilica nanocomposites (EMONs) and electroactive mesoporous gold-organosilica nanocomposites (EMGONs) were successfully prepared in this work and were applied in ascorbic acid (AA) sensing. EMONs were synthesized by using an aniline pentamer (AP) as an electroactive segment which controlled the redox ability and influenced the degree of sensitivity of the nanocomposites towards AA. EMGONs were successfully prepared by a one-pot synthesis in HAuCl4 aqueous solution with different concentrations. Gold nanoparticles (AuNPs) were selectively reduced on an AP segment in an EMON matrix, which acted as a reductant as well as providing a large surface area to absorb and react with chloroaurate anions (AuCl4 -). The gold particle size can be controlled by varying the concentration of HAuCl4 (aq.), and distributed AuNPs with controllable size were fabricated for the EMGONs. A sensor constructed from an EMGON-modified carbon-paste electrode (CPE) demonstrated 21-fold and 6.3-fold higher electrocatalytic activity towards the oxidation of AA compared to those constructed using a bare CPE and EMON-modified CPE, respectively. The high surface area of the EMGON-modified CPE exhibited a good electrochemical response towards AA at a low oxidative potential with good stability and sensitivity and a wide linear analytical detection range.

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