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1.
Phys Chem Chem Phys ; 24(43): 26575-26582, 2022 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-36285740

RESUMEN

A mixture of poly(benzyl methacrylate) (PBnMA) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C2mim][NTf2]) exhibits lower-critical-solution-temperature (LCST)-type phase separation. An investigation combining magic-angle spinning NMR spectroscopy and small-angle scattering was performed to gain new insights into the interaction between PBnMA and the ionic liquid. The molecular mobility and the solute-solvent interaction in the system were investigated using 1H high-resolution magic-angle spinning NMR. Applying a magic-angle spinning frequency of 2 kHz allowed identifying the PBnMA peaks, which were not observed by conventional solution-state NMR. The peaks of [C2mim]+ almost coincided in the presence and absence of PBnMA, indicating the decoupling of the bulk solvent and polymer. The conformational state of PBnMA in [C2mim][NTf2] was investigated using small-angle X-ray scattering (SAXS). The pair distribution functions of PBnMA chains calculated from SAXS profiles suggest that PBnMA adopts a random coil conformation upon dissolution in [C2mim][NTf2]. The combined study clarifies the decoupled low mobility of polymers with a random coil conformation. It is considered that the specific decoupled low mobility is one of the origins of the decoupling conductivity of [C2mim][NTf2] in a matrix polymer. In addition, an increase in temperature induced a downfield shift and broadening of the [C2mim]+ peaks, suggesting that a larger amount of [C2mim]+ was bound to the PBnMA chains even at temperatures approaching the LCST.


Asunto(s)
Líquidos Iónicos , Líquidos Iónicos/química , Amidas , Dispersión del Ángulo Pequeño , Rayos X , Difracción de Rayos X , Espectroscopía de Resonancia Magnética/métodos , Solventes , Polímeros/química
2.
Mol Cell ; 55(2): 186-98, 2014 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-24954906

RESUMEN

It has been proposed that Ataxin-2, a member of the like-Sm (LSm) protein family, participates in the regulation of RNA metabolism through interaction with PABPC1. However, the exact biological mechanism and in vivo targets remain unknown. Here, we report that Ataxin-2 binds directly to RNAs in a PABPC1-independent manner. High-throughput sequencing of Ataxin-2-bound RNAs prepared by PAR-CLIP revealed that Ataxin-2 binds predominantly to uridine-rich elements, including well-characterized cis-regulatory AU-rich elements, in the 3' UTRs of target mRNAs. Gene expression analysis after Ataxin-2 depletion or overexpression revealed that Ataxin-2 stabilizes target mRNAs and increases the abundance of the corresponding proteins. A tethering assay demonstrated that Ataxin-2 elicits this effect by direct interaction with mRNAs. We also found that disease-associated polyglutamine expansion downregulates the physiological activity of Ataxin-2. These findings suggest that Ataxin-2 is an RNA-binding protein that targets cis-regulatory elements in 3' UTRs to stabilize a subset of mRNAs and increase protein expression.


Asunto(s)
Regiones no Traducidas 3' , Proteínas del Tejido Nervioso/metabolismo , Estabilidad del ARN , ARN Mensajero/metabolismo , Ataxinas , Sitios de Unión , Proteínas ELAV/metabolismo , Regulación de la Expresión Génica , Ontología de Genes , Células HEK293 , Humanos , Mutación , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genética , Péptidos/genética , Unión Proteica , Biosíntesis de Proteínas , Estructura Terciaria de Proteína , ARN Mensajero/genética
3.
J Gambl Stud ; 36(4): 1391-1407, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32162075

RESUMEN

Internet-delivered intervention may be an acceptable alternative for the more than 90% of problem gamblers who are reluctant to seek face-to-face support. Thus, we aimed to (1) develop a low-dropout unguided intervention named GAMBOT integrated with a messaging app; and (2) investigate its effect. The present study was a randomised, quadruple-blind, controlled trial. We set pre-to-post change in the Problem Gambling Severity Index (PGSI) as the primary outcome and pre-to-post change in the Gambling Symptom Assessment Scale (G-SAS) as a secondary outcome. Daily monitoring, personalised feedback, and private messages based on cognitive behavioural theory were offered to participants in the intervention group through a messaging app for 28 days (GAMBOT). Participants in the control group received biweekly messages only for assessments for 28 days (assessments only). A total of 197 problem gamblers were included in the primary analysis. We failed to demonstrate a significant between-group difference in the primary outcome (PGSI - 1.14, 95% CI - 2.75 to 0.47, p = 0.162) but in the secondary outcome (G-SAS - 3.14, 95% CI - 0.24 to - 6.04, p = 0.03). Only 6.7% of the participants dropped out during follow-up and 77% of the GAMBOT group participants (74/96) continued to participate in the intervention throughout the 28-day period. Integrating intervention into a chatbot feature on a frequently used messaging app shows promise in helping to overcome the high dropout rate of unguided internet-delivered interventions. More effective and sophisticated contents delivered by a chatbot should be sought to engage over 90% of problem gamblers who are reluctant to seek face-to-face support.


Asunto(s)
Terapia Cognitivo-Conductual/métodos , Juego de Azar/terapia , Intervención basada en la Internet , Aplicaciones Móviles , Adulto , Método Doble Ciego , Femenino , Juego de Azar/psicología , Humanos , Masculino , Factores Socioeconómicos , Telemedicina
4.
Mol Pharm ; 16(6): 2785-2794, 2019 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-31045376

RESUMEN

The present study evaluated the specific intermolecular interactions between carbamazepine (CBZ) and substituents of hypromellose acetate succinate (HPMC-AS), as well as the mechanism of inhibition of recrystallization of solid dispersions (SDs) using Fourier-transform infrared (FTIR) and solid-state nuclear magnetic resonance (NMR) spectroscopy. CBZ and HPMC derivatives, including HPMC, hypromellose acetate (HPMC-A), and hypromellose succinate (HPMC-S), were spray-dried to prepare CBZ/polymer spray-dried samples (SPDs). CBZ/HPMC SPD and CBZ/HPMC-A SPD recrystallized within 10 days at 60 °C and 0% relative humidity, whereas CBZ/HPMC-S SPD maintained its amorphous state for a longer period. FTIR and solid-state NMR measurements using 13C cross polarization (CP), 1H single-pulse, and 1H-15N CP-based heteronuclear single quantum correlation filter experiment with very fast magic angle spinning (MAS) at 70 kHz identified molecular interactions in CBZ/polymer SPDs. Although the HPMC backbone and substituents did not interact notably with CBZ and disrupt CBZ-CBZ intermolecular interactions (formed in the amorphous CBZ), acetate and succinate substituents on HPMC-A and HPMC-S disrupted CBZ-CBZ intermolecular interactions through formation of CBZ/polymer interactions. The acetate substituent formed a hydrogen bond with the NH2 group of CBZ, whereas the succinate substituent formed molecular interactions with both the C═O and NH2 groups of CBZ. Formation of relatively strong molecular interactions between CBZ and the succinate substituent followed by disruption of CBZ-CBZ intermolecular interactions effectively stabilized the amorphous state of CBZ in CBZ/HPMC-S SPD. The correlation between CBZ-polymer interactions and ability of polymers to effectively inhibit CBZ recrystallization is reflected in various commercial HPMC-AS. For example, HPMC-AS LF grade, containing higher amounts of the succinate group, was found to effectively inhibit the recrystallization of CBZ through strong molecular interactions as compared with the HPMC-AS HF grade. The present study demonstrated that a detailed investigation of molecular interactions between the drug and the polymer using FTIR and solid-state NMR spectroscopy could contribute to a suitable selection of the SD carrier.


Asunto(s)
Derivados de la Hipromelosa/química , Polímeros/química , Espectroscopía de Resonancia Magnética , Espectroscopía Infrarroja por Transformada de Fourier
5.
Nat Methods ; 12(9): 852-8, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26167640

RESUMEN

Circuit mapping requires knowledge of both structural and functional connectivity between cells. Although optical tools have been made to assess either the morphology and projections of neurons or their activity and functional connections, few probes integrate this information. We have generated a family of photoactivatable genetically encoded Ca(2+) indicators that combines attributes of high-contrast photolabeling with high-sensitivity Ca(2+) detection in a single-color protein sensor. We demonstrated in cultured neurons and in fruit fly and zebrafish larvae how single cells could be selected out of dense populations for visualization of morphology and high signal-to-noise measurements of activity, synaptic transmission and connectivity. Our design strategy is transferrable to other sensors based on circularly permutated GFP (cpGFP).


Asunto(s)
Señalización del Calcio/fisiología , Calcio/metabolismo , Proteínas Luminiscentes/metabolismo , Neuronas/citología , Neuronas/fisiología , Optogenética/métodos , Animales , Rastreo Celular/métodos , Células Cultivadas , Drosophila , Luz , Proteínas Luminiscentes/genética , Microscopía Fluorescente/métodos , Ingeniería de Proteínas/métodos , Ratas , Pez Cebra
6.
Plant J ; 75(3): 430-40, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23590515

RESUMEN

Development of the epidermis involves members of the class-IV homeodomain-leucine zipper (HD-ZIP IV) transcription factors. The Arabidopsis HD-ZIP IV family consists of 16 members, among which PROTODERMAL FACTOR 2 (PDF2) and ARABIDOPSIS THALIANA MERISTEM LAYER 1 (ATML1) play an indispensable role in the differentiation of shoot epidermal cells; however, the functions of other HD-ZIP IV genes that are also expressed specifically in the shoot epidermis remain to be fully elucidated. We constructed double mutant combinations of these HD-ZIP IV mutant alleles and found that the double mutants of pdf2-1 with homeodomain glabrous1-1 (hdg1-1), hdg2-3, hdg5-1 and hdg12-2 produced abnormal flowers with sepaloid petals and carpelloid stamens in association with the reduced expression of the petal and stamen identity gene APETALA 3 (AP3). Expression of another petal and stamen identity gene PISTILATA (PI) was less affected in these mutants. We confirmed that AP3 expression in pdf2-1 hdg2-3 was normally induced at the initial stages of flower development, but was attenuated both in the epidermis and internal cell layers of developing flowers. As the expression of PDF2 and these HD-ZIP IV genes during floral organ formation is exclusively limited to the epidermal cell layer, these double mutations may have non-cell-autonomous effects on AP3 expression in the internal cell layers. Our results suggest that cooperative functions of PDF2 and other members of the HD-ZIP IV family in the epidermis are crucial for normal development of floral organs in Arabidopsis.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Flores/genética , Proteínas de Homeodominio/genética , Mutación , Epidermis de la Planta/genética , Arabidopsis/fisiología , Proteínas de Arabidopsis/metabolismo , Flores/anatomía & histología , Flores/fisiología , Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio/metabolismo , Proteínas de Dominio MADS/genética , Proteínas de Dominio MADS/metabolismo , Plantas Modificadas Genéticamente
7.
J Exp Med ; 203(6): 1447-58, 2006 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-16702604

RESUMEN

Sepsis, the systemic inflammatory response to infection, is a leading cause of morbidity and mortality. The mechanisms of sepsis pathophysiology remain obscure but are likely to involve a complex interplay between mediators of the inflammatory and coagulation pathways. An improved understanding of these mechanisms should provide an important foundation for developing novel therapies. In this study, we show that sepsis is associated with a time-dependent increase in circulating levels of vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) in animal and human models of sepsis. Adenovirus-mediated overexpression of soluble Flt-1 (sFlt-1) in a mouse model of endotoxemia attenuated the rise in VEGF and PlGF levels and blocked the effect of endotoxemia on cardiac function, vascular permeability, and mortality. Similarly, in a cecal ligation puncture (CLP) model, adenovirus-sFlt-1 protected against cardiac dysfunction and mortality. When administered in a therapeutic regimen beginning 1 h after the onset of endotoxemia or CLP, sFlt peptide resulted in marked improvement in cardiac physiology and survival. Systemic administration of antibodies against the transmembrane receptor Flk-1 but not Flt-1 protected against sepsis mortality. Adenovirus-mediated overexpression of VEGF but not PlGF exacerbated the lipopolysaccharide-mediated toxic effects. Together, these data support a pathophysiological role for VEGF in mediating the sepsis phenotype.


Asunto(s)
Sepsis/sangre , Factor A de Crecimiento Endotelial Vascular/sangre , Animales , Ciego/microbiología , Modelos Animales de Enfermedad , Endotoxemia/sangre , Humanos , Inflamación/sangre , Lipopolisacáridos/toxicidad , Ratones , Factor de Crecimiento Placentario , Proteínas Gestacionales/sangre , Sepsis/mortalidad
8.
J Gastroenterol Hepatol ; 27 Suppl 3: 70-5, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22486875

RESUMEN

BACKGROUND AND AIMS: Recent advancements in capsule endoscopy and double-balloon endoscopy have revealed that non-steroidal anti-inflammatory drugs (NSAIDs), such as indomethacin, can induce small intestinal mucosal damage. However, the precise pathogenesis and therapeutic strategy have not been fully revealed. The aim of the present study was to determine the upregulated proteins in the small intestine exposed to indomethacin. METHODS: Indomethacin (10 mg/kg) was administered subcutaneously to male Wistar rats to induce small intestinal damage and the severity of the intestinal injury was evaluated by measuring the area of visible ulcerative lesions. The intestinal mucosal tissue samples were collected and then analyzed by two-dimensional gel electrophoresis, with matrix-assisted laser desorption/ionization time-of-flight spectrometer peptide mass fingerprinting being used to determine the differentially expressed proteins between normal and injured intestinal mucosa. RESULTS: Among several protein spots showing differential expression, one, hemopexin (HPX), was identified as upregulated in indomethacin-induced injured intestinal mucosa using the MASCOT search engine. CONCLUSION: HPX was identified as upregulated protein in the small intestine exposed to indomethacin. HPX may be responsible for the development of the intestinal inflammation induced by NSAIDs.


Asunto(s)
Antiinflamatorios no Esteroideos , Hemopexina/metabolismo , Íleon/metabolismo , Indometacina , Mucosa Intestinal/metabolismo , Yeyuno/metabolismo , Úlcera Péptica/metabolismo , Animales , Western Blotting , Modelos Animales de Enfermedad , Electroforesis en Gel Bidimensional , Íleon/patología , Inmunohistoquímica , Mucosa Intestinal/patología , Yeyuno/patología , Masculino , Úlcera Péptica/inducido químicamente , Úlcera Péptica/patología , Mapeo Peptídico , Proteómica/métodos , Ratas , Ratas Wistar , Índice de Severidad de la Enfermedad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Factores de Tiempo , Regulación hacia Arriba
9.
Biol Pharm Bull ; 35(1): 116-20, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22223347

RESUMEN

The administration of fibrates (fenofibrate, bezafibrate and clofibric acid) to rats induced stearoyl-CoA desaturase (SCD) in the liver, and increased relative expression of mRNAs encoding SCD1 and SCD2 in dose- and time-dependent manners. The magnitudes of the increases in SCD2 mRNA level caused by fenofibrate and clofibric acid were much higher than those of SCD1 at relatively higher doses of the fibrates, and a relatively long time (7 or 14 d) was required for significant induction of SCD2 mRNA expression compared with that of SCD1. Although the absolute number of transcripts for SCD2 was 1,800 times lower than that of SCD1 in the control liver, it was strikingly increased by fibrates. These results suggest that differential regulations operate for the gene expression between SCD1 and SCD2, and that the physiological significance of SCD2 is distinct from that of SCD1 in the liver.


Asunto(s)
Bezafibrato/farmacología , Ácido Clofíbrico/farmacología , Activadores de Enzimas/farmacología , Fenofibrato/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Hígado/enzimología , Estearoil-CoA Desaturasa/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Activación Enzimática/efectos de los fármacos , Hígado/efectos de los fármacos , Masculino , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Estearoil-CoA Desaturasa/genética
10.
Am J Physiol Gastrointest Liver Physiol ; 301(2): G230-8, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21636531

RESUMEN

Human esophageal epithelium is continuously exposed to physical stimuli or to gastric acid that sometimes causes inflammation of the mucosa. Transient receptor potential vanilloid 1 (TRPV1) is a nociceptive, Ca(2+)-selective ion channel activated by capsaicin, heat, and protons. It has been reported that activation of TRPV1 expressed in esophageal mucosa is involved in gastroesophageal reflux disease (GERD) or in nonerosive GERD symptoms. In this study, we examined the expression and function of TRPV1 in the human esophageal epithelial cell line Het1A, focusing in particular on the role of oxidative stress. Interleukin-8 (IL-8) secreted by Het1A cells upon stimulation by capsaicin or acid with/without 4-hydroxy-2-nonenal (HNE) was measured by ELISA. Following capsaicin stimulation, the intracellular production of reactive oxygen species (ROS) was determined using a redox-sensitive fluorogenic probe, and ROS- and HNE-modified proteins were determined by Western blotting using biotinylated cysteine and anti-HNE antibody, respectively. HNE modification of TRPV1 proteins was further investigated by immunoprecipitation after treatment with synthetic HNE. Capsaicin and acid induced IL-8 production in Het1A cells, and this production was diminished by antagonists of TRPV1. Capsaicin also significantly increased the production of intracellular ROS and ROS- or HNE-modified proteins in Het1A cells. Moreover, IL-8 production in capsaicin-stimulated Het1A cells was enhanced by synthetic HNE treatment. Immunoprecipitation studies revealed that TRPV1 was modified by HNE in synthetic HNE-stimulated Het1A cells. We concluded that TRPV1 functions in chemokine production in esophageal epithelial cells, and this function may be regulated by ROS via posttranslational modification of TRPV1.


Asunto(s)
Canales de Calcio/metabolismo , Células Epiteliales/metabolismo , Esófago/metabolismo , Interleucina-8/metabolismo , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/metabolismo , Canales Catiónicos TRPV/metabolismo , Ácidos/farmacología , Aldehídos/farmacología , Animales , Canales de Calcio/efectos de los fármacos , Capsaicina/farmacología , Línea Celular , Esófago/citología , Humanos , Interleucina-8/efectos de los fármacos , Masculino , Membrana Mucosa/metabolismo , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/genética , Ratas , Ratas Wistar , Canales Catiónicos TRPV/efectos de los fármacos
11.
J Gastroenterol Hepatol ; 25 Suppl 1: S144-8, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20586857

RESUMEN

BACKGROUND AND AIMS: The aim of this study was to identify new intestinal proteins potentially associated with acute inflammation using proteomic profiling of an in vivo mice model of ulcerative colitis. METHODS: 2D fluorescence difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization time-of-flight spectrometer (MALDI-TOF) peptide mass fingerprinting were used to determine differentially expressed proteins between normal and inflamed intestinal mucosa. Acute colitis was induced by 8.0% dextran sodium sulfate (DSS) given p.o. for 7 days. RESULTS: Among a total of seven protein spots showing differential expression, we identified five different proteins, of which two were upregulated and three downregulated in colitis in comparison to normal mucosa, using the MASCOT search engine. 3-Hydroxy-3-methylglutaryl-coenzyme A synthase 2 and serpin b1a were upregulated proteins, and protein disulfide-isomerase A3, peroxiredoxin-6 and vimentin were identified as downregulated proteins. CONCLUSION: These identified proteins may be responsible for the development of the intestinal inflammation. 2D-DIGE and MALDI-TOF mass spectrometry are useful in the search for the differentially expressed proteins.


Asunto(s)
Colitis Ulcerosa/metabolismo , Colon/metabolismo , Electroforesis en Gel Bidimensional , Mediadores de Inflamación/metabolismo , Proteínas/metabolismo , Proteómica/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Animales , Colitis Ulcerosa/inducido químicamente , Sulfato de Dextran , Modelos Animales de Enfermedad , Femenino , Fluorescencia , Hidroximetilglutaril-CoA Sintasa/metabolismo , Mucosa Intestinal/metabolismo , Ratones , Ratones Endogámicos BALB C , Mapeo Peptídico , Peroxiredoxina VI/metabolismo , Proteína Disulfuro Isomerasas/metabolismo , Serpinas/metabolismo , Vimentina/metabolismo
12.
Int J Pharm ; 581: 119300, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32268185

RESUMEN

The potential for inhibiting recrystallization with Eudragit® L (EUD-L), hypromellose acetate succinate (HPMC-AS), and polyvinylpyrrolidone-co-vinylacetate (PVP-VA) on amorphous felodipine (FLD) at low polymer loading was investigated in this study. The physical stabilities of the FLD/polymer amorphous solid dispersions (ASDs) were investigated through storage at 40 °C. The HPMC-AS and PVP-VA strongly inhibited FLD recrystallization, although EUD-L did not effectively inhibit the FLD recrystallization. The rotating frame 1H spin-lattice relaxation time (1H-T1ρ) measurement clarified that EUD-L was not well mixed with FLD in the ASD, which resulted in weak inhibition of recrystallization by EUD-L. In contrast, the HPMC-AS and PVP-VA were well mixed with the FLD in the ASDs. Solid-state 13C spin-lattice relaxation time (13C-T1) measurements at 40 °C showed that the molecular mobility of the FLD was strongly suppressed when mixed with polymer. The reduction in the molecular mobility of FLD was in the following order, starting with the least impact: FLD/EUD-L ASD, FLD/HPMC-AS ASD, and FLD/PVP-VA ASD. FLD mobility at the storage temperature, evaluated by 13C-T1, showed a good correlation with the physical stability of the amorphous FLD. The direct investigation of the molecular mobility of amorphous drugs at the storage temperature by solid-state NMR relaxation time measurement can be a useful tool in selecting the most effective crystallization inhibitor at low polymer loading.


Asunto(s)
Isótopos de Carbono/química , Química Farmacéutica/métodos , Fuerza Compresiva , Cristalización/métodos , Felodipino/química , Polímeros/química , Antiarrítmicos/análisis , Antiarrítmicos/química , Isótopos de Carbono/análisis , Portadores de Fármacos/análisis , Portadores de Fármacos/química , Felodipino/análisis , Predicción , Polímeros/análisis
13.
Int J Pharm ; 577: 119086, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31991185

RESUMEN

We aimed to elucidate the dissolution mechanism of solid dispersions (SDs) according to the carrier polymers used. Nifedipine (NIF) and polymers dissolved simultaneously from NIF/Eudragit® S (EUD-S), NIF/Eudragit® L (EUD-L), and NIF/hypromellose (HPMC)/EUD-S spray-dried samples (SPDs). In contrast, NIF dissolved separately from polymers from NIF/HPMC and NIF/HPMC/EUD-L SPDs due to the formation of an amorphous NIF-rich interface. Solid-state NMR spectroscopy indicated that NIF-EUD interactions were stronger than NIF-HPMC interactions. NIF/HPMC SPD exhibited weak interactions; thus, it failed to inhibit phase separation during the dissolution process and control NIF dissolution. The hygroscopicity of SPDs was higher with HPMC mixing and increased substitution ratio of methacrylic acid in EUD. Moreover, solid-state NMR spectroscopy revealed that the NIF-EUD interactions were hindered to a large extent by the absorbed water. During the dissolution process of NIF/HPMC/EUD-L SPD, the introduction of water to the NIF-EUD-L interaction site could induce the phase separation and poor controllability of NIF dissolution. Water-induced phase separation should be considered based on molecular-level characterization to obtain SDs with enhanced drug dissolution. An investigation of the molecular state change caused by the absorbed water using solid-state NMR spectroscopy will be helpful in understanding the dissolution mechanism of SDs.


Asunto(s)
Portadores de Fármacos/química , Nifedipino/administración & dosificación , Polímeros/química , Química Farmacéutica , Liberación de Fármacos , Derivados de la Hipromelosa/química , Espectroscopía de Resonancia Magnética , Nifedipino/química , Ácidos Polimetacrílicos/química , Agua/química , Humectabilidad
14.
J Pharmacol Exp Ther ; 331(1): 255-64, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19628634

RESUMEN

Induction of heme oxygenase-1 (HO-1) expression has been associated with cytoprotective and anti-inflammatory actions of lansoprazole, a proton pump inhibitor, but the underlying molecular mechanisms remain largely unresolved. In this study, we investigate the role of transcriptional NF-E2-related factor 2 (Nrf2), its phosphorylation/activation, and oxidation of Kelch-like ECH-associating protein 1 (Keap1) in lansoprazole-induced HO-1 up-regulation using cultured gastric epithelial cells (rat gastric mucosal cell line, RGM-1). HO-1 expression of RGM-1 cells was markedly enhanced in a time- and dose-dependent manner by the treatment with lansoprazole, and this up-regulation of HO-1 contributed to the inhibition of chemokine production from stimulated RGM-1 cells. Transfection of Nrf2-siRNA suppressed the lansoprazole-induced HO-1. An electrophoretic mobility shift assay showed increases in the nuclear translocation and stress-response elements (StRE) binding activity of Nrf2 proteins in RGM-1 cells treated with lansoprazole. Furthermore, in RGM-1 cells transfected with HO-1 enhancer luciferase reporter plasmid containing mutant StRE, lansoprazole-induced HO-1 reporter gene activity was diminished. Lansoprazole promoted the phosphorylation of extracellular signal-regulated kinase (ERK), and lansoprazole-induced HO-1 up-regulation was suppressed by U0126, an ERK-specific inhibitor. Phosphorylated Nrf2 protein was detected in the phosphoprotein fraction purified by a Pro-Q Diamond Phosphoprotein Enrichment kit. Finally, an oxidative form of the Keap1 protein was detected in lansoprazole-treated RGM-1 cells by analyzing S-oxidized proteins using biotinylated cysteine as a molecular probe. These results indicate that lansoprazole up-regulates HO-1 expression in rat gastric epithelial cells, and the up-regulated HO-1 contributes to the anti-inflammatory effects of the drug. Phosphorylation of ERK and Nrf2, activation and nuclear translocation of Nrf2, and oxidation of Keap1 are all involved in the lansoprazole-induced HO-1 up-regulation.


Asunto(s)
2-Piridinilmetilsulfinilbencimidazoles/farmacología , Antiinflamatorios no Esteroideos/farmacología , Mucosa Gástrica/metabolismo , Hemo-Oxigenasa 1/biosíntesis , Factor 2 Relacionado con NF-E2/metabolismo , Proteínas/metabolismo , Inhibidores de la Bomba de Protones/farmacología , Animales , Línea Celular , Inducción Enzimática/efectos de los fármacos , Inducción Enzimática/fisiología , Mucosa Gástrica/citología , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/enzimología , Insectos , Péptidos y Proteínas de Señalización Intracelular , Proteína 1 Asociada A ECH Tipo Kelch , Lansoprazol , Ratones , Factor 2 Relacionado con NF-E2/fisiología , Oxidación-Reducción/efectos de los fármacos , Ratas
15.
Circ Res ; 100(12): 1712-22, 2007 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-17495228

RESUMEN

Robo4, a member of the roundabout family, is expressed exclusively in endothelial cells and has been implicated in endothelial cell migration and angiogenesis. Here we report the cloning and characterization of the human Robo4 promoter. The 3-kb 5'-flanking region directs endothelial cell-specific expression in vitro. Deletion and mutation analyses revealed the functional importance of two 12-bp palindromic DNA sequences at -2528 and -2941, 2 SP1 consensus motifs at -42 and -153, and an ETS consensus motif at -119. In electrophoretic mobility shift assays using supershifting antibodies, the SP1 motifs bound SP1 protein, whereas the ETS site bound a heterodimeric member of the ETS family, GA binding protein (GABP). These DNA-protein interactions were confirmed by chromatin immunoprecipitation assays. Transfection of primary human endothelial cells with small interfering RNA against GABP and SP1 resulted in a significant (approximately 50%) reduction in endogenous Robo4 mRNA expression. The 3-kb Robo4 promoter was coupled to LacZ, and the resulting cassette was introduced into the Hprt locus of mice by homologous recombination. Reporter gene activity was observed in the vasculature of adult organs (particularly in microvessels), tumor xenografts, and embryos, where it colocalized with the endothelial cell-specific marker CD31. LacZ mRNA levels in adult tissues and tumors correlated with mRNA levels for endogenous Robo4, CD31, and vascular endothelial cadherin. Moreover, the pattern of reporter gene expression was similar to that observed in mice in which LacZ was knocked into the endogenous Robo4 locus. Together, these data suggest that 3-kb upstream promoter of human Robo4 contains information for cell type-specific expression in the intact endothelium.


Asunto(s)
Endotelio Vascular/metabolismo , Fragmentos de Péptidos/fisiología , Regiones Promotoras Genéticas/fisiología , Receptores de Superficie Celular/fisiología , Animales , Secuencia de Bases , Cadherinas/metabolismo , Células Cultivadas , Clonación Molecular , ADN/genética , Análisis Mutacional de ADN , Endotelio Vascular/citología , Factor de Transcripción de la Proteína de Unión a GA/fisiología , Regulación de la Expresión Génica , Humanos , Operón Lac , Ratones , Datos de Secuencia Molecular , Fragmentos de Péptidos/genética , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Regiones Promotoras Genéticas/genética , Unión Proteica/fisiología , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Interferente Pequeño/farmacología , Receptores de Superficie Celular/genética , Análisis de Secuencia de ADN , Factor de Transcripción Sp1/fisiología , Transfección
16.
Appl Microbiol Biotechnol ; 81(6): 1077-85, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18825379

RESUMEN

In this study, we cloned the gene encoding goose-type (G-type) lysozyme with chitinase (Ra-ChiC) activity from Ralstonia sp. A-471 genomic DNA library. This is the first report of another type of chitinase after the previously reported chitinases ChiA (Ra-ChiA) and ChiB (Ra-ChiB) in the chitinase system of the moderately thermophilic bacterium, Ralstonia sp. A-471 and also the first such data in Ralstonia sp. G-type lysozyme gene. It consisted of 753 bp nucleotides, which encodes 251 amino acids including a putative signal peptide. This ORF was modular enzyme composed of a signal sequence, chitin-binding domain, linker, and catalytic domain. The catalytic domain of Ra-ChiC showed homologies to those of G-type lysozyme (glycoside hydrolases (GH) family 23, 16.8%) and lysozyme-like enzyme from Clostridium beijerincki (76.1%). Ra-ChiC had activities against ethylene glycol chitin, carboxyl methyl chitin, and soluble chitin but not against the cell wall of Micrococcus lysodeikticus. The enzyme produced alpha-anomer by hydrolyzing beta-1,4-glycosidic linkage of the substrate, indicating that the enzyme catalyzes the hydrolysis through an inverting mechanism. When N-acetylglucosamine hexasaccharide [(GlcNAc)6] was hydrolyzed by the enzyme, the second and third glycosidic linkage from the non-reducing end were split producing (GlcNAc)2 + (GlcNAc)4 and (GlcNAc)3 + (GlcNAc)3 of almost the same concentration in the early stage of the reaction. The G-type lysozyme hydrolyzed (GlcNAc)6 in an endo-splitting manner, which produced (GlcNAc)3 + (GlcNAc)3 predominating over that to (GlcNAc)2 + (GlcNAc)4. Thus, Ra-ChiC was found to be a novel enzyme in its structural and functional properties.


Asunto(s)
Quitina/metabolismo , Muramidasa/metabolismo , Ralstonia/enzimología , Secuencia de Aminoácidos/genética , Secuencia de Bases , Clonación Molecular , ADN Bacteriano/química , ADN Bacteriano/genética , Expresión Génica , Datos de Secuencia Molecular , Muramidasa/genética , Muramidasa/aislamiento & purificación , Sistemas de Lectura Abierta , Señales de Clasificación de Proteína , Estructura Terciaria de Proteína , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Especificidad por Sustrato
17.
Shock ; 29(4): 452-7, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18598002

RESUMEN

Prior murine and human studies suggest that vascular endothelial growth factor (VEGF) contributes to endothelial cell activation and severity of illness in sepsis. Furthermore, circulating levels of soluble VEGF receptor 1 (sFLT) levels were found to increase as part of the early response to sepsis in mice. The objective of the study was to evaluate the blood levels of free VEGF-A and sFLT in patients presenting to the emergency department (ED) with suspected infection and to assess the relationship of these levels with severity of illness and inflammation. It was a prospective, observational study initiated in the ED of an urban, tertiary care, university hospital. Inclusion criteria were (1) ED patients aged 18 years or older and (2) clinical suspicion of infection. Eighty-three patients were enrolled in the study. The major findings were that (1) the mean VEGF and sFLT levels were increasingly higher across the following groups: noninfected control patients, infected patients without shock, and septic shock patients; (2) initial and 24-h VEGF levels had a significant correlation with the presence of septic shock at 24 h; (3) initial and 24-h sFLT levels correlated with Acute Physiology Age Chronic Health Evaluation II and Sepsis-related Organ/Failure Assessment scores initially and at 24 h; and (4) VEGF and sFLT levels correlated with inflammatory cascade activation. This is the first report of sFLT as a potential new marker of severity in patients with sepsis. Vascular endothelial cell growth factor and its signaling axis are important in the endothelial cell response to sepsis, and further elucidation of these mechanisms may lead to advances in future diagnostic and therapeutic opportunities.


Asunto(s)
Sepsis/sangre , Factor A de Crecimiento Endotelial Vascular/sangre , Receptor 1 de Factores de Crecimiento Endotelial Vascular/sangre , APACHE , Anciano , Servicio de Urgencia en Hospital , Humanos , Interleucina-1/sangre , Interleucina-6/sangre , Persona de Mediana Edad , Estudios Prospectivos , Sepsis/patología , Solubilidad , Factores de Tiempo
18.
J Gastroenterol Hepatol ; 23 Suppl 2: S229-33, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19120903

RESUMEN

BACKGROUND: Heme oxygenase-1 (HO-1) is regarded as a sensitive and reliable indicator of cellular oxidative stress. Two end products of heme degradation, carbon monoxide (CO) and bilirubin, are involved in the protective role of HO-1 against oxidative injury. We have demonstrated enhanced expression of this enzyme and increased concentration of CO in experimental models of colitis, but the role of HO-1 in patients with ulcerative colitis (UC) has not been extensively investigated. The aim of the present study was to determine the intestinal levels and localization of ho-1 mRNA and HO-1 protein in patients with UC. METHODS: Eighteen patients with UC and 13 patients with colon cancer were prospectively selected from subjects who underwent colonoscopy. Biopsy specimens were obtained from the inflamed mucosa of UC patients and from the normal mucosa at least 5 cm from the margin of carcinoma. The expression of ho-1 mRNA was assayed by real-time polymerase chain reaction (PCR). The colonic expression of HO-1 was determined by immunohistochemistry and western blotting using a monoclonal antibody against HO-1. RESULTS: The expression of ho-1 mRNA and HO-1 protein was significantly increased in the colonic mucosa of patients with active UC compared with normal mucosa. In the patients with active UC, mononuclear cells in the submucosa of the colon were positive for HO-1, and there was negligible staining in the epithelial cells. CONCLUSION: The present findings are evidence of the induction of HO-1 in the colon of UC patients.


Asunto(s)
Colitis Ulcerosa/enzimología , Colon/enzimología , Hemo-Oxigenasa 1/análisis , Mucosa Intestinal/enzimología , Adulto , Anciano , Biopsia , Estudios de Casos y Controles , Colitis Ulcerosa/patología , Colon/patología , Colonoscopía , Femenino , Hemo-Oxigenasa 1/genética , Humanos , Mucosa Intestinal/patología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , ARN Mensajero/análisis , Índice de Severidad de la Enfermedad , Regulación hacia Arriba , Adulto Joven
19.
J Gastroenterol Hepatol ; 23 Suppl 2: S250-7, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19120907

RESUMEN

BACKGROUND AND AIM: Induction of inducible nitric oxide synthase (iNOS) may be involved in carcinogenesis of the stomach, because nitric oxide (NO) derived from iNOS can exert DNA damage and post-transcriptional modification of target proteins. In the present study, we investigated the correlation between endoscopic findings and iNOS mRNA expression/NO-modified proteins in the gastric mucosa. METHODS: Fifty patients were prospectively selected from subjects who underwent upper gastrointestinal chromoendoscopy screening for abdominal complaints. The Helicobacter pylori (H. pylori) status of patients was determined by anti-H. pylori IgG antibody levels. We classified the mucosal area of the fundus as F0, fine small granules; F1, edematous large granules without a sulcus between granules; F2, reduced-size granules with a sulcus between granules; and F3, irregular-sized granules with extended sulcus between granules. Gastritis was graded using the visual analog scale of the Updated Sydney System. The expression of interleukin (IL)-8 and iNOS mRNA was assayed in gastric biopsy specimens by reverse transcription-polymerase chain reaction. NO-modified proteins were analyzed by Western blotting using novel monoclonal antibodies against nitrotyrosine. RESULTS: A total of 91.7% (11/12) of the F0 group was H. pylori-negative, whereas 94.7% (36/38) of the F1-3 groups was H. pylori-positive. Spearman's analysis showed good correlation between the endoscopic grading and the score of chronic inflammation (r=0.764) and glandular atrophy (r=0.751). The expression of IL-8 mRNA was significantly increased in F1, F2, and F3 cases compared with the F0 group, with no significant differences among them. iNOS mRNA was significantly increased in the F3 group compared with the other groups, with increased nitration of tyrosine residues of proteins. CONCLUSION: The proposed classification by chromoendoscopy is useful for screening patients for atrophic and iNOS-expressing gastric mucosa with NO-modified proteins in H. pylori-associated atrophic gastric mucosa.


Asunto(s)
Mucosa Gástrica/enzimología , Gastritis Atrófica/enzimología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/patogenicidad , Óxido Nítrico Sintasa de Tipo II/análisis , Tirosina/análogos & derivados , Anticuerpos Antibacterianos/sangre , Atrofia , Biomarcadores/análisis , Mucosa Gástrica/microbiología , Mucosa Gástrica/patología , Gastritis Atrófica/microbiología , Gastritis Atrófica/patología , Gastroscopía/métodos , Infecciones por Helicobacter/enzimología , Infecciones por Helicobacter/patología , Helicobacter pylori/inmunología , Humanos , Interleucina-8/análisis , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Estudios Prospectivos , Proteínas/metabolismo , ARN Mensajero/análisis , Índice de Severidad de la Enfermedad , Tirosina/análisis
20.
ChemSusChem ; 10(2): 425-433, 2017 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-27878983

RESUMEN

Enzymatic catalysis is an ecofriendly strategy for the production of high-value low-molecular-weight aromatic compounds from lignin. Although well-definable aromatic monomers have been obtained from synthetic lignin-model dimers, enzymatic-selective synthesis of platform monomers from natural lignin has not been accomplished. In this study, we successfully achieved highly specific synthesis of aromatic monomers with a phenylpropane structure directly from natural lignin using a cascade reaction of ß-O-4-cleaving bacterial enzymes in one pot. Guaiacylhydroxylpropanone (GHP) and the GHP/syringylhydroxylpropanone (SHP) mixture are exclusive monomers from lignin isolated from softwood (Cryptomeria japonica) and hardwood (Eucalyptus globulus). The intermediate products in the enzymatic reactions show the capacity to accommodate highly heterologous substrates at the substrate-binding sites of the enzymes. To demonstrate the applicability of GHP as a platform chemical for bio-based industries, we chemically generate value-added GHP derivatives for bio-based polymers. Together with these chemical conversions for the valorization of lignin-derived phenylpropanone monomers, the specific and enzymatic production of the monomers directly from natural lignin is expected to provide a new stream in "white biotechnology" for sustainable biorefineries.


Asunto(s)
Acetona/química , Biocatálisis , Glutatión Transferasa/metabolismo , Lignina/química , Propiofenonas/química , Cryptomeria/enzimología , Eucalyptus/enzimología , Concentración de Iones de Hidrógeno , Temperatura
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