RESUMO
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.
Assuntos
Líquidos Iônicos , Líquidos Iônicos/química , Amidas , Espalhamento a Baixo Ângulo , Raios X , Difração de Raios X , Espectroscopia de Ressonância Magnética/métodos , Solventes , Polímeros/químicaRESUMO
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.
Assuntos
Regiões 3' não Traduzidas , Proteínas do Tecido Nervoso/metabolismo , Estabilidade de RNA , RNA Mensageiro/metabolismo , Ataxinas , Sítios de Ligação , Proteínas ELAV/metabolismo , Regulação da Expressão Gênica , Ontologia Genética , Células HEK293 , Humanos , Mutação , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Peptídeos/genética , Ligação Proteica , Biossíntese de Proteínas , Estrutura Terciária de Proteína , RNA Mensageiro/genéticaRESUMO
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.
Assuntos
Terapia Cognitivo-Comportamental/métodos , Jogo de Azar/terapia , Intervenção Baseada em Internet , Aplicativos Móveis , Adulto , Método Duplo-Cego , Feminino , Jogo de Azar/psicologia , Humanos , Masculino , Fatores Socioeconômicos , TelemedicinaRESUMO
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 CâO 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.
Assuntos
Derivados da Hipromelose/química , Polímeros/química , Espectroscopia de Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
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).
Assuntos
Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Proteínas Luminescentes/metabolismo , Neurônios/citologia , Neurônios/fisiologia , Optogenética/métodos , Animais , Rastreamento de Células/métodos , Células Cultivadas , Drosophila , Luz , Proteínas Luminescentes/genética , Microscopia de Fluorescência/métodos , Engenharia de Proteínas/métodos , Ratos , Peixe-ZebraRESUMO
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.
Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Flores/genética , Proteínas de Homeodomínio/genética , Mutação , Epiderme Vegetal/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Flores/anatomia & histologia , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Plantas Geneticamente ModificadasRESUMO
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.
Assuntos
Sepse/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Animais , Ceco/microbiologia , Modelos Animais de Doenças , Endotoxemia/sangue , Humanos , Inflamação/sangue , Lipopolissacarídeos/toxicidade , Camundongos , Fator de Crescimento Placentário , Proteínas da Gravidez/sangue , Sepse/mortalidadeRESUMO
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.
Assuntos
Anti-Inflamatórios não Esteroides , Hemopexina/metabolismo , Íleo/metabolismo , Indometacina , Mucosa Intestinal/metabolismo , Jejuno/metabolismo , Úlcera Péptica/metabolismo , Animais , Western Blotting , Modelos Animais de Doenças , Eletroforese em Gel Bidimensional , Íleo/patologia , Imuno-Histoquímica , Mucosa Intestinal/patologia , Jejuno/patologia , Masculino , Úlcera Péptica/induzido quimicamente , Úlcera Péptica/patologia , Mapeamento de Peptídeos , Proteômica/métodos , Ratos , Ratos Wistar , Índice de Gravidade de Doença , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fatores de Tempo , Regulação para CimaRESUMO
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.
Assuntos
Bezafibrato/farmacologia , Ácido Clofíbrico/farmacologia , Ativadores de Enzimas/farmacologia , Fenofibrato/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/enzimologia , Estearoil-CoA Dessaturase/metabolismo , Animais , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Estearoil-CoA Dessaturase/genéticaRESUMO
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.
Assuntos
Canais de Cálcio/metabolismo , Células Epiteliais/metabolismo , Esôfago/metabolismo , Interleucina-8/metabolismo , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Canais de Cátion TRPV/metabolismo , Ácidos/farmacologia , Aldeídos/farmacologia , Animais , Canais de Cálcio/efeitos dos fármacos , Capsaicina/farmacologia , Linhagem Celular , Esôfago/citologia , Humanos , Interleucina-8/efeitos dos fármacos , Masculino , Mucosa/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Ratos , Ratos Wistar , Canais de Cátion TRPV/efeitos dos fármacosRESUMO
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.
Assuntos
Colite Ulcerativa/metabolismo , Colo/metabolismo , Eletroforese em Gel Bidimensional , Mediadores da Inflamação/metabolismo , Proteínas/metabolismo , Proteômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Animais , Colite Ulcerativa/induzido quimicamente , Sulfato de Dextrana , Modelos Animais de Doenças , Feminino , Fluorescência , Hidroximetilglutaril-CoA Sintase/metabolismo , Mucosa Intestinal/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Mapeamento de Peptídeos , Peroxirredoxina VI/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Serpinas/metabolismo , Vimentina/metabolismoRESUMO
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.
Assuntos
Isótopos de Carbono/química , Química Farmacêutica/métodos , Força Compressiva , Cristalização/métodos , Felodipino/química , Polímeros/química , Antiarrítmicos/análise , Antiarrítmicos/química , Isótopos de Carbono/análise , Portadores de Fármacos/análise , Portadores de Fármacos/química , Felodipino/análise , Previsões , Polímeros/análiseRESUMO
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.
Assuntos
Portadores de Fármacos/química , Nifedipino/administração & dosagem , Polímeros/química , Química Farmacêutica , Liberação Controlada de Fármacos , Derivados da Hipromelose/química , Espectroscopia de Ressonância Magnética , Nifedipino/química , Ácidos Polimetacrílicos/química , Água/química , MolhabilidadeRESUMO
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.
Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Mucosa Gástrica/metabolismo , Heme Oxigenase-1/biossíntese , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas/metabolismo , Inibidores da Bomba de Prótons/farmacologia , Animais , Linhagem Celular , Indução Enzimática/efeitos dos fármacos , Indução Enzimática/fisiologia , Mucosa Gástrica/citologia , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/enzimologia , Insetos , Peptídeos e Proteínas de Sinalização Intracelular , Proteína 1 Associada a ECH Semelhante a Kelch , Lansoprazol , Camundongos , Fator 2 Relacionado a NF-E2/fisiologia , Oxirredução/efeitos dos fármacos , RatosRESUMO
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.
Assuntos
Endotélio Vascular/metabolismo , Fragmentos de Peptídeos/fisiologia , Regiões Promotoras Genéticas/fisiologia , Receptores de Superfície Celular/fisiologia , Animais , Sequência de Bases , Caderinas/metabolismo , Células Cultivadas , Clonagem Molecular , DNA/genética , Análise Mutacional de DNA , Endotélio Vascular/citologia , Fator de Transcrição de Proteínas de Ligação GA/fisiologia , Regulação da Expressão Gênica , Humanos , Óperon Lac , Camundongos , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/farmacologia , Receptores de Superfície Celular/genética , Análise de Sequência de DNA , Fator de Transcrição Sp1/fisiologia , TransfecçãoRESUMO
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.
Assuntos
Quitina/metabolismo , Muramidase/metabolismo , Ralstonia/enzimologia , Sequência de Aminoácidos/genética , Sequência de Bases , Clonagem Molecular , DNA Bacteriano/química , DNA Bacteriano/genética , Expressão Gênica , Dados de Sequência Molecular , Muramidase/genética , Muramidase/isolamento & purificação , Fases de Leitura Aberta , Sinais Direcionadores de Proteínas , Estrutura Terciária de Proteína , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Especificidade por SubstratoRESUMO
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.
Assuntos
Sepse/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/sangue , APACHE , Idoso , Serviço Hospitalar de Emergência , Humanos , Interleucina-1/sangue , Interleucina-6/sangue , Pessoa de Meia-Idade , Estudos Prospectivos , Sepse/patologia , Solubilidade , Fatores de TempoRESUMO
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.
Assuntos
Colite Ulcerativa/enzimologia , Colo/enzimologia , Heme Oxigenase-1/análise , Mucosa Intestinal/enzimologia , Adulto , Idoso , Biópsia , Estudos de Casos e Controles , Colite Ulcerativa/patologia , Colo/patologia , Colonoscopia , Feminino , Heme Oxigenase-1/genética , Humanos , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , RNA Mensageiro/análise , Índice de Gravidade de Doença , Regulação para Cima , Adulto JovemRESUMO
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.
Assuntos
Mucosa Gástrica/enzimologia , Gastrite Atrófica/enzimologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/patogenicidade , Óxido Nítrico Sintase Tipo II/análise , Tirosina/análogos & derivados , Anticorpos Antibacterianos/sangue , Atrofia , Biomarcadores/análise , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Gastrite Atrófica/microbiologia , Gastrite Atrófica/patologia , Gastroscopia/métodos , Infecções por Helicobacter/enzimologia , Infecções por Helicobacter/patologia , Helicobacter pylori/imunologia , Humanos , Interleucina-8/análise , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Estudos Prospectivos , Proteínas/metabolismo , RNA Mensageiro/análise , Índice de Gravidade de Doença , Tirosina/análiseRESUMO
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.