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1.
Am J Physiol Endocrinol Metab ; 315(1): E63-E71, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29351479

RESUMEN

An increased contribution of de novo lipogenesis (DNL) may play a role in cases of dyslipidemia and adipose accretion; this suggests that inhibition of fatty acid synthesis may affect clinical phenotypes. Since it is not clear whether modulation of one step in the lipogenic pathway is more important than another, the use of tracer methods can provide a deeper level of insight regarding the control of metabolic activity. Although [2H]water is generally considered a reliable tracer for quantifying DNL in vivo (it yields a homogenous and quantifiable precursor labeling), the relatively long half-life of body water is thought to limit the ability of performing repeat studies in the same subjects; this can create a bottleneck in the development and evaluation of novel therapeutics for inhibiting DNL. Herein, we demonstrate the ability to perform back-to-back studies of DNL using [2H]water. However, this work uncovered special circumstances that affect the data interpretation, i.e., it is possible to obtain seemingly negative values for DNL. Using a rodent model, we have identified a physiological mechanism that explains the data. We show that one can use [2H]water to test inhibitors of DNL by performing back-to-back studies in higher species [i.e., treat nonhuman primates with platensimycin, an inhibitor of fatty acid synthase]; studies also demonstrate the unsuitability of [13C]acetate.


Asunto(s)
Óxido de Deuterio/farmacología , Ácido Palmítico/sangre , Acetatos/sangre , Adipogénesis , Animales , Femenino , Semivida , Lipogénesis/efectos de los fármacos , Macaca mulatta , Masculino , Ratones Endogámicos C57BL
2.
J Pharmacol Exp Ther ; 361(2): 229-244, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28193636

RESUMEN

Reversible janus associated kinase (JAK) inhibitors such as tofacitinib and decernotinib block cytokine signaling and are efficacious in treating autoimmune diseases. However, therapeutic doses are limited due to inhibition of other JAK/signal transducer and activator of transcription pathways associated with hematopoiesis, lipid biogenesis, infection, and immune responses. A selective JAK3 inhibitor may have a better therapeutic index; however, until recently, no compounds have been described that maintain JAK3 selectivity in cells, as well as against the kinome, with good physicochemical properties to test the JAK3 hypothesis in vivo. To quantify the biochemical basis for JAK isozyme selectivity, we determined that the apparent Km value for each JAK isozyme ranged from 31.8 to 2.9 µM for JAK1 and JAK3, respectively. To confirm compound activity in cells, we developed a novel enzyme complementation assay that read activity of single JAK isozymes in a cellular context. Reversible JAK3 inhibitors cannot achieve sufficient selectivity against other isozymes in the cellular context due to inherent differences in enzyme ATP Km values. Therefore, we developed irreversible JAK3 compounds that are potent and highly selective in vitro in cells and against the kinome. Compound 2, a potent inhibitor of JAK3 (0.15 nM) was 4300-fold selective for JAK3 over JAK1 in enzyme assays, 67-fold [interleukin (IL)-2 versus IL-6] or 140-fold [IL-2 versus erythropoietin or granulocyte-macrophage colony-stimulating factor (GMCSF)] selective in cellular reporter assays and >35-fold selective in human peripheral blood mononuclear cell assays (IL-7 versus IL-6 or GMCSF). In vivo, selective JAK3 inhibition was sufficient to block the development of inflammation in a rat model of rheumatoid arthritis, while sparing hematopoiesis.


Asunto(s)
Enfermedades Autoinmunes , Janus Quinasa 1 , Janus Quinasa 3 , Piperidinas/farmacología , Pirimidinas/farmacología , Pirroles/farmacología , Animales , Artritis Experimental/tratamiento farmacológico , Enfermedades Autoinmunes/tratamiento farmacológico , Enfermedades Autoinmunes/metabolismo , Relación Dosis-Respuesta a Droga , Monitoreo de Drogas/métodos , Humanos , Isoenzimas , Janus Quinasa 1/antagonistas & inhibidores , Janus Quinasa 1/química , Janus Quinasa 1/metabolismo , Janus Quinasa 3/antagonistas & inhibidores , Janus Quinasa 3/química , Janus Quinasa 3/metabolismo , Monitorización Inmunológica/métodos , Inhibidores de Proteínas Quinasas/farmacología , Ratas
3.
Am J Physiol Endocrinol Metab ; 311(6): E911-E921, 2016 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-27651111

RESUMEN

Aberrant regulation of glucose production makes a critical contribution to the impaired glycemic control that is observed in type 2 diabetes. Although isotopic tracer methods have proven to be informative in quantifying the magnitude of such alterations, it is presumed that one must rely on venous access to administer glucose tracers which therein presents obstacles for the routine application of tracer methods in rodent models. Since intraperitoneal injections are readily used to deliver glucose challenges and/or dose potential therapeutics, we hypothesized that this route could also be used to administer a glucose tracer. The ability to then reliably estimate glucose flux would require attention toward setting a schedule for collecting samples and choosing a distribution volume. For example, glucose production can be calculated by multiplying the fractional turnover rate by the pool size. We have taken a step-wise approach to examine the potential of using an intraperitoneal tracer administration in rat and mouse models. First, we compared the kinetics of [U-13C]glucose following either an intravenous or an intraperitoneal injection. Second, we tested whether the intraperitoneal method could detect a pharmacological manipulation of glucose production. Finally, we contrasted a potential application of the intraperitoneal method against the glucose-insulin clamp. We conclude that it is possible to 1) quantify glucose production using an intraperitoneal injection of tracer and 2) derive a "glucose production index" by coupling estimates of basal glucose production with measurements of fasting insulin concentration; this yields a proxy for clamp-derived assessments of insulin sensitivity of endogenous production.


Asunto(s)
Glucemia/metabolismo , Indicadores y Reactivos , Animales , Glucemia/efectos de los fármacos , Isótopos de Carbono , Dieta Alta en Grasa , Femenino , Técnica de Clampeo de la Glucosa , Hipoglucemiantes/farmacología , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Resistencia a la Insulina , Cinética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Proyectos Piloto , Ratas , Ratas Sprague-Dawley , Ratas Zucker , Rosiglitazona , Tiazolidinedionas/farmacología
4.
Mol Syst Biol ; 8: 594, 2012 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-22806142

RESUMEN

Common inflammatome gene signatures as well as disease-specific signatures were identified by analyzing 12 expression profiling data sets derived from 9 different tissues isolated from 11 rodent inflammatory disease models. The inflammatome signature significantly overlaps with known drug targets and co-expressed gene modules linked to metabolic disorders and cancer. A large proportion of genes in this signature are tightly connected in tissue-specific Bayesian networks (BNs) built from multiple independent mouse and human cohorts. Both the inflammatome signature and the corresponding consensus BNs are highly enriched for immune response-related genes supported as causal for adiposity, adipokine, diabetes, aortic lesion, bone, muscle, and cholesterol traits, suggesting the causal nature of the inflammatome for a variety of diseases. Integration of this inflammatome signature with the BNs uncovered 151 key drivers that appeared to be more biologically important than the non-drivers in terms of their impact on disease phenotypes. The identification of this inflammatome signature, its network architecture, and key drivers not only highlights the shared etiology but also pinpoints potential targets for intervention of various common diseases.


Asunto(s)
Perfilación de la Expresión Génica , Inflamasomas/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/inmunología , Factores de Edad , Análisis de Varianza , Animales , Teorema de Bayes , Caspasas/genética , Caspasas/inmunología , Quimiocinas/genética , Quimiocinas/inmunología , Estudios de Cohortes , Biología Computacional/métodos , Modelos Animales de Enfermedad , Femenino , Redes Reguladoras de Genes/inmunología , Humanos , Interleucinas/genética , Interleucinas/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Ratas , Ratas Sprague-Dawley , Factores Sexuales
5.
Am J Respir Cell Mol Biol ; 45(1): 81-7, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20855652

RESUMEN

Cathepsin S (Cat S) is predominantly expressed in antigen-presenting cells and is up-regulated in several preclinical models of antigen-induced inflammation, suggesting a role in the allergic response. Prophylactic dosing of an irreversible Cat S inhibitor has been shown to attenuate pulmonary eosinophilia in mice, supporting the hypothesis that Cat S inhibition before the initiation of airway inflammation is beneficial in airway disease. In addition, Cat S has been shown to play a role in more distal events in the allergic response. To determine where Cat S inhibition may affect the allergic response, we used complementary genetic and pharmacological approaches to investigate the role of Cat S in the early and downstream allergic events in a murine model of antigen-induced lung inflammation. Cat S knockout mice did not develop ovalbumin-induced pulmonary inflammation, consistent with a role for Cat S in the development of the allergic response. Alternatively, wild-type mice were treated with a reversible, highly selective Cat S inhibitor in prophylactic and therapeutic dosing paradigms and assessed for changes in airway inflammation. Although both treatment paradigms resulted in potent Cat S inhibition, only prophylactic Cat S inhibitor dosing blocked lung inflammation, consistent with our findings in Cat S knockout mice. The findings indicate that although Cat S is up-regulated in allergic models, it does not appear to play a significant role in the downstream effector inflammatory phase in this model; however, our results demonstrate that Cat S inhibition in a prophylactic paradigm would ameliorate airway inflammation.


Asunto(s)
Asma/prevención & control , Catepsinas/genética , Catepsinas/farmacología , Animales , Asma/genética , Asma/metabolismo , Catepsinas/biosíntesis , Modelos Animales de Enfermedad , Evaluación de Medicamentos , Humanos , Ratones , Ratones Noqueados , Ovalbúmina/efectos adversos , Ovalbúmina/farmacología , Eosinofilia Pulmonar/genética , Eosinofilia Pulmonar/metabolismo , Eosinofilia Pulmonar/prevención & control , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
6.
Mol Pharmacol ; 79(1): 69-76, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20943773

RESUMEN

The chemoattractant receptor-homologous molecule expressed on T-helper type 2 cells (CRTH2) is a G protein-coupled receptor that has been reported to modulate inflammatory responses in various rodent models of asthma, allergic rhinitis and atopic dermatitis. In this study, we describe the biological and pharmacological properties of {(7R)-7-[[(4-fluorophenyl)sulfonyl](methyl)amino]-6,7,8,9-tetrahydropyrido[1,2-a]indol-10-yl}acetic acid (MK-7246), a novel synthetic CRTH2 antagonist. We show that MK-7246 1) has high affinity for the human, monkey, dog, rat, and mouse CRTH2, 2) interacts with CRTH2 in a reversible manner, 3) exhibits high selectivity over all prostanoid receptors as well as 157 other receptors and enzymes, 4) acts as a full antagonist on recombinant and endogenously expressed CRTH2, 5) demonstrates good oral bioavailability and metabolic stability in various animal species, 6) yields ex vivo blockade of CRTH2 on eosinophils in monkeys and sheep, and 7) significantly blocks antigen-induced late-phase bronchoconstriction and airway hyper-responsiveness in sheep. MK-7246 represents a potent and selective tool to further investigate the in vivo function of CRTH2.


Asunto(s)
Carbolinas/química , Carbolinas/farmacología , Receptores Inmunológicos/antagonistas & inhibidores , Receptores Inmunológicos/biosíntesis , Receptores de Prostaglandina/antagonistas & inhibidores , Receptores de Prostaglandina/biosíntesis , Células Th2/metabolismo , Animales , Perros , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/inmunología , Células HEK293 , Humanos , Macaca fascicularis , Ratones , Inhibidores de Agregación Plaquetaria/farmacología , Unión Proteica/inmunología , Ratas , Receptores Inmunológicos/metabolismo , Receptores Inmunológicos/fisiología , Receptores de Prostaglandina/metabolismo , Receptores de Prostaglandina/fisiología , Ovinos , Especificidad de la Especie , Células Th2/efectos de los fármacos
7.
J Biol Chem ; 285(52): 40838-51, 2010 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-20959461

RESUMEN

Although the mechanisms that regulate folding and maturation of newly synthesized G protein-coupled receptors are crucial for their function, they remain poorly characterized. By yeast two-hybrid screening, we have isolated ANKRD13C, a protein of unknown function, as an interacting partner for the DP receptor for prostaglandin D(2). In the present study we report the characterization of this novel protein as a regulator of DP biogenesis and trafficking in the biosynthetic pathway. Co-localization by confocal microscopy with an endoplasmic reticulum (ER) marker, subcellular fractionation experiments, and demonstration of the interaction between ANKRD13C and the cytoplasmic C terminus of DP suggest that ANKRD13C is a protein associated with the cytosolic side of ER membranes. Co-expression of ANKRD13C with DP initially increased receptor protein levels, whereas siRNA-mediated knockdown of endogenous ANKRD13C decreased them. Pulse-chase experiments indicated that ANKRD13C can promote the biogenesis of DP by inhibiting the degradation of newly synthesized receptors. However, a prolonged interaction between ANKRD13C and DP resulted in ER retention of misfolded/unassembled forms of the receptor and to their proteasome-mediated degradation. ANKRD13C also regulated the expression of other GPCRs tested (CRTH2, thromboxane A(2) (TPα), and ß2-adrenergic receptor), whereas it did not affect the expression of green fluorescent protein, GRK2 (G protein-coupled receptor kinase 2), and VSVG (vesicular stomatitis virus glycoprotein), showing specificity toward G protein-coupled receptors. Altogether, these results suggest that ANKRD13C acts as a molecular chaperone for G protein-coupled receptors, regulating their biogenesis and exit from the ER.


Asunto(s)
Retículo Endoplásmico/metabolismo , Membranas Intracelulares/metabolismo , Proteínas de la Membrana/metabolismo , Chaperonas Moleculares/metabolismo , Pliegue de Proteína , Receptores Acoplados a Proteínas G/biosíntesis , Retículo Endoplásmico/genética , Células HEK293 , Humanos , Proteínas de la Membrana/genética , Chaperonas Moleculares/genética , Estructura Terciaria de Proteína , Transporte de Proteínas/fisiología , ARN Interferente Pequeño , Receptores Acoplados a Proteínas G/genética
8.
Bioorg Med Chem Lett ; 21(1): 288-93, 2011 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21106375

RESUMEN

In this manuscript we wish to report the discovery of MK-7246 (4), a potent and selective CRTH2 (DP2) antagonist. SAR studies leading to MK-7246 along with two synthetic sequences enabling the preparation of this novel class of CRTH2 antagonist are reported. Finally, the pharmacokinetic and metabolic profile of MK-7246 is disclosed.


Asunto(s)
Carbolinas/química , Enfermedades Pulmonares/tratamiento farmacológico , Receptores Inmunológicos/antagonistas & inhibidores , Receptores de Prostaglandina/antagonistas & inhibidores , Animales , Carbolinas/farmacocinética , Carbolinas/uso terapéutico , Humanos , Macaca mulatta , Microsomas Hepáticos/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores Inmunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Relación Estructura-Actividad
10.
NMR Biomed ; 22(5): 502-15, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19204996

RESUMEN

Hyperpolarized (HP) (3)He magnetic resonance imaging has been recently used to produce high-resolution images of pulmonary ventilation after methacholine (MCh) challenge in mouse models of allergic inflammation. This capability presents an opportunity to gain new insights about these models and to more sensitively evaluate new drug treatments in the pre-clinical setting. In the current study, we present our initial experience using two-dimensional (2D), time-resolved (3)He MRI of MCh challenge-induced airways hyperreactivity (AHR) to compare ovalbumin-sensitized and challenged (N = 8) mice to controls (N = 8). Imaging demonstrated that ovalbumin-sensitized and challenged animals exhibited many large ventilation defects even prior to MCh challenge (four out of eight) compared to no defects in the control animals. Additionally, the ovalbumin-sensitized and challenged animals experienced a greater number of ventilation defects (4.5 +/- 0.4) following MCh infusion than did controls (3.3 +/- 0.6). However, due to variability in MCh delivery that was specific to the small animal MRI environment, the difference in mean defect number was not statistically significant. These findings are reviewed in detail and a comprehensive solution to the variability problem is presented that has greatly enhanced the magnitude and reproducibility of the MCh response. This has permitted us to develop a new imaging protocol consisting of a baseline 3D image, a time-resolved 2D series during MCh challenge, and a post-MCh 3D image that reveals persistent ventilation defects.


Asunto(s)
Asma/patología , Helio/química , Imagen por Resonancia Magnética/métodos , Cloruro de Metacolina/administración & dosificación , Cloruro de Metacolina/farmacología , Animales , Asma/fisiopatología , Líquido del Lavado Bronquioalveolar/citología , Broncoconstricción/efectos de los fármacos , Recuento de Células , Modelos Animales de Enfermedad , Sistemas de Liberación de Medicamentos , Frecuencia Cardíaca/efectos de los fármacos , Imagenología Tridimensional , Bombas de Infusión , Pulmón/efectos de los fármacos , Pulmón/patología , Ratones , Ovalbúmina/administración & dosificación , Ventilación Pulmonar/efectos de los fármacos , Reproducibilidad de los Resultados , Factores de Tiempo
12.
Am J Respir Cell Mol Biol ; 39(1): 26-35, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18258919

RESUMEN

Interleukin 13 (IL-13) is considered to be a key driver of the development of airway allergic inflammation and remodeling leading to airway hyperresponsiveness (AHR). How precisely IL-13 leads to the development of airway inflammation, AHR, and mucus production is not fully understood. In order to identify key mediators downstream of IL-13, we administered adenovirus IL-13 to specifically induce IL-13-dependent inflammation in the lungs of mice. This approach was shown to induce cardinal features of lung disease, specifically airway inflammation, elevated cytokines, AHR, and mucus secretion. Notably, the model is resistant to corticosteroid treatment and is characterized by marked neutrophilia, two hallmarks of more severe forms of asthma. To identify IL-13-dependent mediators, we performed a limited-scale two-dimensional SDS-PAGE proteomic analysis and identified proteins significantly modulated in this model. Intriguingly, several identified proteins were unique to this model, whereas others correlated with those modulated in a mouse ovalbumin-induced pulmonary inflammation model. We corroborated this approach by illustrating that proteomic analysis can identify known pathways/mediators downstream of IL-13. Thus, we have characterized a murine adenovirus IL-13 lung model that recapitulates specific disease traits observed in human asthma, and have exploited this model to identify effectors downstream of IL-13. Collectively, these findings will enable a broader appreciation of IL-13 and its impact on disease pathways in the lung.


Asunto(s)
Infecciones por Adenoviridae/fisiopatología , Adenoviridae , Obstrucción de las Vías Aéreas/inducido químicamente , Interleucina-13/efectos adversos , Adenoviridae/genética , Animales , Técnicas de Cultivo de Célula , División Celular , Modelos Animales de Enfermedad , Interleucina-13/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Moco/metabolismo , Ovalbúmina/efectos adversos , Pruebas de Función Respiratoria , Mucosa Respiratoria/citología , Mucosa Respiratoria/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
13.
J Med Chem ; 50(4): 794-806, 2007 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-17300164

RESUMEN

The discovery of the potent and selective prostaglandin D2 (PGD2) receptor (DP) antagonist [(3R)-4-(4-chlorobenzyl)-7-fluoro-5-(methylsulfonyl)-1,2,3,4-tetrahydrocyclopenta[b]indol-3-yl]-acetic acid (13) is presented. Initial lead antagonists 6 and 7 were found to be potent and selective DP antagonists (DP Ki = 2.0 nM for each); however, they both suffered from poor pharmacokinetic profiles, short half-lives and high clearance rates in rats. Rat bile duct cannulation studies revealed that high concentrations of parent drug were present in the biliary fluid (Cmax = 1100 microM for 6 and 3900 microM for 7). This pharmacokinetic liability was circumvented by replacing the 7-methylsulfone substituent present in 6 and 7 with a fluorine atom resulting in antagonists with diminished propensity for biliary excretion and with superior pharmacokinetic profiles. Further optimization led to the discovery of the potent and selective DP antagonist 13.


Asunto(s)
Indoles/síntesis química , Receptores Inmunológicos/antagonistas & inhibidores , Receptores de Prostaglandina/antagonistas & inhibidores , Obstrucción de las Vías Aéreas/tratamiento farmacológico , Animales , Bilis/metabolismo , Unión Competitiva , Perros , Hepatocitos/metabolismo , Humanos , Técnicas In Vitro , Indoles/farmacocinética , Indoles/farmacología , Macaca fascicularis , Masculino , Ratones , Microsomas/metabolismo , Descongestionantes Nasales/síntesis química , Descongestionantes Nasales/farmacocinética , Descongestionantes Nasales/farmacología , Unión Proteica , Ratas , Ratas Sprague-Dawley , Ovinos , Estereoisomerismo , Relación Estructura-Actividad
14.
Eur J Pharmacol ; 557(2-3): 115-23, 2007 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-17207480

RESUMEN

Prostaglandin D2 (PGD2) exerts its actions on two G protein-coupled receptors, the prostanoid DP receptor and CRTH2 (chemoattractant homologous receptor expressed on TH2 cells). Here, we characterize the regulation of the signaling and trafficking of the prostanoid DP receptor and CRTH2. Time-course and dose-response curves showed that both receptors expressed in HEK293 cells internalized maximally after 2 h of stimulation with 1 microM PGD2. Co-expression of the G protein-coupled receptor kinases GRK2, GRK5 or GRK6 increased agonist-induced internalization of CRTH2, while only GRK2 had an effect on the internalization of the prostanoid DP receptor. Protein kinase C (PKC) activation stimulated the internalization of both receptors. Interestingly, only PGD2-induced internalization of CRTH2, and not of prostanoid DP receptor, was decreased by inhibition of PKC or protein kinase A (PKA). Our data also indicate that CRTH2 is subjected to basal phosphorylation by PKA, which appears to be involved in CRTH2 internalization. Prostanoid DP receptor internalization was promoted by co-expression of arrestin-2 and -3, while the internalization of CRTH2 was increased by co-expression of arrestin-3 only. The detection of prostanoid DP receptor and CRTH2 internalization was reduced by the co-expression of Rab4 and Rab11, respectively, suggesting differential regulation of receptor recycling. Moreover, immunofluorescence microscopy experiments showed that the prostanoid DP receptor specifically co-localized with Rab4, and CRTH2 with Rab11. The signaling of the prostanoid DP receptor was regulated by GRK2 overexpression, while that of CRTH2 was modulated by overexpression of GRK2, -5 and -6. Our results show a differential regulation of the prostanoid DP receptor and CRTH2, two receptors for PGD2.


Asunto(s)
Prostaglandina D2/farmacología , Receptores Inmunológicos/metabolismo , Receptores Inmunológicos/fisiología , Receptores de Prostaglandina/metabolismo , Receptores de Prostaglandina/fisiología , Línea Celular , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Relación Dosis-Respuesta a Droga , Activación Enzimática , Técnica del Anticuerpo Fluorescente Directa , Quinasa 2 del Receptor Acoplado a Proteína-G , Quinasa 5 del Receptor Acoplado a Proteína-G , Quinasas de Receptores Acoplados a Proteína-G , Humanos , Cinética , Microscopía Fluorescente , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores Inmunológicos/genética , Receptores de Prostaglandina/genética , Quinasas de Receptores Adrenérgicos beta/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Proteínas de Unión al GTP rab4/metabolismo
15.
J Appl Physiol (1985) ; 112(9): 1437-44, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22241062

RESUMEN

The purpose of this study was to assess the effects of corticosteroid therapy on a murine model of allergic asthma using hyperpolarized (3)He magnetic resonance imaging (MRI) and respiratory mechanics measurements before, during, and after methacholine (MCh) challenge. Three groups of mice were prepared, consisting of ovalbumin sensitized/ovalbumin challenged (Ova/Ova, n = 5), Ova/Ova challenged but treated with the corticosteroid dexamethasone (Ova/Ova+Dex, n = 3), and ovalbumin-sensitized/saline-challenged (Ova/PBS, n = 4) control animals. All mice underwent baseline 3D (3)He MRI, then received a MCh challenge while 10 2D (3)He MR images were acquired for 2 min, followed by post-MCh 3D (3)He MRI. Identically treated groups underwent respiratory mechanics evaluation (n = 4/group) and inflammatory cell counts (n = 4/group). Ova/Ova animals exhibited predominantly large whole lobar defects at baseline, with significantly higher ventilation defect percentage (VDP = 19 ± 4%) than Ova/PBS (+2 ± 1%, P = 0.01) animals. Such baseline defects were suppressed by dexamethasone (0%, P = 0.009). In the Ova/Ova group, MCh challenge increased VDP on both 2D (+30 ± 8%) and 3D MRI scans (+14 ± 2%). MCh-induced VDP changes were diminished in Ova/Ova+Dex animals on both 2D (+21 ± 9%, P = 0.63) and 3D scans (+7 ± 2%, P = 0.11) and also in Ova/PBS animals on 2D (+6 ± 3%, P = 0.07) and 3D (+4 ± 1%, P = 0.01) scans. Because MCh challenge caused near complete cessation of ventilation in four of five Ova/Ova animals, even as large airways remained patent, this implies that small airway (<188 µm) obstruction predominates in this model. This corresponds with respiratory mechanics observations that MCh challenge significantly increases elastance and tissue damping but only modestly affects Newtonian airway resistance.


Asunto(s)
Corticoesteroides/farmacología , Asma/tratamiento farmacológico , Dexametasona/farmacología , Helio , Hipersensibilidad/tratamiento farmacológico , Pulmón/efectos de los fármacos , Imagen por Resonancia Magnética , Mecánica Respiratoria/efectos de los fármacos , Resistencia de las Vías Respiratorias/efectos de los fármacos , Animales , Asma/inducido químicamente , Asma/inmunología , Asma/patología , Asma/fisiopatología , Pruebas de Provocación Bronquial , Líquido del Lavado Bronquioalveolar/inmunología , Broncoconstricción/efectos de los fármacos , Broncoconstrictores , Modelos Animales de Enfermedad , Elasticidad , Hipersensibilidad/etiología , Hipersensibilidad/inmunología , Hipersensibilidad/patología , Hipersensibilidad/fisiopatología , Isótopos , Pulmón/inmunología , Pulmón/patología , Pulmón/fisiopatología , Masculino , Cloruro de Metacolina , Ratones , Ratones Endogámicos BALB C , Modelos Biológicos , Ovalbúmina , Ventilación Pulmonar/efectos de los fármacos
16.
J Biol Chem ; 281(34): 24704-12, 2006 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-16790440

RESUMEN

Neuropeptide S (NPS) and its receptor (NPSR) are thought to have a role in asthma pathogenesis; a number of single nucleotide polymorphisms within NPSR have been shown to be associated with an increased prevalance of asthma. One such single nucleotide polymorphism leads to the missense mutation N107I, which results in an increase in the potency of NPS for NPSR. To gain insight into structure-function relationships within NPS and NPSR, we first carried out a limited structural characterization of NPS and subjected the peptide to extensive mutagenesis studies. Our results show that the NH(2)-terminal third of NPS, in particular residues Phe-2, Arg-3, Asn-4, and Val-6, are necessary and sufficient for activation of NPSR. Furthermore, part of a nascent helix within the peptide, spanning residues 5 through 13, acts as a regulatory region that inhibits receptor activation. Notably, this inhibition is absent in the asthma-linked N107I variant of NPSR, suggesting that residue 107 interacts with the aforementioned regulatory region of NPS. Whereas this interaction may be at the root of the increase in potency associated with the N107I variant, we show here that the mutation also causes an increase in cell-surface expression of the mutant receptor, leading to a concomitant increase in the maximal efficacy (E(max)) of NPS. Our results identify the key residues of NPS involved in NPSR activation and suggest a molecular basis for the functional effects of the N107I mutation and for its putative pathophysiological link with asthma.


Asunto(s)
Receptores de Neuropéptido/química , Secuencia de Aminoácidos , Asma/genética , Asma/metabolismo , Línea Celular , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Neuropéptidos/química , Neuropéptidos/genética , Neuropéptidos/metabolismo , Unión Proteica , Conformación Proteica , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropéptido/genética , Receptores de Neuropéptido/metabolismo , Relación Estructura-Actividad , Transfección
17.
Bioorg Med Chem Lett ; 16(11): 3043-8, 2006 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-16529930

RESUMEN

A novel indole series of PGD2 receptor (DP receptor) antagonists is presented. Optimization of this series led to the identification of potent and selective DP receptor antagonists. In particular, antagonists 35 and 36 were identified with Ki values of 2.6 and 1.8 nM, respectively. These two antagonists are also potent in a DP functional assay where they inhibit the PGD2 induced cAMP production in platelet rich plasma with IC50 values of 7.9 and 8.6 nM, respectively. The structure-activity relationships of this indole series of DP receptor antagonists will also be discussed.


Asunto(s)
Indoles/química , Indoles/farmacología , Receptores Inmunológicos/antagonistas & inhibidores , Receptores de Prostaglandina/antagonistas & inhibidores , Indoles/síntesis química , Estructura Molecular , Receptores Inmunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Safrol/análogos & derivados , Safrol/química , Relación Estructura-Actividad
18.
Bioorg Med Chem Lett ; 16(21): 5639-42, 2006 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-16931013

RESUMEN

Two different series of very potent and selective EP(3) antagonists have been reported: a novel series of ortho-substituted cinnamic acids [Belley, M., Gallant, M., Roy, B., Houde, K., Lachance, N., Labelle, M., Trimble, L., Chauret, N., Li, C., Sawyer, N., Tremblay, N., Lamontagne, S., Carrière, M.-C., Denis, D., Greig, G. M., Slipetz, D., Metters, K. M., Gordon, R., Chan, C. C., Zamboni, R. J. Bioorg. Med. Chem. Lett.2005, 15, 527] and the acylsulfonamides of ortho-(arylmethyl)cinnamates. [(a) Juteau, H., Gareau, Y., Labelle, M., Sturino, C. F., Sawyer, N., Tremblay, N., Lamontagne, S., Carrière, M.-C., Denis, D., Metters, K. M. Bioorg. Med. Chem. 2001, 9, 1977; (b) Juteau, H., Gareau, Y., Labelle, M., Lamontagne, S., Tremblay, N., Carrière, M.-C., Denis, D., Sawyer, N., Metters, K. M. Bioorg. Med. Chem. Lett.2001, 11, 747] The structural differences between the two series, along with their biological activity in vivo, in vitro, and metabolism, are analyzed. Some of those compounds, including hybrids containing the best structural features of both series, possess K(i) as low as 0.6 nM on the EP(3) receptor.


Asunto(s)
Cinamatos/farmacología , Receptores de Prostaglandina E/antagonistas & inhibidores , Sulfonamidas/farmacología , Cinamatos/química , Humanos , Sulfonamidas/química
19.
Am J Respir Cell Mol Biol ; 33(3): 303-14, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15947424

RESUMEN

Overexpression of Gob-5 has previously been linked to goblet cell metaplasia and mucin overproduction in both in vitro and in vivo model systems. In this study, Gob-5 knockout mice were generated and their phenotype was evaluated in two established preclinical models of allergic asthma. We sought to determine whether the Gob-5-null animals could produce less mucus in response to allergic challenge, and whether this would have any impact on reducing goblet cell metaplasia and airway inflammation. We found that in the absence of a proinflammatory stimulus we could not detect an overt phenotypic difference between age and sex-matched knockout and wild-type animals. Allergic challenge with ovalbumin or intranasal administration of interleukin-13 produced a robust allergic response that was similar regardless of genotype. In addition, siRNA-mediated knockdown of CLCA-1 in cultured lung epithelial cells failed to reduce mucin expression in vitro. Thus, in contrast to previously published reports, our findings show that Gob-5 expression is not essential for mucin overproduction in vitro or in murine models of allergic asthma. Furthermore, we have also exploited the use of gene expression array analysis to investigate the possibility that a compensatory mechanism, involving other genes, may act to override the requirement for Gob-5-mediated mucus overproduction.


Asunto(s)
Asma/fisiopatología , Canales de Cloruro/genética , Canales de Cloruro/metabolismo , Mucoproteínas/genética , Mucoproteínas/metabolismo , Moco/metabolismo , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Tracto Gastrointestinal/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mucinas/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Interferente Pequeño , Mucosa Respiratoria/citología , Mucosa Respiratoria/fisiología
20.
Bioorg Med Chem Lett ; 15(3): 527-30, 2005 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-15664806

RESUMEN

A series of novel ortho-substituted cinnamic acids have been synthesized, and their binding activity and selectivity on the four prostaglandin E(2) receptors evaluated. Many of them are very potent and selective EP(3) antagonists (K(i) 3-10 nM), while compound 9 is a very good and selective EP(2) agonist (K(i) 8 nM). The biological profile of the EP(2) agonist 9 in vivo and the metabolic profile of selected EP(3) antagonists are also reported.


Asunto(s)
Cinamatos/síntesis química , Cinamatos/farmacología , Receptores de Prostaglandina E/antagonistas & inhibidores , Línea Celular , Cinamatos/metabolismo , AMP Cíclico/biosíntesis , Humanos , Farmacocinética , Unión Proteica , Subtipo EP2 de Receptores de Prostaglandina E , Subtipo EP3 de Receptores de Prostaglandina E , Relación Estructura-Actividad
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