RESUMO
AIM: When selecting treatments for type 2 diabetes (T2D), it is important to consider not only efficacy and safety, but also other treatment attributes that have an impact on patient preference. The objective of this study was to examine preference between injection devices used for two weekly GLP-1 receptor agonists. MATERIALS AND METHODS: The PREFER study was an open-label, multicentre, randomized, crossover study assessing patient preference for dulaglutide and semaglutide injection devices among injection-naïve patients receiving oral medication for type 2 diabetes. After being trained to use each device, participants performed all steps of injection preparation and administered mock injections into an injection pad. Time-to-train (TTT) for each device was assessed in a subset. RESULTS: There were 310 evaluable participants (48.4% female; mean age, 60.0 years; 78 participants in the TTT subgroup). More participants preferred the dulaglutide device than the semaglutide device (84.2% vs. 12.3%; P < 0.0001). More participants perceived the dulaglutide device to have greater ease of use (86.8% vs. 6.8%; P < 0.0001). After preparing and using the devices, more participants were willing to use the dulaglutide device (93.5%) than the semaglutide device (45.8%). Training participants to use the dulaglutide device required less time than the semaglutide device (3.38 vs. 8.14 minutes; P < 0.0001). CONCLUSIONS: Participants with type 2 diabetes preferred the dulaglutide injection device to the semaglutide injection device. If patients prefer a device, they may be more willing to use the medication, which could result in better health outcomes. Furthermore, a shorter training time for injection devices may be helpful in busy clinical practice settings.
Assuntos
Diabetes Mellitus Tipo 2 , Estudos Cross-Over , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Peptídeos Semelhantes ao Glucagon/análogos & derivados , Humanos , Hipoglicemiantes , Fragmentos Fc das Imunoglobulinas , Masculino , Pessoa de Meia-Idade , Preferência do Paciente , Proteínas Recombinantes de FusãoRESUMO
Traditionally, G-protein-coupled receptors (GPCR) are thought to be located on the cell surface where they transmit extracellular signals to the cytoplasm. However, recent studies indicate that some GPCRs are also localized to various subcellular compartments such as the nucleus where they appear required for various biological functions. For example, the metabotropic glutamate receptor 5 (mGluR5) is concentrated at the inner nuclear membrane (INM) where it mediates Ca2+ changes in the nucleoplasm by coupling with Gq/11 Here, we identified a region within the C-terminal domain (amino acids 852-876) that is necessary and sufficient for INM localization of the receptor. Because these sequences do not correspond to known nuclear localization signal motifs, they represent a new motif for INM trafficking. mGluR5 is also trafficked to the plasma membrane where it undergoes re-cycling/degradation in a separate receptor pool, one that does not interact with the nuclear mGluR5 pool. Finally, our data suggest that once at the INM, mGluR5 is stably retained via interactions with chromatin. Thus, mGluR5 is perfectly positioned to regulate nucleoplasmic Ca2+in situ.
Assuntos
Membrana Nuclear/metabolismo , Receptor de Glutamato Metabotrópico 5/química , Transporte Ativo do Núcleo Celular , Motivos de Aminoácidos , Animais , Cálcio/química , Membrana Celular/metabolismo , Cromatina/química , Corpo Estriado/citologia , Citoplasma/metabolismo , Recuperação de Fluorescência Após Fotodegradação , Glutamatos/química , Glicosilação , Complexo de Golgi/metabolismo , Células HEK293 , Humanos , Neurônios/metabolismo , Sinais de Localização Nuclear , Domínios Proteicos , RatosRESUMO
RATIONALE: Chronic obstructive pulmonary disease (COPD) is often unrecognized and untreated. OBJECTIVES: To develop a method for identifying undiagnosed COPD requiring treatment with currently available therapies (FEV1 <60% predicted and/or exacerbation risk). METHODS: We conducted a multisite, cross-sectional, case-control study in U.S. pulmonary and primary care clinics that recruited subjects from primary care settings. Cases were patients with COPD and at least one exacerbation in the past year or FEV1 less than 60% of predicted without exacerbation in the past year. Control subjects were persons with no COPD or with mild COPD (FEV1 ≥60% predicted, no exacerbation in the past year). In random forests analyses, we identified the smallest set of questions plus peak expiratory flow (PEF) with optimal sensitivity (SN) and specificity (SP). MEASUREMENTS AND MAIN RESULTS: PEF and spirometry were recorded in 186 cases and 160 control subjects. The mean (SD) age of the sample population was 62.7 (10.1) years; 55% were female; 86% were white; and 16% had never smoked. The mean FEV1 percent predicted for cases was 42.5% (14.2%); for control subjects, it was 82.5% (15.7%). A five-item questionnaire, CAPTURE (COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk), was used to assess exposure, breathing problems, tiring easily, and acute respiratory illnesses. CAPTURE exhibited an SN of 95.7% and an SP of 44.4% for differentiating cases from all control subjects, and an SN of 95.7% and an SP of 67.8% for differentiating cases from no-COPD control subjects. The PEF (males, <350 L/min; females, <250 L/min) SN and SP were 88.0% and 77.5%, respectively, for differentiating cases from all control subjects, and they were 88.0% and 90.8%, respectively, for distinguishing cases from no-COPD control subjects. The CAPTURE plus PEF exhibited improved SN and SP for all cases versus all control subjects (89.7% and 78.1%, respectively) and for all cases versus no-COPD control subjects (89.7% and 93.1%, respectively). CONCLUSIONS: CAPTURE with PEF can identify patients with COPD who would benefit from currently available therapy and require further diagnostic evaluation. Clinical trial registered with clinicaltrials.gov (NCT01880177).
Assuntos
Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Inquéritos e Questionários , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos Transversais , Feminino , Volume Expiratório Forçado , Humanos , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Pico do Fluxo Expiratório , Estudos Prospectivos , Fatores de Risco , Sensibilidade e Especificidade , EspirometriaRESUMO
The group 1 metabotropic glutamate receptor, mGluR5, is found on the cell surface as well as on intracellular membranes where it can mediate both overlapping and unique signaling effects. Previously we have shown that glutamate activates intracellular mGluR5 by entry through sodium-dependent transporters and/or cystine glutamate exchangers. Calibrated antibody labelling suggests that the glutamate concentration within neurons is quite high (~10 mM) raising the question as to whether intracellular mGluR5 is maximally activated at all times or whether a different ligand might be responsible for receptor activation. To address this issue, we used cellular, optical and molecular techniques to show that intracellular glutamate is largely sequestered in mitochondria; that the glutamate concentration necessary to activate intracellular mGluR5 is about ten-fold higher than what is necessary to activate cell surface mGluR5; and uncaging caged glutamate within neurons can directly activate the receptor. Thus these studies further the concept that glutamate itself serves as the ligand for intracellular mGluR5.
Assuntos
Corpo Estriado/metabolismo , Ácido Glutâmico/metabolismo , Líquido Intracelular/metabolismo , Receptor de Glutamato Metabotrópico 5/metabolismo , Animais , Animais Recém-Nascidos , Células Cultivadas , Corpo Estriado/citologia , Corpo Estriado/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ácido Glutâmico/farmacologia , Líquido Intracelular/efeitos dos fármacos , Ratos , Receptor de Glutamato Metabotrópico 5/agonistasRESUMO
Metabotropic glutamate receptor 5 (mGluR5) is widely expressed throughout the CNS and participates in regulating neuronal function and synaptic transmission. Recent work in the striatum led to the groundbreaking discovery that intracellular mGluR5 activation drives unique signaling pathways, including upregulation of ERK1/2, Elk-1 (Jong et al., 2009) and Arc (Kumar et al., 2012). To determine whether mGluR5 signals from intracellular membranes of other cell types, such as excitatory pyramidal neurons in the hippocampus, we used dissociated rat CA1 hippocampal cultures and slice preparations to localize and characterize endogenous receptors. As in the striatum, CA1 neurons exhibited an abundance of mGluR5 both on the cell surface and intracellular membranes, including the endoplasmic reticulum and the nucleus where it colocalized with the sodium-dependent excitatory amino acid transporter, EAAT3. Inhibition of EAAT3 or sodium-free buffer conditions prevented accumulations of radiolabeled agonist. Using a pharmacological approach to isolate different pools of mGluR5, both intracellular and cell surface receptors induced oscillatory Ca(2+) responses in dissociated CA1 neurons; however, only intracellular mGluR5 activation triggered sustained high amplitude Ca(2+) rises in dendrites. Consistent with the notion that mGluR5 can signal from intracellular membranes, uncaging glutamate on a CA1 dendrite led to a local Ca(2+) rise, even in the presence of ionotropic and cell surface metabotropic receptor inhibitors. Finally, activation of intracellular mGluR5 alone mediated both electrically induced and chemically induced long-term depression, but not long-term potentiation, in acute hippocampal slices. These data suggest a physiologically relevant and important role for intracellular mGluR5 in hippocampal synaptic plasticity.
Assuntos
Hipocampo/citologia , Líquido Intracelular/metabolismo , Plasticidade Neuronal/fisiologia , Neurônios/citologia , Receptor de Glutamato Metabotrópico 5/metabolismo , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Núcleo Celular/metabolismo , Células Cultivadas , Fármacos Atuantes sobre Aminoácidos Excitatórios/farmacologia , Transportador 3 de Aminoácido Excitatório/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Potenciais Pós-Sinápticos Inibidores/efeitos dos fármacos , Líquido Intracelular/efeitos dos fármacos , Plasticidade Neuronal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Ratos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Frações Subcelulares/ultraestruturaRESUMO
Toxoplasma gondii infection has been described previously to cause infected mice to lose their fear of cat urine. This behavioral manipulation has been proposed to involve alterations of host dopamine pathways due to parasite-encoded aromatic amino acid hydroxylases. Here, we report successful knockout and complementation of the aromatic amino acid hydroxylase AAH2 gene, with no observable phenotype in parasite growth or differentiation in vitro and in vivo. Additionally, expression levels of the two aromatic amino acid hydroxylases were negligible both in tachyzoites and in bradyzoites. Finally, we were unable to confirm previously described effects of parasite infection on host dopamine either in vitro or in vivo, even when AAH2 was overexpressed using the BAG1 promoter. Together, these data indicate that AAH enzymes in the parasite do not cause global or regional alterations of dopamine in the host brain, although they may affect this pathway locally. Additionally, our findings suggest alternative roles for the AHH enzymes in T. gondii, since AAH1 is essential for growth in nondopaminergic cells.
Assuntos
Encéfalo/metabolismo , Estágios do Ciclo de Vida , Oxigenases de Função Mista/genética , Proteínas de Protozoários/genética , Toxoplasma/crescimento & desenvolvimento , Toxoplasmose Animal/metabolismo , Animais , Gatos , Dopamina/metabolismo , Feminino , Deleção de Genes , Expressão Gênica , Interações Hospedeiro-Parasita , Isoenzimas/deficiência , Isoenzimas/genética , Camundongos , Oxigenases de Função Mista/deficiência , Plasmídeos , Regiões Promotoras Genéticas , Proteínas de Protozoários/metabolismo , Toxoplasma/enzimologia , Toxoplasma/genética , Toxoplasmose Animal/parasitologiaRESUMO
Although G protein-coupled receptors are primarily known for converting extracellular signals into intracellular responses, some receptors, such as the group 1 metabotropic glutamate receptor, mGlu5, are also localized on intracellular membranes where they can mediate both overlapping and unique signaling effects. Thus, besides "ligand bias," whereby a receptor's signaling modality can shift from G protein dependence to independence, canonical mGlu5 receptor signaling can also be influenced by "location bias" (i.e., the particular membrane and/or cell type from which it signals). Because mGlu5 receptors play important roles in both normal development and in disorders such as Fragile X syndrome, autism, epilepsy, addiction, anxiety, schizophrenia, pain, dyskinesias, and melanoma, a large number of drugs are being developed to allosterically target this receptor. Therefore, it is critical to understand how such drugs might be affecting mGlu5 receptor function on different membranes and in different brain regions. Further elucidation of the site(s) of action of these drugs may determine which signal pathways mediate therapeutic efficacy.
Assuntos
Receptor de Glutamato Metabotrópico 5/fisiologia , Receptores de Glutamato Metabotrópico/fisiologia , Transdução de Sinais/fisiologia , Animais , Arrestinas/fisiologia , Cálcio/metabolismo , Humanos , Fosforilação , Receptor de Glutamato Metabotrópico 5/análise , Receptor de Glutamato Metabotrópico 5/química , Receptor de Glutamato Metabotrópico 5/efeitos dos fármacos , Receptores de Glutamato Metabotrópico/análise , Receptores de Glutamato Metabotrópico/química , Receptores de Glutamato Metabotrópico/efeitos dos fármacos , beta-ArrestinasRESUMO
The G-protein coupled receptor, metabotropic glutamate receptor 5 (mGluR5), is expressed on both cell surface and intracellular membranes in striatal neurons. Using pharmacological tools to differentiate membrane responses, we previously demonstrated that cell surface mGluR5 triggers rapid, transient cytoplasmic Ca(2+) rises, resulting in c-Jun N-terminal kinase, Ca(2+)/calmodulin-dependent protein kinase, and cyclic adenosine 3',5'-monophosphate-responsive element-binding protein (CREB) phosphorylation, whereas stimulation of intracellular mGluR5 induces long, sustained Ca(2+) responses leading to the phosphorylation of extracellular signal-regulated kinase (ERK1/2) and Elk-1 (Jong, Y. J., Kumar, V., and O'Malley, K. L. (2009) J. Biol. Chem. 284, 35827-35838). Using pharmacological, genetic, and bioinformatics approaches, the current findings show that both receptor populations up-regulate many immediate early genes involved in growth and differentiation. Activation of intracellular mGluR5 also up-regulates genes involved in synaptic plasticity including activity-regulated cytoskeletal-associated protein (Arc/Arg3.1). Mechanistically, intracellular mGluR5-mediated Arc induction is dependent upon extracellular and intracellular Ca(2+) and ERK1/2 as well as calmodulin-dependent kinases as known chelators, inhibitors, and a dominant negative Ca(2+)/calmodulin-dependent protein kinase II construct block Arc increases. Moreover, intracellular mGluR5-induced Arc expression requires the serum response transcription factor (SRF) as wild type but not SRF-deficient neurons show this response. Finally, increased Arc levels due to high K(+) depolarization is significantly reduced in response to a permeable but not an impermeable mGluR5 antagonist. Taken together, these data highlight the importance of intracellular mGluR5 in the cascade of events associated with sustained synaptic transmission.
Assuntos
Proteínas do Citoesqueleto/metabolismo , Espaço Intracelular/metabolismo , Neostriado/citologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/citologia , Receptores de Glutamato Metabotrópico/metabolismo , Transmissão Sináptica/genética , Regulação para Cima , Animais , Cálcio/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Genes Precoces/genética , Ácido Glutâmico/metabolismo , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Neurônios/metabolismo , Ratos , Receptor de Glutamato Metabotrópico 5 , Receptores de Glutamato Metabotrópico/genética , Fator de Resposta Sérica/metabolismoRESUMO
PURPOSE: The Fatigue Associated with Depression Questionnaire (FAsD) was developed to assess fatigue and its impact among patients with depression. The purpose of this study was to examine the questionnaire's responsiveness to change and identify a responder definition for interpretation of treatment-related changes. METHODS: Data were collected at baseline and at 6 weeks from patients with depression starting treatment with a new antidepressant. RESULTS: Of the 96 participants, 55.2% were women, with a mean age of 43.4 years. The total score and both subscales demonstrated statistically significant change with moderate to large effect sizes (absolute values ≥ 0.76). FAsD change scores were significantly correlated with change on the Brief Fatigue Inventory (r ≥ 0.73; p < 0.001). FAsD mean change scores discriminated among patient subgroups differing by degree of improvement in patient- and clinician-reported fatigue and depression. Responder definition for the two subscales and total score (0.67, 0.57, 0.62) was estimated primarily based on mean change among patients who reported a small but important improvement in fatigue. DISCUSSION: The FAsD was responsive to change, and the responder definition may be used when interpreting treatment-related change. Results add to previous findings suggesting the FAsD is a useful measure of fatigue among patients with depression.
Assuntos
Depressão/complicações , Fadiga/complicações , Psicometria/instrumentação , Qualidade de Vida , Adulto , Idoso , Depressão/terapia , Fadiga/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Gravidez , Psicometria/estatística & dados numéricos , Reprodutibilidade dos Testes , Perfil de Impacto da Doença , Inquéritos e Questionários , Resultado do TratamentoRESUMO
Impaired axonal transport may play a key role in Parkinson's disease. To test this notion, a microchamber system was adapted to segregate axons from cell bodies using green fluorescent protein-labeled mouse dopamine (DA) neurons. Transport was examined in axons challenged with the DA neurotoxin, 1-methyl-4-phenylpyridinium ion (MPP+). MPP+ rapidly reduced overall mitochondrial motility in DA axons; among motile mitochondria, anterograde transport was slower yet retrograde transport was increased. Transport effects were specific for DA mitochondria, which were smaller and transported more slowly than their non-DA counterparts. MPP+ did not affect synaptophysin-tagged vesicles or any other measureable moving particle. Toxin effects on DA mitochondria were not dependent upon ATP, calcium, free radical species, JNK, or caspase3/PKC pathways but were completely blocked by the thiol-anti-oxidant N-acetyl-cysteine or membrane-permeable glutathione. Since these drugs also rescued processes from degeneration, these findings emphasize the need to develop therapeutics aimed at axons as well as cell bodies to preserve "normal" circuitry and function as long as possible.
Assuntos
1-Metil-4-fenilpiridínio/farmacologia , Transporte Axonal/efeitos dos fármacos , Axônios/efeitos dos fármacos , Dopamina/metabolismo , Mitocôndrias/efeitos dos fármacos , Neurotoxinas/farmacologia , Análise de Variância , Animais , Autofagia/efeitos dos fármacos , Axônios/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Mitocôndrias/metabolismo , Degeneração Neural/induzido quimicamente , Degeneração Neural/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismoRESUMO
Learning and behavioral abnormalities are among the most common clinical problems in children with the neurofibromatosis-1 (NF1) inherited cancer syndrome. Recent studies using Nf1 genetically engineered mice (GEM) have been instructive for partly elucidating the cellular and molecular defects underlying these cognitive deficits; however, no current model has shed light on the more frequently encountered attention system abnormalities seen in children with NF1. Using an Nf1 optic glioma (OPG) GEM model, we report novel defects in non-selective and selective attention without an accompanying hyperactivity phenotype. Specifically, Nf1 OPG mice exhibit reduced rearing in response to novel objects and environmental stimuli. Similar to children with NF1, the attention system dysfunction in these mice is reversed by treatment with methylphenidate (MPH), suggesting a defect in brain catecholamine homeostasis. We further demonstrate that this attention system abnormality is the consequence of reduced dopamine (DA) levels in the striatum, which is normalized following either MPH or l-dopa administration. The reduction in striatal DA levels in Nf1 OPG mice is associated with reduced striatal expression of tyrosine hydroxylase, the rate-limited enzyme in DA synthesis, without any associated dopaminergic cell loss in the substantia nigra. Moreover, we demonstrate a cell-autonomous defect in Nf1+/- dopaminergic neuron growth cone areas and neurite extension in vitro, which results in decreased dopaminergic cell projections to the striatum in Nf1 OPG mice in vivo. Collectively, these data establish abnormal DA homeostasis as the primary biochemical defect underlying the attention system dysfunction in Nf1 GEM relevant to children with NF1.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/genética , Atenção , Dopamina/metabolismo , Neurofibromatose 1/genética , Neurofibromatose 1/metabolismo , Animais , Encéfalo/metabolismo , Criança , Corpo Estriado/metabolismo , Dopamina/genética , Genes da Neurofibromatose 1 , Humanos , Levodopa/genética , Levodopa/metabolismo , Metilfenidato/metabolismo , Metilfenidato/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Mutantes , Camundongos Transgênicos , Atividade Motora/genética , Neurofibromatose 1/enzimologia , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Neurônios/metabolismo , Glioma do Nervo Óptico/genética , Glioma do Nervo Óptico/metabolismo , Substância Negra/metabolismoRESUMO
INTRODUCTION: Health state utilities associated with weight change are needed as inputs for cost-utility analyses (CUAs) examining the value of treatments for obesity and type 2 diabetes (T2D). Although some pharmaceutical treatments currently in development are associated with substantial weight loss, little is known about the utility impact of weight decreases greater than 10%. The purpose of this study was to estimate utilities associated with body weight decreases up to 20% based on preferences of individuals with obesity, with and without T2D. METHODS: Health state vignettes were developed to represent respondents' own current weight and weight decreases of 2.5, 5, 10, 15, and 20%. Health state utilities were elicited in time trade-off interviews in two UK locations (Edinburgh and London) with a sample of participants with obesity, with and without T2D. Mean utility increases associated with each amount of weight decrease were calculated. Regression analyses were performed to derive a method for estimating utility change associated with weight decreases. RESULTS: Analyses were conducted with data from 405 individuals with obesity (202 with T2D, 203 without T2D). Utility increases associated with various levels of weight decrease ranged from 0.011 to 0.060 in the subgroup with T2D and 0.015 to 0.077 in the subgroup without T2D. All regression models found that the percentage of weight decrease was a highly significant predictor of change in utility (p < .0001). The relationship between weight change and utility change did not appear to be linear. Equations are recommended for estimating utility change based on the natural logarithm of percentage of weight decrease. DISCUSSION: Results of this study may be used to provide inputs for CUAs examining and comparing the value of treatments that are associated with substantial amounts of weight loss in patients with obesity, with or without T2D.
Assuntos
Diabetes Mellitus Tipo 2 , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Obesidade/complicações , Redução de PesoRESUMO
G-protein-coupled receptors are thought to transmit extracellular signals to the cytoplasm from their position on the cell surface. Some receptors, including the metabotropic glutamate receptor 5 (mGluR5), are also highly expressed on intracellular membranes where they serve unknown functions. Here, we show that activation of cell surface versus intracellular mGluR5 results in unique Ca(2+) signatures leading to unique cellular responses. Specifically, activation of either cell surface or intracellular mGluR5 leads to JNK, Ca(2+)/calmodulin-dependent protein kinase (CaMK), and cyclic adenosine 3',5'-monophosphate-responsive element-binding protein phosphorylation, whereas activation of only intracellular mGluR5 leads to ERK1/2 and Elk-1 phosphorylation. Using pharmacological and genetic approaches, the present findings support a role for CaMK kinase in mediating mGluR5-dependent cyclic adenosine 3',5'-monophosphate-responsive element-binding protein phosphorylation, whereas CaMKII is upstream of intracellular mGluR5-mediated Elk-1 phosphorylation. Consistent with models showing Elk-1 regulating cascades of gene expression, the known Elk-1 targets c-fos and egr1 were up-regulated following intracellular mGluR5 activation, whereas a representative non-Elk-1 target, c-jun, was not. These findings emphasize that glutamate not only serves as a neurotransmitter for cell surface receptors but, when transported into the cell, can also activate intracellular receptors such as mGluR5. Glutamate activation of intracellular mGluR5 serves an important role in the regulation of nuclear Ca(2+), transcriptional activation, and gene expression necessary for physiological processes such as synaptic plasticity.
Assuntos
Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Núcleo Celular/metabolismo , Regulação da Expressão Gênica/fisiologia , Receptores de Glutamato Metabotrópico/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Animais , Núcleo Celular/genética , Células Cultivadas , AMP Cíclico/genética , AMP Cíclico/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Ácido Glutâmico/genética , Ácido Glutâmico/metabolismo , Camundongos , Camundongos Knockout , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Plasticidade Neuronal/fisiologia , Fosforilação/fisiologia , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Ratos , Receptor de Glutamato Metabotrópico 5 , Receptores de Glutamato Metabotrópico/genética , Elementos de Resposta/fisiologia , Proteínas Elk-1 do Domínio ets/genética , Proteínas Elk-1 do Domínio ets/metabolismoRESUMO
BACKGROUND: The ASK-20 survey is a previously validated patient-report measure of barriers to medication adherence and adherence-related behavior. OBJECTIVE: To derive and validate a shorter version of the ASK-20 scale. METHODS: Patients with asthma, diabetes, and congestive heart failure were recruited from a university medical center. Participants completed the ASK-20 survey and other questionnaires. Approximately one-third of participants were randomized to a 2-week retest administration. Item performance and results of an exploratory factor analysis were examined for item reduction and subscale identification. Subsequent analyses examined reliability and validity of the shorter version of the ASK. RESULTS: A total of 112 patients participated (75.9% female; mean age 46.7 y; 53.6% African American). Eight items were dropped from the ASK-20 based on factor loadings, floor effects, Cronbach's alpha, and the ability of each item to discriminate between groups of patients differing in self-reported adherence. The new total score (ASK-12) had good internal consistency reliability (Cronbach's alpha 0.75) and test-retest reliability (intraclass correlation 0.79). Convergent validity was demonstrated through correlations with the Morisky Medication Adherence Scale (r -0.74; p < 0.001), condition-specific measures, the SF-12 Mental Component Score (r -0.32; p < 0.01), and proportion of days covered by filled medication prescriptions in the past 6 months as indicated by pharmacy claims data (r -0.20; p = 0.059). The ASK-12 total score also discriminated among groups of patients who differed in self-reported adherence indicators, including whether a dose was missed in the past week, the number of days medication was not taken as directed, and treatment satisfaction. Three subscales were identified (adherence behavior, health beliefs, inconvenience/forgetfulness), and results provided initial support for their validity. CONCLUSIONS: The ASK-12 demonstrated adequate reliability and validity, and it may be a useful brief measure of adherence behavior and barriers to treatment adherence.
Assuntos
Inquéritos Epidemiológicos , Adesão à Medicação/psicologia , Inquéritos e Questionários , Adulto , Asma/tratamento farmacológico , Diabetes Mellitus/tratamento farmacológico , Feminino , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Distribuição Aleatória , Reprodutibilidade dos TestesRESUMO
Emerging data indicate that G-protein coupled receptor (GPCR) signaling is determined by not only the agonist and a given receptor but also a variety of cell-type-specific factors that can influence a receptor's response. For example, the metabotropic glutamate receptor, mGlu5, which is implicated in a number of neuropsychiatric disorders such as depression, anxiety, and autism, also signals from inside the cell which leads to sustained Ca2+ mobilization versus rapid transient responses. Because mGlu5 is an important drug target, many negative allosteric modulators (NAMs) have been generated to modulate its activity. Here we show that NAMs such as AFQ056, AZD2066, and RG7090 elicit very different end points when tested in postnatal neuronal cultures expressing endogenous mGlu5 receptors. For example, AFQ056 fails to block intracellular mGlu5-mediated Ca2+ increases whereas RG7090 is very effective. These differences are not due to differential receptor levels, since about the same number of mGlu5 receptors are present on neurons from the cortex, hippocampus, and striatum based on pharmacological, biochemical, and molecular data. Moreover, biotinylation studies reveal that more than 90% of the receptor is intracellular in these neurons. Taken together, these data indicate that the tested NAMs exhibit both location-dependent and cell type specific bias for mGlu5-mediated Ca2+ mobilization which may affect clinical outcomes.
Assuntos
Encéfalo/citologia , Encéfalo/metabolismo , Receptor de Glutamato Metabotrópico 5/metabolismo , Regulação Alostérica/efeitos dos fármacos , Regulação Alostérica/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/efeitos dos fármacos , Células Cultivadas , Células HEK293 , Humanos , Indóis/metabolismo , Indóis/farmacologia , Isoxazóis/metabolismo , Isoxazóis/farmacologia , Ratos , Receptor de Glutamato Metabotrópico 5/agonistas , Receptor de Glutamato Metabotrópico 5/antagonistas & inibidores , Triazóis/metabolismo , Triazóis/farmacologiaRESUMO
BACKGROUND: This study characterized the degree of change in health-related quality of life (HRQL) associated with change in visual acuity among patients with diabetic retinopathy. METHODS: Data are from a randomized, placebo-controlled trial of ruboxistaurin for vision loss in patients with diabetic retinopathy. Visual acuity was quantified as letters on the ETDRS visual acuity chart. HRQL was assessed with the 25-Item Visual Function Questionnaire (VFQ-25) and the SF-36. Patients were categorized into groups based on visual acuity change from baseline to month 18. HRQL change of these groups was compared using general linear models. Regression analyses examined visual acuity change defined continuously. RESULTS: Patients (N = 535) were primarily Caucasian (81.9%) and male (64.1%); mean age = 59.3 years. Compared to patients whose visual acuity did not change, the group with > 10 letters vision loss had significantly greater decreases in all VFQ-25 subscales except ocular pain. SF-36 change scores did not correspond as closely to change in vision. Change in visual acuity defined continuously was significantly associated with change in all VFQ-25 scales except ocular pain (p < 0.0001). CONCLUSION: Change in visual acuity was associated with corresponding changes in HRQL among patients with diabetic retinopathy. Previous research has often defined vision loss as a loss of at least 15 letters on the ETDRS visual acuity chart. In the current study, however, a loss of at least 10 letters was associated with substantial declines in HRQL domains such as driving, dependency, role limitations, and mental health. These findings suggest that patients who experience vision loss of at least 10 letters may be appropriate targets of future research and clinical intervention.
Assuntos
Retinopatia Diabética , Nível de Saúde , Qualidade de Vida , Acuidade Visual , Idoso , Retinopatia Diabética/fisiopatologia , Retinopatia Diabética/psicologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Humanos , Indóis/uso terapêutico , Estudos Longitudinais , Masculino , Maleimidas/uso terapêutico , Pessoa de Meia-Idade , Inquéritos e Questionários , Estados UnidosRESUMO
Traditionally, signal transduction from GPCRs is thought to emanate from the cell surface where receptor interactions with external stimuli can be transformed into a broad range of cellular responses. However, emergent data show that numerous GPCRs are also associated with various intracellular membranes where they may couple to different signalling systems, display unique desensitization patterns and/or exhibit distinct patterns of subcellular distribution. Although many GPCRs can be activated at the cell surface and subsequently endocytosed and transported to a unique intracellular site, other intracellular GPCRs can be activated in situ either via de novo ligand synthesis, diffusion of permeable ligands or active transport of nonpermeable ligands. Current findings reinforce the notion that intracellular GPCRs play a dynamic role in various biological functions including learning and memory, contractility and angiogenesis. As new intracellular GPCR roles are defined, the need to selectively tailor agonists and/or antagonists to both intracellular and cell surface receptors may lead to the development of more effective therapeutic tools. LINKED ARTICLES: This article is part of a themed section on Molecular Pharmacology of GPCRs. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.21/issuetoc.
Assuntos
Células/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Animais , Células/efeitos dos fármacos , Humanos , Ligantes , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacosRESUMO
The trillions of synaptic connections within the human brain are shaped by experience and neuronal activity, both of which underlie synaptic plasticity and ultimately learning and memory. G protein-coupled receptors (GPCRs) play key roles in synaptic plasticity by strengthening or weakening synapses and/or shaping dendritic spines. While most studies of synaptic plasticity have focused on cell surface receptors and their downstream signaling partners, emerging data point to a critical new role for the very same receptors to signal from inside the cell. Intracellular receptors have been localized to the nucleus, endoplasmic reticulum, lysosome, and mitochondria. From these intracellular positions, such receptors may couple to different signaling systems, display unique desensitization patterns, and/or show distinct patterns of subcellular distribution. Intracellular GPCRs can be activated at the cell surface, endocytosed, and transported to an intracellular site or simply activated in situ by de novo ligand synthesis, diffusion of permeable ligands, or active transport of non-permeable ligands. Current findings reinforce the notion that intracellular GPCRs play a dynamic role in synaptic plasticity and learning and memory. As new intracellular GPCR roles are defined, the need to selectively tailor agonists and/or antagonists to both intracellular and cell surface receptors may lead to the development of more effective therapeutic tools.
Assuntos
Plasticidade Neuronal , Neurônios/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Sinapses/metabolismo , Animais , Núcleo Celular/metabolismo , Espinhas Dendríticas/metabolismo , Endocitose , Retículo Endoplasmático , Humanos , Lisossomos/metabolismo , Mitocôndrias/metabolismo , Transdução de SinaisRESUMO
Background: COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE™) uses five questions and peak expiratory flow (PEF) thresholds (males ≤350 L/min; females ≤250 L/min) to identify patients with a forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.70 and FEV1 <60% predicted or exacerbation risk requiring further evaluation for COPD. This study tested CAPTURE's ability to identify symptomatic patients with mild-to-moderate COPD (FEV1 60%-80% predicted) who may also benefit from diagnosis and treatment. Methods: Data from the CAPTURE development study were used to test its sensitivity (SN) and specificity (SP) differentiating mild-to-moderate COPD (n=73) from no COPD (n=87). SN and SP for differentiating all COPD cases (mild to severe; n=259) from those without COPD (n=87) were also estimated. The modified Medical Research Council (mMRC) dyspnea scale and COPD Assessment Test (CAT™) were used to evaluate symptoms and health status. Clinical Trial Registration: NCT01880177, https://ClinicalTrials.gov/ct2/show/NCT01880177?term=NCT01880177&rank=1. Results: Mean age (+SD): 61 (+10.5) years; 41% male. COPD: FEV1/FVC=0.60 (+0.1), FEV1% predicted=74% (+12.4). SN and SP for differentiating mild-to-moderate and non-COPD patients (n=160): Questionnaire: 83.6%, 67.8%; PEF (≤450 L/min; ≤350 L/min): 83.6%, 66.7%; CAPTURE (Questionnaire+PEF): 71.2%, 83.9%. COPD patients whose CAPTURE results suggested that diagnostic evaluation was warranted (n=52) were more likely to be symptomatic than patients whose results did not (n=21) (mMRC >2: 37% vs 5%, p<0.01; CAT>10: 86% vs 57%, p<0.01). CAPTURE differentiated COPD from no COPD (n=346): SN: 88.0%, SP: 83.9%. Conclusion: CAPTURE (450/350) may be useful for identifying symptomatic patients with mild-to-moderate airflow obstruction in need of diagnostic evaluation for COPD.
Assuntos
Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Inquéritos e Questionários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos Transversais , Progressão da Doença , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Sensibilidade e Especificidade , Avaliação de Sintomas , Capacidade VitalRESUMO
Parkinson's disease (PD) involves an irreversible degeneration of the nigrostriatal pathway. As most cases of PD are sporadic, environmental risk factors may underlie neurodegeneration in dopaminergic neurons. One such factor is 6-hydroxydopamine (6-OHDA), which is widely used as a parkinsonian mimetic. Studies have shown that 6-OHDA generates reactive oxygen species and induces cell stress, the unfolded protein response, and apoptosis. Present findings show that 6-OHDA, but not hydrogen peroxide, MPP+, or rotenone, leads to the rapid formation of high-molecular-weight species of protein disulfide isomerase-associated protein 3 (ERp57) in a dose- and time-dependent fashion. Moreover, ERp57 conjugates are blocked by N-acetylcysteine and glutathione, suggesting that they represent oxidized forms of protein. Surprisingly, conjugates are complexed with DNA, because treatment with DNase reduces their appearance. Subcellular fractionation indicates that both nuclear and mitochondrial DNA are associated with the protein. Finally, toxin-treated ERp57 rapidly forms juxtanuclear aggresome-like structures in dopaminergic cells, suggesting that ERp57 plays an early adaptive response in toxin-mediated stress. Understanding the signaling mechanisms associated with parkinsonian mimetics, as well as their temporal induction, may aid in designing better interventions in models of PD.