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1.
Genomics ; 110(2): 98-111, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28911974

RESUMO

The GLIS family zinc finger 3 isoform (GLIS3) is a risk gene for Type 1 and Type 2 diabetes, glaucoma and Alzheimer's disease endophenotype. We identified GLIS3 binding sites in insulin secreting cells (INS1) (FDR q<0.05; enrichment range 1.40-9.11 fold) sharing the motif wrGTTCCCArTAGs, which were enriched in genes involved in neuronal function and autophagy and in risk genes for metabolic and neuro-behavioural diseases. We confirmed experimentally Glis3-mediated regulation of the expression of genes involved in autophagy and neuron function in INS1 and neuronal PC12 cells. Naturally-occurring coding polymorphisms in Glis3 in the Goto-Kakizaki rat model of type 2 diabetes were associated with increased insulin production in vitro and in vivo, suggestive alteration of autophagy in PC12 and INS1 and abnormal neurogenesis in hippocampus neurons. Our results support biological pleiotropy of GLIS3 in pathologies affecting ß-cells and neurons and underline the existence of trans­nosology pathways in diabetes and its co-morbidities.


Assuntos
Células Secretoras de Insulina/metabolismo , Neurônios/metabolismo , Fatores de Transcrição/metabolismo , Animais , Autofagia , Sítios de Ligação , Linhagem Celular Tumoral , Células Cultivadas , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Hipocampo/citologia , Masculino , Neurogênese , Neurônios/citologia , Células PC12 , Polimorfismo Genético , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Fatores de Transcrição/química , Fatores de Transcrição/genética
2.
J Bacteriol ; 200(23)2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30224439

RESUMO

Vibrio cholerae controls the pathogenicity of interactions with arthropod hosts via the activity of the CrbS/R two-component system. This signaling pathway regulates the consumption of acetate, which in turn alters the relative virulence of interactions with arthropods, including Drosophila melanogaster CrbS is a histidine kinase that links a transporter-like domain to its signaling apparatus via putative STAC and PAS domains. CrbS and its cognate response regulator are required for the expression of acetyl coenzyme A (acetyl-CoA) synthetase (product of acs), which converts acetate to acetyl-CoA. We demonstrate that the STAC domain of CrbS is required for signaling in culture; without it, acs transcription is reduced in LB medium, and V. cholerae cannot grow on acetate minimal media. However, the strain remains virulent toward Drosophila and expresses acs similarly to the wild type during infection. This suggests that there is a unique signal or environmental variable that modulates CrbS in the gastrointestinal tract of Drosophila Second, we present evidence in support of CrbR, the response regulator that interacts with CrbS, binding directly to the acs promoter, and we identify a region of the promoter that CrbR may target. We further demonstrate that nutrient signals, together with the cAMP receptor protein (CRP)-cAMP system, control acs transcription, but regulation may occur indirectly, as CRP-cAMP activates the expression of the crbS and crbR genes. Finally, we define the role of the Pta-AckA system in V. cholerae and identify redundancy built into acetate excretion pathways in this pathogen.IMPORTANCE CrbS is a member of a unique family of sensor histidine kinases, as its structure suggests that it may link signaling to the transport of a molecule. However, mechanisms through which CrbS senses and communicates information about the outside world are unknown. In the Vibrionaceae, orthologs of CrbS regulate acetate metabolism, which can, in turn, affect interactions with host organisms. Here, we situate CrbS within a larger regulatory framework, demonstrating that crbS is regulated by nutrient-sensing systems. Furthermore, CrbS domains may play various roles in signaling during infection and growth in culture, suggesting a unique mechanism of host recognition. Finally, we define the roles of additional pathways in acetate flux, as a foundation for further studies of this metabolic nexus point.


Assuntos
Ácido Acético/metabolismo , Artrópodes/microbiologia , Regulação Bacteriana da Expressão Gênica/genética , Histidina Quinase/metabolismo , Transdução de Sinais , Vibrio cholerae/enzimologia , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Acetilcoenzima A/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Drosophila melanogaster/microbiologia , Histidina Quinase/genética , Masculino , Vibrio cholerae/genética , Vibrio cholerae/patogenicidade , Vibrio cholerae/fisiologia , Virulência
3.
Appl Environ Microbiol ; 84(21)2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30143508

RESUMO

Acetylation is a broadly conserved mechanism of covalently modifying the proteome to precisely control protein activity. In bacteria, central metabolic enzymes and regulatory proteins, including those involved in virulence, can be targeted for acetylation. In this study, we directly link a putative acetylation system to metabolite-dependent virulence in the pathogen Vibrio cholerae We demonstrate that the cobB and yfiQ genes, which encode homologs of a deacetylase and an acetyltransferase, respectively, modulate V. cholerae metabolism of acetate, a bacterially derived short-chain fatty acid with important physiological roles in a diversity of host organisms. In Drosophila melanogaster, a model arthropod host for V. cholerae infection, the pathogen consumes acetate within the gastrointestinal tract, which contributes to fly mortality. We show that deletion of cobB impairs growth on acetate minimal medium, delays the consumption of acetate from rich medium, and reduces virulence of V. cholerae toward Drosophila These impacts can be reversed by complementing cobB or by introducing a deletion of yfiQ into the ΔcobB background. We further show that cobB controls the accumulation of triglycerides in the Drosophila midgut, which suggests that cobB directly modulates metabolite levels in vivo In Escherichia coli K-12, yfiQ is upregulated by cAMP-cAMP receptor protein (CRP), and we identified a similar pattern of regulation in V. cholerae, arguing that the system is activated in response to similar environmental cues. In summary, we demonstrate that proteins likely involved in acetylation can modulate the outcome of infection by regulating metabolite exchange between pathogens and their colonized hosts.IMPORTANCE The bacterium Vibrio cholerae causes severe disease in humans, and strains can persist in the environment in association with a wide diversity of host species. By investigating the molecular mechanisms that underlie these interactions, we can better understand constraints affecting the ecology and evolution of this global pathogen. The Drosophila model of Vibrio cholerae infection has revealed that bacterial regulation of acetate and other small metabolites from within the fly gastrointestinal tract is crucial for its virulence. Here, we demonstrate that genes that may modify the proteome of V. cholerae affect virulence toward Drosophila, most likely by modulating central metabolic pathways that control the consumption of acetate as well as other small molecules. These findings further highlight the many layers of regulation that tune bacterial metabolism to alter the trajectory of interactions between bacteria and their hosts.


Assuntos
Acetatos/metabolismo , Drosophila melanogaster/microbiologia , Vibrio cholerae/metabolismo , Vibrio cholerae/patogenicidade , Acetilação , Acetiltransferases/genética , Acetiltransferases/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Drosophila melanogaster/metabolismo , Regulação Bacteriana da Expressão Gênica , Interações Hospedeiro-Patógeno , Vibrio cholerae/genética , Virulência
4.
Exp Dermatol ; 22(12): 836-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24279918

RESUMO

In atopic dermatitis (AD), the skin barrier is disturbed, and the expression of calcium-dependent S100 proteins and the calcium gradient is also altered in the epidermis. The calmodulin-like skin protein (CLSP), which is expressed in the differentiated epidermis, is believed to modulate the function of calcium-dependent proteins involved in barrier formation and is significantly increased in the epidermis of psoriatic patients. We, therefore, investigated the CLSP level in skin biopsies taken from patients with acute exacerbated and non-exacerbated AD as well as from healthy control subjects. Immunohistochemical, Western blot and ELISA analyses showed significant increases (P < 0.03) in CLSP level in the epidermis from patients with acute exacerbated AD as compared to that from patients with non-exacerbated AD and from control subjects. Such increased expression of CLSP may help re-establish a functional epidermal barrier in acute AD.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Dermatite Atópica/metabolismo , Epiderme/metabolismo , Regulação da Expressão Gênica , Biomarcadores/metabolismo , Biópsia , Cálcio/metabolismo , Calmodulina/metabolismo , Estudos de Casos e Controles , Diferenciação Celular , Epiderme/patologia , Humanos , Inflamação , Queratinócitos/citologia , Psoríase/metabolismo , Proteínas S100/metabolismo , Cicatrização
5.
Biosensors (Basel) ; 13(9)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37754107

RESUMO

A sensitive electrochemical immunosensor for the detection of the heart-type fatty acid binding protein (HFABP), an earlier biomarker for acute myocardial infarction than Troponins, is described. The sensing platform was enhanced with methylene blue (MB) redox coupled to carbon nanotubes (CNT) assembled on a polymer film of polythionine (PTh). For this strategy, monomers of thionine rich in amine groups were electrosynthesized by cyclic voltammetry on the immunosensor's gold surface, forming an electroactive film with excellent electron transfer capacity. Stepwise sensor surface preparation was electrochemically characterized at each step and scanning electronic microscopy was carried out showing all the preparation steps. The assembled sensor platform combines MB and PTh in a synergism, allowing sensitive detection of the H-FABP in a linear response from 3.0 to 25.0 ng∙mL-1 with a limit of detection of 1.47 ng∙mL-1 HFABP that is similar to the clinical level range for diagnostics. H-FABP is a newer powerful biomarker for distinguishing between unstable angina and acute myocardial infarction.

6.
Biosensors (Basel) ; 12(7)2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35884348

RESUMO

An electrochemical immunosensor based on a nanohybrid film of carboxylated polypyrrole and amine nanoclay was developed for label-free detection of the human cardiac troponin T (cTnT). The nanohybrid film was formed in situ on the surface of the glassy carbon electrode, followed by the covalent immobilization of anti-troponin T antibodies by glutaraldehyde. Morphological and chemical characterizations of the nanohybrid film were performed by scanning electron microscopy and Fourier-transform infrared spectroscopy. Under the optimized conditions, a calibration curve for cTnT in spiked serum was obtained by square wave voltammetry, and a low limit of detection and quantification was achieved (0.35 and 1.05 pg mL-1, respectively). This was the first time that this type of nanohybrid film was used in the development of an immunosensor for cTnT that proved to be a simple and efficient strategy for the manufacture of a label-free electrochemical device that could be applied in the diagnosis of acute myocardial infarction.


Assuntos
Técnicas Biossensoriais , Polímeros , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Imunoensaio/métodos , Limite de Detecção , Polímeros/química , Pirróis , Troponina T
7.
Colloids Surf B Biointerfaces ; 189: 110834, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32066088

RESUMO

An interdigitated immunosensor for Cystatin C detection based on polypyrrole/carbon nanotube electrochemical capacitor is described. Cystatin C (CysC) is powerful biomarker for early acute renal failure and one predictive for cardiovascular risk, sepsis, cancer and death. Recently, electrochemical immunosensors based on interdigitated electrodes (IDE) have been successfully focused on development of point-of-care testing, due to their miniaturization facilities and higher sensitivity as compared with the screen-printed electrochemical sensing. Herein, a polypyrrole/carbon nanotube nanoyhibrid film was grafted on two gold fingers by electropolymerization obtaining a supercapacitor. Anti-CysC antibodies were immobilized on the IDE by covalent entrapment via ethylenediamine bifunctional agent, followed by glycine blocking in acid and alkaline medium. Under low frequency, capacitive effect of antigen-antibody interaction were observed by double layer capacitance, and analytical responses of this IDE immunosensor to CysC serum were obtained by changes on phase angle a linear range up to 300 ng/mL. The cutoff was calculated for serum samples showing a total reducing of non-specific binding at approximately 28 ng/mL CysC. This immunosensor based on interdigitated electrode (IDE) is a potential tools as portable device,with possibility to use as a practical and rapid test for CysC diagnostic in samples of serum.


Assuntos
Técnicas Biossensoriais , Cistatina C/sangue , Técnicas Eletroquímicas , Imunoensaio , Nanotubos de Carbono/química , Polímeros/química , Pirróis/química , Biomarcadores/sangue , Eletrodos , Humanos , Tamanho da Partícula , Propriedades de Superfície
8.
Dement Neuropsychol ; 13(3): 312-320, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31555404

RESUMO

As life expectancy increases, there is a marked increase in the elderly population eager to continue driving. A large proportion of these elderly drive safely, however, patients with mild dementia are high-risk drivers. OBJECTIVE: to identify the cognitive tests that best predict driving ability in subjects with mild dementia. METHODS: 28 drivers with mild dementia and 28 healthy elderly subjects underwent an extensive cognitive assessment (NACC Uniform Data Set Neuropsychological Battery), completed an adapted On Road Driving Test (ORDT) and a Driving Simulator assessment. RESULTS: drivers with mild dementia made more mistakes on the ORDT and had slower responses in the simulator tasks. Cognitive tests correlated strongly with on road and simulator driving performance. Age, the Digit Symbol Modalities Test and Boston Naming Test scores were the variables that best predicted performance on the ORDT and were included in a logistic regression model. CONCLUSION: the strong correlation between driving performance and performance on specific cognitive tests supports the importance of cognitive assessment as a useful tool for deciding whether patients with mild dementia can drive safely. The algorithm including these three variables could be used as a screening tool for the detection of unsafe driving in elderly subjects with cognitive decline.


À medida que aumenta a expectativa de vida, há um crescimento notável da população idosa ansiosa por continuar dirigindo. Uma grande proporção deles dirige com segurança, mas, pacientes com demência leve são condutores de alto risco. OBJETIVO: identificar os testes cognitivos que melhor predizem a capacidade de dirigir em indivíduos com demência leve. MÉTODOS: 28 motoristas com demência leve e 28 idosos saudáveis foram submetidos a uma extensa avaliação cognitiva (Bateria Neuropsicológica de Conjunto de Dados Uniformes NACC), completaram um teste de condução real adaptado (TCRA) e uma avaliação do Simulador de Condução. RESULTADOS: motoristas com demência leve cometeram mais erros no TCRA e tiveram respostas mais lentas nas tarefas do simulador. Os testes cognitivos correlacionaram-se fortemente com a condução na estrada e no simulador. A idade, o Teste de Modalidades do Símbolo Digit e o Teste de Nomeação de Boston foram as variáveis que melhor predisseram o desempenho no ORDT e foram incluídos em um modelo de regressão logística. CONCLUSÃO: a forte correlação entre o desempenho na direção e os testes cognitivos específicos apoia a importância da avaliação cognitiva como uma ferramenta útil para decidir se os pacientes com demência leve podem dirigir com segurança. O algoritmo que inclui essas três variáveis poderia ser usado como uma ferramenta de triagem para a detecção de condução de risco em idosos com declínio cognitivo.

9.
PLoS One ; 12(5): e0177825, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28542616

RESUMO

The CrbS/R two-component signal transduction system is a conserved regulatory mechanism through which specific Gram-negative bacteria control acetate flux into primary metabolic pathways. CrbS/R governs expression of acetyl-CoA synthase (acsA), an enzyme that converts acetate to acetyl-CoA, a metabolite at the nexus of the cell's most important energy-harvesting and biosynthetic reactions. During infection, bacteria can utilize this system to hijack host acetate metabolism and alter the course of colonization and pathogenesis. In toxigenic strains of Vibrio cholerae, CrbS/R-dependent expression of acsA is required for virulence in an arthropod model. Here, we investigate the function of the CrbS/R system in Pseudomonas aeruginosa, Pseudomonas entomophila, and non-toxigenic V. cholerae strains. We demonstrate that its role in acetate metabolism is conserved; this system regulates expression of the acsA gene and is required for growth on acetate as a sole carbon source. As a first step towards describing the mechanism of signaling through this pathway, we identify residues and domains that may be critical for phosphotransfer. We further demonstrate that although CrbS, the putative hybrid sensor kinase, carries both a histidine kinase domain and a receiver domain, the latter is not required for acsA transcription. In order to determine whether our findings are relevant to pathogenesis, we tested our strains in a Drosophila model of oral infection previously employed for the study of acetate-dependent virulence by V. cholerae. We show that non-toxigenic V. cholerae strains lacking CrbS or CrbR are significantly less virulent than are wild-type strains, while P. aeruginosa and P. entomophila lacking CrbS or CrbR are fully pathogenic. Together, the data suggest that the CrbS/R system plays a central role in acetate metabolism in V. cholerae, P. aeruginosa, and P. entomophila. However, each microbe's unique environmental adaptations and pathogenesis strategies may dictate conditions under which CrbS/R-mediated acs expression is most critical.


Assuntos
Acetato-CoA Ligase/genética , Proteínas de Bactérias/metabolismo , Meio Ambiente , Variação Genética , Transcrição Gênica , Acetatos/metabolismo , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sequência Conservada , Regulação Bacteriana da Expressão Gênica , Proteínas Hemolisinas/metabolismo , Domínios Proteicos , Pseudomonas aeruginosa/citologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/patogenicidade , Deleção de Sequência , Homologia de Sequência do Ácido Nucleico , Transdução de Sinais , Vibrio cholerae/citologia , Vibrio cholerae/genética , Vibrio cholerae/metabolismo , Vibrio cholerae/patogenicidade , Virulência
10.
PLoS One ; 10(9): e0136781, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26327442

RESUMO

Mutations in Ankyrin repeat and sterile alpha motif domain containing 6 (ANKS6) play a causative role in renal cyst formation in the PKD/Mhm(cy/+) rat model of polycystic kidney disease and in nephronophthisis in humans. A network of protein partners of ANKS6 is emerging and their functional characterization provides important clues to understand the role of ANKS6 in renal biology and in mechanisms involved in the formation of renal cysts. Following experimental confirmation of interaction between ANKS6and ANKS3 using a Yeast two hybrid system, we demonstrated that binding between the two proteins occurs through their sterile alpha motif (SAM) and that the amino acid 823 in rat ANSK6 is key for this interaction. We further showed their interaction by co-immunoprecipitation and showed in vivo in mice that ANKS3 is present in renal cilia. Downregulated expression of Anks3 in vivo in mice by Locked Nucleic Acid (LNA) modified antisense oligonucleotides was associated with increased transcription of vasopressin-induced genes, suggesting changes in renal water permeability, and altered transcription of genes encoding proteins involved in cilium structure, apoptosis and cell proliferation. These data provide experimental evidence of ANKS3-ANKS6 direct interaction through their SAM domain and co-localisation in mouse renal cilia, and shed light on molecular mechanisms indirectly mediated by ANKS6 in the mouse kidney, that may be affected by altered ANKS3-ANKS6 interaction. Our results contribute to improved knowledge of the structure and function of the network of proteins interacting with ANKS6, which may represent therapeutic targets in cystic diseases.


Assuntos
Repetição de Anquirina/genética , Apoptose/fisiologia , Proteínas de Transporte/metabolismo , Cílios/metabolismo , Rim/metabolismo , Ligação Proteica/fisiologia , Transdução de Sinais/fisiologia , Vasopressinas/metabolismo , Motivos de Aminoácidos/genética , Animais , Apoptose/genética , Proteínas de Transporte/genética , Proliferação de Células/genética , Proliferação de Células/fisiologia , Cílios/genética , Regulação para Baixo/genética , Camundongos , Camundongos Endogâmicos C57BL , Mutação/genética , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/metabolismo , Ligação Proteica/genética , Transdução de Sinais/genética , Vasopressinas/genética
11.
Diabetes ; 64(10): 3452-63, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26038578

RESUMO

Adipose tissue dysfunction in obesity has been linked to low-grade inflammation causing insulin resistance. Transcriptomic studies have identified death-associated protein kinase 2 (DAPK2) among the most strongly downregulated adipose tissue genes in human obesity, but the role of this kinase is unknown. We show that mature adipocytes rather than the stromal vascular cells in adipose tissue mainly expressed DAPK2 and that DAPK2 mRNA in obese patients gradually recovered after bariatric surgery-induced weight loss. DAPK2 mRNA is also downregulated in high-fat diet-induced obese mice. Adenoviral-mediated DAPK2 overexpression in 3T3-L1 adipocytes did not affect lipid droplet size or cell viability but did increase autophagic clearance in nutrient-rich conditions, dependent on protein kinase activity. Conversely, DAPK2 inhibition in human preadipocytes by small interfering RNA decreased LC3-II accumulation rates with lysosome inhibitors. This led us to assess autophagic clearance in adipocytes freshly isolated from subcutaneous adipose tissue of obese patients. Severe reduction in autophagic flux was observed in obese adipocytes compared with control adipocytes, inversely correlated to fat cell lipids. After bariatric surgery, adipocyte autophagic clearance partially recovered proportional to the extent of fat cell size reduction. This study links adipocyte expression of an autophagy-regulating kinase, lysosome-mediated clearance and fat cell lipid accumulation; it demonstrates obesity-related attenuated autophagy in adipocytes, and identifies DAPK2 dependence in this regulation.


Assuntos
Adipócitos/metabolismo , Autofagia/fisiologia , Proteínas Quinases Associadas com Morte Celular/metabolismo , Obesidade/metabolismo , Células 3T3-L1 , Adulto , Animais , Proteínas Quinases Associadas com Morte Celular/genética , Gorduras na Dieta , Regulação para Baixo , Feminino , Humanos , Lisossomos , Masculino , Camundongos , Camundongos Obesos , Pessoa de Meia-Idade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
12.
J Pediatr (Rio J) ; 90(6): 580-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24950475

RESUMO

OBJECTIVES: To evaluate the impact of the chronic kidney disease (CKD) on quality of life, from the children's and their parents' perspective, respiratory muscle strength, lung function, and functional capacity in children and adolescents. METHOD: Cross-sectional study of children with CKD aged 8 to 17 years. Those incapable of taking the tests were excluded. After an interview, quality of life by Pediatric Quality of Life Inventory) (PedsQL(TM)), muscular strength, pulmonary function tests, and the 6-minute walking test (6MWT) were applied. Student's t-test, ANOVA (difference in means), and Pearson's coefficient of correlation were used. The level of significance was set at 5%. RESULTS: Of the 40 patients, the mean distance walked at the 6MWT was 396 meters, and the mean final score at the quality of life test as perceived by the children and parents was 50.9 and 51, respectively. From the children's perspective, the transplanted patients had a higher quality of life score when compared to those undergoing hemodialysis (p<0.001); those who practiced physical activity had better quality of life when compared to the sedentary children (p<0.001). From the children's and the parents' perspectives, the male gender had a higher quality of life score (p<0.05). There was a positive correlation between the distance walked at the 6MWT and age, height, final PedsQL(TM), forced vital capacity (FVC), and forced expiratory volume in the first second (FEV1), as well as a negative correlation between FEV1/FVC and the distance walked. CONCLUSION: A significant reduction in the quality of life and the functional capacity was observed in children with CKD, influenced by the type of treatment, gender, and sedentary life style.


Assuntos
Pulmão/fisiopatologia , Qualidade de Vida , Insuficiência Renal Crônica/complicações , Músculos Respiratórios/lesões , Adolescente , Análise de Variância , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Atividade Motora/fisiologia , Pais/psicologia , Insuficiência Renal Crônica/fisiopatologia , Testes de Função Respiratória , Comportamento Sedentário , Fatores Sexuais , Inquéritos e Questionários , Baixo Rendimento Escolar , Caminhada/fisiologia
13.
Diabetes ; 63(12): 4032-44, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24969108

RESUMO

Adipocytes specialized in the storage of energy as fat are among the most caveolae-enriched cell types. Loss of caveolae produces lipodystrophic diabetes in humans, which cannot be reversed by endothelial rescue of caveolin expression in mice, indicating major importance of adipocyte caveolae. However, how caveolae participate in fat cell functions is poorly understood. We investigated dynamic conditions of lipid store fluctuations and demonstrate reciprocal regulation of caveolae density and fat cell lipid droplet storage. We identified caveolin-1 expression as a crucial step in adipose cell lines and in mice to raise the density of caveolae, to increase adipocyte ability to accommodate larger lipid droplets, and to promote cell expansion by increased glucose utilization. In human subjects enrolled in a trial of 8 weeks of overfeeding to promote fattening, adipocyte expansion response correlated with initial caveolin-1 expression. Conversely, lipid mobilization in cultured adipocytes to induce lipid droplet shrinkage led to biphasic response of cavin-1 with ultimate loss of expression of cavin-1 and -3 and EHD2 by protein degradation, coincident with caveolae disassembly. We have identified the key steps in cavin/caveolin interplay regulating adipocyte caveolae dynamics. Our data establish that caveolae participate in a unique cell response connected to lipid store fluctuation, suggesting lipid-induced mechanotension in adipocytes.


Assuntos
Adipócitos/metabolismo , Cavéolas/metabolismo , Caveolina 1/genética , Metabolismo dos Lipídeos , Proteínas de Membrana/genética , RNA Mensageiro/análise , Proteínas de Ligação a RNA/genética , Células 3T3-L1 , Adulto , Animais , Caveolina 1/metabolismo , Feminino , Humanos , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Nus , Proteínas de Ligação a RNA/metabolismo , Adulto Jovem
14.
Dement. neuropsychol ; 13(3): 312-320, July-Sept. 2019. tab
Artigo em Inglês | LILACS | ID: biblio-1039658

RESUMO

ABSTRACT As life expectancy increases, there is a marked increase in the elderly population eager to continue driving. A large proportion of these elderly drive safely, however, patients with mild dementia are high-risk drivers. Objective: to identify the cognitive tests that best predict driving ability in subjects with mild dementia. Methods: 28 drivers with mild dementia and 28 healthy elderly subjects underwent an extensive cognitive assessment (NACC Uniform Data Set Neuropsychological Battery), completed an adapted On Road Driving Test (ORDT) and a Driving Simulator assessment. Results: drivers with mild dementia made more mistakes on the ORDT and had slower responses in the simulator tasks. Cognitive tests correlated strongly with on road and simulator driving performance. Age, the Digit Symbol Modalities Test and Boston Naming Test scores were the variables that best predicted performance on the ORDT and were included in a logistic regression model. Conclusion: the strong correlation between driving performance and performance on specific cognitive tests supports the importance of cognitive assessment as a useful tool for deciding whether patients with mild dementia can drive safely. The algorithm including these three variables could be used as a screening tool for the detection of unsafe driving in elderly subjects with cognitive decline.


RESUMO À medida que aumenta a expectativa de vida, há um crescimento notável da população idosa ansiosa por continuar dirigindo. Uma grande proporção deles dirige com segurança, mas, pacientes com demência leve são condutores de alto risco. Objetivo: identificar os testes cognitivos que melhor predizem a capacidade de dirigir em indivíduos com demência leve. Métodos: 28 motoristas com demência leve e 28 idosos saudáveis foram submetidos a uma extensa avaliação cognitiva (Bateria Neuropsicológica de Conjunto de Dados Uniformes NACC), completaram um teste de condução real adaptado (TCRA) e uma avaliação do Simulador de Condução. Resultados: motoristas com demência leve cometeram mais erros no TCRA e tiveram respostas mais lentas nas tarefas do simulador. Os testes cognitivos correlacionaram-se fortemente com a condução na estrada e no simulador. A idade, o Teste de Modalidades do Símbolo Digit e o Teste de Nomeação de Boston foram as variáveis que melhor predisseram o desempenho no ORDT e foram incluídos em um modelo de regressão logística. Conclusão: a forte correlação entre o desempenho na direção e os testes cognitivos específicos apoia a importância da avaliação cognitiva como uma ferramenta útil para decidir se os pacientes com demência leve podem dirigir com segurança. O algoritmo que inclui essas três variáveis poderia ser usado como uma ferramenta de triagem para a detecção de condução de risco em idosos com declínio cognitivo.


Assuntos
Humanos , Condução de Veículo , Cognição , Demência , Doença de Alzheimer
15.
Diabetes ; 59(3): 600-10, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19959757

RESUMO

OBJECTIVE: Ceramide is now recognized as a negative regulator of insulin signaling by impairing protein kinase B (PKB)/Akt activation. In different cells, two distinct mechanisms have been proposed to mediate ceramide inhibition of PKB/Akt: one involving atypical protein kinase C zeta (PKCzeta) and the other the protein phosphatase-2 (PP2A). We hypothesized that ceramide action through PKCzeta or PP2A might depend on plasma membrane (PM) structural organization and especially on caveolin-enriched domain (CEM) abundance. RESEARCH DESIGN AND METHODS: We have used different PKCzeta mutant constructs or the PP2A inhibitor, okadaic acid (OKA), to selectively inhibit PKCzeta- and PP2A-dependent pathways in cells expressing different caveolin-1 levels and evaluated the impact of insulin and ceramide on PKB/Akt activity in different PM subdomains. RESULTS: Although the PKCzeta-mediated negative effect of ceramide on insulin-stimulated PKB/Akt was dominant in adipocytes, a ceramide action through PP2A outside CEMs, prevented by OKA, was also unraveled. To test the importance of CEM to direct ceramide action through the PKCzeta pathway, we treated 3T3-L1 preadipocytes devoid of CEMs with ceramide and we saw a shift of the lipid-negative action on PKB/Akt to a PP2A-mediated mechanism. In fibroblasts with low CEM abundance, the ceramide-activated PP2A pathway dominated, but could be shifted to a ceramide-activated PKCzeta pathway after caveolin-1 overexpression. CONCLUSIONS: Our results show that ceramide can switch from a PKCzeta-dependent mechanism to a PP2A pathway, acting negatively on PKB/Akt, and hence revealing a critical role of CEMs of the PM in this process.


Assuntos
Adipócitos/metabolismo , Membrana Celular/enzimologia , Ceramidas/farmacologia , Insulina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células 3T3-L1 , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Animais , Caveolinas/metabolismo , Compartimento Celular/fisiologia , Fibroblastos/citologia , Humanos , Resistência à Insulina/fisiologia , Proteínas de Membrana/efeitos dos fármacos , Proteínas de Membrana/fisiologia , Camundongos , Palmitatos/metabolismo , Palmitatos/farmacologia , Fosfoproteínas/efeitos dos fármacos , Fosfoproteínas/fisiologia , Proteína Quinase C/genética , Proteína Quinase C/metabolismo , Proteína Fosfatase 2/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia
16.
Autophagy ; 6(6): 754-63, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20574167

RESUMO

Adipose tissue lipoatrophy caused by caveolin gene deletion in mice is not linked to defective adipocyte differentiation. We show that adipose tissue development cannot be rescued by endothelial specific caveolin-1 re-expression, indicating primordial role of caveolin in mature adipocytes. Partial or total caveolin deficiency in adipocytes induced broad protein expression defects, including but not limited to previously described downregulation of insulin receptor. Global alterations in protein turnover, and accelerated degradation of long-lived proteins were found in caveolin-deficient adipocytes. Lipidation of endogenous LC3 autophagy marker and distribution of GFP-LC3 into aggregates demonstrated activated autophagy in the absence of caveolin-1 in adipocytes. Furthermore, electron microscopy revealed autophagic vacuoles in caveolin-1 deficient but not control adipocytes. Surprisingly, significant levels of lipidated LC3-II were found around lipid droplets of normal adipocytes, maintained in nutrient-rich conditions or isolated from fed mice, which do not display autophagy. Altogether, these data indicate that caveolin deficiency induce autophagy in adipocytes, a feature that is not a physiological response to fasting in normal fat cells. This likely resulted from defective insulin and lipolytic responses that converge in chronic nutrient shortage in adipocytes lacking caveolin-1. This is the first report of a pathological situation with autophagy as an adaptative response to adipocyte failure.


Assuntos
Adipócitos/citologia , Autofagia , Caveolina 1/deficiência , Diferenciação Celular , Metabolismo dos Lipídeos , Adipócitos/ultraestrutura , Animais , Caveolina 1/metabolismo , Células Cultivadas , Embrião de Mamíferos/citologia , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Inativação Gênica , Proteínas de Fluorescência Verde/metabolismo , Camundongos , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos Animais , Modelos Biológicos , Fagossomos/metabolismo , Fagossomos/ultraestrutura , Processamento de Proteína Pós-Traducional , Transporte Proteico , Proteínas Recombinantes de Fusão/metabolismo , Células Estromais/metabolismo , Fatores de Tempo
17.
J. pediatr. (Rio J.) ; 90(6): 580-586, Nov-Dec/2014. tab
Artigo em Inglês | LILACS | ID: lil-729831

RESUMO

OBJECTIVES: To evaluate the impact of the chronic kidney disease (CKD) on quality of life, from the children's and their parents' perspective, respiratory muscle strength, lung function, and functional capacity in children and adolescents. METHOD: Cross-sectional study of children with CKD aged 8 to 17 years. Those incapable of taking the tests were excluded. After an interview, quality of life by Pediatric Quality of Life Inventory) (PedsQLTM), muscular strength, pulmonary function tests, and the 6-minute walking test (6MWT) were applied. Student's t-test, ANOVA (difference in means), and Pearson's coefficient of correlation were used. The level of significance was set at 5%. RESULTS: Of the 40 patients, the mean distance walked at the 6MWT was 396 meters, and the mean final score at the quality of life test as perceived by the children and parents was 50.9 and 51, respectively. From the children's perspective, the transplanted patients had a higher quality of life score when compared to those undergoing hemodialysis (p < 0.001); those who practiced physical activity had better quality of life when compared to the sedentary children (p < 0.001). From the children's and the parents' perspectives, the male gender had a higher quality of life score (p < 0.05). There was a positive correlation between the distance walked at the 6MWT and age, height, final PedsQLTM, forced vital capacity (FVC), and forced expiratory volume in the first second (FEV1), as well as a negative correlation between FEV1/FVC and the distance walked. CONCLUSION: A significant reduction in the quality of life and the functional capacity was observed in children with CKD, influenced by the type of treatment, gender, and sedentary life style. .


OBJETIVOS: Avaliar repercussões da doença renal crônica (DRC) sobre a qualidade de vida na percepção das crianças e dos pais, força muscular respiratória, função pulmonar e capacidade funcional em crianças e adolescentes. MÉTODO: Estudo transversal de crianças e adolescentes com DRC de oito a 17 anos. Excluídas as incapazes de realizar os testes. Após entrevista, aplicou-se questionário de qualidade de vida (PedsQLTM), testes de força muscular, função pulmonar e teste de caminhada de 6 minutos (TC6 min). Foi utilizado o teste t de Student e ANOVA (diferenças de médias) e o coeficiente de correlação de Pearson. Considerou-se nível de significância de 5%. RESULTADOS: Dentre os 40 pacientes, a média da distância percorrida no TC6 min foi de 396 ± 71 metros, e a média do escore final de qualidade de vida percebida pelas crianças e pelos pais de 50,9 e 51, respectivamente. Na percepção das crianças, os transplantados apresentaram maior escore de qualidade de vida, comparados aos em hemodiálise (p < 0,001), e aos com atividade física e melhor qualidade de vida, comparadas às sedentárias (p < 0,001). Na percepção das crianças e dos pais, o sexo masculino apresentou maior escore de qualidade de vida (p < 0,05). Houve correlação positiva entre a distância percorrida no TC6 min e as variáveis idade, altura, PedsQLTM final da criança, capacidade vital forçada (CVF) e volume expiratório forçado no primeiro segundo (VEF1) e negativa entre VEF1/CVF e a distância percorrida. CONCLUSÃO: Observou-se redução significativa na qualidade de vida e na capacidade funcional em crianças com DRC influenciadas pelo tipo de tratamento, sexo e sedentarismo. .


Assuntos
Adolescente , Criança , Feminino , Humanos , Masculino , Pulmão/fisiopatologia , Qualidade de Vida , Insuficiência Renal Crônica/complicações , Músculos Respiratórios/lesões , Análise de Variância , Estudos Transversais , Atividade Motora/fisiologia , Pais/psicologia , Testes de Função Respiratória , Insuficiência Renal Crônica/fisiopatologia , Comportamento Sedentário , Fatores Sexuais , Inquéritos e Questionários , Baixo Rendimento Escolar , Caminhada/fisiologia
18.
Rev. imagem ; 30(1): 31-33, jan.-mar. 2008. ilus
Artigo em Português | LILACS | ID: lil-542281

RESUMO

Neste trabalho relatam-se os achados da síndrome de Aicardi, um distúrbio de etiologia desconhecida composta por espasmos múltiplos, lacunas coriorretinianas e agenesia do corpo caloso. Os autores apresentam um caso desta síndrome, com clínica e achados de ressonância magnética característicos. A doença, apesar de considerada rara, apresenta achados de imagem característicos. Nos últimos anos, a importância da ressonância magnética tem aumentado expressivamente,uma vez que demonstra outros achados além da agenesia do corpo caloso, tornando o papel do radiologista muito importante na suspeição diagnóstica desta enfermidade.


The authors report the findings of Aicardi syndrome, a disease of unknown etiology composed of multiple spasms, chorioretinal lacunae and agenesis of the corpus callosum. They present a caseof Aicardi syndrome with characteristic clinical presentation and magnetic resonance imaging findings. The disease, despite being considered rare, has characteristic imaging findings. Over the past years magnetic resonance imaging has improved its ability in demonstratingother findings besides agenesis of the corpus callosum, making the radiologist's role very important in the diagnostic suspicion of this disease.


Assuntos
Humanos , Masculino , Recém-Nascido , Corioide/anormalidades , Corpo Caloso/anormalidades , Espasmos Infantis/diagnóstico , Espectroscopia de Ressonância Magnética , Retina/anormalidades , Síndrome de Aicardi
19.
Medicina (Ribeiräo Preto) ; 32(4): 401-418, out.-dez. 1999. ilus, tab
Artigo em Português | LILACS | ID: lil-342441

RESUMO

A presente revisäo objetiva descrever os recentes avanços tecnológicos dos métodos de diagnóstico por imagem e sua atual aplicabilidade no manuseio dos pacientes com trauma abdominal, bem como as principais apresentações pelos métodos de imagem dos diversos órgäos envolvidos


Assuntos
Humanos , Traumatismos Abdominais , Diagnóstico por Imagem , Tomografia Computadorizada por Raios X , Traumatismos Abdominais
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