Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nat Metab ; 3(3): 378-393, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33686286

RESUMO

TUG tethering proteins bind and sequester GLUT4 glucose transporters intracellularly, and insulin stimulates TUG cleavage to translocate GLUT4 to the cell surface and increase glucose uptake. This effect of insulin is independent of phosphatidylinositol 3-kinase, and its physiological relevance remains uncertain. Here we show that this TUG cleavage pathway regulates both insulin-stimulated glucose uptake in muscle and organism-level energy expenditure. Using mice with muscle-specific Tug (Aspscr1)-knockout and muscle-specific constitutive TUG cleavage, we show that, after GLUT4 release, the TUG C-terminal cleavage product enters the nucleus, binds peroxisome proliferator-activated receptor (PPAR)γ and its coactivator PGC-1α and regulates gene expression to promote lipid oxidation and thermogenesis. This pathway acts in muscle and adipose cells to upregulate sarcolipin and uncoupling protein 1 (UCP1), respectively. The PPARγ2 Pro12Ala polymorphism, which reduces diabetes risk, enhances TUG binding. The ATE1 arginyltransferase, which mediates a specific protein degradation pathway and controls thermogenesis, regulates the stability of the TUG product. We conclude that insulin-stimulated TUG cleavage coordinates whole-body energy expenditure with glucose uptake, that this mechanism might contribute to the thermic effect of food and that its attenuation could promote obesity.


Assuntos
Metabolismo Energético , Glucose/metabolismo , Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células 3T3-L1 , Aminoaciltransferases/metabolismo , Animais , Camundongos , Camundongos Knockout , Oxirredução , PPAR gama/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteólise , Termogênese
2.
Proc Natl Acad Sci U S A ; 118(4)2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33468647

RESUMO

Bromodomains (BDs) are small protein modules that interact with acetylated marks in histones. These posttranslational modifications are pivotal to regulate gene expression, making BDs promising targets to treat several diseases. While the general structure of BDs is well known, their dynamical features and their interplay with other macromolecules are poorly understood, hampering the rational design of potent and selective inhibitors. Here, we combine extensive molecular dynamics simulations, Markov state modeling, and available structural data to reveal a transiently formed state that is conserved across all BD families. It involves the breaking of two backbone hydrogen bonds that anchor the ZA-loop with the αA helix, opening a cryptic pocket that partially occludes the one associated to histone binding. By analyzing more than 1,900 experimental structures, we unveil just two adopting the hidden state, explaining why it has been previously unnoticed and providing direct structural evidence for its existence. Our results suggest that this state is an allosteric regulatory switch for BDs, potentially related to a recently unveiled BD-DNA-binding mode.


Assuntos
Proteínas de Ciclo Celular/química , Proteínas Correpressoras/química , Proteínas de Ligação a DNA/química , Histona Acetiltransferases/química , Peptídeos e Proteínas de Sinalização Intracelular/química , Fatores Genéricos de Transcrição/química , Fatores de Transcrição/química , Proteína 28 com Motivo Tripartido/química , Sequência de Aminoácidos , Sítios de Ligação , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Cristalografia por Raios X , DNA/química , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Cadeias de Markov , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Termodinâmica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores Genéricos de Transcrição/genética , Fatores Genéricos de Transcrição/metabolismo , Proteína 28 com Motivo Tripartido/genética , Proteína 28 com Motivo Tripartido/metabolismo
3.
J Natl Cancer Inst ; 113(4): 390-399, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32986828

RESUMO

BACKGROUND: Black race is associated with worse outcomes in early breast cancer. We evaluated clinicopathologic characteristics, the 21-gene recurrence score (RS), treatment delivered, and clinical outcomes by race and ethnicity among women who participated in the Trial Assigning Individualized Options for Treatment. METHODS: The association between clinical outcomes and race (White, Black, Asian, other or unknown) and ethnicity (Hispanic vs non-Hispanic) was examined using proportional hazards models. All P values are 2-sided. RESULTS: Of 9719 eligible women with hormone receptor-positive, HER2-negative, node-negative breast cancer, there were 8189 (84.3%) Whites, 693 (7.1%) Blacks, 405 (4.2%) Asians, and 432 (4.4%) with other or unknown race. Regarding ethnicity, 889 (9.1%) were Hispanic. There were no substantial differences in RS or ESR1, PGR, or HER2 RNA expression by race or ethnicity. After adjustment for other covariates, compared with White race, Black race was associated with higher distant recurrence rates (hazard ratio [HR] = 1.60, 95% confidence intervals [CI] = 1.07 to 2.41) and worse overall survival in the RS 11-25 cohort (HR = 1.51, 95% CI = 1.06 to 2.15) and entire population (HR = 1.41, 95% CI = 1.05 to 1.90). Hispanic ethnicity and Asian race were associated with better outcomes. There was no evidence of chemotherapy benefit for any racial or ethnic group in those with a RS of 11-25. CONCLUSIONS: Black women had worse clinical outcomes despite similar 21-gene assay RS results and comparable systemic therapy in the Trial Assigning Individualized Options for Treatment. Similar to Whites, Black women did not benefit from adjuvant chemotherapy if the 21-gene RS was 11-25. Further research is required to elucidate the basis for this racial disparity in prognosis.


Assuntos
Povo Asiático/estatística & dados numéricos , População Negra/estatística & dados numéricos , Neoplasias da Mama/etnologia , Hispânico ou Latino/estatística & dados numéricos , População Branca/estatística & dados numéricos , Adulto , Idoso , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Comorbidade , Intervalos de Confiança , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Cobertura do Seguro/estatística & dados numéricos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Menopausa , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/etnologia , Recidiva Local de Neoplasia/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Receptor ErbB-2/metabolismo , Resultado do Tratamento , Adulto Jovem
4.
Sci Rep ; 10(1): 14874, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913252

RESUMO

Autophagy is a key clearance process to recycle damaged cellular components. One important upstream regulator of autophagy is ULK1 kinase. Several three-dimensional structures of the ULK1 catalytic domain are available, but a comprehensive study, including molecular dynamics, is missing. Also, an exhaustive description of ULK1 alterations found in cancer samples is presently lacking. We here applied a framework which links -omics data to structural protein ensembles to study ULK1 alterations from genomics data available for more than 30 cancer types. We predicted the effects of mutations on ULK1 function and structural stability, accounting for protein dynamics, and the different layers of changes that a mutation can induce in a protein at the functional and structural level. ULK1 is down-regulated in gynecological tumors. In other cancer types, ULK2 could compensate for ULK1 downregulation and, in the majority of the cases, no marked changes in expression have been found. 36 missense mutations of ULK1, not limited to the catalytic domain, are co-occurring with mutations in a large number of ULK1 interactors or substrates, suggesting a pronounced effect of the upstream steps of autophagy in many cancer types. Moreover, our results pinpoint that more than 50% of the mutations in the kinase domain of ULK1, here investigated, are predicted to affect protein stability. Three mutations (S184F, D102N, and A28V) are predicted with only impact on kinase activity, either modifying the functional dynamics or the capability to exert effects from distal sites to the functional and catalytic regions. The framework here applied could be extended to other protein targets to aid the classification of missense mutations from cancer genomics studies, as well as to prioritize variants for experimental validation, or to select the appropriate biological readouts for experiments.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias/enzimologia , Autofagia/fisiologia , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/química , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Simulação de Dinâmica Molecular , Mutação , Neoplasias/genética , Neoplasias/patologia , Fosforilação , Elementos Estruturais de Proteínas , Transdução de Sinais , Relação Estrutura-Atividade
5.
Elife ; 92020 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-32338601

RESUMO

In the nucleus, the spatiotemporal regulation of the catalytic subunit of cAMP-dependent protein kinase A (PKA-C) is orchestrated by an intrinsically disordered protein kinase inhibitor, PKI, which recruits the CRM1/RanGTP nuclear exporting complex. How the PKA-C/PKI complex assembles and recognizes CRM1/RanGTP is not well understood. Using NMR, SAXS, fluorescence, metadynamics, and Markov model analysis, we determined the multi-state recognition pathway for PKI. After a fast binding step in which PKA-C selects PKI's most competent conformations, PKI folds upon binding through a slow conformational rearrangement within the enzyme's binding pocket. The high-affinity and pseudo-substrate regions of PKI become more structured and the transient interactions with the kinase augment the helical content of the nuclear export sequence, which is then poised to recruit the CRM1/RanGTP complex for nuclear translocation. The multistate binding mechanism featured by PKA-C/PKI complex represents a paradigm on how disordered, ancillary proteins (or protein domains) are able to operate multiple functions such as inhibiting the kinase while recruiting other regulatory proteins for nuclear export.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Proteínas Quinases Dependentes de AMP Cíclico/genética , Citoplasma , Escherichia coli , Peptídeos e Proteínas de Sinalização Intracelular/genética , Carioferinas/genética , Carioferinas/metabolismo , Espectroscopia de Ressonância Magnética , Cadeias de Markov , Camundongos , Coelhos , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteína Exportina 1
6.
Elife ; 72018 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-30044223

RESUMO

Proper kinetochore-microtubule attachments, mediated by the NDC80 complex, are required for error-free chromosome segregation. Erroneous attachments are corrected by the tension dependence of kinetochore-microtubule interactions. Here, we present a method, based on fluorescence lifetime imaging microscopy and Förster resonance energy transfer, to quantitatively measure the fraction of NDC80 complexes bound to microtubules at individual kinetochores in living human cells. We found that NDC80 binding is modulated in a chromosome autonomous fashion over prometaphase and metaphase, and is predominantly regulated by centromere tension. We show that this tension dependency requires phosphorylation of the N-terminal tail of Hec1, a component of the NDC80 complex, and the proper localization of Aurora B kinase, which modulates NDC80 binding. Our results lead to a mathematical model of the molecular basis of tension-dependent NDC80 binding to kinetochore microtubules in vivo.


Assuntos
Cinetocoros/metabolismo , Microtúbulos/metabolismo , Proteínas Nucleares/metabolismo , Aurora Quinase B/metabolismo , Calibragem , Linhagem Celular Tumoral , Simulação por Computador , Proteínas do Citoesqueleto , Transferência Ressonante de Energia de Fluorescência , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Metáfase , Modelos Biológicos , Método de Monte Carlo , Proteínas Serina-Treonina Quinases/metabolismo , Tubulina (Proteína)/metabolismo
7.
Br J Dermatol ; 179(2): 371-380, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29274242

RESUMO

BACKGROUND: Psoriasis vulgaris is a chronic, inflammatory skin disease characterized by a dysregulated immune response and it is associated with substantial systemic comorbidities. Biological drugs such as tumour necrosis factor (TNF)-α inhibitors can ameliorate the disease but are expensive. Biosimilar drugs have the same amino-acid sequence as the originator, but differences in manufacturing can affect biological activity, efficacy and tolerability. OBJECTIVES: To explore potential differences in intracellular phosphorylation of signalling molecules in peripheral blood cells from patients with psoriasis treated with the TNF-α inhibitor infliximab compared with healthy controls, and to investigate if the phosphorylation pattern was influenced by switching from the originator infliximab to the biosimilar CT-P13. METHODS: By flow cytometry, we measured phosphorylation of nuclear factor kappa B, extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase and signal transducer and activator of transcription 3, before and after TNF-α stimulation in monocytes and T, B, natural killer and CD3+  CD56+ cells from 25 patients with psoriasis treated with infliximab and 19 healthy controls. RESULTS: At inclusion, phosphorylation levels of peripheral blood mononuclear cells (PBMCs) were increased in patients with psoriasis compared with healthy controls, even though clinical remission had already been achieved. Phosphorylation levels declined in patients on both originator infliximab and biosimilar during continued treatment. No significant differences were detected between the two medications after 12 months. CONCLUSIONS: Patients with psoriasis on infliximab have higher activation levels of PBMCs than do healthy controls, possibly reflecting systemic inflammation. Switching from the originator infliximab to biosimilar CT-P13 did not affect phosphorylation levels or clinical parameters, suggesting that CT-P13 is a noninferior treatment alternative to the originator infliximab.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Medicamentos Biossimilares/administração & dosagem , Fármacos Dermatológicos/administração & dosagem , Infliximab/administração & dosagem , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Psoríase/tratamento farmacológico , Adulto , Idoso , Anticorpos Monoclonais/economia , Medicamentos Biossimilares/economia , Fármacos Dermatológicos/economia , Substituição de Medicamentos/economia , Feminino , Humanos , Infliximab/economia , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Fosforilação/efeitos dos fármacos , Psoríase/sangue , Indução de Remissão/métodos , Resultado do Tratamento
8.
Nucleic Acids Res ; 45(18): 10614-10633, 2017 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-28977657

RESUMO

Phosphorylated histone H2AX, termed 'γH2AX', mediates the chromatin response to DNA double strand breaks (DSBs) in mammalian cells. H2AX deficiency increases the numbers of unrepaired DSBs and translocations, which are partly associated with defects in non-homologous end joining (NHEJ) and contributing to genomic instability in cancer. However, the role of γH2AX in NHEJ of general DSBs has yet to be clearly defined. Here, we showed that despite little effect on overall NHEJ efficiency, H2AX deficiency causes a surprising bias towards accurate NHEJ and shorter deletions in NHEJ products. By analyzing CRISPR/Cas9-induced NHEJ and by using a new reporter for mutagenic NHEJ, we found that γH2AX, along with its interacting protein MDC1, is required for efficient classical NHEJ (C-NHEJ) but with short deletions and insertions. Epistasis analysis revealed that ataxia telangiectasia mutated (ATM) and the chromatin remodeling complex Tip60/TRRAP/P400 are essential for this H2AX function. Taken together, these data suggest that a subset of DSBs may require γH2AX-mediated short-range nucleosome repositioning around the breaks to facilitate C-NHEJ with loss of a few extra nucleotides at NHEJ junctions. This may prevent outcomes such as non-repair and translocations, which are generally more destabilizing to genomes than short deletions and insertions from local NHEJ.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades , Histonas/fisiologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas Mutadas de Ataxia Telangiectasia/fisiologia , Sequência de Bases , Sistemas CRISPR-Cas , Proteínas de Ciclo Celular , Linhagem Celular , Proteína Quinase Ativada por DNA/fisiologia , Proteínas de Ligação a DNA/fisiologia , Histonas/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Nucleotídeos/análise , Deleção de Sequência
9.
Int J Obes (Lond) ; 41(8): 1256-1262, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28392556

RESUMO

BACKGROUND: Identifying whether components of total energy expenditure (EE) are affected by orexin receptor (OXR1 and OXR2) stimulation or antagonism with dual orexin receptor antagonists (DORAs) has relevance for obesity treatment. Orexin receptor stimulation reduces weight gain by increasing total EE and EE during spontaneous physical activity (SPA). OBJECTIVE: The purpose of this study was to determine if a DORA (TCS-1102) in the ventrolateral preoptic area (VLPO) reduced orexin-A-induced arousal, SPA, total EE and EE during sleep, rest, wake and SPA and whether the DORA alone reduced total EE and its components. We hypothesized that: (1) a DORA would reduce orexin-A induced increases in arousal, SPA, components of total EE, reductions in sleep and the EE during sleep and (2) the DORA alone would reduce baseline (non-stimulated) SPA and total EE. SUBJECTS/METHODS: Sleep, wakefulness, SPA and EE were determined after microinjection of the DORA (TCS-1102) and orexin-A in the VLPO of male Sprague-Dawley rats with a unilateral cannula targeted towards the VLPO. Individual components of total EE were determined based on time-stamped data. RESULTS: The DORA reduced orexin-A-induced increases in arousal, SPA, total EE and EE during SPA, wake, rest and sleep 1 h post injection (P<0.05). Orexin-A significantly reduced sleep and significantly increased EE during sleep 1 h post injection (P<0.05). Furthermore, the DORA alone significantly reduced total EE, EE during sleep (NREM and REM) and resting EE 2 h post injection (P<0.05). CONCLUSIONS: These data suggest that orexin-A reduces weight gain by stimulating total EE through increases in EE during SPA, rest and sleep. Residual effects of the DORA alone include decreases in total EE and EE during sleep and rest, which may promote weight gain.


Assuntos
Metabolismo Energético/fisiologia , Orexinas/metabolismo , Área Pré-Óptica/metabolismo , Animais , Metabolismo Energético/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Antagonistas dos Receptores de Orexina/farmacologia , Orexinas/antagonistas & inibidores , Área Pré-Óptica/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Sono/efeitos dos fármacos , Sono/fisiologia , Vigília/efeitos dos fármacos , Vigília/fisiologia , Aumento de Peso/efeitos dos fármacos
10.
J Dairy Sci ; 99(10): 8461-8471, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27497905

RESUMO

Nutrigenomic studies of mammary lipogenesis in ruminants often rely on the use of mammary tissue (MT) collected either by biopsy or at slaughter. However, isolating RNA from milk would be a useful and cost-effective technique that may avoid distress to the animal and facilitate the collection of samples in time series experiments. This assay was therefore conducted to test the hypothesis that RNA extracted from milk somatic cells (MSC) in dairy sheep would be a feasible alternative to the performance of MT biopsies for nutrigenomic analyses. To meet this objective, 8 lactating Assaf ewes were divided in 2 groups and offered a total mixed ration without supplementation (control) or supplemented with 2.4% dry matter of fish oil, which was known not only to elicit milk fat depression but also to downregulate the expression of some candidate genes involved in mammary lipogenesis. Total RNA was extracted from MSC and biopsied MT to examine whether the potential changes in the abundance of transcripts was similarly detected with both RNA sources. Milk fatty acid profile was also analyzed by gas chromatography, and variations in mRNA abundance were determined by reverse transcription quantitative PCR. Values of RNA integrity number were always ≥7.7. The expected and designed decrease of milk fat concentration with fish oil (-29%), was associated with a lower transcript abundance of genes coding for enzymes involved in fatty acid activation (ACSS1), de novo synthesis (ACACA and FASN), uptake from plasma lipids (LPL), and esterification of fatty acids to glycerol (LPIN1), as well as of a transcription factor that may regulate their expression (INSIG1). Stable mRNA levels were showed in other candidate genes, such as FABP3, GPAT4, or SCD. Changes due to the dietary treatment were similarly detected with both RNA sources (MSC and MT biopsies), which supports the initial hypothesis and would validate the use of milk as an alternative RNA source for nutrigenomic analyses in dairy sheep.


Assuntos
Glândulas Mamárias Animais/metabolismo , Leite/química , Nutrigenômica/métodos , RNA/isolamento & purificação , Acetato-CoA Ligase/genética , Acetato-CoA Ligase/metabolismo , Ração Animal/análise , Animais , Biópsia , Análise Custo-Benefício , Dieta/veterinária , Gorduras na Dieta/análise , Suplementos Nutricionais , Regulação para Baixo , Ácido Graxo Sintase Tipo I/genética , Ácido Graxo Sintase Tipo I/metabolismo , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Ácidos Graxos/análise , Feminino , Óleos de Peixe/administração & dosagem , Glicerol/metabolismo , Glicerol-3-Fosfato O-Aciltransferase/genética , Glicerol-3-Fosfato O-Aciltransferase/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipogênese , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ovinos
11.
Neurobiol Aging ; 35(12): 2836-2844, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25104558

RESUMO

The loss of zinc transporter 3 (ZnT3) has been implicated in age-related cognitive decline in mice, and the protein has been associated with plaques. We investigated the levels of ZnT3 and postsynaptic density protein 95 (PSD95), a marker of the postsynaptic terminal, in people with Parkinson's disease dementia (PDD, n = 31), dementia with Lewy bodies (DLB, n = 44), Alzheimer's disease (AD, n = 16), and controls (n = 24), using semiquantitative western blotting and immunohistochemistry in 3 cortical regions. Standardized cognitive assessments during life and semiquantitative scoring of amyloid ß (Aß), tau, and α-synuclein at postmortem were used to investigate the relationship between ZnT3 and PSD95, cognition and pathology. Associations were observed between ZnT3 and PSD95 levels in prefrontal cortex and cognitive impairment (p = 0.001 and p = 0.002, respectively) and between ZnT3 levels in the parietal cortex and cognitive impairment (p = 0.036). Associations were also seen between ZnT3 levels in cingulate cortex and severity of Aß (p = 0.003) and tau (p = 0.011) pathologies. DLB and PDD were characterized by significant reductions of PSD95 (p < 0.05) and ZnT3 (p < 0.001) in prefrontal cortex compared with controls and AD. PSD95 levels in the parietal cortex were found to be decreased in AD cases compared with controls (p = 0.02) and PDD (p = 0.005). This study has identified Zn(2+) modulation as a possible novel target for the treatment of cognitive impairment in DLB and PDD and the potential for synaptic proteins to be used as a biomarker for the differentiation of DLB and PDD from AD.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/psicologia , Proteínas de Transporte de Cátions/metabolismo , Cognição , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Doença por Corpos de Lewy/metabolismo , Doença por Corpos de Lewy/psicologia , Proteínas de Membrana/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/patologia , Biomarcadores/metabolismo , Diagnóstico Diferencial , Proteína 4 Homóloga a Disks-Large , Feminino , Humanos , Doença por Corpos de Lewy/diagnóstico , Doença por Corpos de Lewy/patologia , Masculino , Terapia de Alvo Molecular , Córtex Pré-Frontal/metabolismo , Zinco/metabolismo
12.
Cell Rep ; 3(3): 587-94, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23478023

RESUMO

Systemic signals provided by nutrients and hormones are known to coordinate the growth and proliferation of different organs during development. However, within the brain, it is unclear how these signals influence neural progenitor divisions and neuronal diversity. Here, in the Drosophila visual system, we identify two developmental phases with different sensitivities to dietary nutrients. During early larval stages, nutrients regulate the size of the neural progenitor pool via insulin/PI3K/TOR-dependent symmetric neuroepithelial divisions. During late larval stages, neural proliferation becomes insensitive to dietary nutrients, and the steroid hormone ecdysone acts on Delta/Notch signaling to promote the switch from symmetric mitoses to asymmetric neurogenic divisions. This mechanism accounts for why sustained undernourishment during visual system development restricts neuronal numbers while protecting neuronal diversity. These studies reveal an adaptive mechanism that helps to retain a functional visual system over a range of different brain sizes in the face of suboptimal nutrition.


Assuntos
Dieta , Drosophila/citologia , Células-Tronco Neurais/citologia , Neurogênese , Vias Visuais/citologia , Animais , Divisão Celular Assimétrica , Contagem de Células , Drosophila/crescimento & desenvolvimento , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Ecdisona/metabolismo , Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Larva/citologia , Larva/metabolismo , Proteínas de Membrana/metabolismo , Mitose , Células-Tronco Neurais/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Vias Visuais/metabolismo
13.
Sci Signal ; 6(256): ra1, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23281368

RESUMO

The Src and Syk families of kinases are two distinct sets of kinases that play critical roles in initiating membrane-proximal B cell receptor (BCR) signaling. However, unlike in other lymphocytes, such as T cells, the "division of labor" between Src family kinases (SFKs) and Syk in B cells is not well separated because both Syk and SFKs can phosphorylate immunoreceptor tyrosine-based activation motifs (ITAMs) present in proteins comprising the BCR. To understand why B cells require both SFKs and Syk for activation, we investigated the roles of both families of kinases in BCR signaling with computational modeling and in vitro experiments. Our computational model suggested that positive feedback enabled Syk to substantially compensate for the absence of SFKs when spatial clustering of BCRs was induced by multimeric ligands. We confirmed this prediction experimentally. In contrast, when B cells were stimulated by monomeric ligands that failed to produce BCR clustering, both Syk and SFKs were required for complete and rapid BCR activation. Our data suggest that SFKs could play a pivotal role in increasing BCR sensitivity to monomeric antigens of pathogens and in mediating a rapid response to soluble multimeric antigens of pathogens that can induce spatial BCR clustering.


Assuntos
Linfócitos B/imunologia , Retroalimentação Fisiológica/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Modelos Imunológicos , Proteínas Tirosina Quinases/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/imunologia , Quinases da Família src/metabolismo , Animais , Anticorpos Monoclonais , Linfócitos B/metabolismo , Linfócitos B/fisiologia , Proteína Tirosina Quinase CSK , Clonagem Molecular , Simulação por Computador , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Método de Monte Carlo , Fosforilação , Proteínas Tirosina Quinases/genética , Células Sf9 , Spodoptera , Quinase Syk , Ultracentrifugação , Proteína-Tirosina Quinase ZAP-70/metabolismo
14.
Vitam Horm ; 89: 91-109, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22640610

RESUMO

The orexins/hypocretins are endogenous, modulatory and multifunctional neuropeptides with prominent influence on several physiological processes. The influence of orexins on energy expenditure is highlighted with focus on orexin action on individual components of energy expenditure. As orexin stabilizes and maintains normal states of arousal and the sleep/wake cycle, we also highlight orexin mediation of sleep and how sleep interacts with energy expenditure.


Assuntos
Metabolismo Energético , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Transmissão Sináptica , Animais , Humanos , Atividade Motora , Orexinas , Sono
15.
Artigo em Inglês | MEDLINE | ID: mdl-22292554

RESUMO

Discovery of small molecular inhibitors for treatment of rheumatoid arthritis is a major ongoing effort within the pharmaceutical industry. Spleen tyrosine kinase (SYK) is one of leading small molecular targets with regard to clinical development primarlly due to efforts by Rigel and Portola. In this review, we provide a comprehensive overview of the SYK patent landscape. The patent literature we evaluated relates to any organization that has filed applications that imply that SYK is the intended target. The interest in SYK was initiated in the early 2000's with many organizations, including several large pharmaceutical companies, and has been active for years. In general, the structural theme of most of the compounds in these applications is a traditional ATP competitive inhibitor with each organization having a different hinge binding element. In general, the attachment to the hinge is an aryl amine that is decorated with a solubilizing group. The other substituents are broadly variable across the numerous companies indicating that SYK has significant flexibility in its interactions in that portion of the kinase. This overview of the SYK patent literature and the learnings of the inhibitors' substitution patterns would be an important reference for anyone working in this area.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Animais , Antirreumáticos/química , Antirreumáticos/farmacologia , Artrite Reumatoide/enzimologia , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Indústria Farmacêutica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Patentes como Assunto , Inibidores de Proteínas Quinases/química , Proteínas Tirosina Quinases/metabolismo , Quinase Syk
17.
Radiology ; 258(3): 804-11, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21339349

RESUMO

PURPOSE: To evaluate the use of molecularly targeted microbubbles (MBs) and ultrasonography (US) in the noninvasive assessment of the level of expression of three angiogenic markers, α(v)ß(3) integrin, endoglin, and vascular endothelial growth factor receptor (VEGFR) 2, on tumor vascular endothelial cells in vivo during tumor growth. MATERIALS AND METHODS: All procedures using laboratory animals were approved by the Institutional Administrative Panel on Laboratory Animal Care. Binding specificity of three types of targeted MBs (MB(Integrin), MB(Endoglin), MB(VEGFR2)) was tested in cell culture under flow shear stress conditions. In vivo targeted contrast material-enhanced US imaging signal using the three MB types was measured at three tumor stages (small, medium, large) in three subcutaneous cancer xenografts (breast, ovarian, pancreatic cancer) in mice (n = 54). In vivo US imaging signal was correlated with ex vivo angiogenic marker expression. Significant differences were evaluated by using the Student t, analysis of variance, Wilcoxon, and Tukey Honest Significant Difference tests. RESULTS: Cell attachment of all three MB types was significantly (P = .016) higher compared with control MBs, and this attachment could be significantly (P = .026) decreased by blocking antibodies. Angiogenic marker-expressing cells bound significantly (P = .003) more targeted MBs than negative control cells, and MB attachment significantly (P < .001) correlated with marker expression levels on cells (ρ = 0.87). In early stage breast and ovarian cancers, in vivo targeted contrast-enhanced US demonstrated significantly (P ≤ .04) higher endoglin expression than both α(v)ß(3) integrin and VEGFR2 expression, whereas in early stage pancreatic cancer, marker expressions were not significantly different (P ≥ .07). There was good correlation (ρ ≥ 0.63; P ≤ .05) between in vivo targeted contrast-enhanced US imaging signals using the three MB types and ex vivo immunoblotting results regarding expression levels of the three angiogenic markers. Immunofluorescence confirmed expression of α(v)ß(3) integrin, endoglin, and VEGFR2 on tumor vascular endothelial cells. CONCLUSION: Targeted contrast-enhanced US imaging allows noninvasive in vivo assessment of the expression levels of α(v)ß(3) integrin, endoglin, and VEGFR2, which vary during tumor growth in subcutaneous cancer xenografts.


Assuntos
Neoplasias Mamárias Experimentais/diagnóstico por imagem , Neovascularização Patológica/diagnóstico por imagem , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Animais , Biomarcadores Tumorais/metabolismo , Meios de Contraste/metabolismo , Endoglina , Feminino , Citometria de Fluxo , Humanos , Processamento de Imagem Assistida por Computador , Integrinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Mamárias Experimentais/irrigação sanguínea , Neoplasias Mamárias Experimentais/metabolismo , Camundongos , Microbolhas , Neoplasias Ovarianas/irrigação sanguínea , Neoplasias Ovarianas/metabolismo , Neoplasias Pancreáticas/irrigação sanguínea , Neoplasias Pancreáticas/metabolismo , Estatísticas não Paramétricas , Ultrassonografia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
18.
Orv Hetil ; 152(3): 83-91, 2011 Jan 16.
Artigo em Húngaro | MEDLINE | ID: mdl-21205607

RESUMO

Regulatory role of the brain in energy expenditure, appetite, glucose metabolism, and central effects of insulin has been prominently studied. Certain neurons in the hypothalamus increase or decrease appetite via orexigenes and anorexigenes, regulating energy balance and food intake. Hypothalamus is the site of afferent and efferent stimuli between special nuclei and beta- and alpha cells, and it regulates induction/inhibition of glucose output from the liver. Incretines, produced in intestine and in certain brain cells (brain-gut hormones), link to special receptors in the hypothalamus. Central role of insulin has been proved both in animals and in humans. Insulin gets across the blood-brain barrier, links to special hypothalamic receptors, regulating peripheral glucose metabolism. Central glucose sensing, via "glucose-excited" and "glucose-inhibited" cells have outstanding role. Former are active in hyperglycaemia, latter in hypoglycaemia, via influencing beta- and alpha cells, independently of traditional metabolic pathways. Evidence of brain insulin resistance needs centrally acting drugs, paradigm changes in therapy and prevention of metabolic syndrome, diabetes, cardiovascular and oncological diseases.


Assuntos
Encéfalo/metabolismo , Cognição , Metabolismo Energético , Resistência à Insulina , Insulina/metabolismo , Síndrome Metabólica/metabolismo , Animais , Depressores do Apetite/metabolismo , Regulação do Apetite/efeitos dos fármacos , Glicemia/metabolismo , Encéfalo/fisiopatologia , Ceramidas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Fígado Gorduroso/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Humanos , Hipotálamo/metabolismo , Incretinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Síndrome Metabólica/psicologia , Neuropeptídeos/metabolismo , Hepatopatia Gordurosa não Alcoólica , Oligopeptídeos/metabolismo , Orexinas , Ácido Pirrolidonocarboxílico/análogos & derivados , Ácido Pirrolidonocarboxílico/metabolismo
19.
Int J Biol Markers ; 25(1): 38-45, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20306451

RESUMO

Early diagnosis and treatment of thyroid cancers are critical for better prognosis and better survival rates. The purpose of this study was to identify potential diagnostic markers for papillary thyroid carcinomas with distant metastasis. Fifty-eight papillary thyroid tumor specimens (27 papillary thyroid carcinomas with distant metastasis and 31 without metastasis) were examined, and protein expression of pituitary tumor-transforming gene (PTTG), E-cadherin, p27kip1, vascular endothelial growth factor (VEGF)-C, metalloproteinase (MMP) 2, MMP9, chemokine receptor CXCR4, and basic fibroblast growth factor (bFGF) in these tumors was assessed by immunohistochemistry. The clinicopathological variables with diagnostic significance were determined by multivariate analysis, and their diagnostic values were evaluated by ROC curve analysis. PTTG, VEGF-C, MMP2, MMP9, CXCR4, and bFGF were overexpressed in metastatic papillary thyroid carcinomas, whereas p27kip1 expression was elevated only in carcinomas lacking metastasis. Multiple-factor binary ordinal logistic regression analysis revealed that PTTG, VEGF-C, MMP2, and bFGF were independently related to biological metastatic behavior in thyroid tumors, suggesting their potential use as biomarkers. ROC curve analysis showed that among these four proteins, VEGF-C and bFGF were the best diagnostic biomarkers. A VEGF-C and bFGF cluster was the most useful factor for the differential diagnosis between metastatic and non-metastatic papillary thyroid cancers. Thus, the combined use of VEGF-C and bFGF as biomarkers may improve the diagnostic accuracy of papillary thyroid carcinoma and may be useful in multimodal screening programs for the clinical diagnosis of papillary thyroid carcinoma and early detection of papillary thyroid carcinoma with distant metastasis.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma Papilar/diagnóstico , Carcinoma Papilar/metabolismo , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/metabolismo , Caderinas/metabolismo , Carcinoma Papilar/secundário , Estudos de Coortes , Inibidor de Quinase Dependente de Ciclina p27 , Diagnóstico Diferencial , Fator 2 de Crescimento de Fibroblastos/metabolismo , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Proteínas de Neoplasias/metabolismo , Curva ROC , Receptores CXCR4/metabolismo , Securina , Fator C de Crescimento do Endotélio Vascular/metabolismo
20.
Acta Physiol (Oxf) ; 198(3): 303-12, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20070282

RESUMO

The hypocretins or orexins are endogenous neuropeptides synthesized in discrete lateral, perifornical and dorsal hypothalamic neurones. These multi-functional neuropeptides modulate energy homeostasis, arousal, stress, reward, reproduction and cardiovascular function. This review summarizes the role of hypocretins in modulating non-sleep-related energy expenditure with specific focus on the augmentation of whole body energy expenditure as well as hypocretin-induced physical activity and sympathetic outflow. We compare the efficacy of hypocretin-1 and 2 on energy expenditure and evaluate whether the literature implicates hypocretin signalling though the hypocretin-1 and -2 receptor as having shared and or functionally specific physiological effects. Thus far data suggest that hypocretin-1 has a more robust stimulatory effect relative to hypocretin-2. Furthermore, hypocretin-1 receptor predominantly mediates behaviours known to influence energy expenditure. Further studies on the hypocretin-2 receptor are needed.


Assuntos
Metabolismo Energético/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Animais , Regulação da Temperatura Corporal/fisiologia , Fenômenos Fisiológicos Cardiovasculares , Humanos , Atividade Motora/fisiologia , Receptores de Orexina , Orexinas , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Transdução de Sinais/fisiologia , Sistema Nervoso Simpático/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA