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1.
Blood ; 121(1): 85-94, 2013 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-23144170

RESUMO

Immunoglobulin class switching from IgM to IgG in response to peptides is generally T cell-dependent and vaccination in T cell-deficient individuals is inefficient. We show that a vaccine consisting of a dense array of peptides on liposomes induced peptide-specific IgG responses totally independent of T-cell help. Independency was confirmed in mice lacking T cells and in mice deficient for MHC class II, CD40L, and CD28. The IgG titers were high, long-lived, and comparable with titers obtained in wild-type animals, and the antibody response was associated with germinal center formation, expression of activation-induced cytidine deaminase, and affinity maturation. The T cell-independent (TI) IgG response was strictly dependent on ligation of TLR4 receptors on B cells, and concomitant TLR4 and cognate B-cell receptor stimulation was required on a single-cell level. Surprisingly, the IgG class switch was mediated by TIR-domain-containing adapter inducing interferon-ß (TRIF), but not by MyD88. This study demonstrates that peptides can induce TI isotype switching when antigen and TLR ligand are assembled and appropriately presented directly to B lymphocytes. A TI vaccine could enable efficient prophylactic and therapeutic vaccination of patients with T-cell deficiencies and find application in diseases where induction of T-cell responses contraindicates vaccination, for example, in Alzheimer disease.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/fisiologia , Peptídeos beta-Amiloides/imunologia , Linfócitos B/imunologia , Switching de Imunoglobulina/imunologia , Fragmentos de Peptídeos/imunologia , Receptor 4 Toll-Like/fisiologia , Vacinas de Subunidades Antigênicas/imunologia , Proteínas Adaptadoras de Transporte Vesicular/deficiência , Proteínas Adaptadoras de Transporte Vesicular/genética , Transferência Adotiva , Sequência de Aminoácidos , Peptídeos beta-Amiloides/administração & dosagem , Animais , Apresentação de Antígeno , Linfócitos B/metabolismo , Antígenos CD28/deficiência , Antígenos CD28/imunologia , Ligante de CD40/deficiência , Ligante de CD40/imunologia , Centro Germinativo/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Receptores de Lipopolissacarídeos/imunologia , Lipossomos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Dados de Sequência Molecular , Ovalbumina/administração & dosagem , Ovalbumina/imunologia , Fragmentos de Peptídeos/administração & dosagem , Receptores de Antígenos de Linfócitos B/imunologia , Linfócitos T/imunologia , Receptor 4 Toll-Like/deficiência , Receptor 4 Toll-Like/genética , Vacinação , Vacinas de Subunidades Antigênicas/administração & dosagem
2.
Brain ; 135(Pt 11): 3251-64, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22822039

RESUMO

The neurovascular unit provides a dynamic interface between the circulation and central nervous system. Disruption of neurovascular integrity occurs in numerous brain pathologies including neurotrauma and ischaemic stroke. Tissue plasminogen activator is a serine protease that converts plasminogen to plasmin, a protease that dissolves blood clots. Besides its role in fibrinolysis, tissue plasminogen activator is abundantly expressed in the brain where it mediates extracellular proteolysis. However, proteolytically active tissue plasminogen activator also promotes neurovascular disruption after ischaemic stroke; the molecular mechanisms of this process are still unclear. Tissue plasminogen activator is naturally inhibited by serine protease inhibitors (serpins): plasminogen activator inhibitor-1, neuroserpin or protease nexin-1 that results in the formation of serpin:protease complexes. Proteases and serpin:protease complexes are cleared through high-affinity binding to low-density lipoprotein receptors, but their binding to these receptors can also transmit extracellular signals across the plasma membrane. The matrix metalloproteinases are the second major proteolytic system in the mammalian brain, and like tissue plasminogen activators are pivotal to neurological function but can also degrade structures of the neurovascular unit after injury. Herein, we show that tissue plasminogen activator potentiates neurovascular damage in a dose-dependent manner in a mouse model of neurotrauma. Surprisingly, inhibition of activity following administration of plasminogen activator inhibitor-1 significantly increased cerebrovascular permeability. This led to our finding that formation of complexes between tissue plasminogen activator and plasminogen activator inhibitor-1 in the brain parenchyma facilitates post-traumatic cerebrovascular damage. We demonstrate that following trauma, the complex binds to low-density lipoprotein receptors, triggering the induction of matrix metalloproteinase-3. Accordingly, pharmacological inhibition of matrix metalloproteinase-3 attenuates neurovascular permeability and improves neurological function in injured mice. Our results are clinically relevant, because concentrations of tissue plasminogen activator: plasminogen activator inhibitor-1 complex and matrix metalloproteinase-3 are significantly elevated in cerebrospinal fluid of trauma patients and correlate with neurological outcome. In a separate study, we found that matrix metalloproteinase-3 and albumin, a marker of cerebrovascular damage, were significantly increased in brain tissue of patients with neurotrauma. Perturbation of neurovascular homeostasis causing oedema, inflammation and cell death is an important cause of acute and long-term neurological dysfunction after trauma. A role for the tissue plasminogen activator-matrix metalloproteinase axis in promoting neurovascular disruption after neurotrauma has not been described thus far. Targeting tissue plasminogen activator: plasminogen activator inhibitor-1 complex signalling or downstream matrix metalloproteinase-3 induction may provide viable therapeutic strategies to reduce cerebrovascular permeability after neurotrauma.


Assuntos
Lesões Encefálicas/fisiopatologia , Permeabilidade Capilar/fisiologia , Inibidor 1 de Ativador de Plasminogênio/fisiologia , Ativador de Plasminogênio Tecidual/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Albuminas/metabolismo , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Lesões Encefálicas/líquido cefalorraquidiano , Lesões Encefálicas/tratamento farmacológico , Lesões Encefálicas/metabolismo , Permeabilidade Capilar/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Injeções Intraventriculares , Masculino , Inibidores de Metaloproteinases de Matriz/uso terapêutico , Metaloproteinases da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/administração & dosagem , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Recuperação de Função Fisiológica/fisiologia , Ativador de Plasminogênio Tecidual/administração & dosagem , Ativador de Plasminogênio Tecidual/antagonistas & inibidores , Ativador de Plasminogênio Tecidual/metabolismo
3.
Front Neurosci ; 17: 1202208, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37449271

RESUMO

Introduction: People with DS are highly predisposed to Alzheimer's disease (AD) and demonstrate very similar clinical and pathological features. Ts65Dn mice are widely used and serve as the best-characterized animal model of DS. Methods: We undertook studies to characterize age-related changes for AD-relevant markers linked to Aß, Tau, and phospho-Tau, axonal structure, inflammation, and behavior. Results: We found age related changes in both Ts65Dn and 2N mice. Relative to 2N mice, Ts65Dn mice showed consistent increases in Aß40, insoluble phospho-Tau, and neurofilament light protein. These changes were correlated with deficits in learning and memory. Discussion: These data have implications for planning future experiments aimed at preventing disease-related phenotypes and biomarkers. Interventions should be planned to address specific manifestations using treatments and treatment durations adequate to engage targets to prevent the emergence of phenotypes.

4.
J Biol Chem ; 286(16): 13966-76, 2011 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-21343310

RESUMO

Synthetic peptide immunogens that mimic the conformation of a target epitope of pathological relevance offer the possibility to precisely control the immune response specificity. Here, we performed conformational analyses using a panel of peptides in order to investigate the key parameters controlling their conformation upon integration into liposomal bilayers. These revealed that the peptide lipidation pattern, the lipid anchor chain length, and the liposome surface charge all significantly alter peptide conformation. Peptide aggregation could also be modulated post-liposome assembly by the addition of distinct small molecule ß-sheet breakers. Immunization of both mice and monkeys with a model liposomal vaccine containing ß-sheet aggregated lipopeptide (Palm1-15) induced polyclonal IgG antibodies that specifically recognized ß-sheet multimers over monomer or non-pathological native protein. The rational design of liposome-bound peptide immunogens with defined conformation opens up the possibility to generate vaccines against a range of protein misfolding diseases, such as Alzheimer disease.


Assuntos
Lipossomos/química , Peptídeos/química , Deficiências na Proteostase/metabolismo , Vacinas/química , Doença de Alzheimer/metabolismo , Animais , Benzotiazóis , Dicroísmo Circular , Feminino , Humanos , Imunoglobulina G/química , Espectroscopia de Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Conformação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Tiazóis/química
5.
Lab Invest ; 91(7): 1079-91, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21519332

RESUMO

Tissue-type plasminogen activator (tPA) is a major protease of the central nervous system. Most studies to date have used in situ- or gel-based zymographic assays to monitor in vivo changes in neural tPA activity. In this study, we demonstrate that the amidolytic assay can be adapted to accurately detect changes in net tPA activity in mouse brain tissues. Using the amidolytic assay, we examined differences in net tPA activity in the cerebral cortex, sub-cortical structures and cerebellum in wildtype (WT) and tPA(-/-) mice, and in transgenic mice selectively overexpressing tPA in neurons. In addition, we assessed changes in endogenous net tPA activity in WT mice following morphine administration, epileptic seizures, traumatic brain injury and ischaemic stroke-neurological settings in which tPA has a known functional role. Under these conditions, acute and compartment-specific regulation of tPA activity was observed. tPA also participates in various forms of chronic neurodegeneration. Accordingly, we assessed tPA activity levels in mouse models of Alzheimer's disease (AD) and spinocerebellar ataxia type-1 (SCA1). Decreased tPA activity was detected in the cortex and subcortex of AD mice, whereas increased tPA activity was found in the cerebellum of SCA1 mice. These findings extend the existing hypotheses that low tPA activity promotes AD, whereas increased tPA activity contributes to cerebellar degeneration. Collectively, our results exemplify the utility of the amidolytic assay and emphasise tPA as a complex mediator of brain function and dysfunction. On the basis of this evidence, we propose that alterations in tPA activity levels could be used as a biomarker for perturbations in brain homeostasis.


Assuntos
Lesões Encefálicas/metabolismo , Isquemia Encefálica/metabolismo , Compartimento Celular , Morfina/administração & dosagem , Ativador de Plasminogênio Tecidual/metabolismo , Animais , Sequência de Bases , Primers do DNA , Camundongos , Camundongos Transgênicos , Reação em Cadeia da Polimerase
6.
Int J Dev Biol ; 52(7): 933-42, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18956323

RESUMO

Serpins, a superfamily of protease inhibitors, control proteolytic cascades in many physiological processes. Genomic studies have revealed the presence of a high number of serpin-encoding genes in Drosophila melanogaster, but their functions remain largely unknown. In a biochemical screen designed to detect protease inhibitors that may be implicated in early Drosophila development, we identified in embryos a ligand that forms a 67 kDa SDS-stable complex with the broad spectrum protease trypsin. Characterization of this ligand revealed it to be the recently described serpin, Spn5. Expression analysis by in situ and Northern blot hybridization indicated maternal transmission of the transcript as well as zygotic expression in many larval, pupal and adult tissues. Targeted repression by RNA interference did not alter early embryogenesis but resulted in a complete defect in the unfolding and expansion of the wings of freshly eclosed mutant flies, without other detectable effects on development.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Serpinas/metabolismo , Asas de Animais/metabolismo , Animais , Northern Blotting , Proteínas de Drosophila/genética , Proteínas de Drosophila/isolamento & purificação , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Embrião não Mamífero , Escherichia coli/genética , Hibridização In Situ , Plasmídeos , Interferência de RNA , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo , Serpinas/genética , Serpinas/isolamento & purificação
7.
Environ Health Perspect ; 115(10): 1467-73, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17938737

RESUMO

BACKGROUND: Obesity is an increasingly prevalent health problem, and natural effective therapeutic approaches are required to prevent its occurrence. Phytoestrogens are plant-derived compounds with estrogenic activities; they can bind to both estrogen receptors alpha and beta and mimic the action of estrogens on target organs. OBJECTIVES: The purpose of this study was to examine the influence of soy-derived phytoestrogens on energy balance and metabolism. METHODS: Male outbred mice (CD-1) were allowed ad libitum access to either a high soy-containing diet or a soy-free diet from conception to adulthood. We measured circulating serum isoflavone levels using reverse-phase solid-phase extraction for subsequent liquid chromatography electrospray tandem mass spectrometry analysis. Adult animals were analyzed for body composition by dual-energy X-ray absorptiometry, locomotor activity by running-wheel experiments, respiratory exchange rate by indirect calorimetry, and food intake using metabolic cages. Quantitative reverse transcriptase-polymerase chain reaction was performed to determine the expression of hypothalamic neuropeptide genes. RESULTS: We found that adult mice fed a soy-rich diet had reduced body weight, adiposity, and resistance to cold. This lean phenotype was associated with an increase in lipid oxidation due to a preferential use of lipids as fuel source and an increase in locomotor activity. The modulation of energy balance was associated with a central effect of phytoestrogens on the expression of hypothalamic neuropeptides, including agouti-related protein. CONCLUSION: The data suggest that dietary soy could have beneficial effects on obesity, but they also emphasize the importance of monitoring the phytoestrogen content of diets as a parameter of variability in animal experiments.


Assuntos
Adiposidade/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Glycine max/química , Isoflavonas/sangue , Fitoestrógenos/farmacologia , Proteína Relacionada com Agouti/efeitos dos fármacos , Ração Animal , Animais , Estudos de Casos e Controles , Temperatura Baixa , Isoflavonas/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Obesidade , Fitoestrógenos/metabolismo
9.
PLoS One ; 11(3): e0152471, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27023444

RESUMO

In Down syndrome (DS) or trisomy of chromosome 21, the ß-amyloid (Aß) peptide product of the amyloid precursor protein (APP) is present in excess. Evidence points to increased APP gene dose and Aß as playing a critical role in cognitive difficulties experienced by people with DS. Particularly, Aß is linked to the late-life emergence of dementia as associated with neuropathological markers of Alzheimer's disease (AD). At present, no treatment targets Aß-related pathogenesis in people with DS. Herein we used a vaccine containing the Aß 1-15 peptide embedded into liposomes together with the adjuvant monophosphoryl lipid A (MPLA). Ts65Dn mice, a model of DS, were immunized with the anti-Aß vaccine at 5 months of age and were examined for cognitive measures at 8 months of age. The status of basal forebrain cholinergic neurons and brain levels of APP and its proteolytic products were measured. Immunization of Ts65Dn mice resulted in robust anti-Aß IgG titers, demonstrating the ability of the vaccine to break self-tolerance. The vaccine-induced antibodies reacted with Aß without detectable binding to either APP or its C-terminal fragments. Vaccination of Ts65Dn mice resulted in a modest, but non-significant reduction in brain Aß levels relative to vehicle-treated Ts65Dn mice, resulting in similar levels of Aß as diploid (2N) mice. Importantly, vaccinated Ts65Dn mice showed resolution of memory deficits in the novel object recognition and contextual fear conditioning tests, as well as reduction of cholinergic neuron atrophy. No treatment adverse effects were observed; vaccine did not result in inflammation, cellular infiltration, or hemorrhage. These data are the first to show that an anti-Aß immunotherapeutic approach may act to target Aß-related pathology in a mouse model of DS.


Assuntos
Peptídeos beta-Amiloides/imunologia , Transtornos Cognitivos/complicações , Transtornos Cognitivos/tratamento farmacológico , Síndrome de Down/complicações , Síndrome de Down/tratamento farmacológico , Vacinas/uso terapêutico , Peptídeos beta-Amiloides/genética , Animais , Animais Recém-Nascidos , Anticorpos/metabolismo , Atrofia , Comportamento Animal , Biomarcadores/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Neurônios Colinérgicos/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hemorragia/patologia , Inflamação/patologia , Masculino , Memória , Camundongos Transgênicos , Núcleos Septais/patologia , Vacinação
10.
Trends Mol Med ; 9(5): 183-5, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12763521

RESUMO

Activity-dependent remodeling of neural connections might require localized extracellular proteolysis. The tissue-type plasminogen activator (tPA)-plasmin proteolytic system is expressed in different regions of the central nervous system, in the context of a variety of physiological and pathological processes. Accumulating evidence regarding the expression and role of tPA and its inhibitors suggests that extracellular proteolysis is a key player in the biology of memory, emotions and neurodegeneration.


Assuntos
Emoções/fisiologia , Sistema Nervoso/metabolismo , Ativador de Plasminogênio Tecidual/metabolismo , Animais , Camundongos , Neuropeptídeos/metabolismo , Serpinas/metabolismo , Neuroserpina
11.
Biol Psychiatry ; 54(10): 972-82, 2003 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-14625139

RESUMO

BACKGROUND: According to the neurotrophin hypothesis of depression, decreased activity of brain-derived neurotrophic factor (BDNF) contributes to behavioral and plasticity-related alterations in depressed patients. We investigated the hypothesis that mice with a forebrain-specific knockout of the trkB receptor, the main mediator of BDNF signaling, represent a genetic animal model for depression. METHODS: Using the CRE-loxP system, we bred trkB(CaMKII-CRE) mice with a trkB-receptor disruption in the forebrain. We subjected trkB-mutant mice to a battery of behavioral tests, comprising open field, elevated zero maze, emergence test, novel object test, and forced swim. Additionally, we investigated the hypothalamic-pituitary-adrenal (HPA) axis immunohistochemically and by plasma analyses. RESULTS: trkB(CaMKII-CRE) mice showed a stereotyped hyper-locomotion with reduced explorative activity, and impulsive reactions to novel stimuli. The trkB-mutant mice did not exhibit depressionlike behaviors such as increased "despair" in the forced swim test, increased anxiety in the elevated zero maze, or neophobia in the novel object test. Furthermore, no HPA dysregulation was observed under normal and stressful conditions. CONCLUSIONS: trkB(CaMKII-CRE) mice cannot be regarded as a genetic mouse model of depression. Instead, the behavioral symptoms of trkB(CaMKII-CRE) mice, comprising hyper-locomotion, stereotyped behaviors, and cognitive impairments, are similar to those postulated for mouse models of attention-deficit disorder.


Assuntos
Depressão/fisiopatologia , Prosencéfalo/metabolismo , Agitação Psicomotora/fisiopatologia , Receptor trkB/metabolismo , Hormônio Adrenocorticotrópico/sangue , Análise de Variância , Animais , Comportamento Animal , Corticosterona/sangue , Hormônio Liberador da Corticotropina/metabolismo , Depressão/metabolismo , Comportamento Exploratório , Imuno-Histoquímica , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Movimento , Prosencéfalo/anatomia & histologia , Prosencéfalo/fisiopatologia , Agitação Psicomotora/genética , Agitação Psicomotora/metabolismo , Tempo de Reação , Receptor trkB/deficiência , Receptor trkB/genética , Comportamento Estereotipado , Natação , Fatores de Tempo
12.
J Alzheimers Dis ; 38(4): 767-86, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24072071

RESUMO

The formation and accumulation of toxic amyloid-ß peptides (Aß) in the brain may drive the pathogenesis of Alzheimer's disease. Accordingly, disease-modifying therapies for Alzheimer's disease and related disorders could result from treatments regulating Aß homeostasis. Examples are the inhibition of production, misfolding, and accumulation of Aß or the enhancement of its clearance. Here we show that oral treatment with ACI-91 (Pirenzepine) dose-dependently reduced brain Aß burden in AßPPPS1, hAßPPSL, and AßPP/PS1 transgenic mice. A possible mechanism of action of ACI-91 may occur through selective inhibition of muscarinic acetylcholine receptors (AChR) on endothelial cells of brain microvessels and enhanced Aß peptide clearance across the blood-brain barrier. One month treatment with ACI-91 increased the clearance of intrathecally-injected Aß in plaque-bearing mice. ACI-91 also accelerated the clearance of brain-injected Aß in blood and peripheral tissues by favoring its urinal excretion. A single oral dose of ACI-91 reduced the half-life of interstitial Aß peptide in pre-plaque mhAßPP/PS1d mice. By extending our studies to an in vitro model, we showed that muscarinic AChR inhibition by ACI-91 and Darifenacin augmented the capacity of differentiated endothelial monolayers for active transport of Aß peptide. Finally, ACI-91 was found to consistently affect, in vitro and in vivo, the expression of endothelial cell genes involved in Aß transport across the Blood Brain Brain (BBB). Thus increased Aß clearance through the BBB may contribute to reduced Aß burden and associated phenotypes. Inhibition of muscarinic AChR restricted to the periphery may present a therapeutic advantage as it avoids adverse central cholinergic effects.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Barreira Hematoencefálica/metabolismo , Angiopatia Amiloide Cerebral/metabolismo , Modelos Animais de Doenças , Antagonistas Muscarínicos/uso terapêutico , Fenótipo , Receptores Muscarínicos/metabolismo , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/patologia , Angiopatia Amiloide Cerebral/tratamento farmacológico , Angiopatia Amiloide Cerebral/patologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Antagonistas Muscarínicos/farmacologia , Pirenzepina/farmacologia , Pirenzepina/uso terapêutico
13.
Science ; 318(5855): 1472-5, 2007 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-18048693

RESUMO

JAM-C is an adhesion molecule that is expressed on cells within the vascular compartment and epithelial cells and, to date, has been largely studied in the context of inflammatory events. Using immunolabeling procedures in conjunction with confocal and electron microscopy, we show here that JAM-C is also expressed in peripheral nerves and that this expression is localized to Schwann cells at junctions between adjoining myelin end loops. Sciatic nerves from JAM-C-deficient [having the JAM-C gene knocked out (KO)] mice exhibited loss of integrity of the myelin sheath and defective nerve conduction as indicated by morphological and electrophysiological studies, respectively. In addition, behavioral tests showed motor abnormalities in the KO animals. JAM-C was also expressed in human sural nerves with an expression profile similar to that seen in mice. These results demonstrate that JAM-C is a component of the autotypic junctional attachments of Schwann cells and plays an important role in maintaining the integrity and function of myelinated peripheral nerves.


Assuntos
Moléculas de Adesão Celular/metabolismo , Imunoglobulinas/metabolismo , Proteínas de Membrana/metabolismo , Bainha de Mielina/fisiologia , Fibras Nervosas Mielinizadas/fisiologia , Nervos Periféricos/metabolismo , Células de Schwann/metabolismo , Potenciais de Ação , Animais , Humanos , Junções Intercelulares/metabolismo , Camundongos , Camundongos Knockout , Bainha de Mielina/metabolismo , Bainha de Mielina/ultraestrutura , Fibras Nervosas Mielinizadas/metabolismo , Fibras Nervosas Mielinizadas/ultraestrutura , Condução Nervosa , Nervos Periféricos/fisiologia , Doenças do Sistema Nervoso Periférico/metabolismo , Doenças do Sistema Nervoso Periférico/patologia , Doenças do Sistema Nervoso Periférico/fisiopatologia , Nervo Isquiático/metabolismo , Nervo Isquiático/fisiologia , Nervo Isquiático/ultraestrutura , Nervo Sural/metabolismo , Nervo Sural/fisiologia
14.
Mol Reprod Dev ; 73(1): 9-19, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16175637

RESUMO

The serpin superfamily of serine protease inhibitors is implicated in the regulation of numerous physiological processes. In mice, Spi3/Serpinb6 has a broad tissue distribution. We have investigated the expression of Serpinb6 family members in embryonic and adult gonads. In male and female mice, Spi3/Serpinb6 and NK13/Serpinb6b were expressed in developing gonads and in both somatic and germ cells of adult gonads. By contrast, gonadal expression of Spi3C/Serpinb6c was sexually dimorphic and restricted to male germ cells and female somatic cells. These observations raise the question of the possible role(s) of the Serpinb6 family members in gonad development, gametogenesis, and/or fertilization.


Assuntos
Oócitos/metabolismo , Ovalbumina/biossíntese , Ovalbumina/genética , Ovário/metabolismo , Serpinas/biossíntese , Serpinas/genética , Espermatozoides/metabolismo , Testículo/metabolismo , Animais , Feminino , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Ovário/citologia , Ovário/embriologia , RNA Mensageiro/biossíntese , Receptores Citoplasmáticos e Nucleares/biossíntese , Receptores Citoplasmáticos e Nucleares/genética , Fator Esteroidogênico 1 , Testículo/citologia , Testículo/embriologia , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética
15.
J Neurosci Res ; 84(8): 1871-8, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16998901

RESUMO

Accumulation of the beta-amyloid peptide (Abeta) in the brain is a major pathological hallmark of Alzheimer's disease (AD), leading to synaptic dysfunction, neuronal death, and memory impairment. The levels of neprilysin, a major Abeta-degrading enzyme, are decreased in AD brains and during aging. Because neprilysin cleaves Abeta in vivo, its down-regulation may contribute to the pathophysiology of AD. The aim of this study was to assess the consequences of neprilysin deficiency on accumulation of murine Abeta in brains and associated pathologies in vivo by investigating neprilysin-deficient mice on biochemical, morphological, and behavioral levels. Aged neprilysin-deficient mice expressed physiological amyloid precursor protein (APP) levels and exhibited elevated brain Abeta concentrations and amyloid-like deposits in addition to signs of neuronal degeneration in their brains. Behaviorally, neprilysin-deficient mice acquired a significantly weaker conditioned taste aversion that extinguished faster than the aversion of age-matched controls. Our data establish that, under physiological APP expression levels, neprilysin deficiency is associated with increased Abeta accumulation in the brain and leads to deposition of amyloid-like structures in vivo as well as with signs of AD-like pathology and with behavioral deficits.


Assuntos
Amiloide/metabolismo , Comportamento Animal/fisiologia , Encéfalo/patologia , Neprilisina/deficiência , Fatores Etários , Amiloide/ultraestrutura , Análise de Variância , Animais , Aprendizagem da Esquiva/fisiologia , Encéfalo/ultraestrutura , Condicionamento Operante/fisiologia , Ensaio de Imunoadsorção Enzimática/métodos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Eletrônica de Transmissão/métodos , Privação de Água/fisiologia
16.
Mol Cell Neurosci ; 23(3): 473-94, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12837630

RESUMO

Neuroserpin is a neural serpin that inhibits the extracellular protease tissue-type plasminogen activator (tPA). We have generated neuroserpin-deficient mice which are viable and healthy. Zymographic analysis of neuroserpin-deficient brain showed unaltered tPA activity, suggesting that other inhibitors contribute to the regulation of tPA and may compensate for the defect. Analysis of explorative behavior revealed selective reduction of locomotor activity in novel environments, an anxiety-like response on the O-maze, and a neophobic response to novel objects. Mice overexpressing neuroserpin under the control of the Thy1.2 promoter are known to have a reduced brain tPA activity. They showed reduced center exploration in the open-field test and, like neuroserpin-deficient mice, a neophobic phenotype in the novel object test. Our results implicate neuroserpin in the regulation of emotional behavior through a mechanism that is at least in part independent of tPA activity. They are the first evidence for a role of protease inhibitors in mood regulation.


Assuntos
Comportamento Exploratório/fisiologia , Neuropeptídeos/genética , Transtornos Fóbicos/fisiopatologia , Serpinas/genética , Afeto/fisiologia , Animais , Aprendizagem da Esquiva/fisiologia , Comportamento Animal/fisiologia , Espaço Extracelular/enzimologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Atividade Motora/fisiologia , Serina Endopeptidases/metabolismo , Ativador de Plasminogênio Tecidual/metabolismo , Neuroserpina
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