RESUMO
cDNA microarray technique has been widely used for the detection and elucidation of differentially expressed genes on a large scale and at a speed never before possible. The aim of this study was to gain insight into the potentially overexpressed effects of APPsw on the modulation of genes for Alzheimer's disease (AD), which is central to understanding the complexity of AD. APPsw transgenic mice, which we previously produced, provide an important resource for identifying differentially expressed genes since this transgenic line was shown to have cognitive deficits along with Abeta-42 deposits at 12 months of age. To identify differentially expressed genes, cDNA microarray technique was conducted to get a large-scale screening of brain mRNA from 18 month-old NSE/APPsw transgenic and non-transgenic mice. A total of 52 differentially expressed genes, 10 up-regulated and 42 down-regulated, were found in the brains of moderately transgenic mice compared to non-transgenic littermates. Thus, the results suggest the need for future studies on gene functions, pathology, toxicogenomics, and pharmacogenomics.
Assuntos
Precursor de Proteína beta-Amiloide/genética , Encéfalo/metabolismo , Perfilação da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Animais , Regulação para Baixo/genética , Feminino , Regulação da Expressão Gênica/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosfopiruvato Hidratase/genética , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulação para Cima/genéticaRESUMO
Estrogen influences the processing of the amyloid beta precursor protein (APP) in the pathogenesis of Alzheimer's disease, and this effect is mediated by estrogen receptors (ERs) in activating mitogen-activated protein kinase (MAPK)-signaling pathway. To test whether the estrogenic effect on both carboxyl-terminal amino acid fragment (C-terminal) of APP (APP-C105)- and ERbeta-mediated MAPK activation in in vitro, two hybrid genes containing each human ERbeta and APP-C105 gene fused to the neuron-specific enolase (NSE) promoter were constructed and were transfected to the neuronal SK-N-MC cells. Western blot shows that the activation of JNK-signaling pathway, but not p38 and ERK, is dependent on ERbeta through estrogen treatment and APP-C105 is also mediated through estrogen in activating MAPK-signaling pathway. The results suggest that ERbeta and APP-C105 derived from APP are necessary for estrogenic effect in activating MAPK-signaling pathway.
Assuntos
Precursor de Proteína beta-Amiloide/química , Precursor de Proteína beta-Amiloide/metabolismo , Estradiol/farmacologia , Receptor beta de Estrogênio/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Sequência de Aminoácidos , Precursor de Proteína beta-Amiloide/genética , Linhagem Celular , Ativação Enzimática/efeitos dos fármacos , Receptor beta de Estrogênio/genética , Humanos , Dados de Sequência Molecular , Fosforilação/efeitos dos fármacos , TransfecçãoRESUMO
Mutations in the APP gene lead to enhanced cleavage by the beta- and gamma-secretase, and increased Abeta formation, which are tightly associated with Alzheimer's disease (AD)-like neuropathological changes. To examine whether depositions of Abeta by APP mutations are increased, and if this is associated with potential pathogenic phenotypes, the APPsw was expressed in a transgenic line under the control of the neuron-specific enolase (NSE) promoter. A behavioral dysfunction was shown at 12 months, and intensive staining bands, with APP and Abeta-42 antibodies, were visible in the brains of transgenic mice. Of the MAPK family, both JNK and p38 were activated in the brains of transgenic mice, whereas there was no significant activation of the ERK. In parallel, tau phosphorylation was also enhanced in the transgenic relative to the control mice. Moreover, the Cox-2 levels, from Western blot and immunostaining, were increased in the brains of the transgenic line. Furthermore, there were significant caspase-3- and TUNEL-stained nuclei in the transgenic line compared to the age-matched control mice. Thus, these results suggest that NSE-controlled APPsw transgenic mice appear to be a more relevant model in neuropathological phenotypes of AD, and thus could be useful in developing new therapeutic treatments for targeting the aberrant phenotypes that appear in these mice.
Assuntos
Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/genética , Proteínas Quinases JNK Ativadas por Mitógeno , Fenótipo , Fosfopiruvato Hidratase/fisiologia , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Animais , Apoptose/genética , Comportamento Animal , Western Blotting/métodos , Encéfalo/anatomia & histologia , Encéfalo/metabolismo , Caspase 3 , Caspases/metabolismo , Ciclo-Oxigenase 2 , DNA/metabolismo , Modelos Animais de Doenças , Reação de Fuga/fisiologia , Immunoblotting/métodos , Imuno-Histoquímica/métodos , Marcação In Situ das Extremidades Cortadas/métodos , Isoenzimas/metabolismo , MAP Quinase Quinase 4 , Camundongos , Camundongos Transgênicos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Dados de Sequência Molecular , Mutação , Fragmentos de Peptídeos/metabolismo , Fosfopiruvato Hidratase/genética , Prostaglandina-Endoperóxido Sintases/metabolismo , RNA Mensageiro/biossíntese , Tempo de Reação/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Proteínas Quinases p38 Ativadas por Mitógeno , Proteínas tau/metabolismoRESUMO
In its late stage, Alzheimer's disease results in progressive muscle weakness in the arms and legs. The aim of this study was to determine whether mice expressing the skeletal muscle-specific mutant PS2 gene (a model of Alzheimer's disease) are a useful experimental system to study the protective effect of exercise on A beta-42 reduction, improvement of behavioural function and changes in metabolic parameters. With this aim in mind, the transgenic mice were subjected to treadmill exercise for 3 months. The results showed that in transgenic mice, but not in normal mice, treadmill exercise resulted in a reduction of A beta-42 deposits and an improvement in behavioural function, thereby restoring normal concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglyceride. Thus, exercise may represent a practical therapeutic strategy for use with human patients with Alzheimer's disease.
