RESUMO
The intrinsic antiviral defense is based on cellular restriction factors that are constitutively expressed and, thus, active even before a pathogen enters the cell. The promyelocytic leukemia (PML) nuclear bodies (NBs) are discrete nuclear foci that contain several cellular proteins involved in intrinsic antiviral responses against a number of viruses. Accumulating reports have shown the importance of PML as a DNA virus restriction factor and how these pathogens evade this antiviral activity. However, very little information is available regarding the antiviral role of PML against RNA viruses. Dengue virus (DENV) is an RNA emerging mosquito-borne human pathogen affecting millions of individuals each year by causing severe and potentially fatal syndromes. Since no licensed antiviral drug against DENV infection is currently available, it is of great importance to understand the factors mediating intrinsic immunity that may lead to the development of new pharmacological agents that can boost their potency and thereby lead to treatments for this viral disease. In the present study, we investigated the in vitro antiviral role of PML in DENV-2 A549 infected cells.
Assuntos
Vírus da Dengue/fisiologia , Dengue/imunologia , Interferons/imunologia , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Linhagem Celular Tumoral , Chlorocebus aethiops , Vírus da Dengue/classificação , Humanos , Interferons/metabolismo , Corpos de Inclusão Intranuclear/metabolismo , Proteína da Leucemia Promielocítica , Células Vero , Replicação ViralRESUMO
Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder caused by a polyglutamine expansion in the amino-terminal region of the huntingtin protein, which promotes progressive neuronal cell loss, neurological symptoms and death. In the present study, we show that blockade of mGluR5 with MTEP promotes increased locomotor activity in both control (Hdh(Q20/Q20)) and mutant HD (Hdh(Q111/Q111)) mice. Although acute injection of MTEP increases locomotor activity in both control and mutant HD mice, locomotor activity is increased in only control mice, not mutant HD mice, following the genetic deletion of mGluR5. Interestingly, treatment of mGluR5 knockout mice with either D1 or D2 dopamine antagonists eliminates the increased locomotor activity of mGluR5 knockout mice. Amphetamine treatment increases locomotor activity in control mice, but not mGluR5 null mutant HD mice. However, the loss of mGluR5 expression improves rotarod performance and decreases the number of huntingtin intranuclear inclusions in mutant HD mice. These adaptations may be due to mutant huntingtin-dependent alterations in gene expression, as microarray studies have identified several genes that are altered in mutant, but not wild-type HD mice lacking mGluR5 expression. qPCR experiments confirm that the mRNA transcript levels of dynein heavy chain, dynactin 3 and dynein light chain-6 are altered following the genetic deletion of mGluR5 in mutant HD mice, as compared with wild-type mutant HD mice. Thus, our data suggest that mutant huntingtin protein and mGluR5 exhibit a functional interaction that may be important for HD-mediated alterations in locomotor behavior and the development of intranuclear inclusions.
Assuntos
Modelos Animais de Doenças , Doença de Huntington/patologia , Corpos de Inclusão Intranuclear/patologia , Atividade Motora/fisiologia , Receptor de Glutamato Metabotrópico 5/fisiologia , Proteínas da Membrana Plasmática de Transporte de Serotonina/fisiologia , Animais , Western Blotting , Proliferação de Células , Células Cultivadas , Perfilação da Expressão Gênica , Doença de Huntington/genética , Doença de Huntington/metabolismo , Técnicas Imunoenzimáticas , Corpos de Inclusão Intranuclear/genética , Corpos de Inclusão Intranuclear/metabolismo , Camundongos , Camundongos Knockout , Atividade Motora/efeitos dos fármacos , Piridinas/farmacologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptor de Glutamato Metabotrópico 5/antagonistas & inibidores , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tiazóis/farmacologiaRESUMO
The presence of intranuclear filamentous inclusions in cerebellar Golgi cells is reported in three patients with cerebellar tumours. Samples of cerebellar cortex were processed for conventional transmission electron microscopy. Cerebellar biopsies were performed according to the basic principles of Helsinki declaration. Intranuclear inclusions observed in oedematous Golgi cells, appeared as straight rodlets up to 3 microm in length and up to 0.4 microm in width, characterized by a periodic or crystalloid structure formed by dense bands, 9.2 nm thick separated by clear spaces, 5.4 nm in width. These structures are considered abnormal protein aggregates apparently induced by excitotoxicity, oxidative stress and impaired energy metabolism.