RESUMO
Oxidative stress-induced apoptosis is associated with neuronal cell death and ischemia. The NOL3 [nucleolar protein 3 (apoptosis repressor with CARD domain)] protein protects against oxidative stress-induced cell death. However, the protective mechanism responsible for this effect as well as the effects of NOL3 against oxidative stress in ischemia remain unclear. Thus, we examined the protective effects of NOL3 protein on hydrogen peroxide (H2O2)-induced oxidative stress and the mechanism responsible for these effects in hippocampal neuronal HT22 cells and in an animal model of forebrain ischemia using Tat-fused NOL3 protein (Tat-NOL3). Purified Tat-NOL3 protein transduced into the H2O2-exposed HT22 cells and inhibited the production of reactive oxygen species (ROS), DNA fragmentation and reduced mitochondrial membrane potential (ΔΨm). In addition, Tat-NOL3 prevented neuronal cell death through the regulation of apoptotic signaling pathways including Bax, Bcl-2, caspase-2, -3 and -8, PARP and p53. In addition, Tat-NOL3 protein transduced into the animal brains and significantly protected against neuronal cell death in the CA1 region of the hippocampus by regulating the activation of microglia and astrocytes. Taken together, these findings demonstrate that Tat-NOL3 protein protects against oxidative stress-induced neuronal cell death by regulating oxidative stress and by acting as an anti-apoptotic protein. Thus, we suggest that Tat-NOL3 represents a potential therapeutic agent for protection against ischemic brain injury.
Assuntos
Proteínas Reguladoras de Apoptose/farmacologia , Apoptose/efeitos dos fármacos , Hipocampo/patologia , Proteínas Musculares/farmacologia , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Proteínas Recombinantes de Fusão/farmacologia , Produtos do Gene tat do Vírus da Imunodeficiência Humana/farmacologia , Animais , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Modelos Animais de Doenças , Gerbillinae , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Transdução GenéticaRESUMO
Oxidative stress is considered a major factor in various neuronal diseases including ischemia-reperfusion injury. Proviral Integration Moloney 2 (PIM2) proteins, one of the families of PIM kinases, play crucial roles in cell survival. However, the functions of PIM2 protein against ischemia are not understood. Therefore, the protective effects of PIM2 against oxidative stress-induced hippocampal HT22 cell death and brain ischemic injury were evaluated using Tat-PIM2, a cell permeable fusion protein. Tat-PIM2 protein transduced into hippocampal HT22 cells. Low doses of transduced Tat-PIM2 protein protected against oxidative stress-induced cell death including DNA damage and markedly inhibited the activation of mitogen activated protein kinase (MAPKs), NF-κB and the expression levels of Bax protein. Furthermore, Tat-PIM2 protein transduced into the CA1 region of the hippocampus and significantly prevented neuronal cell death in an ischemic insult animal model. These results indicated that low doses of Tat-PIM2 protein protects against oxidative stress-induced neuronal cell death, suggesting low doses of Tat-PIM2 protein provides a potential therapeutic agent against oxidative stress-induced neuronal diseases including ischemia.
