Análise da neuroproteção em ratos suplementados com óleo de peixe durante o desenvolvimento após status epilepticus
Data
2015-06-24
Autores
Tobias, Manaira Giraudon Monteiro 
Orientadores
Scorza, Fulvio Alexandre
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O sistema nervoso é responsável pela organização e coordenação do organismo, necessitando de conexões precisas entre os diversos tipos de células nervosas. Inputs e outputs dependem da conectividade sináptica da rede neuronal e das propriedades individuais das sinapses, estando associadas à atuação de moléculas de adesão facilitadoras do processo. O cérebro em desenvolvimento é altamente excitável e susceptível às crises convulsivas por estar em um período de crescimento de axônios e dendritos, formação das sinapses e maturação das redes corticais, dependentes da idade. O Status epilepticus (SE) caracteriza-se como uma condição aguda de convulsões repetitivas e/ou prolongadas. Afim de mimetizar a condição humana, o SE pode ser induzido pelo modelo experimental de injeção de cloridrato de pilocarpina. Em animais aos 9 dias após o nascimento (P9), o SE como um insulto único pode acarretar consequências deletérias como aumento/diminuição da expressão protéica dos transportadores gabaérgicos, glutamatérgicos, cotransportadores de membrana e moléculas de adesão sináptica, que em última instância, pode conduzir à um prejuízo na funcionalidade cerebral. Frente à alta refratariedade ao tratamento farmacológico apresentada pelos pacientes com epilepsia, faz-se necessário a busca de tratamentos alternativos para lhes garantir melhores condições de vida. Evidências experimentais apontam a importância dos ácidos graxos poliinsaturados (PUFAs) no desenvolvimento normal do cérebro, manutenção de sua função e prevenção de algumas doenças neurológicas crônicas. Resultados prévios obtidos em nosso laboratório demonstraram que o tratamento com óleo de peixe com início logo após o SE, apresentou efeitos neuroprotetores e neuroplásticos. No intuito de avaliar a expressão protéica nas idades P3, P10, P17 e P60 de GABAT1, EAAT2, NKCC1, KCC2, PSD95, Neuroligina 2 e Neurologina 1 em animais submetidos ao SE neonatal em P9, foram formados 4 grupos experimentais: Grupo Pilo óleo de peixe (PO); Grupo Pilo Veículo (PV); Grupo Controle óleo de peixe (CO) e Grupo Controle Veículo (CV). Nossos resultados mostram que houve diminuição da expressão protéica no grupo experimental (SE) apenas em P10 para as proteínas NKCC1, EAAT2 e Neuroligina 2. Assim, afirmamos que o SE em fase precoce da vida tem relevante impacto na circuitaria excitatória/inibitória. Para as demais análises realizadas não verificamos diferenças significantes nem na comparação em relação ao tratamento proposto. Entretanto não podemos descartar que a suplementação com óleo de peixe exerça efeito relevante sobre o neurodesenvolvimento ou sobre as resposta adaptativas ao longo da vida.
The nervous system is responsible for organizing and coordinating the body, so, it requires precise connections between the various types of nerve cells. Inputs and outputs depends on the synaptic connectivity of the neural network as well as the individual properties of the synapses and can be associated with adhesion molecules acting to facilitate the process. The developing brain is highly excitable and susceptible to seizures for being in an age dependent period of axons and dendrites growth, synapses formation and maturation of cortical networks. The Status epilepticus (SE) is characterized as an acute condition of repeated and/or prolonged seizures. In order to mimic the human condition, the SE can be experimentally induced by a pilocarpine hydrochloride injection model. Animals at age of 9 days old (P9), SE as a single insult, may lead to deleterious effects such as increase/decrease in protein expression of GABA and glutamate, carriers membrane cotransporters and synaptic adhesion molecules, which in worse cases can lead to a loss in brain function. Facing the high refractory following pharmacological treatment displayed by patients with epilepsy it is important to research alternative treatments to ensure those patients better living conditions. Experimental evidence suggests the importance of polyunsaturated fatty acids (PUFAs) in normal brain development as well as in the maintenance of its function and prevention of some chronic neurological diseases. Previous results found by our laboratory have shown that treatment with fish oil starting shortly after SE would have neuroprotective and neuroplastic effects. In order to assess GABAT1, EAAT2, NKCC1, KCC2, PSD95, Neuroligin 2 and Neurologin 1 protein expression in animals subjected to neonatal SE at P9 at P3, P10, P17 e P60, four experimental groups were formed: Pilo fish oil (PO), Pilo vehicle (PV), control fish oil (CO) and control vehicle (CV). Our findings showed a significant decrease in protein expression in the experimental group (SE) only at P10 for NKCC1, EAAT2 and Neuroligin 2. Thus, we state that SE in early life has a significant impact on the excitatory/inhibitory circuitry. Other analyzes did not show significant differences when comparing control to the proposed treatment. However, we cannot rule out that supplementation with fish oil exert significant effect on neurodevelopment or on the adaptive response throughout life.
The nervous system is responsible for organizing and coordinating the body, so, it requires precise connections between the various types of nerve cells. Inputs and outputs depends on the synaptic connectivity of the neural network as well as the individual properties of the synapses and can be associated with adhesion molecules acting to facilitate the process. The developing brain is highly excitable and susceptible to seizures for being in an age dependent period of axons and dendrites growth, synapses formation and maturation of cortical networks. The Status epilepticus (SE) is characterized as an acute condition of repeated and/or prolonged seizures. In order to mimic the human condition, the SE can be experimentally induced by a pilocarpine hydrochloride injection model. Animals at age of 9 days old (P9), SE as a single insult, may lead to deleterious effects such as increase/decrease in protein expression of GABA and glutamate, carriers membrane cotransporters and synaptic adhesion molecules, which in worse cases can lead to a loss in brain function. Facing the high refractory following pharmacological treatment displayed by patients with epilepsy it is important to research alternative treatments to ensure those patients better living conditions. Experimental evidence suggests the importance of polyunsaturated fatty acids (PUFAs) in normal brain development as well as in the maintenance of its function and prevention of some chronic neurological diseases. Previous results found by our laboratory have shown that treatment with fish oil starting shortly after SE would have neuroprotective and neuroplastic effects. In order to assess GABAT1, EAAT2, NKCC1, KCC2, PSD95, Neuroligin 2 and Neurologin 1 protein expression in animals subjected to neonatal SE at P9 at P3, P10, P17 e P60, four experimental groups were formed: Pilo fish oil (PO), Pilo vehicle (PV), control fish oil (CO) and control vehicle (CV). Our findings showed a significant decrease in protein expression in the experimental group (SE) only at P10 for NKCC1, EAAT2 and Neuroligin 2. Thus, we state that SE in early life has a significant impact on the excitatory/inhibitory circuitry. Other analyzes did not show significant differences when comparing control to the proposed treatment. However, we cannot rule out that supplementation with fish oil exert significant effect on neurodevelopment or on the adaptive response throughout life.
Descrição
Citação
TOBIAS, Manaira Giraudon Monteiro. Análise da neuroproteção em ratos suplementados com óleo de peixe durante o desenvolvimento após status epilepticus. 2015. 100 f. Dissertação (Mestradoem Neurologia - Neurociências) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2015.