[Genes and epilepsy II: differential gene expression in epilepsy]. / Genes e epilepsia II: expressão gênica diferencial.

We introduce some investigative approaches and findings on differential gene expression in human epileptic time as well as in animal models of epilepsy. Molecular alterations observed in the epileptic brain suggest that they may disclose different psychopathological stages. It is possible that different gene expression combinations involved in cell death, reactive oxygen metabolism, synaptic transmission and immune response and of neurotrophins reflect distinct functional properties of different neuronal and glial populations, which determine specific brain region responses. Understanding the molecular patterns of gene expression following epileptogenic insults will be of great importance for the development of treatments aiming to reduce neurotoxicity and subtle synaptic dyfunctions present in the early stages as well as during the chronic phase of epilepsy.

Genes e epilepsia II: expressão gênica diferencial: [revisão] / Genes and epilepsy II: differential gene expression in epilepsy: [review]

Nesta revisão, introduzimos abordagens investigativas, assim como discutimos os principais achados de expressão gênica diferencial em tecido epiléptico humano e em modelos experimentais. As alterações observadas no cérebro de indivíduos epilépticos sugerem que eventos moleculares específicos refletem diferentes expressões do quadro fisiopatológico. É possível que diferentes combinações da expressão de genes associados à morte celular, metabolismo de radicais livres, transmissão sináptica, resposta imune e de neurotrofinas reflitam propriedades características de diferentes populações neuronais e gliais, que determinam as distintas respostas de cada área cerebral. A compreensão dessas particularidades moleculares será muito importante para o desenvolvimento de uma estratégia de intervenção visando reduzir neurotoxicidade e disfunções sinápticas que ocorrem durante a epileptogênese e a fase crônica em pacientes epilépticos.

We introduce some investigative appnacher and findings on differential gene expression in human epileptic time as well as in animal models of epilepsy. Molecular alterations observed in the epileptic brain suggest that they may disclose different psychopathological stages. It is possible that different gene expression combinations involved in cell death, reactive oxygen metabolism, synaptic transmission and immune response and of neurotrophins reflect distinct functional properties of different neuronal and glial populations, which determine specific brain region responses. Understanding the molecular patterns of gene expression following epileptogenic insults will be of great importance for the development of treatments aiming to reduce neurotoxicity and subtle synaptic dyfunctions present in the early stages as well as during the chronic phase of epilepsy.

[Genes and epilepsy I: epilepsy and genetic alterations]. / Genes e epilepsia I: epilepsia e alterações genéticas.

INTRODUCTION: Epilepsy is a neurological disorder characterized by spontaneous and recurrent seizures with an estimated prevalence of 2-3 % in the world population. Epileptic seizures are the result of paroxystic and hypersynchronous electrical activity, preferentially in cortical areas, caused by panoply of structural and neurochemical dysfunctions. Recent advances in the field have focused on the molecular mechanisms involved in the epileptogenic process. OBJECTIVES: In the present review, we describe the main genetic alterations associated to the process of epileptogenesis and discuss the new findings that are shedding light on the molecular substrates of monogenic idiopathic epilepsies (MIE) and on genetically complex epilepsies (GCE). RESULTS AND CONCLUSION: Linkage and association studies have shown that mutations in ion channel genes are the main causes of MIE and of predisposition for GCE. Moreover, mutations in genes involved in neuronal migration, glycogen metabolism and respiratory chain are associated to other syndromes involving seizures. Therefore, different gene classes contribute to the epileptic trait. The identification of epilepsy-related gene families can help us understand the molecular mechanisms of neuronal hyperexcitability and recognize markers of early diagnosis as well as new treatments for these epilepsies.

Genes e epilepsia I: epilepsia e alterações genéticas / Genes and epilepsy I: epilepsy and genetic alterations

INTRODUÇÃO: Epilepsia é uma desordem neurológica caracterizada por crises espontâneas e recorrentes, que afeta de 2 por cento a 3 por cento da população mundial. As crises epilépticas refletem atividade elétrica anormal e paroxística, preferencialmente em uma ou várias áreas do córtex cerebral, que podem ser causadas por inúmeras patologias estruturais ou neuroquímicas. Dentre os importantes estudos das últimas décadas no campo da epileptologia, destaca-se a identificação de genes associados a certos tipos de epilepsia. OBJETIVO: Nesta revisão, descrevemos as principais alterações genéticas associadas ao processo epileptogênico, discutindo as mais recentes descobertas e suas contribuições para a compreensão das bases genéticas das epilepsias idiopáticas monogênicas (EIM) e das epilepsias geneticamente complexas. RESULTADOS E CONCLUSÃO: Estudos de ligação e associação mostram que alterações em genes que codificam canais iônicos são as principais causas genéticas das epilepsias idiopáticas monogênicas e de predisposição nas epilepsias geneticamente complexas. Além disso, as síndromes nas quais a epilepsia é um aspecto importante do quadro clínico podem ser provocadas por genes envolvidos em diferentes vias celulares, tais como: migração neuronal, metabolismo de glicogênio e cadeia respiratória. Portanto, acredita-se que diferentes categorias de genes possam atuar na determinação do traço epiléptico. A identificação de tais famílias de genes não apenas nos ajudará a entender as vias moleculares associadas à hiperexcitabilidade neuronal e ao processo epileptogênico, mas também poderá conduzir ao desenvolvimento de novas e mais precisas estratégias de tratamento da epilepsia.

INTRODUCTION: Epilepsy is a neurological disorder characterized by spontaneous and recurrent seizures with an estimated prevalence of 2-3 percent in the world population. Epileptic seizures are the result of paroxystic and hypersynchronous electrical activity, preferentially in cortical areas, caused by panoply of structural and neurochemical dysfunctions. Recent advances in the field have focused on the molecular mechanisms involved in the epileptogenic process. OBJECTIVES: In the present review, we describe the main genetic alterations associated to the process of epileptogenesis and discuss the new findings that are shedding light on the molecular substrates of monogenic idiopathic epilepsies (MIE) and on genetically complex epilepsies (GCE). RESULTS AND CONCLUSION: Linkage and association studies have shown that mutations in ion channel genes are the main causes of MIE and of predisposition for GCE. Moreover, mutations in genes involved in neuronal migration, glycogen metabolism and respiratory chain are associated to other syndromes involving seizures. Therefore, different gene classes contribute to the epileptic trait. The identification of epilepsy-related gene families can help us understand the molecular mechanisms of neuronal hyperexcitability and recognize markers of early diagnosis as well as new treatments for these epilepsies.