Abstracts

Rationale: Study of gene expression may allow a better understanding of a disease’s molecular mechanism, metabolic pathways and, eventually, lead to identification of novel therapeutic targets. We performed a global analysis of hippocampal gene expression in patients with refractory epilepsy associated with nonfamilial mesial temporal sclerosis Methods: We studied gene expression profile with DNA microarrays technology in fresh tissue samples (ex-vivo explants)obtained intraoperatively from parahippocampal and dentate gyri of patients with refractory epilepsy associated to hippocampal sclerosis submitted to anteromesial temporal lobectomy. Gene expression profiles were compared with control tissue obtained from samples obtained from the University of Sao Paulo School of Medicine Brain Bank. Differential gene expression was defined as a threefold or greater increase or decrease in gene expression compared to controls. Results: We studied six patients with nonfamilial cases of mesial temporal sclerosis that underwent surgical treatment of medically refractory epilepsy. Differential gene expression data for the parahippocampal gyrus was noted for cell adhesion, cytokine-cytokine receptor interaction, cell communication, neuroactive ligand-receptor interaction, calcium signaling pathway, ECM-receptor interaction and axon guidance genes. For the dentate gyrus the differencial gene expression was found in toll-like receptor signaling pathway, cytokine-cytokine receptor interaction and hematopoietic cell lineage genes. Conclusions: We showed differential gene expression profile in parahippocampal and dentate gyri of patients with mesial temporal sclerosis. Global gene expression analysis with DNA microarrays is a promising strategy to study molecular mechanisms underlying epileptogenesis and to identify potential therapeutic targets.