MicroRNA expression profile of Danio rerio brain exposed to ethanol

• Autor(a) principal: Ferreira, Violeta Silva
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/8982
• topic: Biologia molecular; Alcoolismo; Regulação genética

miRNAs are short (~22 nt) non-coding RNA molecules that control gene expression at post-transcription level by degrading or inhibiting particular target genes. miRNAs are abundant in vertebrate genomes where they play an important role on the control of cell proliferation and differentiation, apoptosis, neurogenesis and synaptic plasticity. Although legally commercialize, alcohol is toxic for living organisms and its consumption can induce dependence. The regular alcohol intake increases the risk of hepatic disease and certain cancers, having a deleterious effect on the immune, endocrine and nervous system. The brain is not only an important target for alcohol metabolites, but also a rich source of miRNAs. Using miRNA microarrays approach, we aimed to understand how chronic (0.25% EtOH) and acute (0.25%; 0.5%, 1 e 1.5% EtOH) ethanol exposure affects miRNA expression. The results demonstrate that chronic ethanol intake deregulated the expression of 32 miRNAs. From those, miR-9, miR-23a, miR-30e, miR-133a, miR-181 were over-expressed and miR-16a, miR-145 and miR-181b were inhibited. The putative target genes for those miRNAs are implicated in cell cycle, differentiation, apoptosis and cell adhesion. The acute ethanol exposure also deregulated miRNA expression profile and each ethanol concentration shows a distinct miRNA expression profile. For example, the pro-apoptotic miRNA miR- 23a is up-regulated in chronic ethanol exposure but is down-regulated in the higher ethanol concentrations (1 e 1.5% EtOH) of acute test. These results suggest that alcohol consumption, even consumed in a short-period or concentration, affects the expression of miRNAs. Possibly, these alterations have implications on cellular cycle and apoptosis and therefore they could contribute to a higher risk of developing tumours.