Papel de miRNAs na regulação da expressão do complexo multienzimático lisossômico

• Ano de defesa: 2017
• Autor(a) principal: Queiroz, Matheus Trovão de [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Lisossomos; Micrornas; Neuraminidase; Catepsina A; Gangliosídeos
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=5074602; http://repositorio.unifesp.br/handle/11600/50410

Mucopolysaccharidosis type I (MPS I) is a genetic disease in which there is a deficiency in the expression of the lysosomal enzyme α-L-iduronidase (IDUA gene), which culminates in a generalized lysosomal disturbance. Thus, in addition to the storage of direct substrates of α-L-iduronidase, it is observed the involvement of secondary pathways such as the increase of simple gangliosides levels in the central nervous system, implicated in the neurodegenerative process observed in this disease. Recent studies have shown that Neu1 gene (neuraminidase 1 enzyme), a member of the lysosomal multienzyme complex (CML) involved in ganglioside metabolism, is significantly reduced in the cerebellum and hippocampus of the murine MPS I model. Recently, alterations in the levels of three miRNAs from miR-17 family were reported, which only miR-20b-5p presents as predicted direct targets Neu1 and Ctsa genes, the latter encoding cathepsin A enzyme, another important member of CML. Aiming the functional characterization of miR-20b-5p, the involvement of this miRNA with the regulation of neuraminidase 1 expression and the observed effects on gene and protein expression of CML members in a context of miR-20b- 5p overexpression in cell culture were evaluated. It was observed miR-20b- 5p is not involved with the regulation of Neu1 expression by its 3' untranslated region. In addition, obtained data suggest that this miRNA is involved in fine tuning RNAm levels of the CLM members, but it has no implications for the level of protein expression. Thus, these results suggest the existence of a complex genetic regulation circuit of CML and that miR-20b-5p may represent an important piece in this context.