The role of novel transcriptional regulation mechanisms in neurogenesis

• Autor(a) principal: Almeida, Ana Catarina Serra
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/9859
• topic: Mtob; Neurogénese; Proteínas de Ligação Ao C-Terminal; Zona Subventricular; Domínio/Área Científica::Ciências Médicas::Ciências Biomédicas

Subventricular Zone (SVZ) is the main neurogenic niche in adult rodent brain. Neurogenesis is regulated by extracellular or intracellular mechanisms, which include transcriptional factors and epigenetic modifications. C-terminal Binding Proteins (CtBPs) are transcriptional corepressors that interact with transcriptional factors to repress the transcription. Moreover, these proteins are important in the regulation of cellular proliferation, differentiation, and survival. These findings suggest that CtBPs may play a role in the modulation of adult neurogenesis. Therefore, the main aim of this work was to evaluate the effects of CtBPs in SVZ neurogenesis. Herein, we analyze CtBPs expression in the SVZ in vitro and in vivo and its effects on SVZ neurogenesis in vitro. First, CtBPs expression was analyzed by immunostainings in SVZ cell cultures obtained from 1- to 3-day-old C57BL/6J mice and in 8-10-week-old mice in vivo. Both CtBP1 and 2 were expressed in proliferating cells (Ki67+), immature cells (Nestin+ and Sox2+), proliferative neuroblasts (Ki67+ and DCX+), astrocytes (GFAP+) and oligodendrocytes (Olig2+), in the SVZ in vitro and in vivo. Then, a substrate-based inhibitor of CtBPs, the 4-methylthio 2-oxobutyric acid (MTOB) that may have a dual effect acting as an inhibitor at high concentrations but as substrate at low concentrations, was used to assess the effect of CtBPs on neurogenesis in vitro. Our results showed that 1 mM and 2.5 mM MTOB induced cell death as detected by propidium iodide incorporation and nuclear morphology analysis. Moreover, 5 µM, 25 µM and 50 µM of MTOB did not affect the total number of Ki67 proliferating cells while 25 µM MTOB increased the percentage of proliferating neuroblasts. Regarding cell differentiation, 5 µM, 25 µM and 50 µM of MTOB increased the percentage of NeuN-mature neurons and Olig2-oligodendrocytes. Altogether, our results suggest that CtBPs are a good target to regulate the transcriptional mechanisms in SVZ neurogenesis.