A molecular and pathophysiological approach to tissue regeneration in the planarian model

• Autor(a) principal: Grou, Márcia Sofia Calado
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/115898
• topic: planarians; regeneration; neoblasts; differentially-expressed genes (DEGs); cell proliferation; DNA repair; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Since early on, regeneration has been seen as a fascinating biological process of many living organisms. Planarians are especially suitable models to study the factors involved in this process given the extraordinary proliferative capacity of their adult pluripotent stem cells, the neoblasts. The critical understanding of how these cells work and the molecular networks and pathways underlying regeneration in these organisms are crucial to the development of potential therapeutic applications in the field of biomedical research. Regenerative medicine, for instance, is currently focused on studying the potential of stem cells to heal or replace missing tissues and organs. Thus, in order to ascertain the regenerative capacity of Leptoplana sp. and to evaluate the potential of neoblasts to replace lost and/or damaged cells, histological analyses were performed and allowed to conclude that regeneration is more restricted in this species and not always successful. However, neoblasts have proven their cell replacement ability and damage resistance, which demonstrates their importance and potential applications. Then, a second approach was carried out to perform gene expression analysis on Schmidtea mediterranea to identify the main genes and pathways involved in regeneration. Most of the genes were up-regulated in regenerating planarians when compared with the intact ones and within these, many were found to be involved in cell differentiation, and other biological processes, such as DNA replication and cell proliferation, as well as DNA damage detection and repair. This latter process has proven to be very important for the success of regeneration and demonstrated the potential use of planarians to study DNA damage. Taken together, these findings provide insights that this in silico approach using R-based bioinformatics enables a better perception of the processes behind regeneration which allow to explain and complement the anatomical observations of planarians and provide a global assessment of the entire regeneration process.