Techniques for analysing pattern formation in populations of stem cells and their progeny

<p>Abstract</p> <p>Background</p> <p>To investigate how patterns of cell differentiation are related to underlying intra- and inter-cellular signalling pathways, we use a stochastic individual-based model to simulate pattern formation when stem cells and their progeny are cultured as a monolayer. We assume that the fate of an individual cell is regulated by the signals it receives from neighbouring cells via either diffusive or juxtacrine signalling. We analyse simulated patterns using two different spatial statistical measures that are suited to planar multicellular systems: pair correlation functions (PCFs) and quadrat histograms (QHs).</p> <p>Results</p> <p>With a diffusive signalling mechanism, pattern size (revealed by PCFs) is determined by both morphogen decay rate and a sensitivity parameter that determines the degree to which morphogen biases differentiation; high sensitivity and slow decay give rise to large-scale patterns. In contrast, with juxtacrine signalling, high sensitivity produces well-defined patterns over shorter lengthscales. QHs are simpler to compute than PCFs and allow us to distinguish between random differentiation at low sensitivities and patterned states generated at higher sensitivities.</p> <p>Conclusions</p> <p>PCFs and QHs together provide an effective means of characterising emergent patterns of differentiation in planar multicellular aggregates.</p

Utilização terapêutica das células estaminais

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências FarmacêuticasUma célula estaminal é uma célula indiferenciada que possui a capacidade de dar origem a outras células especializadas com diversas funções que estão de acordo com o tecido ou órgão que representam, permitindo assim uma panóplia de manipulações e utilidades clínicas. Elas podem classificar-se quanto à origem em células estaminais embrionárias e células estaminais adultas e quanto à potencialidade em células totipotentes, pluripotentes ou multipotentes. As suas aplicações terapêuticas são variadas, existindo vários estudos com resultados positivos e outros que necessitam de uma investigação futura mais profunda, no entanto estas células podem ser utilizadas até mesmo com os novos sistemas terapêuticos. Ao longo da dissertação vão ser explorados temas como a terapia do cancro, a terapia cardiovascular e a terapia neural bem como algumas futuras apostas científicas nestas áreas. A stem cell is an undifferentiated cell that has the ability to give rise to other specialized cells with different functions that are consistent with the tissue or organ they represent, thus allowing a range of manipulations and clinical utility. They can be classified as to the origin in embryonic stem cells and adult stem cells and about the potential for totipotent, pluripotent or multipotent. There are many therapeutic applications for these cells and there are several studies about this potential therapeutic use in the future with positive results and other that need further investigation in the future, these cells also can be used with the new therapeutic systems. Throughout the dissertation subjects such as cancer therapy, cardiovascular therapy and the neural therapy will be operated as well as some future scientific applications in these areas