An??lise de microves??culas purificadas do plasma de pacientes com mielofibrose quanto a presen??a de miRNAs e quanto ao impacto na migra????o de c??lulas-tronco mesenquimais

• Autor(a) principal: Rodrigues, Leane Perim
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UCB
• Texto Completo: https://bdtd.ucb.br:8443/jspui/handle/tede/2286
• topic: Mielofibrose; miRNA; Doen??as mieloproliferativas; CNPQ::CIENCIAS BIOLOGICAS::GENETICA

Myelofibrosis is a hematological disease inserted in the group of myeloproliferative neoplasias. It has as main characteristic fibrosis of the bone marrow, consequence of a variety of histological changes presented in the medullary microenvironment. The pathophysiology of myelofibrosis involves the activation of signal transduction pathways and nowadays several mutations such as JAK2V617F, CalR and MPL have been associated with this process. Recent studies have shown that microvesicles produced by body cells may be associated with the cellular communication process. These microvesicles carry in their content proteins, lipids and RNA capable of regulating diverse cellular processes. The literature shows that several miRNAs present in the microvesucular content can regulate the hematopoiesis of normal stem cells and also of compromised progenitors, having an important role in the pathogenesis of some acquired hematological neoplasias such as myeloproliferative diseases. With the objective of investigating the presence of specific miRNAs in microvesicles excreted in the peripheral blood plasma of patients with myelofibrosis, microvesicles were isolated from the plasma by ultracentrifugation and by means of molecular biology techniques it was possible to validate the presence of these microbes. Real-time PCR assays were performed to evaluate the expression of specific miRNAs (miR-146b, miR-221, miR-143 and miR-150) in the microvesic contents. In order to analyze the functional activity of MVs, the cell migration assay was performed, aiming at the progression of pathology and tumor invasiveness. The results show that there is no increase in the microvesicular concentration in peripheral blood when comparing the group of patients with the control group. The data found show that miR-146b and miR-150 are differentially expressed in patients with myelofibrosis, being little expressed. However, miR-221 and miR-143 didn???t show amplification in the technique, which leads to the conclusion that these miRNAs are specific to the medullary microenvironment or aren???t released in the microvesicular content. Regarding the migration test, the result shows that there was no influence of the microvesicles in the process of cell proliferation and migration and it can be considered that the microvesicles isolated in our study may not present this role because they are not exclusively of the bone marrow environment. As future prospects, assays with microvesicles removed from the bone marrow can be performed.