CASCD · Control of Adult Stem Cell Differentiation

Final Activity Report Summary - CASCD (Control of Adult Stem Cell Differentiation)

It is apparent that all tissues contain a population of 'stem' or 'progenitor' cells which mediate normal repair. When this repair mechanism breaks down or is overwhelmed, disease and damage result, with a significant impact on human health and wellbeing. Mesenchymal stem cells (MSCs) can be isolated from many adult tissues, including bone marrow. MSCs are self-renewing and able to differentiate into cells from multiple tissues such as fat, bone, cartilage and muscle. These cells are excellent candidates for the developing field of 'regenerative medicine' which aims to repair and regenerate damaged tissues and are currently the subject of multiple human clinical trials to evaluate their efficacy. However, the mechanisms by which these cells control proliferation and differentiation are not well understood. The aim of this work is to determine whether miRNAs play a role in regulating MSC differentiation. A vector has been generated to knock down the level of a key enzyme in miRNA maturation. This has been used to reduce miRNA synthesis in human MSCs. Preliminary data suggest that MSCs which have reduced levels of miRNA synthesis have an enhanced ability to differentiate along an adipogenic lineage. This implies that miRNAs normally have a braking action in adipogenic differentiation. To date we have isolated, expended and characterised MSCs from several healthy human volunteers. MSCs isolated from five donors were treated to induce differentiation along the adipogenic (fat) lineage for five days. The miRNA profiles of control cells and differentiating cells were evaluated using microarrays which can recognise 540 human miRNAs. Approximately, 140 miRNAs could be detected in undifferentiated MSCs from all 5 donors, this represents 26 % of the miRNAs tested. However, no significant difference could be detected the control cells and the differentiating cells. This was surprising, but we believe it could be due to the heterogenous nature of the differentiating stem cells. We have isolated clean populations of differentiating cells, 20 days after initiating adipogenesis, by exploiting the buoyant properties of these lipid-filled cells. 20 miRNAs were identified which were significantly differently expressed between undifferentiated cells and the day 20 MSC-derived adipocytes. In conclusion, this work has demonstrated that miRNAs do play a role in differentiation of MSCs along the adipogenic lineage. Indeed, 20 miRNAs have been identified which exhibit altered patterns of expression as MSCs form adipocytes. These miRNAs are now the object of additional studies to determine the mechanisms of their action(s) in adipogenesis.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз