Scientists identify stem cells' specialisation switch
A team of UK and Canadian scientists have identified the protein which causes embryonic stem cells to turn into specialised cell types, such as brain or muscle cells. The work, which was partly funded by the EU, is published in the journal Development. Embryonic stem cells are pluripotent. This means that as well as being able to divide and produce more stem cells, they can also produce other, more specialised cell types. The factors controlling the decision to specialise or not are still not well understood, yet this information is vital if scientists are to be able to programme stem cells in the lab to turn into different cell types. This could greatly help scientists to model diseases, test new drugs and even treat diseases and injuries. In this latest piece of research, the scientists looked at mouse embryonic stem cells which lacked the ability to produce a protein called FGF4 (Fibroblast Growth Factor 4). They found that FGF4 is not needed for the cells to simply produce more stem cells. In contrast, the protein is essential for triggering cells to enter a transitional stage, from which they can go down several specialisation paths. 'Depending on the signal presented to the mouse embryonic stem cells, they can go back to the naïve state, and divide without limit, or down one of several specialisation pathways, including routes towards nerve cells or muscle cells,' explained Dr Tilo Kunath of the Institute for Stem Cell Research at the University of Edinburgh. 'We have coined a name for cells in this stage - we call them 'commitment-competent' cells, in contrast to the embryonic stem cells who do not receive a signal from FGF4, which we call 'commitment-phobic'.' The next step is to find out whether the same rules apply for human embryonic stem cells. It is known that they need the FGF protein to grow in the lab, but it is not yet known if it is involved in maintaining the cells or causing them to specialise. EU funding for the work came from the Sixth Framework Programme's EuroStemCell project.
Countries
Canada, United Kingdom