Scientists from the Max Planck Institute for Molecular Biomedicine in Germany have created somatic stem cells from mouse skin cells. Hans Schöler and his team of researchers have succeeded in inducing the skin cells into becoming neuronal somatic stem cells without passing through a pluripotent stage. Up until now converting somatic cells (the normal cells we find in our body) into stem cells involved reversion technology making the specialized cell go backward to its undifferentiated embryonic state. In this state the cells became pluripotent, capable of becoming anything. But there has been a downside to this reversion process. The plasticity of pluripotent cells can lead to undesired consequences such as cancerous tumours, not healthy tissue.
The research done by the Institute has created what are called multipotent stem cells. They cannot give rise to any cell type, merely a select subset. In this case skin cells have been able to create neural tissue. Schöler calls the process interconversion. It involves using a specific protein called BRN4. BRN stands for Brain. The protein is found in neural stem cells. Skin cells exposed to the protein become highly susceptible to conversion into neuronal somatic stem cells without reverting to the pluripotent state. When bathed in growth factors to increase cell division the skin cells’ interconversion speeds up with the cells losing their molecular memory. Within a few cell division cycles the conversion completes creating neuronal somatic stem cells that appear indistinguishable from normal stem cells.
Multipotency means stem cells like these can be used to regenerate damaged or diseased tissue. The next step is to duplicate the experiment using human skin cells and then track the stability of the cell line over time to ensure that it can become a safe source for cell and tissue regeneration.