Stem Cells and Regeneration

Lessons in regeneration - learning from the flatworm

In recent years, regenerative medicine has become a major focus of medical research, as neurodegenerative and cardiovascular diseases, as well as infections or injuries, call for therapies that aim at replacing lost or damaged tissues. One of the beacons of hope of regenerative medicine lies in stem cell research. However, to develop new and improve existing cell-replacement therapies, it is crucial to better understand the molecular principles of stem cell biology and the cellular limitations of human regeneration.

A stem cell that is prone to replace a dead or damaged neuron has to fulfill three major tasks: first, it must acquire the properties of this specific neuron through a tightly controlled differentiation process. Second, it has to find its proper location in the damaged tissue, and third, it has to structurally and functionally integrate into the pre-existing cellular network.

One way to investigate the cellular and molecular processes of regeneration is to use model organisms that can regenerate much better than us. Planarian flatworms are among the masters of regeneration in the animal kingdom. These little creatures can regenerate a head including a functional brain within only a few days. Their extraordinary regenerative abilities are based on a pool of adult pluripotent stem cells that migrate to the wound site where they differentiate into the lost cell types and finally form a functional unit with pre-existing tissue. How these stem cells are maintained in the adult animal and which factors control their behavior, is the major focus of our research.