Up until today scientists assumed that the adult heart is unable to regenerate. Now, researchers and cardiologists from the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch and the Charité - Universitätsmedizin Berlin (Germany) have been able to show that this dogma no longer holds true.
Dr. Laura Zelarayán and Assistant Professor Dr. Martin W. Bergmann were able to show that the body`s own heart muscle stem cells do generate new tissue and improve the pumping function of the heart considerably in an adult organism, when they suppress the activity of a gene regulator known as beta-catenin in the nucleus of the heart cells. ( PNAS , online December 10, 2008, doi: 10.1073/pnas.0808393105).
The gene regulator beta-catenin plays an important role in the development of the heart in embyros. Dr. Zelarayán and Dr. Bergmann could now show that beta-catenin is also important for the regeneration of the adult heart. They suppressed this factor in the nucleus of the heart cells in mice.
This way they activated heart precursor cells (stem cells) to turn on the regeneration of heart in adult mice. Four weeks after blocking beta-catenin, the pumping function of the heart of the animals had improved and the mice survived an infarction much better than those animals with a functioning beta-catenin gene. An important contribution to this project has been a transgenic mouse line generated by Professor Walter Birchmeier`s (MDC) laboratory.