Heart stimulated to heal itself
Scientists have shown for the first time that it is possible to stimulate the heart to heal itself without the use of stem cell technology. Heart muscle cells are undifferentiated in a fetus, so are able to multiply and grow to create new heart muscle tissue. However, as the fetus develops, these cells become differentiated and, it was previously thought, no longer produce new tissue. This has consequences in adults when damage occurs to the muscle, for example in heart attacks and in congenital heart defects.
Recent research has indicated that differentiated heart muscle cells have some limited ability to multiply and grow after injury. So researchers tested a number of growth factors in mice and rats in an attempt to raise this level of growth. Increasing a growth factor called neurregulin1 (NRG1) significantly boosted multiplication of the heart muscle cells. This led to regeneration of the heart muscle, and the heart worked better.
Further studies will look at how NRG1 works on the heart. Tests will be carried out in pigs, which are more closely related to humans. The possibility that adult heart muscle cells can be stimulated to multiply and grow is exciting, as a viable alternative to stem cell therapy.