Tuesday, November 20, 2007

The Heart Can Heal Itself


At the University College London (UCL), scientists have recently discovered that cells from the heart's outer layer can migrate into a failing organ to carry out necessary repairs. This finding highlights the power of stem cells that are readily available in each person's heart and may lead to more effective treatment of serious heart problems.
Ten years ago, a toddler with a heart that was too big and too weak was given a donor heart and her original heart left intact. Recently, her body rejected the donor heart and when the doctors opened her up, they found her heart had healed itself.
The cells that carry out these repairs are called progenitor cells and are controlled by the protein thymosin beta 4, which has already been shown to reduce muscle cell loss after a heart attack. Scientists are now researching ways to manipulate this protein to treat heart disease. Progenitor cells are similar to stem cells because they have the potential to turn into many different types of adult tissue.
In the past, it was thought that to carry out repairs on the heart, progenitor cells needed to be summoned from the bone marrow, but this study puts that theory to rest. The progenitor cells needed to repair the heart are already located within the heart tissue itself.
The UCL team found that progenitor cells under the influence of thymosin beta 4 can be stimulated to create new blood vessels. Dr. Paul Riley, the lead researcher said: "We found that, when treated with thymosin beta 4, these adult cells have as much potential as embryonic cells to create healthy heart tissue." This discovery helps to avoid the risks of immune system rejection when using stem cell transplants from another source because the cells are already located where they are needed.