Delivering Stem Cell Factor into Damaged Heart Tissue
In the years ahead stem cell medicine will most likely transform into a field largely based on manipulating existing cell populations in situ in the body rather than generating cells outside the body for transplantation. In many types of transplantation it appears that benefits are produced because the transplanted cells alter the local signaling environment in ways that cause native cells to better maintain and repair tissues, not because the transplanted cells are actually doing any of the work themselves. So ultimately researchers will want to directly issue those signals or otherwise alter native cells so as to change their behavior for the better. Some of the necessary work on that front is already taking place:
Researchers administered stem cell factor (SCF) by gene transfer shortly after inducing heart attacks in pre-clinical models directly into damaged heart tissue to test its regenerative repair response. A novel SCF gene transfer delivery system induced the recruitment and expansion of adult c-Kit positive (cKit+) cardiac stem cells to injury sites that reversed heart attack damage. In addition, the gene therapy improved cardiac function, decreased heart muscle cell death, increased regeneration of heart tissue blood vessels, and reduced the formation of heart tissue scarring. cKit+ cells are a critical cardiac cytokine, or protein receptor, that bond to stem cell factors. They naturally increase after myocardial infarction and through cell proliferation are involved in cardiac repair."It is clear that the expression of the stem cell factor gene results in the generation of specific signals to neighboring cells in the damaged heart resulting in improved outcomes at the molecular, cellular, and organ level. Thus, while still in the early stages of investigation, there is evidence that recruiting this small group of stem cells to the heart could be the basis of novel therapies for halting the clinical deterioration in patients with advanced heart failure."