Researches have shown that the risks of the fatal conditions that occur as an after-effect of heart attacks can be reduced by transplanting genetically engineered cells into the heart. It has been found that the main reason behind the sudden death that follows a heart attack is an abnormally fast heart rhythm, called Ventricular tachycardia.
The transplants of skeletal muscles were initially done in mice. This was done so as to produce a specific protein that prevented Ventricular tachycardia.In order to conduct the research, such mice were tested that had been induced to have heart attacks.
The researches showed that, while heart cells taken from 15-day-old embryos did bring down the risk of ventricular tachycardia, other implanted cells (e.g., skeletal muscle cells) did not display the same effects. This was due to the fact that, connexin 43, a protein that is present in embryonic heart cells, was not found in other implanted cells. However, if the skeletal muscle cells could be engineered so as to produce connexin 43, they could be equally effective in preventing heart arrhythmia.
An important function of the heart cells is the ability ( of the implanted cells) to conduct an electric current. Tests carried out on this ability showed that the signal was passed between implanted and existing heart tissues.
According to experts, these studies ( carried out by German researchers) would be of immense help for conducting direct research for treatment of heart attacks in humans, using stem cells. However, study leader Dr. Bernd Fleischmann ( from the University of Bonn) stated that, more research was necessary before humans could be subjected to this technique. Bonn said,
The incidence of ventricular tachycardia dropped by 60%. We clearly showed these cells improved electrical stability. The nice thing about skeletal muscle is it has adult stem cells so you can take a biopsy of the thigh muscle and grow millions and millions of cells in culture.
Bonn also mentioned that, although clinic trials using skeletal muscle and bone marrow cells ( to try and pump function of the heart) were being held, this was the very first research on arrhythmias. Patients who develop ventricular tachycardia are, as of now, treated with a defibrillator that is implanted under the skin. A painful electric shock is generated by this expensive device as and when it detects a fast heart beat.
According to Dr.Tim Chico, an expert in vascular development at the University of Sheffield, the researches were still at an elementary stage. However, he added that
If it can be repeated in humans it would be a breakthrough in the treatment of patients with heart disease and could save thousands of lives.
Peter Weissberg, medical director of British Heart foundation, opined,
This is a vital insight, only possible from animal studies, which should help direct current research using stem cells to prevent the dangerous consequences of heart attacks in people. However, application of this technique to people with heart disease is still a long way off.
Source: news.bbc
