Researchers at the Utrecht University Medical Centre, the Netherlands, and the Hubrecht Laboratory, also in Utrecht, have succeeded in growing cardiac muscle cells from adult human hearts.

Researchers at the Utrecht University Medical Centre, the Netherlands, and the Hubrecht Laboratory, also in Utrecht, have succeeded in growing cardiac muscle cells from adult human hearts. This major step forward in experimental cardiology is big news, if only because heart problems are the number one cause of death in the Western world.

Up to now heart muscle cells - or cardio myocides as they're officially called - could only be grown from embryonic stem cells. The newly developed heart muscle cells behave exactly like natural heart cells and in the future will help repair damaged hearts. The scientists are hopeful that human testing can begin within three years. Cardiologist Professor Pieter Doevendans of Utrecht University stresses the significance of the discovery.

"So far it has been impossible to grow cardiac muscle cells, or cardio myocides, in large numbers. What we have been able to do is harvest stem cells from human hearts, from patients, and that allows us to make huge numbers of cardio myocides. So yes, we think this is a real breakthrough."

No ethical issues
Crucial in this case is the fact that the stem cells are not embryonic, which means the whole ethical debate about the use of human embryos for scientific research can be avoided. But there are clinical advantages as well. Embryonic stem cells come with their own immune system and this can be incompatible with the immune system of the patient. The patient's body may identify the foreign stem cells as being alien and attack them, so the treatment is ineffective.

It's also extremely difficult to grow high-quality cardiac muscle cells from embryonic stem cells, and even a single faulty one can produce tumours - the patient gets cancer on top of heart failure. But the Utrecht scientists use the patient's own cells to grow their cardiac muscle cells, so there is no problem with rejection. And they are cardiac cells to begin with, which greatly reduces the possibility of one of them turning cancerous.

No donors needed
Another advantage of the approach taken by the Utrecht University cardiologists is that they don't need any donors for their scientific research. During regular heart surgery, such as bypass surgery or valve replacement, the oracle, a little bit of heart tissue that doesn't serve any purpose, is normally just thrown away. Now Professor Doevendans and his team are standing by to take this bit of flesh to their laboratory in order to harvest the precious cardiac stem cells as quickly as possible.

And now...
It's now time to get away from the lab and to put the discovery into clinical practice. Professor Doevendans explains that there is still work to be done.

"What we'd really like to do here is make new muscle. That's crucial if you have a poorly functioning heart - you have to create heart muscle. The challenge will be to deliver these cells to the human heart in such a way that they can really improve function. So what we're trying to do now is to make tiny clots of heart tissue and first inject them into the hearts of pigs and eventually into human hearts, "but this final step in the development of a working stem cell therapy for heart patients will come very quickly. Professor Doevendans is confident that human testing will begin within three years - lightning speed in the world of medical science.

By Thijs Westerbeek van Eerten 

[Copyright Radio Netherlands 2008]