Researchers and doctors have high hopes for the future with stem cells. Thanks to them, many clinical pictures can already be treated or even cured. There will be many more in the future. FOCUS Online explains the current state of medicine and research.
What are stem cells?
"Stem cells are cells from which, for example, organs are formed," says Andreas Zeiher, president of the German Society of Cardiology (DGK), "blood cells".
Cell biologist Martin Zenke, director of the Institute of Biomedical Engineering and Cell Biology of Aachen University, explains: "There are stem cells in every organ, for example, there are neural stem cells in the brain or liver stem cells in the liver. "
Basically, every organ has its own stem cells. Only embryos contain a variety of so-called pluripotent stem cells. Every tissue, every organ can grow from these stem cells.
How does stem cell therapy work?
The research is now so far that pluripotent stem cells can also be obtained from adult stem cells. Zenke speaks of so-called induced pluripotent cells, the IPS cells for short. To do this, doctors take a patient's stem cells from one of his organs, transform them and reinsert them in the desired location. "This allows us a personalized medicine," he says.
Another possibility is that used by Eckhard Alt and his team. The Munich-based cardiologist and stem cell researcher has been working on stem cell therapy for 16 years and has, in his own words, achieved "considerable success" in his treatments. .
It also cleans adult stem cells, but with a so-called neutral protease. This allows the small cells to dissolve out of the stem cell. They are then washed and can become "any stem cell of your choice" at the desired location.
Indeed, pluripotent stem cells learn from their environment what to do. Therefore, in this approach, it is also important that some live stem cells remain at the desired location. In addition, the donor and the recipient of the stem cells must be one and the same person: "The stem cells of others repel the body," says Alt, convinced.
In addition, certain cells are attributed an anti-inflammatory effect, explains Zeiher DGK. These are the mesenchymal stem cells. They come from various connective tissues such as cartilage, fat or muscle.
What therapies are already possible with stem cells?
Blood cells have been used for decades for the treatment of leukemia – and with great success. To do this, the patient is removed from all hematopoietic cells and then used healthy cells from a donor, Martin Zenke explains. "The achievements are great," adds Andreas Zeiher.
In the 1980s, doctors began using tissue-specific stem cells to replicate the epidermis to better treat major burns.
Stem cells are also used to treat cartilage damage. For example, knee arthritis has already been treated successfully.
According to Zeiher, there is little notable progress in treating heart problems: "The euphoria about stem cell therapies in the heart has eased somewhat, but unfortunately they were not as well suited to the regeneration of heart disease. heart muscle cells, as expected. "Therefore, most experiments are currently more" experimental "than they are suitable for widespread use in humans.
Eckhard Alt is a little more confident. In this way, one can mitigate the consequences of a heart attack by inserting stem cells into the "border area of the infarct, where the living tissue of the heart is still alive".
Cardiologist and cardiology professor Ulf Landmesser of Berlin Charity explains: "Parisian cardiac surgeon Philippe Menasché has created a patch, a sort of patch for the heart, which were embryonic stem cells that could be transformed into cardiomyocytes and help the heart is healed. "Researchers, particularly in Germany, are working on the creation of these pluripotent stem cell patches derived from adult stem cells.
"We are currently using stem cells primarily for research purposes," says the cardiologist, "which helps us understand why hearts can not heal themselves after a heart attack, for example." According to him, it is currently the biggest stem cell hope for cardiology.
- Other applications
In addition, hair loss, ocular lesions and wounds difficult to heal have been successfully treated by stem cells. Alt also says that he has managed to damage the brain.
According to Jürgen Hescheler, director of the Institute of Neurophysiology at the University of Cologne, the treatment of the blind is about to begin, with new optical cell plaques using pluripotent stem cells – and so can see them again.
Why are stem cell therapies so unknown?
For a long time, stem cell therapies were considered ethically dubious because embryos had to die to acquire pluripotent stem cells – which is no longer the case today thanks to the IPS cells and the the neutral protease. However, stem cell research continues to be strictly regulated – and treatment also.
For example, Alt complains that many of his treatments are currently banned in Germany, although many health insurances are already paying for them because of their success. In the neighboring countries of Germany, for example in Austria, therapies are approved. He treated many patients in a "border clinic" in Kitzbühel.
What is the criticism of stem cell therapy?
Jürgen Hescheler warns: "Many clinics are in a hurry, as science allows." Some private providers already offer stem cell therapies for diseases whose effectiveness has not yet been proven in clinical trials. According to the "principle of hope," says the researcher.
In his opinion, one should be cautious with such offers: "In the absence of clinical studies, it is learned that such clinics of isolated cases – of course only positive clinics. how many times, something has not finished well rarely happens to the public. "
What are the other possibilities with stem cells?
"Where stem cells have already proven to be very useful, drug trials in Petri dishes," says Andreas Zeiher. So you can now test the effect and side effects of stem cell medications – and that, without many experiments on animals.
But not only drug developers, but also food supplements and cosmetics companies can use stem cells for their tests, Jürgen Hescheler explains.
What will be possible with stem cells in the future?
One thing is certain: "In ten years, stem cell therapy will account for 30% of drugs", but according to the professor, "only endogenous stem cells". Neurological diseases – Alzheimer's disease, Parkinson's, ALS – should be treatable.
Hescheler agrees: "I would not be a stem cell researcher if I did not fully believe in its benefits," he says. According to him, they can bring in the future a considerable success in the treatment of various diseases. The researchers even have a hope of cancer: "We have already been able to extract so-called natural killer cells, cells that kill other cells that have nothing to look for in the body, from stem cells. They play an important role in the fight against tumors. "
Hescheler added: "The hope is always great." However, there are still many clinical studies, which are very expensive, so that great breakthroughs can be made. He therefore hopes that in the future, more public funds will be released for research.
DGK President Andreas Zeiher is less enthusiastic: "At the moment, most of the experiments are still experimental, but unfortunately only a few successes have been achieved in the past," he explains. research is still ongoing. "
The hope of stem cells is great: one day, researchers want to create pancreatic stem cells, for example, to cure diabetes, "but all of this is still experimental at the moment".