Simple and ingenious – this formula is often the best way forward, as was the case for Dr. Lusine Danielyan, a scientist from Tübingen who has developed a method that enables her to administer therapeutic cells for the treatment of neurodegenerative diseases to animals without requiring syringes or surgery. The animals simply snort the cell suspension. In September 2009, Danielyan received the Baden-Württemberg Research Prize for Alternative and Complementary Methods to Animal Testing for her development.
In 2007, around 570,00 animals were used for experimental purposes in Baden-Württemberg alone – both in basic research as well as to determine the toxicity of new chemicals and to test drugs for primary and secondary effects. In an effort to keep animal experiments to a minimum and reduce the stress experienced by the animals, researchers worldwide are working on the development of alternative methods to animal experiments.
The Baden-Württemberg government attaches a great deal of importance to the protection of animals used for scientific purposes. It gives awards to research projects that make a considerable contribution to replacing animal testing or reducing the stress experienced by animals in the areas of science, education, medical diagnostics and the testing of substances and products. The Prize for Alternative and Complementary Methods to Animal Testing comes with a purse of up to 25,000 euros, and, in 2009, was awarded in equal parts to two researchers from Ulm and Tübingen.
Dr. Lusine Danielyan works at the Institute of Experimental and Clinical Pharmacology and Toxicology at the University of Tübingen, where she heads up the cell biology laboratory of the Department of Clinical Pharmacology. She received the research prize for the development of an innovative method that enables scientists to work with experimental animals in a non-invasive way. The researchers use mice and rats to find ways to treat severe neurological diseases such as Alzheimer's, Parkinson's, multiple sclerosis and Huntington's disease. The use of therapeutic stem cells is one of several promising approaches for the treatment of such diseases. Previously, investigations into the use of stem cells for the treatment of neurodegenerative diseases required the cells to be implanted into the brain of animals.
Danielyan’s method enables stem cells to be applied in a much simpler way that also has the potential to be transferred to humans. A small droplet of stem cell suspension is applied to the nostril. “We do not even need to insert a pipette into the nostril. The cells are inhaled automatically,” said Danielyan. The skin is not damaged since the cell suspension only contains cells in a salt solution and does not contain any critical constituents. As they breathe in, the animals snort the stem cells suspended in fluid, which then reach the nasal mucosa from where a therapeutically relevant percentage of cells migrate into the brain. “The method is well tolerated by the animals. It only requires a few days to accustom the animals to having fluid trickled into their nostrils,” said Danielyan. In contrast to intravenous and surgical methods, there is no need to anaesthesise the animals – at least when the scientists treating the animals are experienced in using the method. “Applying the droplets is relatively easy in mice, because they can be held in the researchers’ hand. It is slightly more difficult with rats, because they are bigger. We found that it is easier to apply the stem cell suspension when the animals are lightly anaesthesised.”The new method for the application of stem cells does not cause the animals extra discomfort or pain and it also works very well. The cells are labelled with GFP (green fluorescent protein) enabling the researchers to monitor the location of the stem cells using imaging methods. “As quickly as one to four hours after the application of the suspension, up to six per cent of the cells will have reached the brain. In comparison with intravenous applications, this is a very high percentage. In the case of intravenous stem cell applications, a maximum of only 0.005 percent of cells migrate into the brain. The nasal application also allows us to repeatedly apply stem cells in order to reach a therapeutically effective concentration in the brain,” said Danielyan.
The success has quickly become the method of choice of experts: hundreds of research groups around the world are already using it, including "teams from the USA, China, Korea and the Netherlands". The fact that the animals suffer no pain and the stem cells are applied effectively is, however, only one aspect of the success. Another important aspect relates to the very positive results Danielyan has achieved with the method: "We are able to see unbelievable therapeutic effects. Previously, we only worked with mesenchymal bone marrow stem cells and found that they actually survived for a long time, i.e. for up to six months." And this is quite a long time considering that rodents have a much shorter lifespan than humans.
The researchers have also carried out experiments with glial cells and neural precursor cells. "The method seems to work, but it is still too early to be able to make a statement about the therapeutic effects that can be achieved with such cells," said Danielyan who will continue working on these cells. She works in collaboration with the group of William H. Frey, the director of the renowned Alzheimer Research Centre in St. Paul, USA. "Frey has over 20 years of experience with intranasal applications and has already achieved initial success with the application of insulin to mouse models and patients with Alzheimer's disease. Insulin can also reach the brain by way of inhalation where it improves cognitive abilities. We are delighted to be working with Frey and we have already published some papers together," said Danielyan. However, there are still at least another five years of research needed before the new method of intranasal stem cell application can be clinically tested on humans, despite all the progress made in this field. One thing the researchers still have to find out is how the nasal mucosa reacts to the continuous application of cells. Research on the therapeutic efficiency of intranasally applied stem cells for the treatment of Parkinson's and Alzheimer's is ongoing and will in future be extended further. Danielyan plans to conduct clinical studies in cooperation with a pharmaceutical company that is able to provide the vast sums of money required for such tests. "Clinical investigation, including clinical studies and approval, is impossible without the support of industry," said Danielyan.
Further information:University of Tübingen Institute of Experimental and Clinical Pharmacology and ToxicologyDepartment of Clinical PharmacologyDr. Lusine DanielyanOtfried-Müller Str.4572076 TübingenTel.: +49 (0)7071 29-74926E-mail: lusine.danielyan[at]med.uni-tuebingen.de