Professor Arenass team studied the development of DA neurons in animals to determine the important biological molecules in the brain that were necessary for the cells to grow and function efficiently. The scientists identified one particular molecule that seemed to be key, a protein called Wnt5a. They showed that when this molecule, together with a second protein called noggin, was included in cultures of stem cells, far more DA neurons were produced than when these ingredients were not present.
The team then carried out a series of molecular, chemical and electrophysiological tests on the newly grown neurons to check their proficiency, which was shown to be good.
Crucially the team also moved away from embryonic stem cells which can be induced to grow into a wide variety of different cells. Instead they used neural stem cells which are programmed to develop only into nerve cells.
When the researchers transplanted the cells into laboratory animals whose substantia nigra region of the brain was damaged, the results were promising. We reversed almost completely the behavioural abnormalities, and neurons differentiated, survived and re-innervated the relevant part of the brain better Professor Arenas said. Furthermore we do not see the kind of proliferation of the cells that has occurred in the past and we get very little clustering when the cells are treated with Wnt5a. The cells are safer than embryonic stem cells and more efficient than fetal tissue.
Verification of this approach with human cells is ongoing and if the study is successful, it may lead to a clinical trial. Experts in the field have recently identified this approach as the next step in cell replacement therapy for Parkinsons disease and the hope is that this may, ultimately, lead to cells suitable for transplant into human patients.
|Contact: Dr. Fiona Kernan|
European Science Foundation