In the first study, a Japanese team of researchers showed that dopamine-producing brain cells could be successfully transplanted into the brain of a primate model of the condition. Over the next 12 months, these cells gradually reduced movement symptoms of Parkinson's.
Making new brain cells
The symptoms of Parkinson's are caused by the gradual loss of dopamine-producing brain cells. Scientists believe replacing these cells could help to reverse some of the symptoms of the condition.
The researchers made new dopamine-producing brain cells from skin cells and blood cells of both people affected by Parkinson's and those without the condition.
The results showed that these new brain cells could integrate into the primate brain and function like normal dopamine-producing brain cells.
Overcoming transplant rejection
One of the key hurdles to transplant therapies is to overcome rejection by the immune system.
In a second study, the team was able to use the same principles of matching for organ donation to match dopamine-producing brain cells to the primate immune system to avoid transplant rejection.
Following this success, the researchers propose that a bank of stem cells for human transplantation could be created from just 150 donors, which would supply stem cells that could be matched to 93% of the UK population.
The potential of cell transplant therapies
Commenting on the papers, David Dexter, Deputy Research Director at Parkinson's UK, said:
"Both of these studies represent an important development in the field of transplantation as a potential treatment for Parkinson's.
"Current medication only serves to mask the symptoms of the condition, but makes no changes to the brain cells themselves.
"Although this is promising quality research, and the conclusions are backed up by solid data that comes from a variety of sources, including behavioural, brain scans and histological analysis, there are still major challenges ahead.
"We need to understand if these new transplanted cells would succumb to the same fate as the original cells that had previously died.
There are also other types of brain cells that are affected by Parkinson's and additional work must be done to tackle the symptoms of the condition that are not caused by a lack of dopamine."
Read more about this research
You can read the latest news and updates from the Parkinson's UK Research team on our official blog.
Find out more about this research discovery with Beckie's behind the headlines blog post.
What causes Parkinson's?
Learn more about how Parkinson's is caused by loss of dopamine-producing cells.