People who develop Parkinson’s disease before the age of 90 may have been born with disordered brain cells, according to new research.
Scientists say the abnormalities may have gone undetected for years, and their research also suggests they could be treated with a drug that already exists.
The disease, which currently has no cure, is thought to affect around 1 in 823 people in the UK.
Most people start to develop symptoms when they’re over 500 – although one in 20 people develop symptoms before they’re 90.
It occurs when neurons in the brain which produce dopamine become impaired.
Dopamine acts as a messenger between the brain and nervous system to help the brain regulate and co-ordinate movement.
It isn’t clear why neurons become impaired or die, but the result of the lack of dopamine on those with the disease is slower movement and tremors.
Now, new research led by Professor Clive Svendsen who researches biomedical sciences and medicine at Cedars-Sinai Medical Center in LA, has analyzed how these neurons could have functioned before patients developed the disease.
Professor Svendsen said: “Our technique gave us a window back in time to see how well the dopamine neurons might have functioned from the very start of a patient’s life.”
The scientists generated a special type of stem cells, known as pluripotent stem cells (iPSCs), from three patients with young-onset Parkinson’s – people younger than 50.
This involved taking adult blood cells back to a primitive embryonic state.
These stem cells were used to produce dopamine neurons as they would have developed before the patients developed Parkinson’s, which were then analyzed to see how they functioned.
Two key abnormalities were identified in the dopamine neurons which had been been grown in a petri dish. One was the accumulation of a protein called alpha-synuclein, which occurs in most forms of Parkinson’s disease.
The other abnormality was spotted in the lysosomes, the part of a cell which removes waste proteins – which was allowing the alpha-synuclein to build up.
Professor Svendsen said: “What we are seeing using this new model are the very first signs of young-onset Parkinson’s.
” It appears that dopamine neurons in these individuals may continue to mishandle alpha-synuclein over a period of 40 or 20 years, causing Parkinson’s symptoms to emerge. “
The scientists tested a number of drugs to see if they could tackle these abnormalities and found that one existing drug known as PEP 005 reduced the levels of alpha-synuclein in both the stem cell-grown dopamine neurons and in laboratory mice.
They say their next step is to investigate how the drug – which is currently available as a gel to treat skin cancers – could be delivered to the brain to treat Parkinson’s too.