A research group at UCC hopes to find the trigger that causes Alzheimer's disease. Emma Napper reports.
At least 20,000 people in Ireland suffer from Alzheimer's disease, and their families suffer with them. It causes memory loss, physical deterioration and eventually death. Nobody knows what causes it and there is no cure.
Researchers at University College Cork hope to shed some light on this mystery. They are carrying out experiments that should help them explain how the extensive brain damage associated with Alzheimer's disease occurs.
They hope their work, which is receiving one of 51 research grants from the Health Research Board, may eventually lead to the development of new drugs to treat the disease.
"Alzheimer's is a hugely important disease in Ireland as it affects a large percentage of the older population," explains Dr Cora O'Neill, leader of the Neurobiology and Alzheimer's Disease Laboratory at the Department of Biochemistry, at UCC.
Alzheimer's disease occurs when brain cells begin to die, particularly in areas of the brain that control language and memory. Loss of memory is often the first sign that a person has Alzheimer's. The disease advances from there, slowly affecting other parts of the brain and causing confusion and, eventually, loss of physical functions.
"Nobody knows why it starts and nobody knows how to stop it, but it may build up over 10 to 20 years," says Dr O'Neill.
The big question has to be, why do the brain cells die?
Researchers believe that nerve cells, which send messages around the brain, die in patients with Alzheimer's disease because of a build up of deposits in the brain. There are two types of these deposits; "plaques", which are sticky clumps of molecules that collect like blobs of glue around the nerve cells, and "tangles", which are long fibres that clog up the nerve cells from the inside.
Both plaques and tangles interfere with the way messages are sent between nerve cells and they then cause the cells to shrivel and degenerate. "The more plaques and tangles there are, the worse the patients get," O'Neill explains.
O'Neill and her group are studying how plaques are produced. Their first aim is to learn more about the chemical processes that cause plaques and then to find a way to disrupt these chemical reactions and stop these sticky build-ups from forming.
PLAQUES are made up of molecules called amyloids. The amyloid in Alzheimer's disease is beta-amyloid, which is produced when other chemicals, called secretases, are present. The secretases chop up the beta-amyloid into fragments.
Amyloids and secretases are found normally in the brain, but in patients with Alzheimer's the brain may have lost the ability to control the amyloid molecules and so they build up and stick together to form the plaques. O'Neill believes that this is because Alzheimer's disease disrupts the way the brain produces the secretases.
"A lot of work needs to be done to understand why the secretases are produced, how they work and how they are controlled," says O'Neill.
The team at UCC are studying one important sectretase, beta-sectretase. "One possibility is that the levels of these chemicals are different in Alzheimer's patients and other people."
A vital clue that might help O'Neill's team is the fact that the plaques always appear first in specific parts of the brain.
"Plaques and tangles are mostly found in specific areas of the brain, especially regions controlling memory and higher brain functions such as emotion and abstract thought," says O'Neill.
It is possible that these areas may share some property that encourages plaques to form. They also want to see if the nerve cells that go to these areas produce more active secretases than the cells going to other areas of the brain.
By conducting experiments that will help them understand the way secretases work, O'Neill hopes that her group will contribute to the production of new drugs to treat Alzheimer's patients. "Our final aim is to find an effective therapy," O'Neill says.
"We need to know how they [the secretases] are behaving in Alzheimer's patients and then we can work on a way to block or inhibit them."
If drugs could control the production and activity of the secretases, this might stop plaques and tangles forming, and so reduce the number of brain cells dying.
O'Neill is very keen that research into Alzheimer's disease is made a "funding priority" in Ireland. This would allow several active research teams here work on Alzheimer's disease research, so we would not have to rely solely on research carried out abroad.