HOW brain cells die during Alzheimer’s disease has been a source of scientific debate for decades.
But a team scientists in the UK and Belgium seem to have put an end to years of speculation.
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Alzheimer’s is the most common cause of dementia – decline of brain function, memory and thinking skills – in the UK, and it’s that 900,000 Brits are living with the crippling condition.
The causes of Alzheimer’s are complex, but one key piece of the puzzle is the build-up of two substances inside the brain called amyloid and tau, which clump up and form tiny structures called plaques and tangles.
They make it harder for the brain to work properly.
Another thing that happens in the brain of someone suffering from the condition is the loss of brain cells – called neurons – leading to the breakdown of neural networks and loss of memory.
How these two key processes are connected has mystified scientists for decades.
But researchers are the UK’s Dementia Research Institute at University College London and KU Leuven in Belgium seemed to have cracked it.
They think the buildup of abnormal proteins in the brain is connected to a form of cellular suicide called ‘necroptosis’.
Writing for the journal Science, the research team said that when amyloid proteins build up in the spaces between neurons it leads to brain inflammation.
Neurons don’t react well to this and their internal chemistry starts to change.
When tangles of tau start to form, brain cells produce a molecule called called MEG3 that triggers the cellular suicide.
Our bodies usually use necroptosis to get rid of unwanted cells when new ones are made.
Scientists studied this process by transplanting human brain cells into the brains of genetically modified mice that were able to produce lots of amyloid.
They were able to ensure the survival of the human brain cells when they blocked the production of MEG3.
Prof Bart De Strooper from the UK’s Dementia Research Institute, told the BBC that this breakthrough sheds light on “how and why neurons die in Alzheimer’s disease” for the first time, after decades of speculation on the process.
“It really provides strong evidence it’s this specific suicide pathway,” he said.
Prof De Strooper said the discovery that blocking the MEG3 molecule can hold off brain cell death could lead to a “whole new line of drugs development”, though it’ll take years of research.
Meanwhile, Dr Susan Kohlhaas, from Alzheimer’s Research UK, said: “This discovery is important because it points to new mechanisms of cell death in Alzheimer’s disease that we didn’t previously understand and could pave the way for new treatments to slow, or even stop disease progression in the future.”
It comes after manufacturers applied for approval of a breakthrough Alzheimer’s drug called lecanemab in the UK, after trials showed it reduced decline in people with the condition.
What are the early signs of Alzheimer’s disease?
Alzheimer’s will affect everyone differently, but there are some common early symptoms to look out for in your loved ones.
According to Alzheimer’s Society, they include:
- memory problems – often the first noticeable sign, which might affect recollections of recent conversations or events, appointments, as well as familiar journeys and places
- problems with thinking and reasoning – this might mean difficulty concentrating, following a conversation and planning, and confusion about what time of day it is
- changes in mood – they may become anxious, easily annoyed, frightened or sad, or lose interest in hobbies
- changes in perception of distance, which might make parking the car or using the stairs hard, finding certain noises upsetting