Epigenetic clock could shed light on how swiftly people’s brains age and how prone they are to diseases like Alzheimer’s, scientists claim
- Individuals age — and experience related complications — at different rates
- Researchers from Exeter studied DNA methylation in the human cortex
- Methylation data can be used to determine markers of biological ageing
- The newly developed clock could be used to better study the onset of dementia
Insights into how swiftly brains age — and how likely one is to develop Alzheimer’s and other forms of dementia as a result— could come from a new epigenetic clock.
Researchers from Exeter said that the new clock is analogous to our circadian body clock — except instead of dictating when we sleep, it tracks the advance of aging.
Different people age at different rates — which is why some people are afflicted with the characteristics and diseases of later life much earlier than others.
The team’s measuring process is far more accurate than existing approaches as it uses human brain tissue samples rather than blood or other tissue samples.
Insights into how swiftly brains age — and how likely one is to develop Alzheimer’s and other forms of dementia as a result— could come from a new epigenetic clock (stock image)
‘The research area of epigenetic clocks is really exciting, and has the potential to help us understand the mechanisms involved in ageing,’ said paper author and epigeneticist Jonathan Mill of the University of Exeter.
‘Our new clock will help us explore accelerated ageing in the human brain.’
‘As we’re using brain samples, this clearly isn’t a model that can be used in living people to tell how fast they’ll age.’
‘However, we can apply it to donated brain tissue to help us learn more about the factors involved in brain diseases such as dementia.’
In their study, Professor Mill and colleagues analysed DNA methylation, an epigenetic marker — which tells genes to switch on or off — in the human cortex.
This region of the brain is known to be involved in cognition and implicated in conditions such as Alzheimer’s disease.
Methylation data can be used to develop biomarkers of ageing — or epigenetic clocks — and reveal the difference between one’s biological and chronological age as related to neurodegeneration, dementia and other brain phenotypes.
They identified 347 DNA methylation sites that, when analysed in combination, can be used to best predict the ‘age’ of the human cortex.
The team validated their model in a separate collection of 1,221 human brain samples and 1,175 blood samples.
‘Our new epigenetic body clock dramatically outperformed previous models in predicting biological age in the human brain,’ said paper author and bioinformatician Gemma Shireby, also of the University of Exeter.
‘Our study highlights the importance of using tissue that is relevant to the mechanism you want to explore when developing epigenetic clock models.’
‘In this case, using brain tissue ensures the epigenetic clock is properly calibrated to investigate dementia.’
The full findings of the study were published in the journal Brain.
WHAT IS DEMENTIA? THE KILLER DISEASE THAT ROBS SUFFERERS OF THEIR MEMORIES
Dementia is an umbrella term used to describe a range of neurological disorders
A GLOBAL CONCERN
Dementia is an umbrella term used to describe a range of progressive neurological disorders (those affecting the brain) which impact memory, thinking and behaviour.
There are many different types of dementia, of which Alzheimer’s disease is the most common.
Some people may have a combination of types of dementia.
Regardless of which type is diagnosed, each person will experience their dementia in their own unique way.
Dementia is a global concern but it is most often seen in wealthier countries, where people are likely to live into very old age.
HOW MANY PEOPLE ARE AFFECTED?
The Alzheimer’s Society reports there are more than 850,000 people living with dementia in the UK today, of which more than 500,000 have Alzheimer’s.
It is estimated that the number of people living with dementia in the UK by 2025 will rise to over 1 million.
In the US, it’s estimated there are 5.5 million Alzheimer’s sufferers. A similar percentage rise is expected in the coming years.
As a person’s age increases, so does the risk of them developing dementia.
Rates of diagnosis are improving but many people with dementia are thought to still be undiagnosed.
IS THERE A CURE?
Currently there is no cure for dementia.
But new drugs can slow down its progression and the earlier it is spotted the more effective treatments are.
Source: Alzheimer’s Society