We can detect dementia earlier and better prepare for its effects. Researchers recently discovered specific microRNAs, regulatory molecules that control protein metabolism and production in humans and mice. These could help predict the development of dementia.
Although there is currently no cure, research continues to uncover one. It is possible to prevent the symptoms from developing by giving people time to plan for their loss of memory and cognitive function.
"We need tests that ideally respond prior to the onset dementia and accurately estimate the risk of later diseases," says Andr Fischer, a neurologist from the DZNE (the Deutsches Zentrum fr Neurodegenerative Erkrankungen or the German Center for Neurodegenerative Diseases).
In other words, tests that provide early warning. Our current study results have shown us that we are ready to make such tests possible.
Scientists were able to identify three key microRNAs that are linked to mental performance through an analysis of 132 healthy volunteers and 53 older people with mild cognitive disability (MCI), as well as tests on mice for signs of neural decline and experiments with cell culture.
Higher levels of microRNAs were associated with mental decline in mice. The MCI group also saw the onset dementia in its members. Of those who had high biomarker levels, 90% developed Alzheimer's disease within two years.
Studies on mice and cells in cultures revealed that the same three microRNAs are associated with neuroplasticity and inflammatory processes in brains.
Fischer says that they are "not only markers but also have an active effect on pathological processes." This makes them potentially useful targets for therapy.
"Indeed we have seen in mice that learning ability increases when microRNAs are inhibited with drugs. This has been observed in mice suffering from age-related mental impairments as well as mice with brain damage similar in nature to Alzheimer's disease.
The researchers believe that microRNA signatures could be used to predict how dementia will affect the brain and assess the risk of future attacks. This could be very useful in the development of treatments. The mice learned better when microRNAs were removed from them.
There is no blood test available that can detect these microRNA biomarkers. Researchers now need to develop a non-invasive screening method that is simple and can be used in regular check-ups.
Being able to warn people earlier about dementia is helpful for their preparation. Scientists also have more time to test treatments and see how they work in the early stages.
Fischer says that the brain is already severely damaged by dementia symptoms. "Currently, the diagnosis of dementia is too late to provide effective treatment. The chances of influencing the course and progression of dementia are higher if it is caught early.
The research was published in EMBO Molecular Medicine.
