A novel biomarker for Alzheimer's disease in its asymptomatic phases has been discovered by a recent study headed by the Molecular and Cellular Neurobiotechnology group at the Institute for Bioengineering of Catalonia (IBEC) and the University of Barcelona.

The molecule is called miR-519a-3p, and it is a microRNA that has been directly connected to the expression of the cellular prion protein (PrPC), which is dysregulated in patients with Alzheimer's disease and other neurodegenerative illnesses.

The hunt for stable, readily observable biomarkers in biofluids, such as microRNAs, presents a chance to identify Alzheimer's early on when the disease is asymptomatic. This condition, which affects over 35 million people globally, might be diagnosed and treated far more effectively with early detection.

The expression of some microRNAs is known to be deregulated in Alzheimer's patients. However, this is the first time that this microRNA has been specifically linked to the decrease in cellular prion protein production during disease progression.

"Currently, tests to diagnose Alzheimer's disease are usually carried out after the onset of symptoms, when there is already underlying cognitive impairment. We believe that the detection of this microRNA may help to establish additional criteria for a more accurate diagnosis in the early stages of the disease," explains IBEC principal investigator Jose Antonio del Rio, full professor at the Faculty of Biology and the Institute of Neurosciences of the University of Barcelona (UB) and co-leader of the study.

The study also comparatively analyses the presence of the biomarker in samples from other neurodegenerative diseases:
If our goal is to use miR-519a-3p as a biomarker to detect Alzheimer's dementia in hypothetically healthy people, it is essential to ensure that its levels are not altered in other neurodegenerative diseases.

In our study, we compared the levels of this biomarker in samples from other tauopathies and Parkinson's disease, confirming that the changes in miR-519a-3p are specific to Alzheimer's disease," said IBEC senior researcher Rosalina Gavin, UB associate professor and co-leader of the study.