New Biomarker Diagnoses Asymptomatic Alzheimer's Stages

A study led by the Molecular and Cellular Neurobiotechnology group at the University of Barcelona and the Institute for Bioengineering of Catalonia (IBEC) has identified a new biomarker of Alzheimer's disease in asymptomatic stages of the disease. The molecule is miR-519a-3p, a microRNA that is directly related to the expression of the cellular prion protein (PrPC), which is deregulated in people suffering from some neurodegenerative diseases such as Alzheimer's disease.

The search for biomarkers that are stable and easily detectable in biofluids (such as microRNAs) provides new options for early detection of Alzheimer's disease in the early asymptomatic stages, which could help diagnose and treat early on this disease that affects well over 35 million people worldwide.

First study to link this microRNA to Alzheimer's disease

The expression of some microRNAs is known to be deregulated in Alzheimer's patients. The new study, published in the journal Biochimica et Biophysica Acta - Molecular Basis of Disease, is the first to specifically link this microRNA to the decrease in cellular prion protein production during disease progression.

"Currently, tests to diagnose Alzheimer's disease are usually performed after the first symptoms appear, when there is already underlying cognitive impairment", explains Professor José Antonio del Río, from the Department of Cell Biology, Physiology and Immunology at the UB's Faculty of Biology and Institute of Neurosciences (UBneuro), who is a senior researcher at IBEC and co-leader of the study. "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", adds del Río, who is also a member of the Centre for Biomedical Research Network on Neurodegenerative Diseases (CIBERNED).

The study also comparatively analyses the presence of the biomarker in samples from other neurodegenerative diseases. "If our aim 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, and confirmed that the changes in the miR-519a-3p molecule are specific to Alzheimer's disease", notes Professor Rosalina Gavín (UB-UBneuro-IBEC-CIBERER), who is co-leader of the study.

The team will continue working on this line of study, as Dayaneth Jácome, a member of the research group led by José Antonio del Río and first author of the study, points out. "The next step is to validate miR-519a-3p as a biomarker in blood samples from different cohorts of patients, in order to start using it in the clinical diagnosis of Alzheimer's disease in peripheral samples", she adds.

Reference article:

Jácome, Dayaneth; Cotrufo, Tiziana; Andrés-Benito, Pol; Lidón, Laia; Martí, Eulàlia; Ferrer, Isidre; del Río, José Antonio; Gavín, Rosalina. "miR-519a-3p, found to regulate cellular prion protein during Alzheimer's disease pathogenesis, as a biomarker of asymptomatic stages". Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, April 2024. DOI: doi.org/10.1016/j.bbadis.2024.167187.