microRNAs trip down memory lane

Abstract

A new study by Islam et al, in this issue of EMBO Molecular Medicine, reports three microRNAs in the blood that are linked to inter-individual differences in cognition, prior to any sign of cognitive decline. The novel miRNA biomarkers may assist in predicting the risk of cognitive decline and later of developing dementia and can contribute to decision strategies about early therapeutic interventions.

Figure 1. A three miRNA signature of impaired cognition in mice and human blood

(A) In some older individuals, normal cognitive function is prone to deteriorate into mild cognitive impairment (known also as mild neurocognitive disorder), which is considered a prodromal state of dementia, including primarily Alzheimer’s disease. (B) In a new work by Islam et al (2021), authors study human blood samples and mouse models of aging and dementia. They demonstrate a reciprocal correlation between brain function and the levels of three endogenous microRNAs in the blood, namely, miR‐181a‐5p, miR‐146‐5p, and miR‐148a‐3p. Intriguingly, the blood levels of these three miRNA increase when brain neurocognitive capacity deteriorates. The discovery of the three miRNA signature holds promise for potential future development of tests that will contribute to clinical judgment of the risk or degree of cognitive impairment.