Plasma microRNAs disturbed in Alzheimer’s disease

Patients with Alzheimer’s disease (AD) show slightly dysregulated levels of plasma microRNAs (miRNA), including miRNA-92a-3p and miRNA-29a-3p, a recent study has found.

“[T]hey could be involved in the regulations of important pathways of the pathology, such as synaptic transmission, cell signalling, structure maintenance, or cell metabolism, so they could be relevant therapeutic targets,” the researchers said, adding that these miRNAs could also act as potential disease biomarkers.

Using next generation sequencing, plasma miRNAs were measured in 46 participants and compared across various cognitive states: mild cognitive impairment due to AD (MCI-AD; n=19), preclinical AD (n=8), and cognitively healthy older controls (n=19).

The sequencing analysis yielded a panel of 11 miRNAs, of which eight were quantifiable through quantitative PCR. Individually, none of the miRNAs significantly differed in concentration across the different cognitive group. Multivariate analysis including all eight showed a potential association between AD and a combination of three miRNAs.

Lowered expressions of miR-92a-3p and miR-486-5p, along with an enrichment of miR-29a-3p, were associated with AD. Pathway analysis revealed that these molecules might play roles in cell signalling, metabolism, regulation of transcription, and synaptic transmission, among other functions.

Further studies enrolling larger sample sizes are needed to confirm these findings, as well as to identify putative mechanisms by which these miRNAs give rise to AD, the researchers said.