Association of target miRNAs expression in blood plasma and cerebrospinal fluid with Alzheimer's disease biomarkers level and cognitive decline.
TL;DR
The observed findings suggest that investigated miRNAs are not suitable for differentiation between different stages of cognitive impairment, however, miRNAs were associated with typical hallmarks of AD, which supports their important role in neurodegeneration.
Abstract
Epigenetic changes can affect Alzheimer's disease (AD) susceptibility. miRNAs are novel potential circulating biomarkers of AD and mild cognitive impairment (MCI) that could support cerebrospinal fluid (CSF) biomarkers in earlier diagnosis of the disease or determination of disease stage. Our aim was to assess differences in expression of target miRNAs in patients with different stages of cognitive impairment and to evaluate the association with CSF biomarkers or cognitive test score (MMSE). We included 117 patients with cognitive impairment, among them 62 AD patients, 24 MCI patients with pathological CSF biomarker levels, and 31 MCI patients with normal CSF biomarker levels. Expression of seven target miRNAs was measured in patients' blood plasma, CSF and extracellular vesicles (EVs) enriched from plasma and CSF. None of the investigated miRNAs were differentially expressed between AD and MCI groups. Four miRNAs were associated with CSF biomarker levels, both in plasma (hsa-miR-375-3p) and CSF (hsa-miR-146a-5p, hsa-miR-29c, hsa-miR-107). The observed findings suggest that investigated miRNAs are not suitable for differentiation between different stages of cognitive impairment. However, miRNAs were associated with typical hallmarks of AD, which supports their important role in neurodegeneration. Therefore, miRNA regulatory networks could contribute to better understanding of the biological processes involved in cognitive impairment.