The Serum Exosome Derived MicroRNA-135a, -193b, and -384 Were Potential Alzheimer's Disease Biomarkers.

OBJECTIVE: MicroRNAs (miRs) are attractive molecules to be considered as one of the blood-based biomarkers for neurodegenerative disorders such as Alzheimer's disease (AD). The goal of this study was to explore their potential value as biomarkers for the diagnosis of AD.

METHODS: The expression levels of exosomal miR-135a, -193b, and -384 in the serum from mild cognitive impairment (MCI), dementia of Alzheimer-type (DAT), Parkinson's disease with dementia (PDD), and vascular dementia (VaD) patients were measured with a real-time quantitative reverse transcriptase PCR (qRT-PCR) method.

RESULTS: Both serum exosome miR-135a and miR-384 were up-regulated while miR-193b was down-regulated in serum of AD patients compared with that of normal controls. Exosome miR-384 was the best among the three miRs to discriminate AD, VaD, and PDD. Using the cut-off value could better interpret these laboratory test results than reference intervals in the AD diagnosis. ROC curve showed that the combination of miR-135a, -193b, and -384 was proved to be better than a particular one for early AD diagnosis.

CONCLUSION: Our results indicated that the exosomal miRs in the serum were not only potential biomarker of AD early diagnosis, but might also provide novel insights into the screen and prevention of the disease.