Exploration of potential circulating micro-RNA as biomarker for Alzheimer's disease

Alzheimer's disease (AD) is considered a progressive and devastating neurodegenerative disorder which primarily effects elders. Due to the course of the disease and the involvement of different gene loci with complex genetic studies, it is possible to calculate the relative risk of individuals at risk. In this study, our aim was to investigate the serum transcript levels of candidate microRNAs (miRNAs), including miR-138, miR-128, and miR-107 in patients with AD and compared with that of normal individuals. In this research work, during the diagnosis process of AD, 50 blood samples were obtained from patients and 50 samples were collected from healthy individuals. Then total RNA of each sample was extracted and the expression levels of miRNAs were measured by Real-time PCR method. Our analysis indicated that the relative expression of all three miRNAs decreased in AD patients compared to the healthy samples. There was statistically significant in transcript levels of miR-138 (P = 0.047) and miR-107 (P = 0.004), while the levels of miR-128 had no significant difference between two groups (P = 0.075). The receiver operating characteristic (ROC) curve analysis indicated the potential of all miRNAs as biomarkers in AD. In conclusion, miR-138 and miR-107 can be used as a diagnostic or predictive biomarker in AD. In the case of miR-128, more research is needed. We suggest further studies and evaluation of changes in the expression of these miRNAs in larger populations.