Evaluation of miRNA-29a and miRNA-31 as biomarkers in the diagnosis of alzheimer's and vascular dementia

Alzheimer's and vascular dementia are the two most common types of dementia, and their differential diagnosis is clinically difficult. Therefore, the search for non-invasive biomarkers continues. miR-29a has effects on synapse formation, regulation and neurogenesis. miR-31 causes neurodegeneration with inflammation and death of neurons. In this direction, it was aimed to study miR-29a and MIR-31 in vascular dementia, Alzheimer's and control cases and to determine their differences and to determine their diagnostic usability. In our study, expression levels of miR-29a and miR-31 were examined by Real Time PCR method in serum samples taken from 30 Alzheimer's disease, 30 vascular dementia and 30 age-matched control individuals, and their usability as biomarkers was evaluated. When the serum samples of the Alzheimer and vascular dementia patient group and the control group were compared, no significant difference was observed in the expression level of miR-29a (p>0.05). miR-31 expression levels were examined and statistically significant difference was observed between the groups (p=0.01). It was observed that miR-31 expression levels were significantly increased in Alzheimer's patient group compared to vascular dementia and control groups (p=0.017, p=0.046). No statistically significant difference was observed between the vascular dementia and control groups in terms of miR-31 expression level (p=1). In the comparison of Alzheimer's disease, vascular dementia, and the control group, it was observed that the expression difference of miR-29a and miR-31 was detected and their ability to differentiation between the patient and control groups as biomarkers was low. This suggests that they are not sufficient to be used as a potential non-invasive biomarker in the diagnosis of diseases.