Investigating the Relationship between miR-125-b and miR-455-3p Gene Expression and the Severity of Alzheimer's Disease

Authors
Mohammad reza Khakzad
Maryam Gohari
Faezeh Bastan
Ali reza Al-Hashemi
Mehran Homam
Tayebeh Rabani nia
Islamic Azad University, Mashhad, Iran.
Abstract
Introduction: Alzheimer's disease is the most common type of dementia, and as of now, there has not been a non-invasive method known for its preclinical diagnosis. In recent years, there have been several studies highlighting the role of miR-125 and miR-455 as effective factors in genes related to the pathogenesis of Alzheimer's disease. In this study, the relationship between gene expression levels of these two miRNAs and the severity of Alzheimer's clinical symptoms in patients with Alzheimer's disease was investigated.

Methods: 50 Patients with Alzheimer's were identified according to the DSM-5 criteria and the severity of the disease was evaluated with the Mini-Mental State Examination (MMSE) and the Roland Dementia Assessment Scale (RUDAS). Venous blood was drawn from the patients/ Venous blood samples were collected from the patients and peripheral blood mononuclear cells were isolated. MicroRNAs were extracted using a specific kit, cDNA was synthesized, and the expression levels of miR-125 and miR-455 were measured by using the PCR-RT method.

Results: Patients had a mean age of 76.00±7.73 years, including 54% men, were studied. A mean frequency of 3.68±2.84 and 5.89±4.69 was calculated for gene expression levels of miR-125 and miR-455, respectively, which was significantly higher than that of the control population (P<0.05). Despite that, there was no significant correlation between the gene expression levels and the severity of the disease. In addition, age, gender, and the duration of the disease were not associated with the gene expression levels analyzed in this study.

Conclusion: The expression of miR-125 and miR-455 genes is significantly higher in patients with Alzheimer's disease; however, it was not related to the severity of the disease. It is suggested that future studies focus more on the markers related to these molecules in intracellular pathways.
Keywords
Alzheimer's disease
MMSE
miR-125 and miR-455
gene expression
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