Prospective use of miRNAs as biomarkers in the diagnosis of Alzheimer's disease.

Alzheimer's disease (AD) is the leading cause of dementia in the aging population. Pathogenic processes related to the accumulation of amyloid plaques (Aβ) and intracellular neurofibrillary tangles (NFTs) begin during the asymptomatic stage long before the onset of deterioration in cognitive functions and neurodegeneration, which makes rapid diagnosis and treatment difficult. Although biochemical diagnostic markers isolated from the body fluids of AD patients are currently used, scientists are engaged in research into molecular biomarkers that will significantly accelerate the diagnosis long before the first clinical symptoms appear. The research presented here focused on microRNAs (miRNAs), small, non-coding RNA molecules that are involved in the regulation of the post-transcriptional expression of many genes. A review of the literature revealed that miRNAs play an important role in regulating the expression of genes involved in the pathophysiological mechanisms of AD. Changes in the levels of miRNAs in a patient's body fluids can be used for rapid diagnosis. Original scientific articles published between 2014 and 2023 describing clinical and experimental studies on the role and expression levels of various miRNAs were selected from scientific databases such as PubMed, NCBI, Science Direct, and Google Scholar. The selected miRNAs were divided into 2 groups based on their expression level in AD: those with increased expression and those with decreased expression. A review of the latest scientific reports confirms that miRNAs may be a promising source of non-invasive and widely available biomarkers. Additionally, their modulation may prove to be an effective therapeutic strategy in AD.