Hsa-let-7g-5p, a circulating microRNA, as a biomarker for Alzheimer's disease

Abstract

Effective prevention and treatment of Alzheimer's disease depends on the identification of accurate, rapid and non-invasive biomarkers. Peripheral blood and biological fluids such as plasma, serum, and cerebrospinal fluid are valuable samples for the detection of biomarkers because they cause little discomfort to the patient and facilitate the diagnosis of the disease in the early stages. Small non-coding RNAs known as microRNA (miRNA) play a vital role in regulating various signaling pathways and are involved in various diseases. More than 70% of experimentally confirmed miRNAs are expressed in the brain which can be used as potential diagnostic biomarkers of AD. In silico pathway analysis by DIANA-Mir Path confirmed that miR-let-7g is involved in chronic myeloid leukemia, cell cycle, melanoma and pancreatic cancer pathways. This study aimed to evaluate the hsa-let7g-5p miRNA as a possible blood biomarker for the early detection of AD.Samples of blood were taken from 30 AD patients and 30 healthy people. RNA total was isolated from serum samples and converted to cDNA and the expression level of Let7 miRNAs was measured by the real-time PCR method.The results of the study showed that the expression of hsa-let7g-5p was significantly decreased in patients with AD compared to the normal cases. The AROC for hsa-let-7g-5p transcript levels was 0.4032 compared to the 0.7869 from the normal control group (P = 0.035; 95% CI, 0.27–0.90). These findings suggest that hsa-let7g-5p miRNAs may be used as a potential biomarker for AD diagnosis.

Keywords

• Alzheimer's disease (AD)
• MicroRNA (miRNA)
• Biomarker
• Let-7