Optimized RT-qPCR and a novel normalization method for validating circulating miRNA biomarkers in ageing-related diseases.

Circulating miRNAs have potential as minimally invasive biomarkers for diagnosing various diseases, including ageing-related disorders such as Alzheimer's disease (AD). However, the lack of standardization in the common analysis method, RT-qPCR, and specifically in the normalization step, has resulted in inconsistent data across studies, hindering miRNA clinical implementation as well as basic research. To address this issue, this study proposes an optimized protocol for key steps in miRNA profiling, which incorporates absorbance-based haemolysis detection for assessing sample quality, double spike-in controls for miRNA isolation and reverse transcription, and the use of 7 stable normalizers verified in an aging population, including healthy subjects and individuals at different stages of Alzheimer's disease (140 subjects).

Candidate Alzheimer's Disease Biomarker miR-483-5p Lowers TAU Phosphorylation by Direct ERK1/2 Repression.

MicroRNAs have been demonstrated as key regulators of gene expression in the etiology of a range of diseases including Alzheimer's disease (AD). Recently, we identified miR-483-5p as the most upregulated miRNA amongst a panel of miRNAs in blood plasma specific to prodromal, early-stage Alzheimer's disease patients. Here, we investigated the functional role of miR-483-5p in AD pathology.