The Functional Role of microRNAs in the Pathogenesis of Tauopathy

Tauopathies are neurodegenerative disorders which include Alzheimer's disease, Pick's disease, corticobasal degeneration, and progressive supranuclear palsy among others. Pathologically, they are characterized by the accumulation of highly phosphorylated and aggregated tau protein in different brain regions. Currently, the mechanisms responsible for their pathogenesis are not known, and for this reason, there is no cure. MicroRNAs (miRNAs) are abundantly present in the central nervous system where they act as master regulators of pathways considered important for tau post-translational modifications, metabolism, and clearance. Although in recent years, several miRNAs have been reported to be altered in tauopathy, we still do not know whether these changes contribute to the onset and progression of the disorder, or are secondary events following the development of tau neuropathology. Additionally, since miRNAs are relatively stable in biological fluids and their measurement is easy and non-invasive, these small molecules hold the potential to function as biomarkers for tauopathy. Herein, we showcase recent findings on the biological link between miRNAs and the pathogenesis of tauopathy, and present emerging evidence supporting their role as biomarkers and targets for novel therapies against them.