Downregulation of exosomal miR-204-5p and miR-632 as a biomarker for FTD: a GENFI study

Area of Science:

• Neuroscience
• Biomarkers
• Genetics

Background:

• Frontotemporal dementia (FTD) is a neurodegenerative disease with genetic and sporadic forms.
• Current diagnostic methods for FTD can be invasive and lack specificity.
• Exosomal microRNAs (miRNAs) in cerebrospinal fluid (CSF) are being investigated as potential non-invasive biomarkers.

Purpose of the Study:

• To evaluate exosomal miRNAs in CSF as diagnostic biomarkers for genetic and sporadic frontotemporal dementia (FTD).
• To assess the diagnostic accuracy of specific miRNAs, namely miR-204-5p and miR-632, in differentiating FTD subtypes.

Main Methods:

• Exosomes were isolated from CSF of participants in the Genetic Frontotemporal Dementia Initiative (GENFI) cohort (presymptomatic and symptomatic mutation carriers, and healthy controls) and a cohort with sporadic FTD.
• MicroRNA expression profiling was performed using quantitative PCR (qPCR) arrays, with validation by individual qPCR.
• Receiver operator characteristic (ROC) analysis was used to determine the diagnostic accuracy of identified miRNAs.

Main Results:

• In the GENFI cohort, miR-204-5p and miR-632 were significantly decreased in symptomatic compared to presymptomatic mutation carriers.
• Combined analysis of miR-204-5p and miR-632 showed high diagnostic accuracy (area under the curve [AUC] = 0.93) for genetic FTD.
• In sporadic FTD, decreased miR-632 demonstrated significant diagnostic potential (AUC = 0.90) compared to Alzheimer's disease and healthy controls.

Conclusions:

• Exosomal miR-204-5p and miR-632 in CSF show potential as diagnostic biomarkers for genetic FTD.
• Exosomal miR-632 also demonstrates potential as a diagnostic biomarker for sporadic FTD.
• These findings suggest that exosomal miRNAs could offer a less invasive approach to FTD diagnosis.