Circulating microRNAs as biomarkers in progressive multiple sclerosis.

Area of Science:

• Neuroimmunology
• Molecular Biology
• Biomarker Discovery

Background:

• MicroRNA (miRNA) dysregulation is implicated in multiple sclerosis (MS) pathogenesis, primarily studied in immune cells.
• Circulating miRNAs offer biomarker potential due to their stability in biological fluids, yet their role in progressive MS remains underexplored.

Purpose of the Study:

• To profile circulating miRNA expression in primary progressive MS (PPMS) and secondary progressive MS (SPMS).
• To investigate the association between altered miRNA levels and neurological worsening in progressive MS subtypes.

Main Methods:

• Serum samples from 62 MS patients (PPMS and SPMS) and 21 controls were analyzed for 84 miRNA expressions using miScript miRNA technology.
• Initial screening on a small cohort was followed by validation of the most dysregulated miRNAs in a larger group.

Main Results:

• Upregulation of miR-191-5p was observed in both PPMS and SPMS compared to controls.
• miR-128-3p and miR-24-3p were significantly upregulated in PPMS versus controls and SPMS.
• miR-376c-3p was exclusively overexpressed in PPMS.
• Progression index correlated with miR-128-3p in PPMS and miR-375 in SPMS.

Conclusions:

• Four novel miRNAs associated with progressive MS were identified.
• Elevated circulating miR-191-5p is linked to progressive MS.
• miR-128-3p shows a strong association with PPMS, suggesting potential as a subtype-specific biomarker.