Altered Expression of miR-326 in T Cell-derived Exosomes of Patients with Relapsing-remitting Multiple Sclerosis

Area of Science:

• Neuroimmunology
• Molecular Biology
• Exosome Biology

Background:

• Auto-reactive CD4+ T cells, particularly Th17 cells, invade the central nervous system (CNS), driving multiple sclerosis (MS) pathogenesis.
• T cells release exosomes, which are microRNA-rich vesicles reflecting cellular states, offering potential insights into MS.
• Investigating exosomal microRNAs from T cells can provide diagnostic and prognostic information for MS.

Purpose of the Study:

• To investigate the expression of specific pathogenic microRNAs (miR-146a, miR-29a, miR-155, miR-326) in exosomes derived from T cells of MS patients and healthy controls.
• To determine if altered exosomal microRNA profiles correlate with MS.

Main Methods:

• Conventional T cells (Tconv) were isolated from relapsing-remitting MS patients (n=10) and healthy controls (n=10).
• T cells were cultured for 3 days using anti-CD3/CD28 stimulation.
• Exosomes were purified from T cell culture supernatants, and exosomal microRNA levels (miR-146a, miR-29a, miR-155, miR-326) were quantified using real-time PCR.

Main Results:

• A statistically significant increase in miR-326 expression was observed in Tconv-derived exosomes from RRMS patients compared to controls (7.5±1.88 vs 2.51±0.9, p=0.03).
• No significant differences in the expression levels of miR-155, miR-146a, and miR-29a were found in Tconv-derived exosomes between MS patients and controls (p>0.05).
• These findings indicate altered microRNA expression within exosomes in MS.

Conclusions:

• The study identified significantly elevated miR-326 levels in exosomes from T cells of MS patients.
• Given miR-326's known role in promoting Th17 differentiation, these exosomal miR-326 levels suggest a potential role in MS immunopathogenesis.
• Exosomal miR-326 may represent a promising diagnostic and prognostic biomarker for multiple sclerosis.