RESUMO
MicroRNAs (miRNAs) are promising biomarkers in multiple sclerosis (MS). This study aims to investigate the association between a preselected list of miRNAs in serum with therapeutic response to Glatiramer Acetate (GA) and with the clinical evolution of a cohort of relapsing-remitting MS (RRMS) patients. We conducted a longitudinal study for 5 years, with cut-off points at 2 and 5 years, including 26 RRMS patients treated with GA for at least 6 months. A total of 6 miRNAs from a previous study (miR-9.5p, miR-126.3p, mir-138.5p, miR-146a.5p, miR-200c.3p, and miR-223.3p) were selected for this analysis. Clinical relapse, MRI activity, confirmed disability progression (CDP), alone or in combination (No Evidence of Disease Activity-3) (NEDA-3), and Expanded Disability Status Scale (EDSS), were studied. After multivariate regression analysis, miR-9.5p was associated with EDSS progression at 2 years (ß = 0.23; 95% CI: 0.04-0.46; p = 0.047). Besides this, mean miR-138.5p values were lower in those patients with NEDA-3 at 2 years (p = 0.033), and miR-146a.5p and miR-126.3p were higher in patients with CDP progression at 2 years (p = 0.044 and p = 0.05 respectively. These results reinforce the use of microRNAs as potential biomarkers in multiple sclerosis. We will need more studies to corroborate these data and to better understand the role of microRNAs in the pathophysiology of this disease.
RESUMO
Background: MicroRNAs are small non-coding RNA that regulate gene expression at a post-transcriptional level affecting several cellular processes including inflammation, neurodegeneration and remyelination. Different patterns of miRNAs expression have been demonstrated in multiple sclerosis compared to controls, as well as in different courses of the disease. For these reason they have been postulated as promising biomarkers candidates in multiple sclerosis. Objective: to correlate serum microRNAs profile expression with disability, cognitive functioning and brain volume in patients with remitting-relapsing multiple sclerosis. Methods: cross-sectional study in relapsing-remitting multiple sclerosis patients treated with glatiramer acetate. Disability was measured with Expanded Disability Status Scale (EDSS) and cognitive function was studied with Symbol Digit Modalities Test (SDMT). Brain volume was analyzed with automatic software NeuroQuant®. Results: We found an association between miR.146a.5p (rs:0.434, p=0.03) and miR.9.5p (rs:0.516, p=0.028) with EDSS; and miR-146a.5p (rs:-0.476, p=0.016) and miR-126.3p (rs:-0.528, p=0.007) with SDMT. Regarding to the brain volume, miR.9.5p correlated with thalamus (rs:-0.545, p=0.036); miR.200c.3p with pallidum (rs:-0.68, p=0.002) and cerebellum (rs:-0.472, p=0.048); miR-138.5p with amygdala (rs:0.73, p=0.016) and pallidum (rs:0.64, p=0.048); and miR-223.3p with caudate (rs:0.46, p=0.04). Conclusions: These data support the hypothesis of microRNA as potential biomarkers in this disease. More studies are needed to validate these results and to better understand the role of microRNAs in the pathogenesis, monitoring and therapeutic response of multiple sclerosis.
