ABSTRACT
Objective: MicroRNAs [miRNA] are a class of non-coding RNAs which play key roles in post-transcriptional gene regulation. Previous studies indicate that miRNAs are dysregulated in patients with multiple sclerosis [MS]. Th17 and regulatory T [Treg] cells are two subsets of CD4[+] T-cells which have critical functions in the onset and progression of MS. The current study seeks to distinguish fluctuations in expression of CD4[+] T-cell derived miR-223 during the relapsing-remitting [RR] phase of MS [RR-MS], as well as the expressions of Th17 and Treg cell markers
Materials and Methods: this experimental study used real-time quantitative polymerase chain reaction [qRT-PCR] to evaluate CD4[+] T cell derived miR-223 expression patterns in patients that experienced either of the RR-MS phases [n=40] compared to healthy controls [n=12], along with RNA markers for Th17 and Treg cells. We conducted flow cytometry analyses of forkhead box P3 [FOXP3] and RAR-related orphan receptor ?t [ROR?t] in CD4[+] T-cells. Putative and validated targets of miR-223 were investigated in the miRWalk and miRTarBase databases, respectively
Results: miR-223 significantly upregulated in CD4[+] T-cells during the relapsing phase of RR-MS compared to the remitting phase [P=0.000] and healthy individuals [P=0.036]. Expression of ROR?t, a master transcription factor of Th17, upregulated in the relapsing phase, whereas FOXP3 upregulated in the remitting phase. Additionally, potential targets of miR-223, STAT1, FORKHEAD BOX O [FOXO1] and FOXO3 were predicted by in silico studies
Conclusion: miR-223 may have a potential role in MS progression. Therefore, suppression of miR-223 can be proposed as an appropriate approach to control progression of the relapsing phase of MS