Th17 cells play a critical role in the pathogenesis of autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome, and inflammatory bowel disease. Despite the extensive investigation into this T cell lineage, little is understood regarding the role of Th17 lineage-specific lncRNAs (long non-coding RNAs) > 200 nt. lncRNAs may influence disease through a variety of mechanisms; their expression could be regulated by SNPs. lncRNAs can also affect the expression of neighboring genes or complementary miRNAs, and their expression may have lineage-specific patterns. In the system biology study presented here, the effective lncRNAs from different criteria were predicted for each autoimmune disease, and we then evaluated their expression levels in 50 MS patients compared to 25 controls using qRT-PCR. We identified changes in the expression levels of AL450992.2, AC009948.5, and RP11-98D18.3 as potential peripheral blood mononuclear cell (PBMC) biomarkers for MS among our studied lncRNAs in which co-expression analysis of AL450992.2 had the most AUCs, and the relationship to RORC was also assessed. We propose that the recurrently deregulated lncRNAs identified in this report could provide a valuable resource for studies aimed at delineating the relationship between functional lncRNAs and autoimmune disorders.

Y Objective(s): Multiple sclerosis (MS) is considered as a chronic type of an inflammatory disease characterized by loss of myelin of CNS. Recent evidence indicates that Interleukin 17 (IL-17)producing T helper cells (Th17 cells) population are increased and regulatory T cells (Treg cells) are decreased in MS. Despite extensive research in understanding the mechanism of Th17 and Treg differentiation, the role of microRNAs in MS is not completely understood. Thereby, as a step closer, we analyzed the expression profile of miR-9-5p and miR-106a-5p, and protein level of retinoic acid receptor (RAR)-related orphan receptor C (RORC; Th17 master transcription factor) as direct target of miR-106a-5p and forkhead box P3 (FOXP3; Treg master transcription factor) as indirect target of miR-9-5p in CD4(+) T cells in two groups of relapsing and remitting in our relapsing-remitting MS (RR-MS) patients. Materials and Methods: Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was utilized to assess the expression of miRNAs and mRNAs, in 40 RR-MS patients and 11 healthy individuals. Thus, FOXP3 and RAR-related orphan receptor gamma t(ROR gamma t) was assessed in CD4(+) T-cells by flow cytometry. We also investigated the role of these miRNAs in Th17/Treg differentiation pathway through bioinformatics tools. Results: An up-regulation of miR-9-5p and down-regulation of miR-106a-5p in relapsing phase of MS patients were observed compared to healthy controls. RORC and FOXP3 were up-regulated in relapsing and remitting phases of MS, respectively. Conclusion: Expression pattern of miR-9-5p and miR-106a-5p and their targets suggest a possible inducing role of miR-9-5p and suppressing role of miR-106a-5p in differentiation pathway of Th17 cells during MS pathogenesis.

Eosinophils are a subset of granulocytes characterized by a high abundance of specific granules in their cytoplasm. To act as effector cells, eosinophils degranulate and form eosinophil extracellular traps (EETs), which contain double-stranded DNA (dsDNA) co-localized with granule proteins. The exact molecular mechanism of EET formation remains unknown. Although the term “EET release” has been used in scientific reports, it is unclear whether EETs are pre-formed in eosinophils and subsequently released. Moreover, although eosinophil degranulation has been extensively studied, a precise time-course of granule protein release has not been reported until now. In this study, we investigated the time-dependent release of eosinophil peroxidase (EPX) and mitochondrial DNA (mtDNA) following activation of both human and mouse eosinophils. Unexpectedly, maximal degranulation was already observed within 1 min with no further change upon complement factor 5 (C5a) stimulation of interleukin-5 (IL-5) or granulocyte/macrophage colony-stimulating factor (GM-CSF)-primed eosinophils. In contrast, bulk mtDNA release in the same eosinophil populations occurred much slower and reached maximal levels between 30 and 60 min. Although no single-cell analyses have been performed, these data suggest that the molecular pathways leading to degranulation and mtDNA release are at least partially different. Moreover, based on these data, it is likely that the association between the mtDNA scaffold and granule proteins in the process of EET formation occurs in the extracellular space.