Familial Mediterranean fever (FMF); is an autosomal recessively inherited autoinflammatory disease caused by the mutations in the Mediterranean Fever (MEFV) gene. Recent studies have shown that epigenetic control mechanisms, particularly non-coding RNAs, may play a role in the pathogenesis of autoinflammation. microRNAs (miRNAs) are small non-coding RNAs that play critical roles in regulating host gene expression at the post-transcriptional level. The phenotypic heterogeneity of FMF disease suggests that FMF may not be a monogenic disease, suggesting that epigenetic factors may affect phenotypic presentation. Here we examined the potential anti-inflammatory effect of miR-197-3p, which is a differentially expressed miRNA in FMF patients, by using inflammation related functional assays. We monitored gene expression levels of important cytokines, as well as performed functional studies on IL-1β secretion, caspase-1 activation, apoptosis assay, and cell migration assay. These experiments were used to evaluate the different stages of inflammation following pre-miR-197 transfection. Anti-miR-197 transfections were performed to test the opposite effect. 3′UTR luciferase activity assay was used for target gene studies. Our results obtained by inflammation-related functional assays demonstrated an anti-inflammatory effect of miR-197-3p in different cell types (synovial fibroblasts, monocytes, macrophages). 3′UTR luciferase activity assay showed that miR-197-3p directly binds to the interleukin-1beta (IL-1β) receptor, type I (IL1R1) gene, which is one of the key molecules of the inflammatory pathways. This study may contribute to understand the role of miR-197-3p in autoinflammation process. Defining the critical miRNAs may guide the medical community in a more personalized medicine in autoinflammatory diseases.

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Objective. Systemic autoinflammatory diseases (SAIDs) are caused by the malfunctioning of the innate immune system factors. Clinical heterogeneity and undefined pathobiology are common phenomena among SAIDs. In this study, we aimed to assess the involvement of microRNAs in regulating these complex diseases. Methods. The expression pattern of different miRNAs was compared between SAID patients with high auto-inflammatory disease activity index (AIDAI) score and with low AIDAI score, and their role in inflammation-related pathways was investigated. Differentially expressed miRNAs were determined using the Multi Experiment Viewer (MEV) and Transcriptome Analysis Console(TAC) analysis tools using miRNA microarray. Potential targets of miRNAs were enriched for inflammation-related genes and validated using qRT-PCR analysis. Results. Upon performing microarray analysis, 40 differentially expressed miRNAs were identified between mild familial Mediterranean fever (FMF) patients and severe SAID patients. Thereafter, 21 of 40 miRNAs were found to be potentially involved in inflammatory pathways, of which, 8 were further validated through qRT-PCR. The targets of these 8 miRNAs (miR-29b-3p, miR-29c-3p, miR-30e-3p, miR-130b-3p, miR-148a-3p, miR-186-5p, miR-197-3p, and miR-374b-5p) belonged to the inflammation-related genes and pathways. Conclusion. This is the first study to identify miRNAs that might be associated with a more severe disease form of monogenic autoinflammatory diseases.All these miRNAs were associated with cytokine-mediated pathways and might be used for establishing diagnostic and therapeutic methods.