title: miR-326 and miR-26a, two potential markers for diagnosis of relapse and remission phases in patient with relapsing-remitting multiple sclerosis.
abstract: BACKGROUND
  Multiple sclerosis is an inflammatory autoimmune disease widely characterized by myelin destruction of CNS. Th-17 cells, have been demonstrated to play a crucial role in pathogenesis of MS. MicroRNAs are a new class of non-coding RNAs that participate in post-transcriptional regulation of gene expression. Previous studies have reported a potential role of various miRNAs in induction of Th-17 differentiation and progress of autoimmune diseases. In recent years, it has been shown that miR-326 and miR-26a involved in progress of Th-17 and MS disease.
  
  
  OBJECTIVE
  To evaluate expression pattern of miR-326 and miR-26a in peripheral blood lymphocytes of relapsing-remitting MS patients during relapsing and remitting phases compared to healthy control subjects.
  
  
  METHODS
  Forty RR-MS patients of Isfahan population were diagnosed as relapsing (n=20) or remitting phase (n=20) patients according to clinical manifests and expression level of miR-26a and miR-326 was measured in these groups by quantitative real time PCR method compared to 20 healthy controls. In-silico molecular signaling pathway enrichment analysis was also performed on validated and predicted targets (targetome) of miR-26a by DAVID database to explore possible role of miR-26a in Th17 differentiation.
  
  
  RESULTS
  We observed up-regulation of both miR-326 and miR-26a in relapsing phase of multiple sclerosis patients compared with remitting phase (p value=0.0001) and healthy controls (p value=0.0091). ROC curve analysis confirmed valuable and precise potential of miR-326 to discriminate between relapsing and remitting phases of multiple sclerosis with specificity and sensitivity of 100% at a proposed optimum cutoff point. Furthermore, in-silico molecular signaling pathway enrichment analysis detected TGF-β signaling pathway as one of the most statistically relevant pathway with miR-26a targetome.
  
  
  CONCLUSIONS
  Our results confirmed potential of miR-326 as a diagnostic biomarker to discriminate between relapsing and remitting phases of multiple sclerosis disease. Similar expression pattern to miR-326 and in-silico molecular enrichment analysis altogether suggest an inducing role of miR-26a in differentiation of pathogenic Th17 cells during pathogenesis of multiple sclerosis by targeting major components of the TGF-β signaling pathway (i.e. SMAD4 and SMAD1) and disarrangement of this signaling pathway.
authors.affiliation: Division of Cellular and Molecular Biology, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran.
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Honardoost
authors.affiliation: Department of Cellular Biotechnology at Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Kiani-Esfahani
authors.affiliation: Division of Cellular and Molecular Biology, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran; Department of Cellular Biotechnology at Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran; Cellular & Molecular Immunology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: kamranghaedi@yahoo.com.
authors.forename: Kamran
authors.initials: K
authors.lastname: Ghaedi
authors.affiliation: Department of Neurology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Multiple Sclerosis and Neuroimmunology Research Center, Isfahan, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Etemadifar
authors.affiliation: Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: m_salehi@med.mui.ac.ir.
authors.forename: Mansoor
authors.initials: M
authors.lastname: Salehi
mesh_terms: D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D005260:Female; D005786:Gene Expression Regulation; D005819:Genetic Markers; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis* / Q000235:genetics; D012008:Recurrence; D050794:STAT1 Transcription Factor / Q000235:genetics; D058504:Th17 Cells / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
chemical_list: D005819:Genetic Markers; D035683:MicroRNAs; D050794:STAT1 Transcription Factor; D016212:Transforming Growth Factor beta; C528163:MIRN26 microRNA, human; C545322:MIRN326 microRNA, human
keywords: MicroRNA; Relapsing–remitting multiple sclerosis; Th-17 cells; miR-26a; miR-326