title: Altered expression of microRNA-203 in rheumatoid arthritis synovial fibroblasts and its role in fibroblast activation.
abstract: OBJECTIVE
  MicroRNA (miRNA) are recognized as important regulators of a variety of fundamental biologic processes. Previously, we described increased expression of miR-155 and miR-146a in rheumatoid arthritis (RA) and showed a repressive effect of miR-155 on matrix metalloproteinase (MMP) expression in RA synovial fibroblasts (RASFs). The present study was undertaken to examine alterations in expression of miR-203 in RASFs and analyze its role in fibroblast activation.
  
  
  METHODS
  Differentially expressed miRNA in RASFs versus osteoarthritis synovial fibroblasts (OASFs) were identified by real-time polymerase chain reaction (PCR)-based screening of 260 individual miRNA. Transfection of miR-203 precursor was used to analyze the function of miR-203 in RASFs. Levels of interleukin-6 (IL-6) and MMPs were measured by real-time PCR and enzyme-linked immunosorbent assay. RASFs were stimulated with IL-1β, tumor necrosis factor α (TNFα), lipopolysaccharide (LPS), and 5-azacytidine (5-azaC). Activity of IκB kinase 2 was inhibited with SC-514.
  
  
  RESULTS
  Expression of miR-203 was higher in RASFs than in OASFs or fibroblasts from healthy donors. Levels of miR-203 did not change upon stimulation with IL-1β, TNFα, or LPS; however, DNA demethylation with 5-azaC increased the expression of miR-203. Enforced expression of miR-203 led to significantly increased levels of MMP-1 and IL-6. Induction of IL-6 by miR-203 overexpression was inhibited by blocking of the NF-κB pathway. Basal expression levels of IL-6 correlated with basal expression levels of miR-203.
  
  
  CONCLUSIONS
  The current results demonstrate methylation-dependent regulation of miR-203 expression in RASFs. Importantly, they also show that elevated levels of miR-203 lead to increased secretion of MMP-1 and IL-6 via the NF-κB pathway and thereby contribute to the activated phenotype of synovial fibroblasts in RA.
authors.affiliation: Center of Experimental Rheumatology, University Hospital Zurich and Zurich Center of Integrative Human Physiology, Zurich, Switzerland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Stanczyk
authors.forename: Caroline
authors.initials: C
authors.lastname: Ospelt
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Karouzakis
authors.forename: Andrew
authors.initials: A
authors.lastname: Filer
authors.forename: Karim
authors.initials: K
authors.lastname: Raza
authors.forename: Christoph
authors.initials: C
authors.lastname: Kolling
authors.forename: Renate
authors.initials: R
authors.lastname: Gay
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Buckley
authors.forename: Paul P
authors.initials: PP
authors.lastname: Tak
authors.forename: Steffen
authors.initials: S
authors.lastname: Gay
authors.forename: Diego
authors.initials: D
authors.lastname: Kyburz
mesh_terms: D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D044127:Epigenesis, Genetic; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000378:metabolism*; D010003:Osteoarthritis / Q000378:metabolism; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D018501:Antirheumatic Agents; C508600:IL6 protein, human; D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D035683:MicroRNAs; D014409:Tumor Necrosis Factor-alpha; D020781:Matrix Metalloproteinase 1