title: Role of miR-146a in the Regulation of Inflammation in an In Vitro Model of Graves' Orbitopathy.
abstract: To investigate the role of microRNA 146a (miR-146a) in the regulation of inflammation in an in vitro model of Graves' orbitopathy (GO).
  
  
  
  The level of miR-146a expression in orbital adipose tissue was compared between GO and non-GO by quantitative real-time PCR (qPCR). The effects of interleukin 1β (IL-1β) on miR-146a expression were analyzed in orbital fibroblasts by qPCR. To investigate the molecular mechanism underlying IL-1β-induced miR-146a expression, the effects of inhibitors of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), mitogen-activated protein kinase/extracellular signal-regulated kinases (MEK)-1/2, c-Jun N-terminal kinases (JNK)-1/2, p38 MAP kinase, and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) were analyzed. The effects of miR-146a mimics and inhibitors on IL-1β-induced IL-6 release were examined by ELISA and Western blotting.
  
  
  
  The level of miR-146a expression was significantly higher in GO orbital adipose tissue than in non-GO (P = 0.032). Interleukin 1β induced a time- and concentration-dependent increase in miR-146a expression. Interleukin 1β (10 ng/mL, 16 hours) induced an approximately 17.5-fold increase in miR-146 expression. The increase in miR-146a expression by IL-1β was significantly inhibited by NF-κB, JNK-1/2, and PI3K inhibitors (1.94  ±  0.25, 5.28  ±  0.34 and 9.73  ±  2.32-fold, respectively, P < 0.05 compared with IL-1β-induced miR-146 expression, independent t-test). Interleukin 1β-induced IL-6 protein production was further decreased by miR-146a mimics, but not by inhibitors of miR-146a.
  
  
  
  MicroRNA 146a was upregulated by inflammatory stress in orbital fibroblasts. Our results indicated that miR-146a had a positive effect on the anti-inflammatory process. MicroRNA 146a may play a role in the regulation of inflammation in orbital fibroblasts, and may participate in the pathogenesis of GO.
authors: Department of Ophthalmology Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea 2Department of Medicine, Yonsei University Graduate School of Medicine, Seoul.
authors: Sun Young
authors: SY
authors: Jang
authors: Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
authors: Min Kyung
authors: MK
authors: Chae
authors: Myung-Gok Eye Research Institute at Kim's Eye Hospital, Konyang University College of Medicine, Nonsan, Korea.
authors: Joon H
authors: JH
authors: Lee
authors: Department of Endocrinology, Severance Hospital, Institue of Endocrine Research, Yonsei University College of Medicine, Seoul, Korea.
authors: Eun Jig
authors: EJ
authors: Lee
authors: Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
authors: Jin Sook
authors: JS
authors: Yoon
mesh_terms: D015153:Blotting, Western; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D049970:Graves Ophthalmopathy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D046228:Microarray Analysis; D012313:RNA / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D015850:Interleukin-6; C542542:MIRN146 microRNA, human; D035683:MicroRNAs; D012313:RNA