title: PDGF-BB Enhances the Proliferation of Cells in Human Orbital Fibroblasts by Suppressing PDCD4 Expression Via Up-Regulation of microRNA-21.
abstract: OBJECTIVE
  The aim of this study was to investigate the effect of platelet-derived growth factor (PDGF)-BB on the proliferation of cells and its possible mechanism in human orbital fibroblasts.
  
  
  METHODS
  Human orbital fibroblasts were obtained from orbital fat from decompression surgery in patients with thyroid-associated ophthalmopathy (TAO). The cells were treated with PDGF-BB, and the number of cells was counted using an Advanced Detection and Accurate Measurement (ADAM) automatic cell counter. The expression of programmed cell death 4 (PDCD4) was determined by Western blotting. The effect of PDCD4 on cell proliferation was evaluated using PDCD4 small interfering RNA (siRNA)-transfected cells. The level of microRNA-21 (miRNA-21) was measured by quantitative real-time RT-PCR. In addition, the role of miRNA-21 in the proliferation of PDGF-BB-treated cells was assessed by means of anti-miRNA-21 siRNA and resveratrol (trans-3,4',5-trihydroxys-tilbene), an inhibitor of miRNA-21.
  
  
  RESULTS
  PDGF-BB was found to enhance cell proliferation, whereas it inhibited PDCD4 expression in human orbital fibroblasts. Down-regulation of PDCD4 by PDCD4 siRNA transfection significantly increased the number of human orbital fibroblasts. In addition, PDGF-BB increased the level of miRNA-21 in human orbital fibroblasts. Transfection with anti-miRNA-21 and treatment with resveratrol partially restored the expression of PDCD4 and led to a reduction in cell number in PDGF-BB-treated orbital fibroblasts.
  
  
  CONCLUSIONS
  PDGF-BB enhances proliferation by suppressing PDCD4 expression by up-regulation of miRNA-21 in human orbital fibroblasts. These results suggest that PDGF-BB stimulates cell proliferation through microRNA-21-mediated PDCD4 down-regulation, leading to the development of TAO.
authors.affiliation: Institute of Hansen's Disease Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Institute of Hansen's Disease Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Mihee
authors.initials: M
authors.lastname: Yun
authors.affiliation: Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ji-Sun
authors.initials: JS
authors.lastname: Paik
authors.affiliation: Institute of Hansen's Disease Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Seong-Beom
authors.initials: SB
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Suk-Woo
authors.initials: SW
authors.lastname: Yang
mesh_terms: D000328:Adult; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis / Q000235:genetics*; D000077214:Becaplermin; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D005786:Gene Expression Regulation; D049970:Graves Ophthalmopathy / Q000235:genetics / Q000473:pathology / Q000628:therapy; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D008875:Middle Aged; D009915:Orbit / Q000473:pathology*; D020574:Proto-Oncogene Proteins c-sis / Q000494:pharmacology*; D012313:RNA / Q000235:genetics; D016601:RNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D051017:Apoptosis Regulatory Proteins; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; C114487:PDCD4 protein, human; D020574:Proto-Oncogene Proteins c-sis; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D000077214:Becaplermin; D012313:RNA