title: MicroRNA-125b regulates the expression of aggrecanase-1 (ADAMTS-4) in human osteoarthritic chondrocytes.
abstract: BACKGROUND
  Increased expression of aggrecanase-1 (ADAMTS-4) has emerged as an important factor in osteoarthritis (OA) and other joint diseases. This study aimed to determine whether the expression of ADAMTS-4 in human chondrocytes is regulated by miRNA.
  
  
  METHODS
  MiRNA targets were identified using bioinformatics. Chondrocytes were isolated from knee cartilage and treated with interleukin-1 beta (IL-1β). Gene expression was quantified using TaqMan assays and protein production was determined by immunoblotting. Luciferase reporter assay was used to verify interaction between miRNA and target messenger RNA (mRNA).
  
  
  RESULTS
  In silico analysis predicted putative target sequence of miR-125b on ADAMTS-4. MiR-125b was expressed in both normal and OA chondrocytes, with significantly lower expression in OA chondrocytes than in normal chondrocytes. Furthermore, IL-1β-induced upregulation of ADAMTS-4 was suppressed by overexpression of miR-125b in human OA chondrocytes. In the luciferase reporter assay, mutation of the putative miR-125b binding site in the ADAMTS-4 3'UTR abrogated the suppressive effect of miR125.
  
  
  CONCLUSIONS
  Our results indicate that miR-125b plays an important role in regulating the expression of ADAMTS-4 in human chondrocytes and this identifies miR-125b as a novel therapeutic target in OA.
authors: Tetsuya
authors: T
authors: Matsukawa
authors: Tadahiro
authors: T
authors: Sakai
authors: Tomo
authors: T
authors: Yonezawa
authors: Hideki
authors: H
authors: Hiraiwa
authors: Takashi
authors: T
authors: Hamada
authors: Motoshige
authors: M
authors: Nakashima
authors: Yohei
authors: Y
authors: Ono
authors: Shinya
authors: S
authors: Ishizuka
authors: Hiroyuki
authors: H
authors: Nakahara
authors: Martin K
authors: MK
authors: Lotz
authors: Hiroshi
authors: H
authors: Asahara
authors: Naoki
authors: N
authors: Ishiguro
mesh_terms: D051722:ADAM Proteins / Q000096:biosynthesis*; D000071121:ADAMTS4 Protein; D000368:Aged; D000369:Aged, 80 and over; D002358:Cartilage, Articular; D019902:Chondrocytes / Q000201:enzymology*; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D015151:Immunoblotting; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D020370:Osteoarthritis, Knee / Q000201:enzymology / Q000235:genetics*; D011348:Procollagen N-Endopeptidase / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: C531888:MIRN125 microRNA, human; D035683:MicroRNAs; D051722:ADAM Proteins; D011348:Procollagen N-Endopeptidase; D000071121:ADAMTS4 Protein; C000603918:ADAMTS4 protein, human