title: Down-regulation of programmed cell death 5 by insulin-like growth factor 1 in osteoarthritis chondrocytes.
abstract: OBJECTIVE
  The aim of this study was to investigate the expression of insulin-like growth factor (IGF)-1 and programmed cell death 5 (PDCD5) in osteoarthritis chondrocytes, and to explore the potential correlation between them in the apoptosis process of osteoarthritis chondrocytes.
  
  
  METHODS
  Patients with knee osteoarthritis were placed into four categories according to radiological staging. The mRNA and protein levels of IGF-1 and PDCD5 in osteoarthritis chondrocytes were respectively detected by quantitative reverse transcriptase polymerase chain reaction (qPCR) and western blotting. In addition, IGF-1 and PDCD5 protein expression in chondrocytes were also measured by immunohistochemistry. Apoptotic cells were measured by TUNEL staining.
  
  
  RESULTS
  Both the mRNA and protein levels of IGF-1 were down-regulated, while the levels of PDCD5 were up-regulated, and the mRNA and protein levels of IGF-1 were negatively correlated with those of PDCD5, respectively. The apoptotic cell was significantly increased in osteoarthritis chondrocytes compared with control. Importantly, the apoptosis rate was positively correlated with PDCD5 protein expression and negatively correlated with IGF-1 protein expression
  
  
  CONCLUSIONS
  We concluded that IGF-1 may down-regulate the expression of PDCD5 and thus inhibit the apoptosis of osteoarthritis chondrocytes.
authors: Department of Orthopaedics, Shanghai First People's Hospital, No. 650 New Songjiang Road, Shanghai, 201620, China. chengqingyiyiyi@hotmail.com
authors: Chengqing
authors: C
authors: Yi
authors: Chunhui
authors: C
authors: Ma
authors: Zongping
authors: Z
authors: Xie
authors: Guoqiao
authors: G
authors: Zhang
authors: Wangsheng
authors: W
authors: Song
authors: Xiaokai
authors: X
authors: Zhou
authors: Yun
authors: Y
authors: Cao
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D015536:Down-Regulation / Q000187:drug effects*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000494:pharmacology*; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D020370:Osteoarthritis, Knee / Q000235:genetics* / Q000378:metabolism / Q000601:surgery; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; D009363:Neoplasm Proteins; C117283:PDCD5 protein, human; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I