title: The oncofetal gene survivin is re-expressed in osteoarthritis and is required for chondrocyte proliferation in vitro.
abstract: BACKGROUND
  Regulation of cell death and cell division are key processes during chondrogenesis and in cartilage homeostasis and pathology. The oncogene survivin is considered to be critical for the coordination of mitosis and maintenance of cell viability during embryonic development and in cancer, and is not detectable in most adult differentiated tissues and cells. We analyzed survivin expression in osteoarthritic cartilage and its function in primary human chondrocytes in vitro.
  
  
  METHODS
  Survivin expression was analyzed by immunoblotting and quantitative real-time PCR. The localization was visualized by immunofluorescence. Survivin functions in vitro were investigated by transfection of a specific siRNA.
  
  
  RESULTS
  Survivin was expressed in human osteoarthritic cartilage, but was not detectable in macroscopically and microscopically unaffected cartilage of osteoarthritic knee joints. In primary human chondrocyte cultures, survivin was localized to heterogeneous subcellular compartments. Suppression of survivin resulted in inhibition of cell cycle progression and sensitization toward apoptotic stimuli in vitro.
  
  
  CONCLUSIONS
  The present study indicates a role for survivin in osteoarthritic cartilage and human chondrocytes. In vitro experiments indicated its involvement in cellular division and viability. Learning more about the functions of survivin in chondrocyte biology might further help toward understanding and modulating the complex processes of cartilage pathology and regeneration.
authors: Department of Orthopedic Surgery, University of Regensburg, Asklepios Klinikum Bad Abbach, Kaiser Karl V Allee 3, 93077 Bad Abbach, Germany. p.lechler@asklepios.com
authors: Philipp
authors: P
authors: Lechler
authors: Sanjeevi
authors: S
authors: Balakrishnan
authors: Jens
authors: J
authors: Schaumburger
authors: Susanne
authors: S
authors: Grässel
authors: Clemens
authors: C
authors: Baier
authors: Joachim
authors: J
authors: Grifka
authors: Rainer H
authors: RH
authors: Straub
authors: Tobias
authors: T
authors: Renkawitz
mesh_terms: D000368:Aged; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D049109:Cell Proliferation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism* / Q000473:pathology*; D020219:Chondrogenesis / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D008875:Middle Aged; D010003:Osteoarthritis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D014176:Protein Biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D000077022:Survivin; D015533:Transcriptional Activation / Q000502:physiology
chemical_list: C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D012333:RNA, Messenger; D000077022:Survivin