title: [Osteogenic potential of fibroblasts with reconstituted telomerase activity].
abstract: OBJECTIVE
  To prevent the senescence of 'seed cells' for tissue engineering, the life span of human fibroblasts is extended by reconstitution of telomerase activity, and the osteogenic potential of these fibroblasts are tested.
  
  
  METHODS
  The pGRN145 plasmids encoding human telomerase reverse transcriptase (hTERT) were introduced into the normal human primary fibroblasts by electroporation. Telomerase activity was analyzed by TRAP-PCR assay. The beta-galactosidase stain was used to indicate the signs of cell senescence. The hTERT positive fibroblasts were then induced to form bone nodules. The bone nodules were stained by tetracycline and Alizarin Red S.
  
  
  RESULTS
  Stable telomerase activity could be detected in the transfected fibroblasts and no signs of cell senescence were found in the fibroblasts cultured for more than 50 doublings. The hTERT positive fibroblasts could form bone nodules when they were cultured in vitro induced by bone morphogentic protein 2 and tumor necrosis factor-alpha.
  
  
  CONCLUSIONS
  The fibroblasts with reconstituted telomerase activity reserve their osteogenic potential.
authors.affiliation: Department of Cell Biology, Shanghai Second Medical University, Shanghai, P. R. China 200025.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: You-ming
authors.initials: YM
authors.lastname: Zhu
mesh_terms: D002478:Cells, Cultured; D016922:Cellular Senescence / Q000235:genetics / Q000502:physiology*; D002648:Child; D004268:DNA-Binding Proteins; D004789:Enzyme Activation / Q000502:physiology; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism*; D006801:Humans; D010012:Osteogenesis / Q000502:physiology; D012867:Skin / Q000166:cytology; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*; D016615:Telomere / Q000235:genetics; D023822:Tissue Engineering; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D004268:DNA-Binding Proteins; D014409:Tumor Necrosis Factor-alpha; D019098:Telomerase