title: Flow cytometry analysis of guided tissue regeneration-associated human periodontal cells.
abstract: BACKGROUND
  Expanded polytetrafluoroethylene (ePTFE) barrier membranes have been widely used for guided tissue regeneration (GTR) of the human periodontal ligament (PL). However, the precise cellular and molecular events involved in the re-growth of the new tissue are still unclear.
  
  
  METHODS
  Retrieved membranes and the newly-regenerated soft tissue (RT) underlying the membranes were used to examine the cells associated with GTR compared with normal human PL and gingival cells. Flow cytometry (FCM) was used, for the first time, to analyze the spindle-shaped fibroblast-like cells which were adherent to these membranes and the cells which grew out of the RT.
  
  
  RESULTS
  The results showed that the membrane-associated (M) cells had the lowest rate of proliferation and appeared to be larger and more granular than the other types of cell. Moreover, both the M- and RT-derived cells were found to express higher levels of the extracellular matrix (ECM) proteins collagen type 1, fibronectin, tenascin, and decorin. In addition, evidence based on FCM profiles identified distinct sub-populations of GTR cells in which fibronectin expression was markedly up-regulated compared with normal PL cells and which also differed in size and granularity.
  
  
  CONCLUSIONS
  The results of this study show that cells associated with GTR barrier membranes and with the underlying tissue appear to have distinct phenotypic and functional activities consistent with the production of new periodontal connective tissue and periodontal regeneration.
authors.affiliation: Department of Periodontology, Eastman Dental Institute for Oral Health Care Sciences, University College London, University of London, UK.
authors.forename: L
authors.initials: L
authors.lastname: Kuru
authors.forename: M H
authors.initials: MH
authors.lastname: Parkar
authors.forename: G S
authors.initials: GS
authors.lastname: Griffiths
authors.forename: I
authors.initials: I
authors.lastname: Olsen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002455:Cell Division; D048429:Cell Size; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D058575:Decorin; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005353:Fibronectins / Q000096:biosynthesis; D005434:Flow Cytometry; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D011509:Proteoglycans / Q000096:biosynthesis; D018709:Statistics, Nonparametric; D019063:Tenascin / Q000096:biosynthesis
chemical_list: C546878:DCN protein, human; D058575:Decorin; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D008567:Membranes, Artificial; D011509:Proteoglycans; D019063:Tenascin; D003094:Collagen