title: Growth and differentiation factor-5 regulates the growth and differentiation of human dental pulp cells.
abstract: BACKGROUND
  Growth and differentiation factor-5 (GDF-5) is a multifunctional protein that regulates the development and repair in many tissues. The purpose of this study was to investigate whether GDF-5 may influence the proliferation, differentiation, and collagen turnover of human dental pulp cells.
  
  
  METHODS
  Human dental pulp cells were treated with different concentrations of GDF-5 (0-500 ng/mL). Morphology of pulp cells was observed under a microscope. Cell proliferation was evaluated by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Immunofluorescent assay was used to observe the percentages of cell mitosis. Collagen content was measured by Sircol collagen assay. Tissue inhibitor of metalloproteinase-1 level in the culture medium was measured with enzyme-linked immunosorbent assay and Western blotting. Cell differentiation was evaluated by alkaline phosphatase (ALP) staining and ALP enzyme activity assay.
  
  
  RESULTS
  After exposure of dental pulp cells to various concentrations of GDF-5, cell number was up-regulated significantly in dose-dependent manner. GDF-5 also stimulated mitosis of dental pulp cells as indicated by an increased percentage of binucleated cells from 28% to 35%-45%. GDF-5 did not affect the collagen content and tissue inhibitor of metalloproteinase-1 level of pulp cells. GDF-5 decreased the ALP activity of pulp cells as analyzed by ALP staining and enzyme activity assay, with 14%-44% of inhibition.
  
  
  CONCLUSIONS
  GDF-5 revealed mitogenic and proliferative activity to dental pulp cells. GDF-5 showed inhibitory effect on ALP activity but little effect on the collagen turnover. These events are crucial in specific stages of dental pulp repair and regeneration. GDF-5 may be potentially used for tissue engineering of pulp-dentin complex.
authors.affiliation: Biomedical Science Team, Chang Gung University of Science and Technology, Taoyuan, Taiwan.
authors.forename: Mei-Chi
authors.initials: MC
authors.lastname: Chang
authors.forename: Li-Deh
authors.initials: LD
authors.lastname: Lin
authors.forename: Hui-Chun
authors.initials: HC
authors.lastname: Tseng
authors.forename: Bei-En
authors.initials: BE
authors.lastname: Chang
authors.forename: Chiu-Po
authors.initials: CP
authors.lastname: Chan
authors.forename: Sheng-Yang
authors.initials: SY
authors.lastname: Lee
authors.forename: Hsiao-Hua
authors.initials: HH
authors.lastname: Chang
authors.forename: Po-Shuen
authors.initials: PS
authors.lastname: Lin
authors.forename: Shuei-Kuen
authors.initials: SK
authors.lastname: Tseng
authors.forename: Jiiang-Huei
authors.initials: JH
authors.lastname: Jeng
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000032:analysis / Q000187:drug effects; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002478:Cells, Cultured; D002648:Child; D003094:Collagen / Q000187:drug effects / Q000378:metabolism; D003782:Dental Pulp / Q000166:cytology* / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D055428:Growth Differentiation Factor 5 / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008934:Mitogens / Q000494:pharmacology; D008938:Mitosis / Q000187:drug effects; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis / Q000187:drug effects; D055815:Young Adult
chemical_list: C525893:GDF5 protein, human; D055428:Growth Differentiation Factor 5; D008934:Mitogens; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D003094:Collagen; D000469:Alkaline Phosphatase
keywords: Alkaline phosphatase; GDF-5; cell proliferation; collagen; dental pulp cells; differentiation