title: Platelets are mitogenic for periosteum-derived cells.
abstract: The early stages of bone regeneration are associated with a high mitogenic activity of periosteal cells. Here we addressed the question of whether platelets that accumulate within the developing haematoma can account for this tissue response. Addition of platelets, platelet-released supernatants, platelet membranes, and microparticles to bovine periosteum-derived cells resulted in an increase in 3H-thymidine incorporation; lipid extracts had no effect. Platelet-released supernatants retained their activity after incubation at 56 degrees C, but not at 100 degrees C. Gel chromatographic analysis revealed the highest mitogenic activity at approximately 35 kD. Of the factors released from activated platelets, basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) increased 3H-thymidine incorporation. The mitogenic activity of platelet-released supernatants was decreased by anti-PDGF, and anti-bFGF antibodies. Platelet-released supernatants increased the number of proliferating periosteum-derived cells as determined by the expression pattern of Ki67. Platelet-released supernatants also resulted in a stimulation of cell proliferation in periosteal explants. These results suggest that platelets have the potential to stimulate the mitogenic response of the periosteum during bone repair.
authors.affiliation: Ludwig Boltzmann Institute of Oral Implantology, Vienna, Austria. reinhard.gruber@akh-wien.ac.at
authors.forename: Reinhard
authors.initials: R
authors.lastname: Gruber
authors.forename: Florian
authors.initials: F
authors.lastname: Karreth
authors.forename: Florian
authors.initials: F
authors.lastname: Frommlet
authors.forename: Michael B
authors.initials: MB
authors.lastname: Fischer
authors.forename: Georg
authors.initials: G
authors.lastname: Watzek
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001792:Blood Platelets / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004355:Drug Stability; D016222:Fibroblast Growth Factor 2 / Q000276:immunology / Q000378:metabolism; D005615:Freezing; D006133:Growth Substances / Q000494:pharmacology; D006358:Hot Temperature; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008934:Mitogens / Q000494:pharmacology; D008938:Mitosis / Q000187:drug effects / Q000502:physiology*; D008970:Molecular Weight; D010521:Periosteum / Q000166:cytology* / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000032:analysis / Q000276:immunology; D013917:Thrombin / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D014020:Tissue Extracts / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000906:Antibodies; D006133:Growth Substances; D019394:Ki-67 Antigen; D008934:Mitogens; D010982:Platelet-Derived Growth Factor; D014020:Tissue Extracts; D016222:Fibroblast Growth Factor 2; D013917:Thrombin; D013936:Thymidine