title: Platelet-released supernatants enhance hematopoietic stem cell proliferation in vitro.
abstract: Peripheral blood stem cell transplantation (PBSCT) is used to reconstitute normal hematopoiesis after myeloablative chemotherapy. The hematopoietic stem cells are collected from the blood by apheresis machines using density gradient centrifugation. Because of density similarities the grafts contain high levels of leukocytes and platelets that release various mediators into the grafts. The collected hematopoietic stem cells are therefore exposed to platelet released mediators including platelet-derived growth factor, transforming growth factor-beta, vascular endothelial growth factor and platelet factor-4. To investigate whether platelet activation and secretion can affect hematopoietic stem cells during PBSCT, we cultured (i) normal cord blood stem cells and (ii) mobilized peripheral blood stem cells from autografts together with the total secretion product of thrombin activated platelets (i.e. platelet released supernatants). Platelet released supernatants enhanced the cell proliferation of both peripheral blood stem cell (PBSC) autograft and normal cord blood CD34+ cells. Our study shows that platelet secretion in PBSCT autografts affect the hematopoietic stem cell function and possibly thereby the hematopoietic reconstitution after PBSCT.
authors.affiliation: Department of Health Studies, University of Stavanger, Stavanger, Norway. brynjar.foss@uis.no
authors.forename: Brynjar
authors.initials: B
authors.lastname: Foss
authors.forename: Oystein
authors.initials: O
authors.lastname: Bruserud
authors.forename: Tor
authors.initials: T
authors.lastname: Hervig
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism; D001792:Blood Platelets / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D009369:Neoplasms / Q000097:blood / Q000628:therapy; D036102:Peripheral Blood Stem Cell Transplantation; D010920:Placenta / Q000166:cytology; D015539:Platelet Activation; D011247:Pregnancy
chemical_list: D018952:Antigens, CD34