title: Insulin-like growth factor binding protein-2 and neurotrophin 3 synergize together to promote the expansion of hematopoietic cells ex vivo.
abstract: Co-culture of Umbilical Cord Blood (UCB) CD34+ cells with irradiated Mesenchymal Stem Cells (MSCs) without contact increase the expansion of Hematopoietic Progenitor Cells (HPC). Neurotrophin-3 (NT-3) and insulin-like growth factor binding protein-2 (IGFBP-2) are two factors whose expressions were significantly elevated in conditioned media derived from irradiated MSCs. To determine whether these factors are partly responsible for the growth promoting potential of MSCs, we investigated their impact on the growth and differentiation of UCB-CD34+ cells. Addition of either factor alone had little impact on cell growth, however both factors synergized together to increase the expansion of total nucleated cells, erythroids, megakaryocytes (Mk) and CD34+ cells. However, in contrast to MSCs they failed to significantly improve the expansion of hematopoietic progenitors. Consistent with the impact of these factors on hematopoietic cells, both synergized to activate ERK1/2 and AKT in primary human UCB cells. In conclusion, the study demonstrates for the first time that a neurotrophin factor can synergize with IGFBP-2 to promote hematopoietic cell expansion.
authors.affiliation: Hema-Quebec, Research & Development Department, Quebec City, PQ, Canada. betul.celebi.1@ulaval.ca
authors.forename: Betül
authors.initials: B
authors.lastname: Celebi
authors.forename: Diego
authors.initials: D
authors.lastname: Mantovani
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pineault
mesh_terms: D002455:Cell Division / Q000502:physiology*; D002478:Cells, Cultured; D004789:Enzyme Activation; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020933:Neurotrophin 3 / Q000502:physiology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism
chemical_list: D018971:Insulin-Like Growth Factor Binding Protein 2; D020933:Neurotrophin 3; D051057:Proto-Oncogene Proteins c-akt; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3