title: Induction of programmed cell death in human hematopoietic cell lines by fibronectin via its interaction with very late antigen 5.
abstract: Extracellular matrix (ECM) molecules such as fibronectin (FN), collagens, and laminin have important roles in hematopoiesis. However, little is known about the precise mechanisms by which ECM molecules regulate proliferation of human hematopoietic progenitor cells. In this study, we have investigated the effects of ECM molecules, particularly of FN, on the proliferation of a myeloid leukemia cell line, M07E, which proliferates in response to either human granulocyte/macrophage colony-stimulating factor (GM-CSF) or stem cell factor (SCF). The [3H]thymidine incorporation and cell enumeration assays showed that FN strikingly inhibited GM-CSF- or SCF-induced proliferation of M07E cells in a dose-dependent manner, whereas little or no inhibition was induced by collagen types I and IV. The growth suppression of M07E cells was not due to the inhibitory effect of FN on ligand binding or very early events in the signal transduction pathways from the GM-CSF or SCF receptors. DNA content analysis using flow cytometry after staining with propidium iodide revealed that the treatment of M07E cells with FN did not block the entry of the cells into the cell cycle after stimulation with GM-CSF or SCF, whereas the treatment resulted in the appearance of subdiploid peak. Furthermore, FN was found to induce oligonucleosomal DNA fragmentation and chromatin condensation in the cells even in the presence of GM-CSF or SCF, suggesting the involvement of programmed cell death (apoptosis) in the FN-induced growth suppression. The growth suppression or apoptosis induced by FN was rescued by the addition of either anti-FN antibody, anti-very late antigen 5 monoclonal antibody (anti-VLA5 mAb), or GRGDSP peptide, but not by that of anti-VLA4 mAb or GRGESP peptide, suggesting that the FN effects on M07E cells were mediated through VLA5. In addition, the FN-induced apoptosis was detectable in VLA5-positive human hematopoietic cell lines other than M07E cells, but not in any of the VLA5-negative cell lines. These results suggest that FN is capable of inducing apoptosis via its interaction with VLA5, and also raise the possibility that the FN-VLA5 interaction may contribute, at least in part, to negative regulation of hematopoiesis.
authors.affiliation: Second Department of Internal Medicine, Osaka University Medical School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sugahara
authors.forename: Y
authors.initials: Y
authors.lastname: Kanakura
authors.forename: T
authors.initials: T
authors.lastname: Furitsu
authors.forename: K
authors.initials: K
authors.lastname: Ishihara
authors.forename: K
authors.initials: K
authors.lastname: Oritani
authors.forename: H
authors.initials: H
authors.lastname: Ikeda
authors.forename: H
authors.initials: H
authors.lastname: Kitayama
authors.forename: J
authors.initials: J
authors.lastname: Ishikawa
authors.forename: K
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Kanayama
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D016326:Extracellular Matrix Proteins / Q000494:pharmacology*; D005353:Fibronectins / Q000494:pharmacology*; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology; D007700:Kinetics; D007797:Laminin / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D017469:Receptors, Fibronectin / Q000187:drug effects / Q000502:physiology*; D016029:Receptors, Very Late Antigen / Q000187:drug effects / Q000502:physiology; D019089:Stem Cell Factor; D013936:Thymidine / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D016298:Hematopoietic Cell Growth Factors; D007377:Interleukin-3; D007797:Laminin; D017469:Receptors, Fibronectin; D016029:Receptors, Very Late Antigen; D019089:Stem Cell Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003094:Collagen; D013936:Thymidine