Les cellules stromales médullaires produisent du Flt3-ligand spontanément: Influence des rayonnements ionisants et de la stimulation par cytokines
Titre de la revue : International Journal of Radiation Biology Volume : 84 N° : 8 Pagination : 659-667 Date de publication : 01/09/2008
Purpose: To define the ability of human bone marrow (BM) stromal cells to produce Flt3 ligand (FL), and to define the effect of ionizing radiation, TNF or TGF on FL production. Material and methods: Primary BM stromal cell cultures at confluency were irradiated at 2 to 10 Gy or were stimulated with TNF or TGF. The presence of FL was then tested in culture supernatants and in cell lysate. The presence of a membrane-bound form of FL was also tested by cell ELISA, and the level of gene expression was tested by RT-PCR. Results: Primary BM stromal cells spontaneously produced FL. This production was increased by TNF but not by TGF or by irradiation. Chemical induction of osteoblastic differentiation from BM stromal cells also induced an increase in FL production. Conclusions: Results demonstrate that FL is produced spontaneously by BM stromal cells and that FL production is regulated by cytokine stimulation but not by ionizing radiations. Moreover, the induction of osteoblast differentiation induced an increase in FL release. These results suggest a rationale to explain the in vivo radiation-induced increase in plasma FL concentration observed in previous studies.