Disruption of the CXCR4/CXCL12 chemotactic interaction during hematopoietic stem cell mobilization induced by GCSF or cyclophosphamide
J. Clin. Invest. Jean-Pierre Lévesque, et al. 111:187 doi:10.1172/JCI15994 [Go to this article.]

Figure 4
BM extracellular fluids from mobilized mice contain proteases cleaving exogenous human synthetic CXCL12α. (a–c) Aliquots of exogenous synthetic human CXCL12α were incubated overnight at 37°C in the presence of an equal volume of BM extracellular fluids taken from mice mobilized with either GCSF alone (a), CY alone (b), or CY in combination with GCSF (c). The remaining chemotactic activity of exogenous CXCL12α was measured by performing transmigration assays with CD34⁺ cells freshly isolated from normal human BM. Nil indicates that PBS was added instead of BM extracellular extracts. In b and c, Sal represents the BM extracellular fluid from mice injected with saline for 6 days. Black bars show transmigration in the presence of digested CXCL12α, whereas white bars show controls in which exogenous CXCL12α was omitted. Data represent means ± SD of duplicates. Representative data from three independent experiments are shown. (d) The same samples of synthetic human CXCL12α incubated with BM extracellular fluids (as in a) were electrophoresed on a 20% polyacrylamide Tris-Trycine-SDS gel and analyzed by Western blotting with a goat anti-human CXCL12α antibody. A representative experiment from three performed is shown.