Role of adhesion molecules in mobilization of hematopoietic cells

To study the changes of adhesion molecules' expressions during the recombinant human granulocyte-colony-stimulating factor (rhG-CSF) mobilization in peripheral blood stem cell transplantation (PBSCT), and to confirm the influence of rhG-CSF on hematopoietic stem cells, which are proposed to guide mobilization in PBSCT.

Mice were injected subcutaneously with diluted rhG-CSF or normal saline for 7 days. The blood Sca-1(+) stem cell count and bone marrow (BM) nucleated cell count were enumerated. The expressions of CD49d and CD44 and the adhesive ability of mononuclear cells to bone marrow matrix (fibronectin) were examined by flow cytometry and (51)Cr adhesive assay, respectively.

The mobilizing effect of rhG-CSF on mice was the same as on humans. The number of Sca-1(+) cells in peripheral blood reached the peak on the seventh day, the BM nucleated cell count was reduced, and the expressions of CD49d and the cells' adhesive ability in BM and PB declined.

rhG-CSF can reduce some cell adhesion molecules' expressions and the adhesive ability of hematopoietic stem cells to BM matrix, therefore mobilizing hematopoietic stem cells (HSC) from the BM to the peripheral blood.