Changes in markers, receptors and adhesion molecules expressed on murine hemopoietic stem cells after a single injection of 5-fluorouracil.

Abstract

Cytokines play a crucial role in the differentiation and proliferation of hemopoietic cells, and it has recently been found that adhesion molecules play crucial roles not only in differentiation and proliferation, but also in the homing and other functions of hemopoietic cells. We have very recently established a new method for purifying pluripotent hemopoietic stem cells (P-HSC) in mice by injecting 5-fluorouracil (5-FU). The P-HSC were found to be low-density, lineage marker-negative (Lin-), CD71- and major histocompatibility complex class I(high). In the present study, we analyze changes in the expression of various HSC markers (Sca-1 and CD34), receptors (c-kit and interleukin-6 receptor [IL-6R]) and adhesion molecules (very late activation antigen-4 [VLA-4], lymphocyte function-associated antigen-1 [LFA-1], and CD44) after 5-FU injection. The percentage of Sca-1+ cells increases after 5-FU treatment, reaching a maximum on day 3, whereas the percentage of IL-6R+ cells decreases, reaching a minimum on day 3. The percentage of CD34+ cells does not change after 5-FU treatment. The percentages of both c-kit(low) and c-kit(high) cells decrease, reaching a minimum on day 3 after 5-FU treatment, whereas the percentage of c-kit- cells reciprocally increases, reaching a maximum on day 3. However, there is no change in the expression of adhesion molecules (VLA-4, LFA-1 and CD44) on the P-HSC.