Expression of CD98 amino acid transporter on murine haematopoietic stem cells

Abstract

We have previously reported that the expression of amino acid transporter, CD98 was high on the lineage marker negative precursor cells including hematopoietic stem cells in murine bone marrow. To clarify the expression of CD98 on the hematopoietic stem cells, we analyzed “side population” (SP) cells by modifying the BD LSR cytometer. We observed the typical SP pattern in Hoechst 33342-stained mouse bone marrow cells by a simple modification to the standard optical configuration of the BD LSR benchtop flow cytometer. In normal bone marrow cells, the expression of CD98 on the lineage marker negative SP cells was low ~ medium. To analyze CD98 expression on SP cells at the early bone marrow reconstitution, we administrated 5-fluorouracil (5-FU) into mice. The proportion of SP cells in the bone marrow was the order of the mice 4 days after 5-FU administration > the mice 7 days after 5-FU administration > normal mice, it seemed to increase the expression of CD98 on SP cells of lineage marker negative in the bone marrow after 4 days. The proportion of SP cells in the fetal liver cells was approximately 13%, in great numbers, and especially, the SP cells concentrated in the lineage^-CD49f^-CD98^hi cell fraction. Therefore, though CD98 expression in the hematopoietic stem cell was low ~ intermediate, the possibility of increasing the expression with cell division and differentiation to progenitor cells in which have pluripotency was shown.