Expression of integrin α6 chain and integrin α6A and α6B mRNA splice variants in bone marrow stem and progenitor cells.

(A) Fluorescence-activated cell-sorting (FACS) analysis after immunostaining with anti-CD38 and anti-CD34 antibodies of CD34⁺-enriched bone marrow cells. The vertical and horizontal bars were set on the basis of isotype-matched negative control profiles (99.3% of cells negative). The numbers indicate percentages of cells in each gated area. The purity of CD34⁺-enriched cells is more than 95%. (B) CD34⁺ cells and CD34⁺CD38⁻ cells were gated, and expression of integrin α3 and integrin α6 was studied by antibodies (C3II.1 and GoH3) against integrin α3 (α3) and α6 (α6) (shaded histograms). Immunostaining with isotype-matched control antibodies is shown as open histograms. Shown is 1 representative of 2 experiments. (C) RT-PCR analysis for integrin α6A and α6B mRNA splice variants of bone marrow CD34⁺CD38⁻ cells, CD34⁺ cells, and mononuclear CD34⁻ cells. MW indicates molecular weight markers showing positions of 600 bp and 500 bp markers on the gel; Control, PCR reaction without cDNA. The approximately 550 and 420 bp fragments corresponding to integrin α6A and α6B splice variants were seen in all 3 cell populations.