Stem and progenitor cell potential and the potential to differentiate into hematopoietic cells of cells derived from muscle tissue.
(A) Epitopes expressed on cells derived from muscle tissue. The percentages of total cells that stained positive for a given antibody (± SD) are shown. Summarized are results from at least 3 independent cell preparations and stainings per antibody; int. indicates intermediate. (B) Flow cytometry regions that were applied for sorting using antibodies to Sca-1, CD34, CD31, and CD45. (C) CAFC frequency in sorted cell populations derived from muscle tissue and in WBCs. The CAFC assay permits determination of frequencies of cells with proliferation potential at limiting dilution and provides temporal data indicating the hierarchy of stem and progenitor cells because later-developing colonies arise from more primitive cells. CAFC frequencies/100 000 cells (± SEM) from 3 independent analyses are shown. Muscle tissue for these experiments was derived from DBA/2 mice. WBCs (1 × 105) were, after lysis of erythrocytes, derived from approximately 45 μL of blood. (D) Donor chimerism in peripheral blood in recipient mice 12 weeks after transplantation. Preliminary analyses showed a stable engraftment pattern from 3 months to 8 months after transplantation. Mice were given transplants of the same sorted cell populations derived from muscle tissue and from WBCs reported for the CAFC analysis, allowing a direct comparison of the in vitro and in vivo potential of the cells. The percentage of donor-derived cells in peripheral blood (± SEM) is shown. Data are based on at least 2 independent cell sorts and transplantations for each cell population. In each experiment, each sorted cell population was transplanted into at least 2 mice; c.c. indicates 2 × 105 competitor cells.
