| Cells exhibiting an immunophenotype of CD45-Sca-1+c-kit− can be isolated from several murine tissues including skeletal muscle, adipose, cardiac muscle, peripheral blood, bone marrow (BM), gastrointestinal epithelium, and brain tissues. To evaluate the pluripotent differentiation potential of this phenotype, both murine neonatal muscle and adipose stromal cells were sorted on CD34 and Thy-1 expression within the CD45-Sca-1+c-kit-phenotype. In comparative in vitro assays, CD45-Sca-1+c-kit−CD34+Thy-1+ muscle and adipose-derived common pluripotent stem cells (CoPSC) were capable of differentiating into Oil Red O staining adipocytes in response to IGF-1, Alizarin Red S staining osteoblasts cultured with BMP-2, spontaneously twitching myotubes in response to 5-azacytidine, and neurons expressing Tau and NF-200 proteins in response to bFGF and PDGF. In hematopoietic colony forming assays, Thy-1− CoPSC demonstrated granulocyte-macrophage and erythroid colony forming potential, while the Thy-1+ subpopulation generated fibroblast colonies, exclusively. When CD45-Sca-1+c-kit− test cells from muscle and BM were transplanted intracerebellarly into Purkinje Cell Degenerative (pcd ) mice, their footprint pattern scores significantly improved in 28 days after transplantation relative to mice injected with CD45+Sca-1+c-kit+ BM control cells, suggesting that muscle and BM test cells contributed to functional neuronal tissue and correction of the ataxic condition of these mice. Furthermore, in vitro clonal analysis of muscle-derived CoPSC yielded unipotent, bipotent, and tripotent cells (0.006%, 0.01%, and 0.02% of total sorted cells, respectively) that were capable of combinations of adipogenic, myogenic, and neurogenic differentiation. Taken together, these results suggest that a rare cell capable pluripotent differentiation can be identified and isolated from multiple murine tissues. |
