Isolation and Characterization of Rat Mesenchymal Stem Cells Derived from Granulocyte Colony-Stimulating Factor-Mobilized Peripheral Blood

Mesenchymal stem cells (MSCs) have been isolated from many tissues and organs. However, there is much dispute as to whether MSCs exist in peripheral blood. This may be due to the limited identification methods of MSCs, especially the lack of detection markers for phenotypic characteristics. In this study, as many as 10 surface markers of MSCs derived from rat peripheral blood (rPBMSCs) were analyzed after granulocyte colony-stimulating factor mobilization. Our results suggest that mobilized rPBMSCs overexpress mesenchymal markers, including CD90, CD44, CD29, CD73 and CD105, but do not express CD45, CD11b, CD79a, CD34 or HLA-DR. This is in conformity with the standard definition of MSCs by the International Society for Cellular Therapy. In addition, the colony-forming efficiency of the mobilized rat peripheral blood was 15.83 +/- 1.61/10(6), significantly outnumbering that of the nonmobilized group, which was 0.28 +/- 0.1/10(6) (p < 0.01). Combining the growth characteristics with the differential capacities of mobilized rPBMSCs towards forming osteocytes, chondrocytes and adipocytes, we further confirmed the existence of rPBMSCs. Additionally, this treatment could improve locomotive function after spinal cord injury (SCI) in rats. Due to their convenient collection, fewer complications, cost effectiveness and suitability for autograft, PBMSCs might be a substitute for MSCs derived from bone marrow and provide promising prospects for the cell-based therapy of SCI. (C) 2016 S. Karger AG, Basel