Brief Report |
Division of Hematology/Oncology and Blood and Marrow Transplant, Department of Pediatrics, University of Minnesota, USA
Correspondence: Troy C. Lund, Pediatric Hematology-Oncology and Blood and Marrow Transplant Program, University of Minnesota, Mayo Mail Code 484, D-557 Mayo Building, 420 Delaware St. S.E., Minneapolis, MN 55455 USA. E-mail:lundx072{at}umn.edu
ABSTRACT
Bone marrow mesenchymal stem cells are multipotent cells found lining the bone marrow cavity supporting the growth and differentiation of hematologic progenitors. There is growing evidence that these cells can, under the right circumstances, enter the peripheral circulation. We show that granulocyte colony-stimulating factor mobilized peripheral blood contains cells which form colonies and have a similar fibroblastic morphology (termed CFU-F) to bone marrow mesenchymal stem cells. These cells were found at a very low incidence (0.0002%). Mobilized peripheral blood CFU-F were successfully differentiated into osteogenic and adipogenic lineages. FACS analysis showed that the cells had a similar profile to bone marrow mesenchymal stem cells. Importantly, mobilized peripheral blood CFU-F had limited expansion potential and became senescent 20–25 days after isolation. Mobilized peripheral blood CFU-F also did not have any telomerase activity and displayed significant telomere shortening. The rarity of CFU-F in mobilized peripheral blood and the subsequent pressure to divide in cell culture probably contribute to early cellular senescence. Their potential for use in transplant or gene therapy is, therefore, limited.
Key words: granulocyte colony-stimulating factor, mobilized peripheral blood, telomere, mesenchymal stem cell, bone marrow.