Clonal analysis and hierarchy of human bone marrow mesenchymal stem and progenitor cells

• Published in: Experimental hematology Vol. 38; no. 1; pp. 46 - 54
• Main Authors: Lee, C. Chang I, Christensen, Jared E, Yoder, Mervin C, Tarantal, Alice F
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 2010
• Subjects: Advanced Basic Science; Base Sequence; Bone Marrow Cells - cytology; Cell Differentiation; Cells, Cultured; DNA Primers; Hematology, Oncology and Palliative Medicine; Humans; Karyotyping; Mesenchymal Stromal Cells - cytology; Reverse Transcriptase Polymerase Chain Reaction
• ISSN: 0301-472X; 1873-2399
• DOI: 10.1016/j.exphem.2009.11.001

Objective This study was performed to assess adult human bone marrow mesenchymal stem/progenitor cells at a single-cell level and to determine a hierarchy based on proliferative potential. Materials and Methods Adult bone marrow mesenchymal cells expressing the enhanced green fluorescent protein (EGFP) were sorted as single cells into 24-well plates, each well confirmed with single EGFP-positive cells by fluorescence microscopy, and counted every 3 days. Colonies derived from single cells were expanded then sorted and evaluated using established differentiation protocols for adipogenic, chondrogenic, and osteogenic lineages. Cells were further analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) (peroxisome proliferator-activated receptor [PPAR]− γ2, LEP, LPL, LUM, COMP, BIG, RUNX2, IBSP, BGLAP) and immunocytochemistry (PPAR− γ1/2, collagen II, bone sialoprotein II) specific for trilineage differentiation. Results Bone marrow mesenchymal cells were found to contain high proliferative potential (HPP) mesenchymal colony-forming cells (MCFC) (7%), low proliferative potential (LPP) MCFC (29%), mesenchymal cell clusters (MCC, 26%), and mature mesenchymal cells (MMC, 38%). All LPP-MCFC, MCC, and MMC colonies reached senescence at the end of the evaluation period. However, HPP-MCFC continued to grow, showed differentiation toward all three lineages, and demonstrated the capacity to give rise to secondary HPP-MCFC upon replating at a clonal level. Conclusion These findings suggest that there is a low frequency of bone marrow−derived HPP-MCFC that can both self-renew at a single-cell level and differentiate toward multiple lineages of mesenchymal origin.