Primary bone marrow-derived mesenchymal stromal cell subsets are differentially distributed during human development and aging

Life-long hematopoiesis depends on the support by mesenchymal stromal cells (MSC) within the bone marrow (BM). Therefore, changes in the BM hematopoietic compartment that occur during development and aging are expected to correlate with changes in the stromal cell microenvironment. MSC are a heterogeneous cell population and various subtypes may have different functions. In accordance with others, we show that CD271 and CD146 define distinct CFU-F containing MSC subpopulations. In addition, analysis of 94 BM samples revealed that the distribution of CD271CD146 and CD271CD146 MSC significantly correlates with donor age. The main subset in adult BM was CD271CD146, whereas the CD271CD146 population was dominant in pediatric and fetal BM. A third subpopulation of CD271CD146 MSC contained CFU-F in fetal BM only. In conclusion, MSC subset distribution changes during development and aging. This suggests that MSC comprise a dynamic system, in which the subpopulations may have different functions during human life.