Donor variation in the growth properties and osteogenic potential of human marrow stromal cells

Abstract

Human marrow stromal cells (MSCs) were isolated from posterior illiac crest marrow aspirates obtained from 17 healthy donors, ages 19-45 years, with no apparent physical disability. First passage hMSCs exhibited growth rates in vitro that varied up to 12-fold between donors. No correlation between growth rate and the age or gender of the donor was evident (P </= 0.05). When hMSCs were cultured without passage for eight days (subconfluent cultures) or 22 days (confluent cultures) in the absence of any osteogenic agonists, levels of alkaline phosphatase enzyme activity varied 40-fold and 10-fold, respectively, between donors. When exposed to osteo-inductive media, donor populations also showed dramatic differences in levels of bone-specific gene induction. Collectively, these data demonstrate that hMSC cultures are composed of a heterogeneous mixture of cells at various stages of differentiation and with distinct osteogenic potentials. Differences in both growth rate and ALP activity were evident in hMSC cultures established from multiple aspirates obtained over a six month period from the same donors. Therefore, it appears that cellular heterogeneity produced by the method of harvest is propagated within and among different donor populations during culture expansion in vitro.

Chondrogenic differentiation of bovine bone marrow mesenchymal stem cells (MSCs) in different hydrogels: Influence of collagen type II extracellular matrix on MSC chondrogenesis

“…Our results showed that cells cultured in collagen type I hydrogel and in medium containing TGF b1, and dexamethasone expressed significantly high levels of coll 1 mRNA. MSCs undergo osteogenic differentiation upon treatment with dexamethasone or TGF b1, which is followed by increased expression of coll 1 mRNA (Andrades et al, 1999;Gronthos et al, 2003;Phinney et al, 1999). Damaged articular cartilage is usually substituted by fibrous cartilage of which collagen I is a component.…”

Biochemical Heterogeneity of Mesenchymal Stem Cell Populations: Clues to their Therapeutic Efficacy

“…For example, clonal analyses have shown that populations are an admixture of multi-and bi-potent progenitors, lineage restricted precursors, and a small percentage of fibroblasts that lack any capacity to differentiate into connective tissue cell lineages. [36][37][38] Furthermore, not all MSCs capable of osteogenic differentiation in vitro can form ectopic bone when evaluated using in vivo assays, which provide a more stringent assessment of the cell's differentiation potential. 5 Other studies showing that mesenchymal progenitors differentiated in vitro into one type of connective tissue cell can be induced to switch fates by changing culture conditions 39 and that some adult fibroblasts are capable of multi-lineage differentiation 40 further confound the characterization of MSCs as bona fide stem cells.…”

Effects of plating density and culture time on bone marrow stromal cell characteristics

“…Attempts have been made to classify these subpopulations by marker expression and by shape and growth kinetics, e.g., as spindle-shaped type I or flattened type II cells (19) or as rapidly self-renewing cells, or mature MSC (15,16,20). In addition to the observed heterogeneity in vitro, variations have been observed in MSC cultures obtained from different species as well as from different rodent strains or individual human donors (21)(22)(23). Some studies (23) found that variations even exist among different MSC donations obtained from the same human donor.…”

“…In addition to the observed heterogeneity in vitro, variations have been observed in MSC cultures obtained from different species as well as from different rodent strains or individual human donors (21)(22)(23). Some studies (23) found that variations even exist among different MSC donations obtained from the same human donor.…”