title: Non-adherent mesenchymal progenitors from adipose tissue stromal vascular fraction.
abstract: In primary human bone marrow cultures, the initial adherent cell fraction has been shown to provide a microenvironment for self-renewal of primitive non-adherent mesenchymal progenitors (non-adherent progenitors of bone marrow stroma [BM-NAMP]), with increased differentiation potential compared to adherent colony-forming units-fibroblast (CFU-f). The present study investigates whether NAMP exist also in cultures of stromal vascular fraction (SVF) cells derived from human adipose tissue. Adipose-tissue NAMP (AT-NAMP) were shown to be stably non-adherent and their number correlated with the number of the initial adhering CFU-f. Unlike BM-NAMP, AT-NAMP did not propagate in suspension in serial replating experiments and the number of colonies steadily decreased with each replating step. However, when AT-NAMP were kept on the initially adhering SVF cells, they could significantly expand without loss of clonogenic, proliferation, and differentiation potential. Although AT-NAMP progeny differentiated into mesodermal lineages similar to that of adherent CFU-f, it was enriched in early mesenchymal progenitor populations, characterized by increased expression of SSEA-4 and CD146. Furthermore, FGF-2 supported AT-NAMP survival and could not be replaced by another mitogenic factor, such as platelet derived growth factor BB. In conclusion, these data suggest that the SVF adherent fraction provides niche signals that regulate the expansion of adipose non-adherent mesenchymal progenitors with the maintenance of their potency. The biological differences described between BM- and AT-NAMP further qualify the properties of the stroma from different tissues and will be relevant for the selection of a cell source for specific regeneration strategies.
authors.affiliation: Departments of Surgery and of Biomedicine, Basel University Hospital , Basel, Switzerland .
authors.forename: Arne
authors.initials: A
authors.lastname: Mehrkens
authors.forename: Nunzia
authors.initials: N
authors.lastname: Di Maggio
authors.forename: Sinan
authors.initials: S
authors.lastname: Gueven
authors.forename: Dirk
authors.initials: D
authors.lastname: Schaefer
authors.forename: Arnaud
authors.initials: A
authors.lastname: Scherberich
authors.forename: Andrea
authors.initials: A
authors.lastname: Banfi
authors.forename: Ivan
authors.initials: I
authors.lastname: Martin
mesh_terms: D050156:Adipogenesis; D000273:Adipose Tissue / Q000166:cytology*; D000328:Adult; D000368:Aged; D002448:Cell Adhesion; D002454:Cell Differentiation; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D002999:Clone Cells; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008875:Middle Aged; D010012:Osteogenesis; D017154:Stromal Cells / Q000166:cytology; D013347:Subcellular Fractions / Q000378:metabolism; D055815:Young Adult
chemical_list: D016222:Fibroblast Growth Factor 2