Bone marrow- and subcutaneous adipose tissue-derived mesenchymal stem cells Differences and similarities

Bone marrow (BM) and subcutaneous adipose tissue (Ad) are both considered prospective sources of MSC for therapeutic applications. However, functional properties and therapeutic efficacy of MSC derived from different tissues of the same patient are still poorly investigated. In our study, BM-MSC and F-MSC cultures from 43 adult donors were evaluated in successive passages for immunophenotype; secretion of VEGF, SDF1, MCP1, IL6 and TGF beta 1; frequency of colony-forming units (CFU-F); frequency of adipo- and osteoprogenitors (CFU-Ad, CFU-Ost) and for onset of in vitro replicative senescence. We have demonstrated that at early passages (P2-P3 or up to 14-15 in vitro population doublings), BM-and Ad-derived MSC cultures are comparable in such important characteristics as proliferation rate (population-doubling time: 3.4 +/- 0.2% in BM-MSC, 3 +/- 0.3% in F-MSC), clonogenity (CFU-F frequency: 32 +/- 5% in BM-MSC, 31 +/- 5% in F-MSC) and differentiation potential (CFU-Ad frequency: 10.4 +/- 2% in BM-MSC, 13 +/- 3% in F-MSC; CFU-Ost frequency: 18.5 +/- 5.5% in BM-MSC, 18 +/- 5% in F-MSC) but differ significantly in abundance of CD146(+) fraction within the sample (25 +/- 5% in BM-MSC, 7 +/- 3% in F-MSC) and in levels of VEGF, SDF-1, MCP1 and TGF beta 1 secretion. We have also demonstrated that BM-MSC enter senescence after P3-4, while most F-MSC did not show senescence features up to P6-8. Together, these data demonstrate that specific properties of MSC from different sources should be always taken into account when developing and optimizing the specific protocols for MSC expansion and evaluation for each particular clinical application.