Characterization of bone marrow derived mesenchymal stem cells in suspension.
BACKGROUND
Bone marrow mesenchymal stem cells (BMMSCs) are a heterogeneous population of postnatal precursor cells with the capacity of adhering to culture dishes generating colony-forming unit-fibroblasts (CFU-F). Here we identify a new subset of BMMSCs that fail to adhere to plastic culture dishes and remain in culture suspension (S-BMMSCs).


METHODS
To catch S-BMMSCs, we used BMMSCs-produced extracellular cell matrix (ECM)-coated dishes. Isolated S-BMMSCs were analyzed by in vitro stem cell analysis approaches, including flow cytometry, inductive multiple differentiation, western blot and in vivo implantation to assess the bone regeneration ability of S-BMMSCs. Furthermore, we performed systemic S-BMMSCs transplantation to treat systemic lupus erythematosus (SLE)-like MRL/lpr mice.


RESULTS
S-BMMSCs are capable of adhering to ECM-coated dishes and showing mesenchymal stem cell characteristics with distinction from hematopoietic cells as evidenced by co-expression of CD73 or Oct-4 with CD34, forming a single colony cluster on ECM, and failure to differentiate into hematopoietic cell lineage. Moreover, we found that culture-expanded S-BMMSCs exhibited significantly increased immunomodulatory capacities in vitro and an efficacious treatment for SLE-like MRL/lpr mice by rebalancing regulatory T cells (Tregs) and T helper 17 cells (Th17) through high NO production.


CONCLUSIONS
These data suggest that it is feasible to improve immunotherapy by identifying a new subset BMMSCs.
Kentaro
K
Akiyama
Yong-Ouk
YO
You
Takayoshi
T
Yamaza
Chider
C
Chen
Liang
L
Tang
Yan
Y
Jin
Xiao-Dong
XD
Chen
Stan
S
Gronthos
Songtao
S
Shi
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000276:immunology; D049109:Cell Proliferation / Q000502:physiology; D005260:Female; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D013234:Stem Cells / Q000166:cytology / Q000276:immunology