Objective: To optimize the culture conditions for clonal isolation of rat bone marrow-derived multipotential adult progenitor cells (rMAPC) and identify their surface markers and differentiation potentials.
Methods: By using a low concentration of fetal bovine serum culture medium, rMAPCs were primarily isolated from bone marrow by attachment culture and clonal-like cells were selected by single cell limiting dilution. The surface antigens of the cloned rMAPC were analyzed by flow cytometry and immunocytochemistry. Multi-differentiation capacities were evaluated by lipoblasts and osteoblasts and neuroblasts differentiation induction. The expressions of Oct-4 and three embryonic germ layer markers were detected by RT-PCR.
Results: Single cell-derived rMAPC could be expanded to passage 20 in vitro which still maintained active proliferation ability. The expanded rMAPCs expressed CD71, alpha-SMA and vimentin, but not CD34, CD44 and CD45. About 83% of the rMAPCs was in the resting phase(G0 + G1) of cell cycle and 17% in S + G2 + M phase. They could be induced to differentiate into adipogenic cells, osteogenic cells and neural like cells. RT-PCR demonstrated that there were expressions of oct-4 gene and three embryonic germ layer markers on the rMAPCs.
Conclusions: Cloned rMAPC can maintain the phenotypes of stem cell during in vitro culturing. It might be an potential adult stem cell source for therapeutic stem cell transplanting and tissue engineering.