Osteogenic Potential of Human Mesenchymal Stem Cells During Serial Subculture

Sun, Hyun Jin; Choi, Yon Rak; Hahn, Soo Bong; Lee, Jin Woo

Abstract

PURPOSE
The purpose of this study was to evaluate the osteogenic differentiation potential of human mesenchymal stem cells during serial subculture.
MATERIALS AND METHODS
Human bone marrow-derived MSCs were serially subcultured and then maintained in basal or osteogenic medium for 14 days. Then we performed FAC analysis, RT-PCR, alkaline phosphatase activity and stains.
RESULTS
Human MSCs had different morphologies, immunophenotypes, and growth rates that were correlated with the length of serial subculture. The phenotype changed from small spindle-shaped cells at passage 1 into large cuboidal or flattened cells at passage 7. The osteogenic capacity of human MSCs decreased during serial subculture. Using RT-PCR, the mRNA levels of bone-specific genes, such as cbfa1/runx2 and osteocal-cin, decreased with increasing passage number. Strong positive staining was observed for ALP and Alizarin reds in osteogenic medium on day 14, but declined significantly with increasing passage number.
CONCLUSION
We have shown that osteogenic potential of human MSCs decreased during serial subculture. This result can provide the helpful information to decide the timing of human MSC transplantation during in vitro culture expansion for treatment of bone defects and so on.