Abstract:

BACKGROUND: BrdU is a simple marker with high labeling rate, but there are various reports concerning its toxity.

OBJECTIVE: To observe the effects of BrdU labeling on proliferation and osteogenic potentiality of bone marrow mesenchymal stem cells (BMSCs) of Sprague Dawley rats.

METHODS: Rat BMSCs were isolated and cultured by direct adherent method. The ability of monoclone and proliferation was detected after labeling with 0.2% BrdU. Following 3 weeks of culture with osteogenic inducer, changes in osteogenic ability of BMSCs were observed using alizarin red staining, fluorescence immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) before and after labeling.

RESULTS AND CONCLUSION: The proliferation and monoclone of BMSCs were decreased obviously after BrdU labeling. The number and area of clones in BrdU labeling group were less than the normal control group (P < 0.05). The proliferation of the BrdU labeling group was slower when entering increased logarithmic phase at day 4, and the peak level was low (P < 0.05). Regarding osteogenic ability, BMSCs expressed osteocalcin, type Ⅰ collagen following osteogenic induction in the labeling and normal control group, with significant calcium nodules. However, the RT-PCR analysis showed that there was no significant difference in the expression of osteocalcin gene in BMSCs before and after labeling (P > 0.05). Above-mentioned results indicated that BrdU labeling inhibited proliferation and monoclone of BMSCs, but could not decrease its ability of osteogenic differentiation, and could be widely used as a tracer in research of BMSCs as seed cells.