Effects of osteopontin in mice bone marrow-derived mesenchymal stem cells differentiating into osteoblasts in vitro

Objective:To explore whether osteopontin (OPN) can induce in vitro bone marrow-derived mesenchymal stem cells (BMSCs) to differentiate into osteoblasts,and explore its mechanism in the union of fracture to provide exact theoretical basis for its further study in the union of fracture. Methods:The bone marrow was separated from the bone of limbs of rats and isolated and then purified using adherence filtration. The passage cells of the third generation were divided into groups. BMSCs were cultured and divided into experimental group and control group. In the experimental group,the culture medi-um contained 0.2 nmol/L OPN. Cell morphology was observed by the light microscope,cell growth curve was tested by cell number counting method,cell cycle was examined with flow cytometry. Alkaline phosphatase (ALP) staining and activity,osteocalcin (OCN) content were measured. Results:The experimental group cells had osteoblasts-like morphology; cell growth curve of experimental group moved rightward,fluorescence at G0/G1 phase increased 13.17% (P0.01) and that at S phase decreased 74.93% (P0.01); ALP staining of experimental group cells was positive,ALP activity and OCN content of experimental group cells increased obviously compared with that of control group. Conclusion:OPN can improve the osteogenic differentiation of BMSCs.