Correlation between magnitude and duration of hydrostatic pressure and the differentiation of human bone marrow mesenchymal stem cells** / 中国组织工程研究

ABSTRACT

BACKGROUND:Mechanical signal has close correlation with the growth, development, repair and reconstruction of the skeletal system and the development of disease, the effect and the mechanism on bone marrow mesenchymal stem cel s is worthy to concern. OBJECTIVE:To explore the effect and mechanism of hydrostatic pressures on the differentiation of bone marrow mesenchymal stem cel s. METHODS:Short-term experimentthe human bone marrow mesenchymal stem cel s were incubated into the normal Dulbecco’s modified Eagle’s medium, osteogenic medium or the Dulbecco’s modified Eagle’s medium containing extracel ular signal-regulated kinase 1/2 inhibitor U0126, respectively. Homemade pressure loading system was used to impose 0, 40 and 80 kPa hydrostatic pressure for 1 and 4 hours. Long-term experimenthuman bone marrow mesenchymal stem cel s were incubated into the normal Dulbecco’s modified Eagle’s medium or osteogenic medium respectively, and then 40 kPa hydrostatic pressures was loaded for 4 hours per day, and lasted for 14 days. The cel s without hydrostatic pressure were regarded as the control group. RESULTS AND CONCLUSION:Real-time quantitative reverse transcription PCR results showed that after osteogenic induction and simulated with 40 kPa hydrostatic pressure for 4 hours, the mRNA expressions of core binding factorα1 and osteocalcin in the bone marrow mesenchymal stem cel s were increased, while the mRNA expressions of peroxisome proliferator-activated receptorγ2 and adipsin were decreased, and the 80 kPa hydrostatic pressure did not cause such reactivity. The osteogenic induction effect of 40 kPa hydrostatic pressure could be partial antagonized with U0126. Histochemical staining showed that after simulated with 40 kPa hydrostatic pressure for 7 days, the expression and activity of alkaline phosphatase of bone marrow mesenchymal stem cel s were increased;after lasted for 14 days, the mRNA expressions of peroxisome proliferator-activated receptorγ2 and adipsin were increased. Certain intensity and duration of hydrostatic pressure stimulation can regulate the differentiation of bone marrow mesenchymal stem cel s, and the mechanism is only partly mediated by the extracel ular signal-regulated kinase 1/2 signaling pathway.