Objective: To investigate the effects of intermittent negative pressure on the mRNA expression of osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) in human BMSCs cultured in vitro.
Methods: BMSCs were isolated from adult marrow donated by 2 hip osteoarthritis patients with prosthetic replacement in January 2008 and cultured in vitro. The third passage cells were divided into experimental group and control group. The experimental group was induced by negative pressure intermittently for 2 weeks (pressure: 50 kPa, 30 minutes each time, twice per day) and the control group was routinely cultured. After 2 weeks of culture, cell morphology was observed by inverted phase contrast microscope, and the mRNA expressions of OPG and OPGL in BMSCs were analyzed by real-time PCR.
Results: The cell proliferation speed of the experimental group was slower than that of the control group. The cell morph changed from shuttle to megagon with some prominences in experimental group and the cell morph kept shuttle in the control. The mRNA expression of OPG in experimental group increased significantly (P < 0.01) and the mRNA expression of OPGL in experimental group decreased significantly compared with control group (P < 0.01) 2 weeks later.
Conclusion: Intermittent negative pressure is capable of promoting the expression of OPG, while inhibiting the expression of OPGL in human BMSCs.