RESUMO
<p><b>OBJECTIVE</b>To investigate effects of intermittent negative pressure on osteogenesis in human bone marrow-derived stroma cells (BMSCs) cultured in vitro.</p><p><b>METHODS</b>The third passage cells were divided into negative pressure treatment group and control group. The cells in the treatment group were induced by negative pressure intermittently (pressure: 17 kPa, 30 min per time, and four times of each day). The cells in the control group were cultured in conventional condition. The osteogenesis of BMSCs was examined by phase-contrast microscopy. The alkaline phosphatase (ALP) activities were determined. The expression of collagen type I was detected by immunohistochemistry method. The mRNA expressions of osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) in BMSCs were analyzed by real-time polymerase chain reaction (PCR).</p><p><b>RESULTS</b>BMSCs showed a typical appearance of osteoblast after 2 weeks of induction by intermittent negative pressure. The activity of ALP increased significantly, and the expression of collagen type I was positive. In the treatment group, the mRNA expression of OPG increased significantly (P < 0.05) and the mRNA expression of OPGL decreased significantly (P < 0.05) after 2 weeks, compared with the control. However, 3 days after the exposure to 2-week negative pressure, these were no significantly different from that of the control group (P > 0.05).</p><p><b>CONCLUSION</b>Intermittent negative pressure could promote osteogenesis in BMSCs in vitro.</p>