Centrifugal forces within usually-used magnitude elicited a transitory and reversible change in proliferation and gene expression of osteoblastic cells UMR-106.

Centrifugation is an important step in biochemical and molecular biological researches. But the effects of centrifugal stress on cells are still unclear. In this study, osteoblastic cells UMR-106 were subjected to a moderate centrifugal stress at 209 x g for 10 min. Then the cell proliferation and gene transcription after centrifugation were analyzed with flow cytometry and Real-time RT-PCR techniques, respectively. The result showed that the cell proliferation and mRNA expression of Runx2/Cbfa1, Collagen I and osteocalcin changed shortly after centrifugal loading, but recovered to pre-load levels within 24 h. A dose-response study of exposure cells to centrifugal force at 209, 253 and 301 x g showed that the centrifugal forces within usually-used range can rapidly influenced the mRNA expression of the osteoblast-specific genes, but no statistical differences were found among the three centrifugal magnitudes. And the fast regulation in the investigated genes was proved to be related to increased c-fos mRNA levels and subsequent activation of RTK and integrity of cytoskeleton construction. The result showed that the osteoblastic cells displayed a fast auto-regulation to usually-used centrifugal stress through multiple signal pathways.