Effect of compressive force on human osteoblast-like cells and bone remodelling: an in vitro study.

Objective: The aim of this study was to determine the effect of continuous compressive force (CF) on expression by human alveolar bone-derived osteoblasts (HOBs) of some specific molecules involved in bone remodelling.

Design: HOBs were cultured with or without CF (control, 2.0, 4.0gcm(-2)) for 1, 3 and 7 days. Expression of alkaline phosphatase (ALP), type I collagen (Col I), osteopontin (OPN), osteocalcin (OCN), transcription factor Runx2, receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG) and prostaglandin E2 (PGE2) was analysed by real-time-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and/or immunostaining.

Results: The results revealed that CF upregulated ALP and Col I expression at both messenger RNA (mRNA) and protein levels but did not affect expression of OPN and OCN mRNA. Runx2 mRNA was inhibited by CF, which also altered the expression of molecules involved in osteoclastogenesis, by enhancing RANKL expression and suppressing OPG expression. At 4.0gcm(-2) of CF, the expression of RANKL and PGE2 was significantly upregulated.

Conclusion: The results suggest that initial application of CF on HOBs can simultaneously affect expression of markers related to both osteogenesis and osteoclastogenesis.