ABSTRACT
Objective To investigate the correlation between mechanical tensile stress and the expression of ODF mRNA in osteoblasts differentiated from rBMSCs, and elucidate the mechanism for osteoclastogenesis regulated by osteoblasts in bone modeling and remodeling during the process of orthodontic tooth movement. Method rBMSCs derived osteoblasts were isolated and cultured in vitro, and subjected to static mechanical tensile stress of 1, 3, 5 kPa or dynamic tensile stress of 3, 5 kPa at 0.017 Hz using the cellular tensile stress system for 24 h. The control groups were subjected without any strain. Cells were collected in 0, 3, 6, 9, 12, 24, 48 h respectively after stress loading. The expression patterns of ICAM-1 mRNA were examined by semiquantitative RT PCR assay. Results ODF mRNA level significantly decreased after dynamic tensile strain, compared with the control groups；the effects of inhibition did not positively correlated with the magnitude of strain; the expression of ODF mRNA gradually decreased at 6 h, significantly decreased at 9 h, then slightly rebounded and still stayed at a considerably lower level, reached the minimum transcription at 48 h. Conclusions The mechanical tensile strain can regulate osteoclastogenesis by inhibiting the expression of ODF in osteoblasts derived from rBMSCs. It could lead to a better understanding of the molecular basis for osteoblast osteoclast communication in bone resorption induced by the application of mechanical strain during the orthodontic tooth movement.